B 405567
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3.
1
24.
ARTES
1837
SCIENTIA
VERITAS
LIBRARY
OF THE
UNIVERSITY OF MICHIGAN
PLURIBUS UNUM
SQUAERIS PENINSULAM AMOE NAM
CIRCUMSPICE
10
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11035-4
CIRCUIT COURT OF THE UNITED STATES,
DISTRICT OF NEW JERSEY.
IN EQUITY. No. 20.
THE EDISON ELECTRIC LIGHT COMPANY
VS.
WESTINGHOUSE, CHURCH, KERR & COMPANY.
On Letters Patent No. 264,642.
Vol. IV.
COMPLAINANT'S REBUTTAL.
EXHIBITS.
FREDERIC H. BETTS,
S. B. EATON,
EATON & LEWIS,
Complainant's Solicitors.
Of Counsel.
KERR & CURTIS,
Defendants' Solicitors.
G. BURGOYNE, WALKER AND CENTRE STREET, N. Y.
INDEX TO VOL. IV.
49234
Complainant's Exhibits.
PAGE.
DEFENDANT'S PLANT:
Defendant's Plant at Trenton, N. J., Chart of......
(Offered on page 1821, Vol. III.)
2734
ELECTRICAL PERIODICALS:
Central Electric Lighting Station of Milan, The-
The Electrician and Electrical Engineer, Au-
gust, 1885...........
(Offered on page 1818, Vol. III.)
Electric Lighting--
2163
Telegraphic Journal, London, Apr. 15, 1878……….. 2807
(Offered on page 1822, Vol. III.)
Electric Lighting Act of 1882, The-
The Electrician, London, July 5, 1884......
(Offered on page 1822, Vol. III.)
Gas vs. Electric Lighting-
2891
The Telegraphic Journal, London, Oct. 15, 1878. 2803
(Offered on page 1822, Vol. III.)
Geraldy's La Lumiere Electrique Article-
La Lumiere Electrique, Paris, 1881
(Offered on page 1820, Vol. III.)
Geraldy's La Lumiere Electrique Article, Translation
of-
La Lumiere Electrique, Paris, 1881.....
(Offered on page 1820, Vol. III.)
Preece, W. H., Extract from Lecture by-
The Telegraphic Journal and Electrical Review,
2611
2618
London, Feb. 15, 1879......
(Offered on page 1822, Vol. III.)
Progress of the Electric Light-
1878.
• •
2911
The Telegraphic Journal, London, Nov. 1,
(Offered on page 1822, Vol. III.)
Siemens' Presidential Address-
...
2810
The Electrician, London, Nov. 18, 1882...
(Offered on page 1822, Vol. III.)
2915
II
PAGE
ELECTRICAL PERIODICALS-(CONTINUED) :
Sprague's Electrician Article-
The Electrician, London, Sept. 9, 1882............. 2372
(Offered on page 1819, Vol. III.)
Stayton's Report, The Electric Light".
The Telegraphic Journal and Electrical Review,
London, Sept. 1, 1878......
(Offered on page 1820, Vol. III.)
FOREIGN PATENTS:
.....
2607
Edison French Patent No. 130,910, and the English
Translation thereof......
2387
(Offered on page 1820, Vol. III.)
Edison British Patent No. 2402 of 1879
2475
(Offered on page 1820, Vol. III.)
Edison British Patent No. 602 of 1880.....
2323
(Offered on page 1819, Vol. III.)
Gravier, M., French Patent and Certificates of Addi-
tion thereto........
2502
(Offered on page 1820, Vol. III.)
2561
...
........
2495
Gravier, M., French Patent and Certificates of Addi-
tion thereto, Official Translation of.......
(Offered on page 1820, Vol. III.)
King's British Patent No. 10,919 of 1845……………..
(Offered on page 1820, Vol. III.)·
MISCELLANEOUS :
Edison Caveat, filed August 19, 1879, Certified Copy of. 2585
(Offered on page 1820, Vol. III.)
Edison Caveat, filed April 21, 1879, Certified Copy of.... 2724
(Offered on page 1821, Vol. III.)
Electric Lighting in New York-
Harper's Weekly, July 27, 1889.....
2244
(Offered on page 1819, Vol. III.)
Gas Lighting Extract-
Johnson's New Universal Cyclopedia, Vol. II.,
New York, 1876.......
2595
(Offered on page 1820, Vol. III.)
•
(Offered on page 1820, Vol. III.)
Official Certificate of Transfer of U. S. Patents from
"The Edison Electric Light Co." to "Edison Elec-
tric Light Co."
Parliamentary Committee on Electric Lighting, 1879,
2597
Extracts from Report of..
2256
(Offered on page 1819, Vol. III.)
Trenton Map ....
2385
(Offered on page 1819, Vol. III.)
III
PAGE
SCIENTIFIC LITERATURE :
Comparative Economy of Electric and Gas Light—
American Gas Light Journal, Jan. 2, 1879...... 2291
(Offered on page 1819, Vol. III.)
....
(Offered on page 1818, Vol. III.)
Crystal Palace Report. F. J. Sprague.
Divisibility of the Electric Light, The—
Jan. 11, 1879.
... 2119
Scientific American Supplement, New York,
(Offered on page 1818, Vol. III.)
Electric and Gas Illumination—
2229
Popular Science Monthly, September, 1882
2182
•
(Offered on page 1818, Vol. III).
Electric Lighting—
Scientific American Supplement, New York,
Electric Lighting by Incandescence-
Nos. 264 and 265, Jan. 22 and 29, 1881 ...... 2198
(Offered on page 1818, Vol. III.)
Scientific American Supplement, New York, No.
307, Nov. 19, 1881......
2219
....
(Offered on page 1818, Vol. III.)
Electric Light, The. (By W. H. Preece)—
The London, Edinburgh and Dublin Philosophi-
cal Magazine and Journal of Science
2234
(Offered on page 1818, Vol. III.)
'Electricity as a Motive Power”—
By Count Du Moncel and F. Geraldy.
(Offered on page 1822, Vol. III.)
2874
"Electric Lighting," by Robert Briggs-
Engineering, London, Oct. 18, 1878 ………….
(Offered on page 1818, Vol. III.)
Engineer Article of February 13, 1880-
Engineer, London
•
(Offered on page 1821, Vol. III.)
2156
..... 2721
2655
Fontaine's Electric Lighting, Extract from
(Offered on page 1820, Vol. III.)
(Offered on page 1820, Vol. III.)
Fontaine, Higgs' Translation, Preface First Edition of….. 2673
Fontaine, Higgs' Translation, Chapters XI. and XII.,
First Edition of.......
.....
(Offered on page 1821, Vol. III.)
Fontaine, Preface Second Edition of
2679
2713
D
(Offered on page 1821, Vol. III.)
(Offered on page 1821, Vol. III.)
Fontaine, Chapter XIII., Second Edition, Extracts from. 2718
Fontaine, Extracts from Third Edition of..
2722
(Offered on page 1821, Vol. III.)
Forbes' Cantor Lectures.....
2337
(Offered on page 1819, Vol. III.)
IV
PAGE
SCIENTIFIC LITERATURE-(CONTINUED) :
Gatehouse Nature Article-
Nature, Nov. 14, 1878........
(Offered on page 1819, Vol. III.)
2377
General Incandescent Electric Lighting in New York-
Scientific American, Sept. 16, 1882.........……………………. 2241
(Offered on page 1818, Vol. III.)
Incandescent Electric Lights—
Nature, December 2, 1880......
(Offered on page 1822, Vol. III.)
Morton's, Prof., Lecture--
2858
American Gas Light Journal, Jan. 2, 1879....... 2295
(Offered on page 1819, Vol. III.)
On the Present State of Electric Lighting-
Report of the British Association for the Ad-
vancement of Science, Meeting of Aug. 20,
1878......
(Offered on page 1818, Vol. III.)
Preece, W. H., Editorial by-
Nature, Jan. 23, 1879.
(Offered on page 1822, Vol. III.)
President's Inaugural Address-
2153
2847
The Journal of the Iron and Steel Institute,
Nov. 1, 1877..
...
.....
(Offered on page 1822, Vol. III.)
Some Electrical Measurements of one of Mr. Edison's
Horseshoe Lamps-
2813
Scientific American, New York, Apr. 17, 1880... 2852
(Offered on page 1822, Vol. III.)
Thompson's Engineering Article of Oct. 25, 1878-
Engineering, Vol. 26, London........
(Offered on page 1821, Vol. III.)
Thomson, Sir William, Address of—
Report of the 51st Meeting of the British Associa-
2707
tion for the Advancement of Science......
2861
(Offered on page 1822, Vol. III.)
Tyndall's Address, "The Electric Light”—
The Fortnighly Review, Toronto, Feb., 1879.... 2625
(Offered on page 1820, Vol. III.)
UNITED STATES PATENTS:
Andrews, W. S. and Spencer, T... No. 318,157.
2968
Bergmann, S....
Bradley, C. S.
398,121....
2976
....
287.501.....
2960
...
66
Byllesby, H. M…....
Doubleday, H. M…………..
Edison, T. A......
(6
"
353,915...... 2964
329,621....
2988
335,060.......
2993
223,898....
2320
""
230,255........
2317
.....
239,374........ 2313
PAGE
UNITED STATES PATENTS—(CONTINUED) :
Edison, T. A………….
("
..No. 248,421.......
.......... 2735
251,550...... 2738
(6
(6
((
""
"
(6
"
("
เ
•
(3
251,555...... 2740
.....
"
251,556.....
2743
.....
"(
263,134
2746
(6
263,136.....
2749
((
264,658.......
2754
CC
264,659......
2757
•
264,660 ..
2760
(C
264,661....
2763
264,662.....
2769
264,663
264,664 ..
2771
2773
"
264,665......
2776
A
"
264,666...
2779
66
...
264,667.... ..... 2782
264,668.... ..... 2785
(
"
264,669....
2787
"
264,670............ 2791
"
"
264,671.... .... 2794
264,672............ 2797
"
264,673.....
2801
"
266,793............ 2922
274,290............ 2926
"
280,727....
2943
283,983........
2932
and C. L. Clarke..
287,525......
2938
"
339,279
2947
(6
365,978...
2951
"
438,308 ...
2957
Howell, J. W……...
Rice, E. W., Jr.
Shallenberger, O. B.
""
(6
Spencer, T...………………….
Stillwell, L. B, ……..
""
.....
Thomson, E......
"
342,748.......
2984
352,691
2979
(6
372,330.....
3028
((
337,628......
3001
66
380,942.
3006
378,738...... 2998
399,218............ 3009
399,219...... 3014
349,912.....
3025
(
Waddell, M..………………..
425,470.....
3019
374,381
2972
....
(Offered on pp. 1819 and 1821 and 1996, Vol. III.)
WITNESSES' DIAGRAMS AND CALCULATIONS:
Brevoort's Gas Pressure Diagram......
2379
(Offered on page 1819, Vol. III.)
Clarke's Calculations No. 1......
2380
(Offered on page 1819, Vol. III.)
VI
PAGE
WITNESSES' DIAGRAMS AND CALCULATIONS (CONTINUED);
Clarke's Calculations No. 2 …………..
2381
(Offered on page 1819, Vol. III.)
Clarke's Calculations No. 3………………………….
2382
(Offered on page 1819, Vol. III.)
Clarke's Calculations No. 4………....
2383
......
(Offered on page 1819, Vol. III.)
Clarke's Calculations No. 5 .....
2384
(Offered on page 1819, Vol. III.)
Diagram of Illustrative Model of Feeder System......
2909
(Offered on page 1822, Vol. III.)
Feeder System Diagram No. 3.........
2920
(Offered on page 1972, Vol. III.)
Feeder System Diagram No. 4
2921
(Offered on page 1972, Vol. III.)
Tree System Diagram No. 1………..
2918
(Offered on page 1972, Vol. III.)
Tree System Diagram No. 2............
(Offered on page 1972, Vol. III.)
2919
Crystal Palace Report-1882.
2119
Complainant's Exhibit Crystal Palace Re-
port. F. J. Sprague.
REPORT
ON
THE EXHIBITS
AT THE
CRYSTAL PALACE ELECTRICAL EXHIBITION,
1882.
BY
ENSIGN FRANK J. SPRAGUE,
United States Navy.
·
Published by the Navy Department, Bureau of Navi-
gation, 1884, pages 110-136.
KINDS OF CIRCUITS.
Considering lamps and conductors in simple circuits,
there are several arrangements possible :
1st. Series (Fig. 8).—In this method the lamps are
arranged so that the same current passes through each.
The potential at the terminals of the circuit must be
the sum of the differences of potentials existing at the
lamps, and the current should have the same strength,
whether one or a hundred lamps are in operation.
2d. Multiple (Fig. 1).—In this the two conductors
are run out side by side, and the lamps branched across
from one to the other. The potential at the lamp
terminals in about that existing at the machine termi-
nals.
With the arrangement shown, where both lamp
2120
Crystal Palace Report-1882.
terminals are at like relative distances from the machine
terminals, there is a drop of the potential as the dis-
tance from the machine increases. By the reverse
arrangement shown in Figs. 2 and 6, where the lamp
nearest the machine has one terminal nearest and the
other farthest from the machine terminals, an unsuccess-
ful attempt has been made to overcome this difficulty.
The currents in the lamps are nearly proportional to
their resistances, and the sum of the currents in all the
lamps flows through the machine.
3d. Multiple series (Fig. 4).-Equal numbers of lamps
are arranged in series, and the terminals of the series
are connected.
4th. Series multiple (Figs. 3 and 5).-Consists of a
series of sets of lamps, the lamps of each set being
arranged in multiple circuit.
Classes 1 and 2 are the only ones of any real import-
ance, the others being make-shifts for using a dynamo
not properly constructed for this purpose for incan-
descent lighting without too great loss of efficiency.
*
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Crystal Palace Report-1882.
2123
INCANDESCENT LAMPS AND SYSTEMS OF LIGHTING.
I will first describe the lamp in detail:
Lane Fox.-Fig. 12 (section): 7 is an ellipsoidal
globe, with a long neck, n, made either of clear or
opalescent glass. The ends of the carbon filament a
are held in place, and electrical connection made by
means of the carbon cylinders, hh, which enclose plat-
inum electrodes, bb, the main parts of which are em-
bedded in lead glass dd. These platinum wires are
quite short, and the connection to the copper-leading
wire, cc, is made by means of little mercury-filled re-
sceptacles, ee, the mercury being held in place with a
cotton wad, o, and stopper of plaster of Paris. A luting
of India ink, kk, tapers off the end of the carbon fer-
rules. The filament is made from natural grass fibers,
that known as French whisk or bass broom being pre-
ferred. It is the same as is used in certain kind of car-
pet brushes. It is first cleaned by being boiled in a
strong solution of caustic soda, and the skin is removed.
The remnants of the soda are then expelled by boiling,
and a number of the fibers, which are now quite pliable,
are stretched around a plumbago mold, being then
baked in a crucible at a white heat out of contact with
the air. The carbon filaments thus formed are more or
less irregular and uneven in quality. They are then
suspended in globes filled with benzole or coal gas, and
a current through them to raise them to incandescence.
The gas is decomposed, and a very fine deposit of
carbon takes place, being most abundant where the
temperature is greatest, that is, at the points of greatest
resistance, which would ordinarily, though not neces-
sarily, be at the points of smallest cross-section.
The filaments are thus covered with an exceedingly
hard, brilliant skin of carbon; they are made more even
in surface and section, and capable of sustaining higher
temperatures. This is what is generally known as the
Berthollet process, and is adopted by some other
makers. While producing an exceeding durable car-
2124
Crystal Palace Report-1882.
bon, it has the disadvantage of increasing the diameter
of the carbon and thus reducing its resistance. After
the carbons are mounted in the globe, 7, the air
is exhausted through a tube at p by means
of a mercury pump.
After a good vacuum is
obtained a current of gradually increasing strength
is sent through the filament to
the filament to drive out all
contained gases, the exhaust being maintained to a high
degree. This is continued for some time, the degree of
incandescence to which the filament is raised being
much higher at the end of the process than it is in-
tended to run the lamp at ordinarily. This process
being complete, the tube is melted off, and the hole
sealed by fusion of the glass.
Considering.the progress which has been made in the
manufacture of lamps, I must think this lamp has some
very objectionable features. As regards the carbon it-
self, it is circular in section, presenting much less sur-
face than should be for its bulk. It is of course of a very
low resistance, there being, when run at the normal
power of twenty candles, only about 18-20 ohms.
With such a low resistance, a large current, compara-
tively speaking, must be used, which means great loss
in conductors and very limited economical distribution.
The ferrules, hh, because of their greater diameter, can-
not be raised to at all the same temperature as the fila- .
ment, and, consequently, in exhausting the globe, all
the contained gases and air cannot be driven out, but
are left to finally help reduce the vacuum. I cannot
approve of the use of mercury for making connection
in a lamp when simpler methods are more readily
available. The heat developed in conductors and fila-
ment is detrimental to this kind of connection. It
would be better for the looks of the lamp if the exhaust
tube were out of sight when the globe is mounted in
its socket. This socket encloses the neck of the globe,
and the connection to the circuit is made by the hooks,
cc. These small connections are liable to oxidization
by arcing when the lamp is removed, and I have noticed
Crystal Palace Report-1882.
2125
frequent examples of poor contact or broken circuit in
the use of these lamps.
At the Crystal Palace the multiple arc system was
adopted. About 300 to 400 lamps were supplied by
Brush dynamos or the Sellon-Volckmar accumulators.
Some were on independent circuits, and two or three
machines were also joined in parallel circuit to supply
a number of lamps. The effect in the Alhambra Court,
supplied by the dynamo machines, and in well-furnished
rooms, where the accumulators were used, was very
fine. The arrangement of the latter was good, but,
looking at that of the lamps and dynamos as a system,
it was sadly deficient. In fact, it was not a system,
for the simple coupling together of a machine which
will give a current of electricity, of a maze of wires, and
of lamps which are kept at a state of incandescence by
the passage through them of a current, without regard
to safety, economy and reliability, cannot be properly
so dignified. I will not enter into any detailed criti-
cism, for I scarcely think it necessary. As a test of the
quality of manufacture, the current was reduced by
lowering the speed of the dynamos until the incandes-
cence was just generally apparent. The degree of
redness was very uneven, and the test by no means
satisfactory.
Mr. Lane Fox has not only invented some incan-
descent lamps, but he has proposed one or two systems
for distribution of light, heat, and power by means of
electricity. Fig. 17 shows one plan proposed. One
set of mains C C', is used, to which are coupled the
like poles of the dynamos A A A. The mains, sub-
mains and branches C" C", ramify in various direc-
tions, supplying the lamps directly, or accumulators S,
which in turn feed the lamps. Each house and the
dynamos are connected to earth by earth conductors
and plates E E E, making thus one system of conduct-
ors answer the purpose of distribution.
It is proposed to maintain the difference of potential
at 100 volts, and to do this by a regulator R, of ingen-
2126
Crystal Palace Report-1882.
ious design, in which a shunted current controls a lever
armature playing between contact pins, which by its
movement one way or other throws resistance into or
out of the field magnet circuit F F. The current sup-
plied either to lamps or accumulators is to be measured
by one of the several kinds of motor-meters devised. I
cannot express my approval of this arrangement. A
system of domestic lighting which proposes the use of
earth conductors, with all the known attendant perils
and inconveniences, cannot be too severelly condemned
as lacking in every real essential of practicability or
efficiency, economy or reliability, and of the commonest
safety.
BRITISH LAMP (Fig. 13).
The filament, a, of this lamp is, like the Lane-Fox, a
natural fiber carbonized at a very high heat. It is
joined to coarse copper wires, bb, by small carbon cylin-
ders, or more recently by small spirals, cc. To these
copper wires are joined short pieces of platinum wire,
pp, which are sealed at the base of the neck, n, in a hot-
pressed joint, e. To the platinum pieces are joined
other pieces of copper wire, ff, to make connections to
the mains through the socket. The exhaust, which is
made while the carbon is in a state of incandescence, is
through a tube at the base of the neck, at the point t.
This leaves the surface of the globe, l, perfectly smooth,
and is an improvement. The carbon is of much smaller
section than that of the lamp just described, and its
resistance is much higher, being about 80 ohms when
at 20 candle-power. The carbons are quite elastic, but
the use of long copper wires is apt to render the lamp
less capable of withstanding shocks.
It would seem
that such large wires would injure the vacuum also be-
cause of the contained gases, but I have no real evi-
dence that is the case.
At the Crystal Palace the lamps were generally, if not
always, coupled in multiple arc, and the current was
>
Crystal Palace Report-1882.
2127
supplied by Gramme dynamo machines.
The fixtures
were used as a part of the return circuit; but this is a
most objectionable feature, and in any general distri-
bution cannot be tolerated. The whole arrangement,
although showy, was not a good specimen of electrical
engineering. No plan of a real system was shown. As
a test of the quality of the manufacture the dyname
speed was lowered till the lights were at a low incan-
descence. They stood the test much better than the
Lane-Fox lamps, but quite a number of variations were
noticed.
GATEHOUSE LAMP.
This inventor proposes to combine platinum and
carbon to make a lamp which will not break,
or change incandescence materially when the main
potential changes. The resistance of platinum
increases with heat; that of carbon is diminished.
Two methods are proposed of utilizing these oppo-
site qualities. One is by shunting a platinum wire
with a carbon loop, one or both being in a vacuum; as
the potential at the lamp terminals increases, an in-
creased current flows over both paths; but because of
the opposite changes in resistance the greater part of
the increased current flows over the carbon path, at
least so it is claimed. This carbon may or may not be
in sight. A second method is to prolong the platinum
connections at the ends of the carbon filament into
spirals, to introduce into the circuit a resistance which
increases with an increase of current. The most that
can be said of any such combination is that it is ingeni-
ous, hardly that. In the first place, in any properly
designed system there will be no great changes of
potential. Then again, to constantly throw away en-
ergy, in view of a most improbable and entirely unnec-
essary fluctuation of potentials, is very poor economy.
In short, the lamp as designed shows a lack of com-
prehension of the demands of incandescent lighting.
2128
Crystal Palace Report-1882.
MAXIM LAMP (Fig. 14).
The filament a is made of cardboard. It is first cut
out with a die from a very fine hard quality of board
and then carbonized at a white heat. After carboniza-
tion several filaments are mounted on loose clips, which
project above a rubber cap, and complete, with the car-
bons, branch circuits from two mains. In the branch
circuits are also included electro-magnets, whose arma-
tures hold in place trip levers, which, on being released
by the movement of armatures, fall and break the con-
tinuity of the individual circuits. Glass receivers or
cups are inverted over the carbons, the mouths being
closed by the rubber caps. Besides the wires in the
caps there are small tubes, all connected to one main
tube. Through these the air is pumped out, replaced
by gasoline and the current sent over the mains. The
carbonized papers being of different resistances, are
differently heated, and the resistance of all are lowered
as the carbon set free by the decomposition of the gas-
oline is deposited on the incandescent filament. As
soon as the current in any branch becomes sufficiently
strong, that is, the resistance reduced to a certain limit,
the magnet in that circuit draws down the armature,
frees the lever and breaks its own circuit, the current
in the others being unaffected. At first the fall of the
levers is very irregular, but two or three exhausts and
refillings of gasoline, with the passing of the current
for the proper length of time, makes the fall of the
levers practically simultaneous, and the carbons are
then ready for mounting. This process has made the
carbons very homogeneous, and reduced them to one
uniform standard of resistance. They are covered
with a very hard skin and their durability much in-
creased.
The platinum leading wires de de are embedded a short
distance apart in a rod of soft glass, f. The upper
ends are flattened and crooked, and to these ends are
secured the widened ends of the carbons by small
Crystal Palace Report-1882.
2129
platinum clamps, or nuts and bolts cc. The lower end
of the rod f terminates in the apex of a reantrant cone,
g, which closes the neck of the globe. The exhaust is
by mercury pumps, while the carbons are gradually
brought to a high incandescence. The lamps are well
made, but the cost of manufacture can be somewhat
reduced by using shorter lengths of plantinum and
other fastening than plantinum clamps.
The lamps can be run at as high, if not higher, power
than any other made. If the exhaust were made at
the neck, instead of at the top, of the globe it would be
better. The normal power of the lamp is 20 candles,
and the resistance 44 ohms, which is too small for any
widespread distribution. At the Crystal Palace there
were 100 to 150 lamps, about 100 being maintained.
These were supplied by a Maxim dynamo, the field
magnets of which were excited by a second machine
with movable commutator brushes. The lamps were
run in the multiple arc system, with two lamps as a
unit. The Maxim plan of distribution, whether with
one or more lamps for units, is that of simple multiple
arc of main and derived circuits, as in Fig. 18. No
meters or general arrangement for distribution were
shown. The lamps, when tested at low incandescence,
were very satisfactory.
SWAN LAMP (Fig. 16).
We now come to a lamp which, although not to my
mind without faults, is one of remarkable excellence of
manufacture, and which in many things is not sur-
passed. One of its most noticeable features is its
apparent simplicity, a result attained, however, only
after much experimenting. Unlike the carbons already
described, this has a full turn in it, thus diminishing
the space required. The filament is made of a loose
cotton thread which is immersed in sulphuric acid,
which entirely changes its character, making of it really
a vegetable parchment. It is next run between rollers
to flatten it, and thus increase its surface. It is then
2130
Crystal Palace Report-1882.
fitted to a form, buried in powdered charcoal and car-
bonized at a very high heat. The attachment of the
carbon filament to the platinum leading wires, d d, is
probably the best devised, being at once exceedingly
neat and capable of standing every heat that the car-
bons can, or, rather, the leading wires. The ends, c c,
of the platinum wires are first flattened, then run into a
die which forms little split tubes, into which are in-
serted the ends of the carbons. The tubes are slightly
compressed, a clip put in the carbons on the line o o
just above the tubes, the parts immersed in a hydro-
carbon liquid and a current sent through the leading
wires, dd, and across the bridge, o o, sufficiently strong
to heat to incandescence the tubular connections. The
liquid is decomposed and a hard carbon deposit formed
over the joint, making a through connection.
The leading wires are sealed in a stem, e, which
closes the neck of the globe; the exhaust is from the
top in the usual manner, that is, during incandescence.
The globe is smaller than in other makes of lamps, and
is blown from a small glass ball.
In later forms the stem e is replaced by a tube for
the support of the wires and the exhaust of the globe-a
much better arrangement: Lamps have been made of
from one to one hundred and fifty candle-power, the
standard being 20 candles, with a resistance of about
37 ohms. I do not think a sufficiently fine filament is
used, and hence I believe the resistance of the lamp
may be much increased. It is in this direction that I
think the improvement is to be made, and the later
form of lamps tend this way. There is one thing about
the lamp that I do not think good, although it has met
with much commendation, and this is the holder of the
socket. This consists of a small ebonite base k, with a
screw j, two small nuts ii, in connection with two small
hooks hh, and a brass spring s. The circuit connec-
tions are to the nuts ii, and then to the hooks hh. The
neck of the globe is inverted in the spring this last
pressed down, the eyes gg hooked, and the lamp re-
Crystal Palace Report-1882.
2131
leased, when the spring s presses the lamp out to make
contact.
It is impossible to prevent a little arcing when this
connection is made; this arcing takes place with small
contact surfaces, and these contacts are always apt to
be unequal. A jar may cause a break of contact if the
spring is at all weak. The result of this arcing is to
oxidize the metal and make a resistance. I have
measured such a resistance of over 5,000 ohms, and used
a file to reduce it. This formation of a high resistance
coating, when the lamp is jarred, has frequently, ac-
cording to my own observation, caused the lamp to go
out or to flicker. Again, the connections are exposed
and then liable to interference, and in the case of damp-
ness to a short circuit and leakage. I cannot too
strongly express my own conviction that all parts of
the conductors of a circuit should be thoroughly pro-
tected.
At the Crystal Palace there were two or three hun-
dred lamps in very satisfactory operation, the majority
being run by a Siemens alternate current machine, sep-
arately excited; but owing to the irregularity of the
motive power, they were not always of the same brill-
iancy. They stood the test of low incandescence re-
markably well, the speed of the dynamo being lowered.
A safety plug, that is, a weak spot of lead and tin
foil, was used, but I do not think to any wide extent.
Mr. Swan's lamps, much of whose excellence is due
to Messrs. Stearne and Dillingham, are used on all
sorts of machines, in all sorts of combinations of series
and multiple arc. No particular system is insisted on,
nor are the lamps made comparable with any standard
of resistance when of different powers. That is, the
production of a good lamp is looked upon
desideratum, and it is not an integral part of a system.
designed as a whole. As I have said, the tendency is
towards lamps of high resistance, but as to Mr. Swan's
idea of a system, I quote from his address to the Lit-
erary and Philosophical Society of Newcastle :
as the great
2132
Crystal Palace Report-1882.
"As it is only necessary, in order to maintain a
given current, to increase the force which pro-
"duced it in the same proportion as you increase
"the resistance to its flow, it follows that the cost
"of raising to a certain degree of incandescence a
"longer or shorter length of carbon, or of main-
"taining a 10-candle light or 100-candle light, will
"be exactly proportional to the light produced.
"If you have an electric motive force sufficient to
"drive such a current through 100 inches of my
"carbon filament as will render it incandescent,
"you may either have the 100 inches in one con-
"tinuous length all in one lamp, or you may cut
up the 100 inches into 100 pieces, and place each
66
((
piece in a separate lamp, and the 100 lamps in
"100 different places, without any difference in
"the aggregate amount of light from the one un-
"divided light and from the 100 separate lights.
"You may even contemplate on this principle the
“economical production of an electric light as
"small as a rush-light."
Speaking of the multiple arc system, he says that it
has the advantage of simplicity, but does not think it
will answer for other than very short distances:
"When a number of lamps are grouped together
“in that manner, it is necessary that the individual
lamps should offer a very high resistance to the
current, for if each lamp does not offer an ex-
"tremely high resistance to the passage of the
"current there must be great waste, a large pro-
portion of energy being in that case spent in
"heating the conducting wires instead of the car-
((
bon in the lamps. Mr. Edison accordingly pro-
"poses to make his lamp of a very high resistance;
"but if the carbon pure and simple is used, then
"I submit it had better be in as stable and con-
"densed a state as possible, because in process of
Crystal Palace Report--1882.
2133
use it tends to consolidate, and it is undesirable
"that any change should take place in the lamp
during use. A filament of carbon in its best
"state for incandescent lamps, as thin as it is
"safe to use in a lamp, and of a length sufficient
"to give a light equal, say, to one burner or ten
"standard candles (a unit of light which I think
we must not go beyond in planning an extensive
system of town lighting) will not offer so high a
"resistance as that which Mr. Edison has made
"the basis of his scheme of distribution. With
""
lamps of this resistance the result would be that
"before many were bridged across from one main
"to the other, as much or more work would be
"done in the conducting wire as in the lamps.
"The only way of avoiding this waste of energy,
"without abandoning the idea of small units of
light, would be either to employ enormously
"thick conductors or have a very limited area
supplied from one source.
(C
"I think the difficulty is capable of being sur-
"mounted in this way: Instead of grouping the
lamps, as Mr. Edison proposes, each lamp being
"as it were a loop or bridge between two mains,
"I propose to string them in series, 10, 50, or
perhaps 100 lamps being all interposed in one
"and the same line.
(C
"In this way every lamp would add to the re-
"sistance of the line instead of, as in Mr. Edison's
plan, diminishing its resistance. The waste of
energy in the conducting wire would then be
avoided. A copper wire less than one-eighth of
"an inch thick would supply current for one such
"series of, say, from 10 to 100 lamps at five miles
"distance, with a very small percentage of loss;
"while to supply at the same distance a corre-
"sponding number of lamps on Mr. Edison's plan
"would demand copper conductors of such thick-
"ness as would certainly make the plan far
2134
Crystal Palace Report-1882.
"too expensive; or, if such thick conductors
((
((
(C
((
((
((
were not used, there would be an impracticably
"extravagant waste of energy in the wire. Even if
fifty per cent. of the energy was expended in the
"wire, the size of the conductor required to transmit
"the current, say, even two miles, would be far too
great. There is no way of escape I know of from
"this dilemma, viz. : that either we must make our
"unit of light larger than necessary for a very
"great many purposes and so give up the idea of
"extensive division, extensive distribution, or, in
"order to gain these points, we must group the
lamps in the manner I have proposed. There
are, no doubt, difficulties in the carrying out of
my plan, but none that are not easily surmount-
"able. For example, if 20, 50, 100 lights were in
"a series, a break in any part of the line would
"extinguish all the lights. This danger can be
"met in two ways. I would have only one lamp
belonging to a given line in any one house, so
"that the extinction of such a line of lights as we
are contemplating would not be a very serious
mishap; but I would make such a mishap ex-
"tremely unlikely to occur by placing along with
"each lamp an automatic circuit closer. This
"would so act as to bridge over the gap made by
"the accidental breaking or failure of a lamp, and so
prevent the extinction of the rest of the lamps of
"the series, while a fresh lamp was put in the place.
"of the broken one- -a thing no more difficult, and
((
((
(6
((
probably not more costly, than the replacement
"of a broken gas burner, chimney or globe. There
" is another difficulty occasioned by the variation
"of the current in proportion to the number of
lamps in action. What is required in this case
"is to maintain a uniform current in the line of
lamps, whether 1 or 100 arc a light. This can be
accomplished by self-acting apparatus, somewhat
"on the principle of the governor of the steam
Crystal Palace Report-1882.
2135
"
engine, and which would automatically raise or
"lower the electro-motive force by steps of one-
hundredths, according to the number of lamps in
(( use. I have also considered the question of
measuring the current, and, if time allowed, I
"could show that that can be done as easily as
"the measuring of gas.
"Similarly, all other practical difficulties arising
"out of this method of distribution can be met."
This address was delivered in October, 1880, and in
May, 1882, the revised copy was officially issued to
myself and others; hence at this latter date it is rea-
sonable to suppose Mr. Swan's opinion had not been
changed. In August, at the meeting of the British As-
sociation, in some remarks after a paper I had read on
the Edison system, Mr. Swan, amongst other things,
said:
((
"The only escape from that limitation (extent of
distribution) lay in having secondary batteries
"at stations or in houses, and in these batteries
being connected in series and fed by currents of
higher tension; the principle still holding of
"multiple arc, not from the central station, but
"from the subsidiary ones at which the batteries.
"
are charged. Once imagine the possibility of
"these secondary batteries being kept at a perfectly
"constant condition of charge by some automatic
"arrangement, and we might look to that as a
means of escaping from the difficulties of wide
distribution."
(C
He did not give the idea of supplying the lamps en-
tirely in series.
"It would not be necessary that each lamp
"should be provided with an automatic arrange-
"ment for maintaining continuity of circuit.
2136
Crystal Palace Report-1882.
"The only condition necessary would be the
"maintenance of the lamp in a condition of
((
((
equality of light, that the current should be kept
"constant, and that there should be automatic ar-
"rangement for varying the electro-motive force
"at the station in proportion to the number of
lamps operating, whether one or a thousand. To
"avoid the use of a high potential in such a sys-
"tem of feeding in series the resistance might
"be very considerably reduced by variation of the
"internal sectional area of the carbon by using
"short and flat carbons."
More than two years have passed since the Newcastle
address. The Swan has reached a point of high per-
fection, yet we see no large system of lamps arranged
in series, and the many practical difficulties foreseen by
the inventor and by others still await solution. Had it
not been for his recent utterances, and for the fact that
the lamp is still used in multiple series combinations,
I should look upon the project as practically aban-
doned, and the place taken either by the multiple arc
direct supply, or multiple arc from central accumulator
station. I am not yet converted to the faith of accum-
ulators in private houses.
The plan proposed by Mr. Swan, of having several
subsidiary central stations of accumulators which de-
rive their charge from a distant station, supplying cur-
rents of high tension, is a thoroughly practicable one;
but accumulators must be first much improved, both in
regard to space occupied and economy of conversion,
and in this case I still claim the necessity of the abso-
lute multiple arc system for both streets and houses in
a sub-district. That is, the accumulators would simply
take the place of the dynamos and engines, they being
charged by these last, or by high tension currents from
a distant station. Which method would be most eco-
nomical would depend on circumstances.
With regard to the series arrangement I have already
Crystal Palace Report-1882.
2137
expressed my views at some length. I will not again
enter into a discussion of the mechanical details; the
difficulty of running, changing and repairing a multi-
plicity of high tension circuits, of the dangers to life
and property, the practical demands of insulation, the
liability of leakage, the unsatisfactory character of any
measuring arrangements, and the complex character of
the electro-motive force regulators, and for securing
continuity of circuit. But I wish to dwell for a mo-
ment on the mistaken idea that, leaving out the many
disadvantages which must be inherent to any series
system, there will be a great gain in economy.
It has been admitted that the very high tensions
which would obtain when lamps are arranged in series,
if each lamp was of considerable resistance, would be
objectionable. It then becomes necessary to use lamps
requiring a low potential at their terminals. We must
not fall into the error of thinking that because a lamp
of 100 ohms resistance, with a potential of 100 volts,
and hence a current of 1 ampere, will give an illumina-
tion, say, 15 candles, that the same effect would be pro-
duced by 1 ampere in a lamp of 1 ohm resistance re-
quiring 1 volt potential, for, if it were so, this latter
lamp would be 100 times as economical as the former.
We must remember that there is a perfectly definite law
governing the relation of potential, current and resist-
ance and the energy expended in a unit of time.
Let us suppose the economy of lamps is increased so
that but 1,000 foot-pounds per minute are used in a 15
candle lamp, a half or less of the present expenditure.
We will note the required currents and resistances for
different potentials at the lamp terminals.
Let us suppose, further, that there are 500 of these
lamps on a circuit, and that they are distributed over a
distance, say, of only one mile from the central station.
The length of wire necessary could not be less than six
miles, the turnings and the return wire being consid-
ered. Not over one-fifth of the lamps would be in
operation on an average. This would give an average
2138
Crystal Palace Report-1882.
of 317 per feet in actual operation. In practice we can-
not admit that it is the same thing to run 1 lamp of
100 candle-power or 100 lamps of 1 candle-power in
different places. We have then over 300 feet of wire
through which the current which supplies the lamp must
flow. Now, to reduce the aggregate potential, we must
diminish the resistance of the lamp, increase the cur-
rent, and, in order to keep the ratio of the resistance of
lamp to that of the conductor, this last must be in-
creased in weight and section at least as rapidly as the
lamp diminishes. We have, however, the fact remain-
ing that this conductor must ramify throughout our
houses, and hence its size must be limited. No. 18
B. W. G. is sufficiently large to be everywhere admis-
sible.
The following table not only gives the relation of
potentials, currents and resistances, but also the size of
wire, allowing the liberal loss of 10 per cent.
The formulæ :
Work ce 44.24
= e²
44.24
r
- c² r 44.24
are used, and the resistance of perfectly pure copper
for 100 feet, and 1-100th in diameter as equal to 10
ohms.
Crystal Palace Report-1882.
2139
E. M. F. of
each Lamp.
500 Lamps.
100 Lamps.
Amperes.
Current
Resist. of
TOTAL E. M. F. WITH-
Lamp.
20
10,000
2,000
1.13
17.7
1.77
.014
10 5,000
1,000
2.26
4.42
.442
.027
9
4,500
900
2.51
3.59
.359
.030
4,000
800
2.83
2.83
.283
.034
3,500
700
3.23
2.17
.217
.039
3,000
600
3.77
1.59
.159
.045
2,500
500
4 52
1.11
.111
.055
2,000
400
5.65
.11
.071
.068
1,500
300
7.53
.40
.040
.091
1,000
200 11.30
.18
.018
.136
1
500
100
22.60
.044
.0044
.272
It seems unnecessary to dwell longer on the series
system and its disadvantages. If a large number of
lamps are so run they must be of low resistance, need
large currents and large conductors, or else have more
than ten per cent. conductor loss, an allowance suf-
ficiently liberal for a good multiple arc system in the
limit proposed.
EDISON LAMP (Fig. 15).
There are three classes: The A, sixteen candles; B,
eight candles; and C, ten candles. A and C are stand-
ard lamps, that is, they require the normal difference of
potentials at their terminals, while B is a lamp of half
resistance of A, and intended to be used in two series.
There are two forms of globes, a pear-shaped and a
cylindrical, the latter of which is better adapted to the
form of carbon used, that of the horseshoe. This car-
bon, A, differs in one particular very much from all
others. Mr. Edison has aimed at a lamp of very high
resistance, this being an absolute essential to the system
Resist. of 317
ft. of Wire
10%.
Diam. of Pure
Copper Wire.
•
2140
Crystal Palace Report-1882.
of distribution he has elaborated and in this aim he
has been highly successful. Carbon, in a pure and
simple form, except when in a filament so fine as to be
impracticable for use, does not seem to present as high
a resistance as desirable. Hence Mr. Edison sought to
obtain a structural form, that is, a natural fiber, and
to retain this after the carbonizing and exhausting
process. In this he differs directly from Mr. Swan,
who prefers an unstructural carbon, the material for
forming which is in a very condensed form before
carbonization. A very even-fibered species of bam-
boo has been selected, which is cut into strips and
shaved by machinery, after which they are cut into
filaments, with widened ends ready for carbonization.
These are then bent in nickel forms and subjected to
intense heat, as with other makes, when they are ready
for mounting. The platinum parts dd of the leading
series are very short, and are sealed in the tube t, by
a hot pressed joint, e. To both ends are united small
copper wires, the lower gg leading to the brass or
copper connection hi, and the upper being flattened
and turned back upon themselves. These lips cc clasp
the widened copper plate ends of the carbon filament
ɑ, and the joints are plated in a bath to make a perfect
joint. The tube t being sealed in the neck of the
globe, the usual process of exhaustion from a tube at
m takes place, the increase of current being gradual,
and the incandescence being finally much higher than
intended for normal work. It is this process which
Mr. Edison applied with such remarkable success to
the platinum lamp, and for which he and Mr. Swan
deserve the highest credit.
The neck of the globe is enclosed by plaster of paris,
k, which supports a screw connection, h, and a butt
connection, i. These engage corresponding connections
in an exceedingly neat socket, which reduces arcing to
a minimum, and well encloses and protect the leading
wires.
The Edison lamp is especially intended for low
Crystal Palace Report-1882.
2141
powers. It cannot be run to the same intensity that a
lamp made of a more condensed fiber, or by the de-
position of carbon from a hydro-carbon gas, can be.
Probably one reason, and it may be the chief one, is
that with the ends of the carbon close together the
potential that is necessary for high power is sufficient
to cause a discharge, which of course wears away the
structure. The carbon will, however, stand a stronger
current than the copper connection. I do not think
that lamps of high power will be made of bamboo fiber,
but rather of a non-structural filament of lower resist-
ance, and capable of withstanding higher temperatures.
We must not lose sight, however, of the fact that high
resistance and low power have been the objects, and
the resistances obtained have been remarkable. When
hot, that of the A is about 140 ohms, the B 70 ohms,
the C 275 ohms, and I understand that recent advances
which have been made will bring the standard A very
much higher. It is probably impossible to make
lamps of a natural fiber of equal resistances, while this
can be done by a further treatment by the Berthollet
process, the resistance will thereby be lessened,
and it should not be resorted to, as the lamps are
of sufficiently even quality for practical purposes.
More care should be taken about the size of the globes
and the exhaust should be from the tube t to avoid
the projection m. The flange j is intended for handling
in screwing on the lamp, but is really unnecessary for
this purpose. If used in a damp place it would be well
to have a small rubber ring under j to bear against the
lip of the socket. The filament has a marvelous elas-
ticity, freely vibrating from one side of the globe to the
other.
The lamp, as great an achievement as it is, is but one
integral part of a thoroughly worked out and practical
system; and, I may add, the only one which is in
actual operation to-day. Mr. Edison early recognized
the fact that the production of a lamp was not the only
desideratum, but that the distribution of electricity for
2142
Crystal Palace Report-1882.
the purposes of light and power as well would require
the careful elaboration of a system of supply and de-
mand; that all parts of such system must be mutually
dependent, and that they must be designed with refer-
ence to each other. Hence, he laid down certain princi-
ples of guidance and has worked steadily with one end
in view-to bring out a thoroughly practical, efficient,
reliable and economical system. That he has done
this, there is to me, after months of careful study, no
doubt, and I cannot refrain from adding my testimony
to the success of his labors.
There was shown, at the Crystal Palace, a thoroughly
good piece of engineering for the distribution of about
1,100 lights, standard and half standard, the equivalent
of 800-850 A lamps. They were distributed over a
wide extent and at considerable distance from the
dynamos. There were several distinct circuits, but all
derived the current from one pair of mains and one set
of dynamos. Figs. 19 and 20 show the arrangement
of these last, Fig. 19 giving the plan of dynamos and
engines and Fig. 20 of the circuits.
The plant was designed so that it should be com-
posed of several independent parts, such that the break-
ing down of one would not interfere with the rest. To
this end, there twelve dynamos of the kind previously
described nn, which were arranged in three sets. Each
set derived its motion from a semi-fixed engine i, with
double cylinders and fly wheels.
Between the engines and dynamos was a short line
of shafting, t, with driving pulleys, which could be
thrown in or out of action by movable cone pulleys oo.
By this arrangement the stoppage of one engine
would stop four dynamos, and two could be thrown out
by shifting the cone pulley.
The mains dd' drew their current from two others, cc',
which were each connected by leading wires ef to the
commutator brushes, all the positive terminals being,
of course, connected to one wire and the negative to
the other.
Crystal Palace Report-1882.
2143
From one of the leads on each machine e a branch
circuit supplied the field magnets m, and the other ends
of the field magnets were connected to three branches
LL' L", four to each, and these branches were in turn
joined by a plug connection, p, to the regular circuit,
which was completed by joining to the other sub-main c´.
By the plug connection p any of the fields correspond-
ing to an engine could be cut out. The regulator »
consisted of a series of open wire coils, one or more of
which could be thrown into circuit with the field mag-
nets by the lever a. Hence by a movement of the lever
the fields could be made stronger or weaker, and the
entire system of light regulated in intensity at will.
7
The whole arrangement worked perfectly, and such
was the theoretical and practical efficiency of the whole
that 140 A lamps were frequently thrown in and out of
circuit without very appreciably effecting the remainder.
Not only was it a most successful piece of lighting,
but a thorough piece of electrical engineering, and
many of the essential features of the Edison system
were in operation. I will note some of these in detail.
PARTS OF SYSTEM.
Conductors. The main conductors are of a most sub-
stantial character. The section is in the shape of a
segment of a circle. Two of these conductors, with the
flat sides facing each other and somewhat separated,
are steadied apart by perforated wooden blocks and in-
serted in iron pipes about 20 feet in length. The space
between and around the conductors is then filled with
asphaltum. These pipes are connected by junction
blocks, and the house circuits make connections at
these. The house conductors are run a short distance
apart and covered with a molding, or run through the
walls of the structures. Paraffine covered wires have
been discarded, and a cotton covered wire which has
been soaked in a fire-proof composition substituted.
From observations made in testing dynamos, I think
2144
Crystal Palace Report -1882.
this is apt to take up moisture, and thus cause leakage.
Whether it is still in use I know not.
Safety Arrangements. The widespread application
of these in the Edison system is one of its most com-
mendable features, and one of the most necessary in
any and all systems. Should a wire become short cir-
cuited, the current flowing is such as to almost instantly
heat the wire to incandescence and destroy it; hence
it becomes necessary to provide against this danger.
For this purpose there is established in every main
and in every derived circuit, as well as at individual
switches, a weak point, consisting of a bit of wire of
lead and tin alloy. This is mounted in a screw plug,
which completes the circuit when in place, and breaks
it on failure. If, for any reason, this is made to carry
above a certain strength of current, whether by over-
loading or by short circuiting, it is instantly fused, and
no damage is done to a lamp or circuit otherwise.
Switches. The circuit is completed by a turn of a
handle pushing into place three or four, or less, split
conical plugs, and thus bridging across two or three
breaks in the switch. On turning still further, a cam
allows a pin to be cleared, which frees all the cones at
once and draws them back from the connection plates.
Arcing is then prevented if the switch is properly
turned, and, on closing circuit, a rubbing contact is
provided for. Each is fitted with a safety wire, and
they worked well.
Meters. Several forms have been tried that has been
adopted which depends on electrical disposition of
metals. In a self-registering form two cylinders are hung
from the two ends of a balance beam. These are im-
mersed in a solution of zinc or copper sulphate, and in
the containing vessels are larger zinc or copper cylinders,
which enclose the first-mentioned. The arrangement of
circuit is such that a shunted current flows so as to add
to the weight of the lighter, and consequently uppermost
cylinder, while taking away from the other. When suffi-
cient inequality has been established to overcome the
Crystal Palace Report-1882.
2145
•
governor weight, the balance-arm tilts, the register is
actuated, and the current is changed in the opposite
direction. While exceedingly ingenious, I should
think a change of resistances would take place to make
it inaccurate; of this I have no knowledge, however.
The meter which seems to be adopted is composed
of two jars, each containing two small amalgamated
zinc plates at fixed distances, and immersed in a satu-
rated solution of zinc sulphate. The materials are
very pure and the polarization very slight. The change
of resistance for change of temperature is small, and,
since it is in opposite direction for plates and liquids,
compensation ensues. To prevent freezing a lamp is
placed in a chamber in the lower part of the meter, the
circuit being closed in time to prevent freezing, and in
cool weather to maintain an almost perfect quality of
temperature by an adjustable bimetallic spring. About
one seven-hundreth part of the current flows through
the solutions, and the amount is ascertained by careful
weighing, after washing and drying. I think this meter
is remarkably accurate, but the weighing of a large
number of monthly and quarterly check plates is a mat-
ter of no little labor, and the public will only be satis-
fied by having a public supervisor of weighing who is
unconnected with a company.
CENTRAL STATION SYSTEM (Fig. 21).
As already mentioned, the large "C" dynamos, each
capable of supplying 1,000 standard full power lamps,
are used, and the general arrangement is that of multi-
ple arc, as at the Crystal Palace exhibit of smaller
machines. Steam is supplied by "Babbock & Wilcox":
tubular boilers, adapted for quick steam and high pres-
sure. While the simple multiple arc system is perfectly
practicable for house circuits, it is evident that some
modification must be made for supplying a district.
Suppose we have a huge plate of copper extending
over a district, and that differences of potential exist
2146
Crystal Palace Report-1882.
in its several parts. It is evident that if such differ-
ences exist currents will be set up which will flow
from the points of highest to those of lowest potential,
tending to produce an equilibrum precisely as takes
place in the earth. Let there be two such plates, and
these in juxtaposition. If these two plates be at dif-
ferent potentials and paths be opened between them,
currents will flow from one to the other, depending on
the difference of potentials existing and the number
and resistances of the paths. Should the demand for
current at one point be greater than at another-that
is, the number of paths greater or their resistance less—
the currents will flow towards this point to maintain
the potential existing and supply the demand. If such
plates are the terminals of a machine or, better still, of
several machines, and the points of supply are at dif-
ferent places, there will be a thoroughly efficient means
of supplying the district, especially if the thickness of
the plates is properly proportioned. Such plates are
obviously impossible, but replace them by meshes or
networks CC', and we have a perfectly practicable
means of supply.
All that is necessary is to lay the properly propor-
tioned mains in the streets, and wherever they cross
join like to like. The mains FF', from the station,
would be joined at several places. The outlying
branches of different stations should be joined together,
so that even in the most improbable event of a total
failure of one station its district could still be sup-
plied.
The theory advanced by certain "electricians" that
such a system of conductors would act like a Leyden
jar, or a condenser, is destitute of common sense, and
entirely opposed to the clearest laws of electricity.
Wires from different parts of the district can be
brought to the central station, and thus a graphic rec-
ord of the potentials at all times existing be kept. A
regulator can be worked automatically by one of these
circuits to maintain the potential.
>
Cryslal Palace Report-1882.
2147
The proper laying out of such a district is a matter
of most careful engineering, involving the cost of land,
property, labor, coal and copper, capital invested and
interest required, depreciation of plant and life of
lamps; in short, how much coal can be wasted and how
much return to be sought for.
But it is perfectly practicable, and already is being
accomplished in New York. Since becoming thoroughly
acquainted with the system I have had no doubt of its
ultimate success, which recent developments show to
be established. In the matter of making the trans-
mission of light and power a practical success, in bring-
ing it home to every-day domestic economy, Mr. Edi-
son, without doubt, has done more than all others;
and while his system is by no means yet perfect it
is unquestionably far ahead of the work of any one
else.
CONCLUSION.
Before giving the results of our experimental work
I will repeat that it is my belief that incandescent
lights will take the place of gas in all important central
lighting. That there is a future for individual lights,
but it is subordinate to the system of general distribu-
tion, and it is to this latter I chiefly look forward. No
lamp, machine or system is as yet perfect; all admit
of improvement; and even while writing the news con-
tinually comes of great and rapid advances.
2148
Fig. 12. Lane-Fox.
Fig. 13. British.
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2149
Fig. 17 Lane-Fox Distribution.
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Fig. 19 Edison Exhibit: Plon of Engines.
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Shoolbred-On Electric Lighting-1878. 2153
Complainant's Exhibit "On the Present
State of Electric Lighting."
BY
JAMES N. SHOOLBRED, B.A., M. Inst. C. E.
REPORT OF THE BRITISH ASSOCIATION FOR THE ADVANCE-
MENT OF SCIENCE, MEETING OF AUGUST 20th,
1878; PAGE 706.
Electric lighting has only attained to its present
development by certain marked stages of progress.
་
Though the electric light was first produced at the
commencement of the century as a chemical experi-
ment, yet its first stage of practical application did not
take place till towards 1849, when, on the recommenda-
tion of Professor Nollet, of Brussels, the large cumbrous
mageto-electric machines of Holmes, of London, and
the Alliance Company of Paris were constructed to pro-
duce a current alternating in direction for the supply of
a single light of considerable intensity. Machines of
this kind were erected at the South Foreland Light-
house in this country, in France at those of Cape
Grinez and of Cape La Heve, and at a few lighthouses
in the north of Europe. With these exceptions, these
machines may now be considered as obsolete.
The next stage of progress in electric machines was
the result of the important discovery, in 1867, almost
simultaneously, by Sir Charles Wheatstone, Dr. Siemens
and by Mr. S. R. Varley, of the principle of "reaction "
between the currents created by the rotation of one
electro-magnet in front of another fixed one, whereby
these currents, on being passed backwards and forwards
between them, are gradually augmented to a very con-
siderable degree, the result being a small, economical
and much more powerful machine, termed " dynamo-
electric" (electro-magnets being used), than are the
previously described "inagneto-electric" ones (where
permanent magnets were employed). The best known
machines of this class are the "Siemens and the
""
2154 Shoolbred-On Electric Lighting-1878.
"Gramme" in this country, and in the United States
the "Brush" and the "Wallace-Farmer."
The third and present stage of electric lighting is
that of the divisibility of the light-i. e., the production
of a number of lights from one machine. This has
been effected in practical use by Lontin with his double
machine, and the double Gramme feeding the well-
known Jablochkoff candles. With these last an Alliance
machine was first used, but latterly M. Gramme devised
his second machine, and which has the appearance of
the already existing Lontin.
<<
In the double machine (of Lontin, and also in that
of Gramme) the current is created in a small one,
termed the "generating " one, and passed on
in one continuous direction current to the larger
or dividing" one; on the outer envelope of which it
is received divided into a number of distinct circuits,
which may be coupled together at will. The Lontin
machines, so far, have produced twelve circuits from
such a machine with a maximum, in lengthened use, of
thirty lights; while the Gramme generally works with
four circuits and feeds sixteen Jablochkoff candles.
Of the lamps or regulators, those most in use for
single lights are the Serrin and the Siemens; while,
where many lights are produced, the Jablochkoff "can-
dles" and the divers forms of Lontin regulators are
available. The Jablochkoff candle consists of the two
carbons placed vertically side by side, with an insu-
lating layer of plaster of paris between them; which
is an attempt to dispense with the delicate mechanism
of the regulating apparatus, and attended only with
very moderate success. The arrangements of the Lon-
tin regulators are very ingenious and very sensitive;
some of the forms may be placed in any position what-
ever and be used with currents, either continuous or
alternating in direction.
The very careful preparation of the carbon sticks be-
tween which the electric light is produced is at present
receiving attention, so as to render their composition as
homogeneous as possible and thereby to reduce the
flickerings in the light produced.
Shoolbred-On Electric Lighting-1878. 2155
The motor power to cause the necessary rate of mo-
tion to the revolving electro-magnet or induction coil-—
generally between 400 and 1,000 revolutions per min-
ute-may be either hydraulic power, in the form of a
turbine or otherwise, or a gas engine or a steam engine.
But whichever of the three is used, extreme regularity
of motion is an absolute necessity; otherwise any want
of steadiness in running is productive of flickering in
the electric light. Therefore, where possible, the
engine performing this duty should be special for the
purpose, and not have other work to do at the same
time.
A most important consideration in connection with
electric lighting is, apart from the prime cost of the
machines, motor, lamp, &c., the amount of the working
expenses thereof, and chiefly the proportion and coșt
of the motor power to the amount of light produced.
A rough estimate is given of this by the designers of
these machines as one indicated horse-power for each
light of 1,000 standard candles. Where the number of
lights are considerable this may hold good, but for a
few, or for single lights, a larger allowance for engine-
power should be made, even when running ordinarily
and without the sudden and severe strains to which
they are exposed. Many manufacturers at and near
Paris, at Rouen, and at other places in France, have
made use of electric lighting in spinning and weaving
sheds, in iron works, &c., for the last two years, and
they generally consider that they have been supplied
with a vastly augmented amount of illumination at con-
siderably less than one-half the cost of the previous
and much poorer one by means of gas.
Though electricity may replace gas lighting to some
extent in the illumination of large areas and in certain
manufactures, yet it cannot pretend to trench upon the
special and the most extensive field for the use of gas
-the lighting of private houses-until some perma-
nent, indestructible light-producing points very differ-
ent from the present carbon sticks be discovered.
Nor should the sanitary advantages of electric illu-
mination in buildings over that by gas be overlooked.
2156
Briggs-Electric Lighting-1878.
Complainant's Exhibit "Electric Light-
ing," by Robert Briggs.
ENGINEERING, LONDON, OCTOBER 18, 1878, AT PAGE 207.
TO THE EDITOR OF ENGINEERING :
SIR-The remarks made by me in the discussion of Mr.
Shoolbred's paper on electric lighting, which he pre-
sented at the recent meeting of the British Association
for the Advancement of Science, can be properly sup-
plemented or extended by an inquiry into the relation
of the expenditure of heat in the production of light by
means of the burning of coal gas or by electrical force.
These relations can be looked upon from several points
of view. The first of these would be the purely theo-
retic one, and is based on the absolute heat which
would be evolved under the condition of perfect com-
bustion and absolute absorption of heat of coal gas in
producing a given light as compared with the heat
which represents the same light as derived from the
power expended in producing it.
There is produced the light effect of one standard ·
candle by the combustion of one-third of a cubic foot
of coal gas each hour. That is, this result is that of the
tests for quality of coal gas as established by law, but in
practice of gaslighting with the usual imperfect burners
not much above (if so much as) one-half the quantity
of light is obtained. Accepting this quantity it can be
asserted that the heat effect of a cubic foot of coal gas
is 690 heat units (pounds of water heated one degree
Fahrenheit), and that a candle-power of light is repre-
sented by 230 units.
The Franklin Institute experiments did not give the
light power claimed by most makers of dynamo-electric
machines; they only gave as the result 380 candles of
light as proceeding from one-horse power, while the
general claim for at least two of the dynamo-electric
machines is nearly five times this value (200 becs Carcel
being claimed for the Lontin machine and lamps as
given by one-horse power. As each Carcel burner
Briggs-Electric Lighting-1878.
2157
equals 9.6 candles of the English standard, it follows
that this claim is for 1,920 candles per horse-power).
The Franklin Institute expériments alsó gave 31 to 38
per centum of the whole power as all that appeared in
the resistance of the electric arc, which evolves the
light, the remainder being expended in friction of
machine and in the circuit, being dissipated as heat to
the air probably.
Taking the value of 380 candles from one-horse
power, we have the force corresponding to one-horse
power equals 1,980,000 lb. raised 1 ft. high per hour—a
unit of heat=772 foot-pounds.. one-horse power=2565
units of heat per hour, and 2565÷380 gives 6 units of
heat per candle.
From which it appears that the theoretic expenditure
of heat (or force) in producing gaslight is to that in
producing electric light as 230 to 6, or as 34 to 1,
while the theoretic expenditure of heat in producing
gaslight is to that of the electric light in the arc alone
is very nearly as 100 to 1. All these are based on the
Franklin Institute values; if the figures of M. Lontin
are accepted the ratios become five times more favor-
able for electric lighting.
But the heat which can be evolved by the burning of
coal gas does not represent the heat which appertains
to the coal that would have produced the same coal gas.
Each pound of gas coal which has undergone the pro-
cess of destructive distillation will have produced very
nearly, on the average, 4 cubic feet of illuminating gas,
and there will remain, as a residue of the process of gas
making, about 0.85 lb. of gas coke, and some 0.04 lb.
or 0.05 lb. of gas tar, both of which substances are
combustible. The quantity of coke, however, is re-
duced by the necessary use of coke in obtaining the
heat for distillation until only 0.55lb. to 0.60lb. of un-
consumed coke remains for each pound of coal origi-
nally charged in the retorts. Again, much of this coke
is in the condition of dust or very fine breeze, so that
practically only about 0.35 to 0.40 of gas coke is derived
2158
Briggs--Electric Lighting--1878.
in merchantable or usable shape for each pound of coal
originally treated; while the coal tar, although it pos-
sesses the constituents of a fuel, is not easily burned as
such. Ordinary gas coal can be taken to have the value
of 15,000 units of heat to each pound, and if it is sup-
posed that from this quantity of heat there be deducted
the heat value of, say, 0.6 lb. of coke, taken at 13,000
units to the pound=7,800 units, together with the heat
value of 0.05 lb. of gas tar, taken at 20,000 units to the
pound=1,000 units (total deduction 8,800), we have
6,200 units as the value of the fuel which yielded 4
cubic feet of gas. And, as before, taking each cubic
foot of gas as evolving three candles of light, it follows
that 517 units of heat will have been expended for each
candle of light emitted, and this value should be taken
as the expenditure of heat in lieu of the 230 units which
the gas would produce after it is manufactured.
This statement, compared with the theoretic heat of
electric lighting, as before estimated at 6 units per
candle-power, gives the heat in producing gaslight to
that of producing electric light as 517 to 62, or as 76.6 to
1, while the theoretic expenditure of heat in producing
gaslight is to that of the electric light in the arc itself
as 230 to 1—with the publication of these ratios by five
to follow, if M. Lontin's development of light per horse-
power is taken in place of that of the Franklin Institute.
Unfortunately for this statement, in a practical point
of view, the production of the electric light by the
dynamo-electric machines involves the employment of
motive power in the form of the steam engine (I omit
to consider the gas engine as the source of motive
power, thinking that its adaptation to general use should
precede a discussion of its economy in this special ap-
lication). And in none of the utilisations of natural
forces is quite so great waste of original force as in the
combustion of fuel in the steam engine. The best of
engines can scarcely be claimed to give out a horse-
power with less than two pounds of coal per hour, while
the average of good engines of such size as would be at
Briggs--Electric Lighting--1878. 2159
all available for power to run dynamo-electric machines
of supposable smallness, cannot be taken to average
less than 6 lb. per horse-power per hour. The former
of these weights of coal represents 30,000 units of heat
per hour to produce 2,563 units of effect, or only 8.55
per centum of the expended fuel and the latter only
2.85 per centum (one thirty-fifth) of the same.
Taking this latter value as the practical one, the 6
units of heat per candle, which were the theoretic result
of the Franklin Institute experiments, becomes 235
units of heat, in fact, needful to produce each candle.
Our previous figures have given 230 units of heat as
what would proceed from the best consumption of coal
gas capable of producing one candle's light, and con-
sequently the comparison of the heat practically de-
manded to produce electric light by the dynamo-electric
machine actuated by the ordinary steam engine with
the theoretic heat from coal gas is about two per centum
against the electric system.
But the previous figures also give 517 units of heat
as what is expended in the making of coal gas for each
candle's light, and this value compared with that for
the dynamo-electric light with its motive (steam) power
is 2.2 times less favorable for the system of gas lighting.
There is another way to look at the practical question.
One pound of coal will produce four cubic feet of illumi-
nating gas, each foot of which will have three candles'
power; then omitting the other products of coal,
0.083 lb. of coal represents the fuel expended in giving
the light of one candle in the same time by coal gas-
lighting. Following the previous assumption that 6 lb.
of coal will, under the boiler of a steam engine, evolve
one-horse power, and taking the Franklin Institute
value of 380 candles per horse-power from the dynamo-
electric machine, then 0.0158 lb. of coal represents the
fuel in this case. This gives the practical relation of
expenditure of coal (as fuel) in producing gaslight to
that of the electric light under discussion equal 5.25 to
1. This last view of the case is practically not an un-
2160
Briggs-Electric Lighting-1878.
fair one, for while the coke and the coal tar are not
absolutely waste products in process of gas making,
they are by no means profitable ones in themselves,
and it is questionable if they pay much more than the
cost of handling and disposing of them, especially at
places where coal for fuel is relatively cheap.
It must be noticed all through this paper that the
assumption has been for the combustion of fuel by an
ordinary steam engine and boiler at 6 lb. of coal per
horse-power, while a moderately good engine with
boiler ought and will give a horse-power for 3 lb. of
fuel, and the best engines will only require under 2 lb.
for the same result, so that all the practical ratios are
two to three times less favorable towards the electric
system than they might be.
It remains, however, that the most unfavorable state-
ment of the relative expenditures of heat and fuel practi-
cally, of the electric system by the dynamo-electric ma-
chines and steam engine, as compared to that of coal
gas for equal quantities of light is, at present, 1 to 2.2;
while in the processes there will have been burned as
fuel 1 lb. of coal under a steam boiler, against 5 lb.
of coal treated in the retort for the manufacture of
coal gas. Whether the cost of manipulation of the fires
or the retorts, the wear and tear of machinery and
engines employed in either processes, the interest upon
the prime cost of apparatus, from the fireplaces to the
points of illumination may be in the same ratio as
either the heat demanded or the coal used, is a ques-
tion for further consideration and for future develop-
ment.
Coal gaslighting would seem to have attained nearly
to its ultimate development and improvement. Minor
advantages of cost of manufacture, and possibly in the
direction of quantity of light evolved by a given con-
sumption, can be confidently looked for. The public
have been and are habituated to all the defects of the
system, and from the beginning to the end they are
grave and essential. On the other hand the electric
Briggs-Electric Lighting-1878.
2161
light has the promise of the greatest improvement in
methods of production, in its adaptation to defined wants,
and in its relative cost, so that the unfavorable view of
it which I have here presented should not be taken, and
it is far within the limits of probability that the best
statement I have presented underrates its possibilities.
It may be proper to advert here to the low result in
candle-power for the electric light found by the Franklin
Institute experiments. The power of light emitted by the
candle or the gas-burner usually tested by it is so small
that the radiant light from the sides of a dark chamber
may be neglected. The measurement of light is taken in
all instances from the rays of a standard candle as emitted
on the horizontal plane through the centre of the flame.
It was found first that this radiant light upon the walls
of a dark box from the electric light was very great, and
the means shown in the report of the committee (where
it will be seen that only a pencil of light of not over a
single degree of aperture was directed into the box or
tube carrying the photometer) were found effectual to
give a highly satisfactory comparison of the greater
with the lesser source of light under investigation.
Next it was found in the carbon experiments that there
was an apparent unsteadiness of light of great amount
emitted from the carbons. As the experiments pro-
ceeded it became evident that this unsteadiness was
occasioned by the formation of an arc upon one side of
the point (in place of a symmetrical brush, which
traversed around the points as they wore away),
emitting much the largest part of the light through a
small arc of radiation in the horizontal plane, and pre-
senting on one side of the points a brilliant reflection
from them, and a corresponding obscuration on the
opposite side. This difficulty was met and overcome
by the adaptation of carbons of suitable sectional
dimension for the current of electricity employed, until
a uniform brush, emitting rays of very nearly equal
value in all directions, was obtained. The Franklin
Institute experiments consequently do not give the
2162
Briggs-Electric Lighting-1878.
value of an apparent maximum of effect but the mean
effect from the electric lamps experimented with.
For a practical data it may be well to state in con-
clusion that the result of 380 candles per horse-power
is that 90 lb. weight falling one foot per minute repre-
sents the power demanded to afford a light of the best
spermaceti candle by means of the dynamo-electric
system. A man ascending a flight of steps at very
moderate rate will have exerted a force equal to three
candles. And the results claimed by many makers of
dynamo-electric machines are four to five times as good
as these.
The problem of electric lighting to-day is the pro-
duction of small enough quantity of light with equal
economy to that attained for large illuminating effects,
and of the distribution into small sources of light of the
great light capacity now obtained as a single point of
emission. To these ends the intelligence of all elec-
tricians is now directed, and the attainment of some
measure of success can be confidently anticipated.
I am, Sir, yours truly,
ROBERT BRIGGS.
Paris, September 23, 1878.
Colombo --Milan Station-1885.
2163
Complainant's Exhibit “The Central Elec-
tric Lighting Station of Milan.1 "
THE ELECTRICIAN AND ELECTRICAL ENGINEER, AUGUST,
1885, p. 298.
BY G. COLOMBO.
We propose to offer our readers, after 18 months of
regular operation, a description of the Milan central
station, together with its plant, its system of wires, the
results hitherto achieved and those that may be hoped.
for in the future.
The construction of this central station was decided
on towards the latter end of 1882 by a committee
selected to introduce the Edison system in Italy, who
formed later the existing company, having a capital of
$600,000, bearing the name of the Società generale ital-
iana di elettricità Sistema Edison, with headquarters at
Milan.
The company, having purchased a building situated
in the street Santa Radegonda, formerly used as a the-
atre, began to demolish the theatre and to construct the
new station in the month of October, 1882. The work
was pushed so rapidly that the station with the first
four machines was ready for work in June, 1883, the
underground wires having been laid throughout the
principal part of the territory to be covered during the
winter. Toward the end of June, 1883, the station
began to work regularly every night until 1 o'clock
A. M., with an average of 1,100 lamps. In August,
1883, the lighting of the famous theatre de la Scala was
undertaken, two machines being added to the existing
four for that purpose; and in November, 1883, continu-
ous service by day and night was begun, until by the
end of December, 1884, the number of lamps had
1 La Lumière Electrique.
2164
Colombo-Milan Station-1885.
reached 5,500, equivalent to 4,700 lamps of the normal
standard of 16 c. p.
We will divide our description of the Milanese instal-
lation, for convenience sake, into the following sections:
1. The central station of Ste. Radegonda; 2. The
system of conductors; 3. The principal installations;
4. The general working of the system.
I.
THE CENTRAL STATION OF STE. RADEGONDA.
This is a rectangular two-story and basement build-
ing of 147 x 42 feet, situated between the two parallel
streets, Agnello and Santa Radegonda. The basement
contains the machines, the next floor the boilers and
the top floor the store room and laboratory. This is a
different arrangement to that usually adopted, which is
to place the boilers in the basement, and was dictated
by considerations of stability in consequence of the
great speed of the machines.
The machine room. -This occupies the whole ground
floor and contains at present six machines, with vacant
spaces and foundations for four more, making a total of
10 for the station when it shall be worked to its fullest
capacity.
The machines now in use are of the type known as
the "Edison C," of which the following are the data:
900 ampères
Electro-motive force at the electrodes__110 to 120 volts
Maximum current at 110 volts
Resistance of armature...
Resistance of field magnets...
Diameter of armature (8 ft. 2 in.).
Length of armature (5 ft. 2 in.)
Number of field magnets.
1
0.0039 ohms
2.28 ohms
2 m. 737
1 m. 630
12
Each of these machines has its own independent
steam engine, of which the shaft is the prolongation of
Colombo-Milan Station-1885.
2165
the axis of the armature. The normal speed of the
armature, therefore, of the engine shaft is 350 revolu-
tions per minute. Of the engines two are of the Porter-
Allen type and the other four of the Armington-Sims
pattern. Each of these machines can develop, at a
maximum pressure of eight atmospheres, a maximum
force of 130 to 150 h. p., corresponding to the demand,
of 1,200 lamps of 16 c. p. per dynamo. A small sepa-
rate steam engine actuates a ventilator for the aeration
of the dynamo armatures and a steam pump sends a
current of cold water through the interior of the frames
and foundations. These means of refrigeration are
only needed when the machines are developing their
maximum of work.
74
All the dynamos are coupled in quantity to two prin-
cipal conductors of 1,700 square millimetres (2.6 sq. in.)
section and connected by means of the necessary
switches and flexible copper conductors to the regula-
tors and to the indoor test circuit, and to the two ex-
terior feeding conductors, which enter the building at
the opposite corners of this room. A current regulator
is provided for each machine. Each regulator is formed
of 50 bobbins, coupled so as to interpose in the field
circuit of each dynamo a resistance varying from 18
ohm to 7 ohms in all. The regulation is accomplished
by hand, either for each dynamo singly or for all at
once, by means of a common shaft which rotates all of
the contact arms. These are movable over the six
discs of the regulators, each having 57 connectors rep-
resenting 57 degrees of strength of current. Two indi-
cators of electro-motive force with electric bells and two
dial voltmeters are used by the persons who have
charge of the regulation of the current. These instru-
ments are regulated by a standard voltmeter, graduated
by means of a standard Daniell cell and by a Thomson
reflecting galvanometer. By this means the current is
promptly regulated without alteration in the quantity
of light furnished, even when the greatest alterations
are made—such, for instance, as the sudden lighting or
2166
Colombo-Milan Station-1885.
extinction of hundreds of lights at a time, for scenic
effect, in the theatre de la Scala. A local circuit, called
the test circuit, is arranged so as to be traversed at the
will of the attendant by the current from each of the
dynamos. On this circuit are connected 1,000 lamps,
or as many as should be operated by one machine at
its maximum rate of work. These 1,000 lamps can be
lit by groups of 50 at a time by the aid of a switch.
At the junction of the two principal conductors with
the feeding conductors of the system are interposed
feed regulators, which will be explained later in our
description of the system of conductors; their function
is to equalize the electro-motive force, and consequently
the intensity of the light at all points: In this room
are also placed the ammeters used to indicate the quan-
tity of current flowing through the system of conduct-
ors, and therefore the number of lamps lighted in the
territory supplied by the station. These ammeters are
simple needles, deflected by the current which passes
through the principal conductors placed beneath them,
and can indicate up to 2,000 amperes with a trifling
error; they are verified from time to time by standard
lamps. Although it would be easy to furnish these
ammeters with automatic registering devices, which
may be done later, at present it is considered sufficient
to read the indications once every quarter hour, as
much for regulating the machines then working as for
registering the course and amount of the daily work
performed. Other apparatus, unnecessary to describe
here, serves for diverse observations, such as the vari-
ations in the electro-motive force at the ends of the
feeding conductors of the system, indicators of leakage
to earth on either pole of the system of conductors,
measures of the corresponding electro-motive force, etc.
Boiler room.--The boilers are installed in the first
story and at present are five in number, of which one
is isolated and the other four connected in groups or
batteries of two boilers each. They are of the Babcock
& Wilcox manufacture, perfected in many details by
·
Colombo-Milan Station-1885.
2167
Root. The choice of boilers was determined by the
local conditions, which demanded boilers of a pattern
at once light, small in comparison with the considerable
force required and inexplosive. Each boiler is com-
posed of a group of inclined tubes, connected at the
two extremities to horizontal reservoirs of steel plates,
from whence the steam is drawn. The interior extremity
of the tubes is in communication with a drum, from
whence the smoke passes to the chimney. The princi-
pal data of each of these five boilers follow:
Number of tubes...
Number of collecting reservoirs.
Length of tubes...
Length of reservoirs
Surface of grate…….
Heating surface, nearly-
Estimated h. p.---
Total weight.
Surface occupied.
1
1
1
1
1
1
}
}
I
96
2
15 feet
15
12 sq.
510 "
(C
((
160
42,944 lbs.
60 sq. feet
Space has been left unoccupied for four more boilers,
in case the wants of the service shall render them neces-
sary. The boilers are fed by five Koerting injectors,
two of which pump the water from the bottom of a well
and empty it into reservoirs situated on the lower
floor. There are also two direct-action steam pumps,
of which one is ordinarily used for the refrigeration of
the machines; but the piping is so arranged that either
of these pumps, or both together, may be used for
feeding the boilers. The steam pipes are so arranged
that either machine can be detached from the others in
case of accident or for repairs.
The smoke from the boiler furnaces is carried to a
chimney of 6 feet constant interior diameter and is 156
feet in height from the street pavement.
Other apparatus is used for the hoisting and distribu-
tion of the coal. The coal burned is the best Cardiff,
which produces very little smoke when the furnaces are
2168
Colombo-Milan Station-1885.
charged, and practically none during combustion. No
smoke-consuming devices are used.
Organization of the central office staff.-The direction
of the service is confided to an electrician-in-chief, who
has under his immediate orders: One or two engineers,
according to the season, charged with the oversight of
the work; one chief mechanician, one foreman elec-
trician, one foreman mechanician, one foreman of fire-
men, and the working electricians (for the commutators),
steam engineers and firemen. The staff is divided into
gangs for day and night service.
During the summer season the number of lamps used
in the district during the late hours of the night and
during the day is only from 100 to 200; during the
winter this number increases, and there are some days
on which the lamps are in use by hundreds from day-
break and in some places of public resort remain in use
all night. During the hours when the lamps in use are
only some hundreds a small 400-light dynamo is used.
As soon as the ammeters indicate that the number of
lamps in use approaches 400, one of the large dynamos
is started and the small one stopped. A second C dy-
namo is added when more than 900 lamps are indicated;
for although the C dynamos will feed 1,000 lamps, and
even more (with the maximum electro-motive force of
116 volts), it is preferred not to charge them in actual
service with more than 900 or 950. The same proceed-
ing is repeated in proportion as the number of lamps
used in the district increases, until the full capacity of
four dynamos is reached, and this has not been exceeded
up to the present time. The remaining two machines
are kept in reserve, one of them being run at a reduced
speed on open circuit, ready for use in a few moments
if the occasion arises. Experience has shown that the
introduction of a new dynamo or the substitution of
one for another can be made in a few seconds, and in
such a manner that an accident to a machine, such as
the breaking or the heating of a part, has no injurious
effect on the regularity of the service.
Colombo-Milan Station-1885.
2169
•
The increase in the number of lamps takes place very
rapidly from twilight to 7 or 8 o'clock in the evening.
The process above described is reversed in removing
dynamos one after another from the circuit, when at a
later hour the number of lamps begin to decrease. Or-
dinarily, one hour after the closing of the theatres the
small dynamo is put in use.
The normal electro-motive force of the station is
shown by the indicators previously mentioned, whilst
that at the end of the feeding conductors is regulated
by means of the feed regulators according to the indi-
cations of the ammeters. Thus the director of the
station has completely under his hand the working of
the lighting at all points of the system.
All of the statistics relating to the work of the station,
as well as the number of lamp hours, the consumption
of coal and oil, etc., are registered daily and tabulated
monthly for the information of the engineer-in-chief
and for the administration.
II.
SYSTEM OF CONDUCTORS.
The central station of Ste. Radegonda, which at pres-
ent is eccentrically situated in respect to the district
served by its conductors, will, on account of recent de-
velopments of the system of conductors, soon be in a
central position, with radii of 1,500 to 1,600 feet in all
directions.
The conductors are divided into two classes, called
respectively conducteurs d'alimentation (feeders) and
conducteurs distribution (mains), the distinctive uses of
each being explained hereafter. Each line comprises
two conductors, one going and the other returning;
that is to say, each line is a tube containing two copper
conducting bars separated by an insulating composition
according to the well-known Edison system, which has
2170
Colombo--Milan Station-1885.
been previously described in these columns (see page
95).
The organization and manner of calculating the de-
tails of such a system are quite different from those
required for any other conduits, as for water, air or gas.
In such cases we start with a certain initial pressure
(in the reservoirs or in the gasometer), and the conduit
is so designed as to lose a certain determined fraction
of the initial pressure at the most distant points of the
system. We have then at different points of the system
a pressure, which is less and less in proportion as the
distance from the origin of the conduit. The maximum
loss of pressure may represent a considerable fraction
of the initial pressure, since we can always proportion
the delivery of the water, or gas, by appropriate orifices,
whatever may be the pressure or rate of flow, and thus
compensate for diminished pressure.
For an electric lighting conduit the problem is en-
tirely different. Admitting, as a general principle, that
it is desirable to employ for the service throughout the
whole of a system lamps of one standard form, which is
equivalent to demanding the same electro-motive force
to develop their normal luminous intensity, it is evident
that the permissible falls of potential between the two
conductors at any two points of the system must not
vary much between themselves, without having lamps
which would give a luminous intensity varying too much
according to their positions relatively to the source of
current.
Then, recalling the fact that for the standard Edison
16 c. p. lamp a difference of one volt in the electro-
motive force is equivalent, at the limits of the luminous
intensity, to nearly one candle, one can easily compre-
hend that the greatest available difference in electro-
motive force at any two points of the system cannot
without inconvenience exceed one and a half or two per
cent. It is then necessary to design the system so that
this condition may always be fulfilled; and this con-
sideration forcibly excludes the application of the sys-
Colombo-Milan Station-1885.
2171
tem in use for the distribution of water or gas. Strictly
speaking, one could make up for a great variation in
the available electro-motive force by using lamps giving
the same luminous intensity with different electro-mo-
tive forces (that is to say, having different resistances),
but that would entail complications in the service
which are entirely inadmissible.
To satisfy the condition stated it is necessary to
divide the system of conductors into two parts: first, a
system of conductors called mains, forming a circuit
entirely closed and isolated from the central station;
and second, a system of conductors called feeders,
which, starting from the central station, carry the cur-
rent to conveniently chosen points on the mains. This
might be compared to a distribution of water by a sys-
tem of intercommunicating canals, into which the water
would be carried by feeding trenches proceeding from
the source of supply, so as to establish an equal level at
all points of the system.
The conductors forming the closed system of mains
are those which run along the streets and serve directly
for the distribution of the current to the houses of con-
sumers.
They are inter-connected by joint-boxes containing
fusible lead safety-plugs, calculated so as to interrupt
the circuit whenever from any cause the delivery be-
comes abnormal and threatens to heat the conductors
above the fixed limit.
The feeding conductors all start from the central
station and are all connected with the mains in joint-
boxes of the same sort as those used for the mains.
These joint-boxes have openings flush with the pave-
ment for the purpose of examining the joints and of
making galvanometer tests.
The designing of a system of this sort can all be
done with a battery and galvanometer in the laboratory.
An artificial system, on a reduced scale, is constructed
to represent the actual system; the current is passed
from the battery by feeding conductors branching to
2172
Colombo-Milan Station-1885.
different points and always of the same resistance;
then by experiment it is determined which are the most
convenient points at which to make the junctions be-
tween the feeders and the mains, so that the difference
of potential between any two points on the mains shall
not exceed the fixed limit. Only, as it is impossible
that a system thus planned shall not be subjected to
subsequent changes by reason of the addition of new
consumers, it becomes necessary to also arrange for the
growth of the mains; this requires a somewhat labo-
rious calculation to determine whether one or more
feeders shall be supplied or whether the points of junc-
tion between the feeders and the mains shall be dis-
placed.
It was in this fashion that the existing system, planned
first in the laboratory for about 3,000 lamps and ex-
tending only to la Scala theatre, about 1,380 ft. from
the central station, has since been enlarged by the ad-
dition of two feeders, the displacement of several junc-
tion boxes and the lengthening of all of the mains, so
as to suffice for the 5,500 lamps now served, with the
possibility of serving 7,000 without any further alter-
ation, at a maximum distance, by the conductors of
1,890 feet and 1,440 feet in a straight line.
The mains generally run on both sides of each street
in the district served by this station, and are buried at
a depth varying from 20 to 30 inches beneath the pave-
ment. The tubes containing the mains are of No. 4
size, having two bars of copper of 930 square millime-
tres (1.44 sq. in.) each and 6 metres (19 feet) long.
The joints are made on the well-known system, by arcs
of copper in cast-iron boxes filled with the insulating
composition. Twelve joint-boxes are used for the
mains.
The loops to the houses of consumers are made by
boxes of a special shape, from which the conductors are
carried either in smaller tubes (Nos. 5, 6 or 7) or by
lead-covered cables, and are then subdivided into dis-
tributing wires leading to the different places to be
lighted.
Colombo-Milan Station-1885.
2173
}
The feeders are placed at the same depth, branching
to the selected points on the mains by the shortest
route and connected to the mains by six-joint boxes
similar to those used on the mains. The feeders are
large tubes of Nos. 1 and 2 size, containing bars of
589 and 443 square millimetres (0.91 to 0.68 sq. in.)
section. The shortest is 118 metres (383 feet) long and
the longest 504 metres (1,638 feet). Their resistance
is from 0.0101 to 0.0393 ohm. The insulation resist-
ance of all of the underground conductors connected
together is 192,000 ohms.
The maximum loss for which the conductors have
been calculated is 12 volts when all of the lamps served
by the station are in use. Adding the loss in the in-
stallations in the consumers' premises, calculated to be
from 2 to 2 volts for all of the installations, there is a
maximum loss of electro-motive force between the
dynamos and the lamps of 14 to 14 volts.
•
With the great variations in the consumption of the
current caused by the addition of new consumers, the
opening and closing of theatres, etc., it would not be
possible to preserve a constant electro-motive force,
even within the limits indicated, at different points of
the system, without the use of the feed regulators at
the ends of the feeders in the central station. By the
aid of these the greatest variation in the available
electro-motive force at any two points of the system
never exceeds 2 volts, or less than two per cent. of the
standard electro-motive force, adopted from the start,
which is 102 volts. Thus all consumers of Milan are
served by lamps of 101 to 103 volts, limits which are
never passed.
The theatre of la Scala being the most important.
consumer of the system, has been the object of special
precautions in designing the arrangements.
Notwithstanding the doubts expressed by many elec-
tricians, including Mr. Edison himself, the theatre has
been connected directly with the system, although it
uses an equivalent of 2,580 16 c. p. lamps, and that
2174
Colombo-Milan Station-1885.
exhibitions take place there only during the first three
or four months of the year. It has been arranged so
that it can be operated by an isolated plant if necessary,
but up to the present time it remains connected with
the general system.
We give below some data as to the extent of the
system:
Length of tubes for feeders and mains.
Average distance from the centre of gravity of
the lighting from the station, measured on the
conductors_
Feet.
23,075
1,430
Distance from the station to the centre of the
principal group of lamps (around the theatre
of La Scala) measured on the conductors___ 1,625
Distance from the station to the most distant
lamp (Banca generale) measured on the con-
ductors.
2,047
Distance from the station to the most distant
lamp in a straight line (Hotel Continental and
Cercle des Artists) of maximum radius. 1,560
III.
THE PRINCIPAL INSTALLATIONS OF THE SYSTEM.
On January 1st the system comprised 5,530 lamps,
equivalent to 4,745 of the standard 16 c. p. lamps, thus
distributed:
Theatre de la Scala_
Theatre Manzoni
Hotel Continental__.
Cercles (clubs) - -
Cafes and restaurants_
Banks...
Stores and dwellings.
Total
1
1
1
1
I
Lamps.
2,890
391
476
335
725
103
610
5,530
[
1
Colombo-Milan Station-1885.
2175
Of these the most important is that of la Scala the-
atre. This is the largest opera house in the world, so
far as the dimensions of the stage and auditorium are
concerned, although the spaces allotted to the necessary
portions not used by the public are somewhat restricted
owing to lack of ground. The stage is 147 feet deep
by 121 feet wide. The auditorium is 81 by 71 feet and
65 feet in height. There are 194 boxes, distributed in
five galleries, not
counting the upper gallery. The
theatre was first opened on August 3d, 1778.
The municipal authorities insisted that the whole
theatre should be lighted by electricity, to the entirə
exclusion of gas, at a time when the central station had
just begun operations, allowing only five months in
which to complete the installation. Happily, the in-
stallation of the Theatre Manzoni, just then completed,
furnished an opportunity for the study of the apparatus
for stage lighting which was to be used on a ten-fold
greater scale at la Scala. Yet much special apparatus
for the purpose had to be invented to fill the peculiar
demands of a stage so vast and where so much luxury
is displayed in the mounting of the operas. The gas
was entirely displaced and the theatre wholly lighted
by incandescent electric lamps in time for the season
1883-84. The following are some of the details of this
important installation: The total number of lamps in
the theatre and its annexes is 2,890, of 32, 16, 10 and 8
c. p., respectively, equivalent to 2,580 of the normal 16
c. p. standard lamps. The current is furnished to the
theatre, as to all other consumers, night and day, and
during one season the consumption has amounted, in
round numbers, to 900,000 lamp hours. Not a single
accident to or interruption in the service has occurred
since its inauguration in November, 1883, up to the
present time. A second and much smaller installation
is that of the Theatre Manzoni-391 lamps-from
whence gas is also excluded.
Another installation, that of the Grand Hotel Conti-
nental, is, we believe, unique. This hotel is entirely
2176
Colombo-Milan Station-1885.
lighted by incandescence, to the absolute exclusion of
gas, and even of candles, since every room is furnished
with the electric light. Portable lamps with flexible
conductors and circuit-closers similar to those used for
electric bells, are used. There are 476 lamps here, 32
and 16 c. p. being used for the public halls and saloons
and 10 c. p. for the chambers.
Two or three other installations are now in course of
construction and are rapidly approaching completion.
As the gas company in this city has an unexpired
monopoly, it is impossible to hope for a much greater
extension of the system to streets and squares other
than those now covered, although the public much de-
sire it. The electric light has, however, brought about
a reduction of 40 per cent. in the price of gas within the
district served.
IV.
THE GENERAL WORKING OF THE SYSTEM.
When this enterprise was undertaken there was only
one other like it in the world, at New York, and even
there the Pearl street station had only just started to
furnish light. It follows, therefore, that its operations
were conducted slowly, and often tentatively. Never-
theless, it prospered so well that on December 31st last
it had a number of consumers which represented an
annual revenue of $40,000.
At the present moment the capacity of the six ma-
chines now installed at Ste. Radegonde is nearly
reached. As the principle has been adopted of always
keeping one in reserve, even in the times of greatest
consumption (the month of February), and calculating
the capacity of the C machine at 1,000 16 c. p. lamps,
the present equipment will only supply 5,000 of 16 can-
dles, or their equivalent in 32, 16, 10 and 8 c. p. lamps.
The station can contain, however, and has fixtures
ready for four more machines and all accessories capa-
Colombo-Milan Station-1885.
2177
ble of supplying, omitting the reserve, 9,000 16 c. p.
lamps, or about 11,000 of assorted sizes. This number
will suffice for the probable extreme wants of the entire
district.
The new machines can be added at a less proportion-
ate cost than the six original ones, on account of the
preparation already made to receive them. The cost
will be simply the purchase price of the machines and
conductors and cost of laying them. In regard to the
conductors, any additions to the number of consumers
will result in allowing a more favorable arrangement of
the junctions between the feeders and the mains, so
that the cost of these will be, per lamp, about 40 francs
($8.00), as against 56 francs ($12.00) for the original
outlay per lamp. It may therefore be concluded that
the first year of working the Ste. Radegonde station
does not represent exactly the results that may be ex-
pected in 1885. So, if the first year of working has not
only left the capital intact, but has produced a margin
for renewal of the plant, it may be expected that the
succeeding years will produce dividends. Not only
will the diminution in the first cost of installation tend
to this result, but also the greater economies which will
be realized in the maintenance. In launching a new
enterprise where it is imperative to succeed at any cost,
notwithstanding obstacles, details receive little atten-
tion; but when the business is once well under way,
the staff have leisure to economize in the working.
One example suffices to prove this: The consumption
of coal, which was at .50 kilos (1.1 lbs.) per 16 c. p.
lamp per hour, has been reduced to .35 kilos (.77 lbs.)
at present, with a prospect of a still greater economy in
this particular. All of the other factors in the cost of
working have been diminished in like proportion.
When the enterprise was started it was judged con-
venient to adopt a mixed tariff, depending on the nature
of the consumption, viz., a fixed tariff of so much per
lamp per year for places like theatres, cafes, clubs, etc.,
where the average consumption per year varied little;
2178
Colombo-Milan Station—1885.
and a tariff depending on the actual consumption, meas-
ured by the Edison metre, for private houses, stores,
banks, offices, etc.
As to the tariff itself, the system adopted from the
start was the most rational and the most convenient
that could be adopted for an electric lighting enterprise,
especially at its inception. Each lamp installed with a
consumer represented a capital permanently invested
for real estate, building, machinery and conductors.
Even supposing that lamp to be used only one hour per
year, the installation must provide for illuminating that
lamp, since it might happen that all of the lamps in the
system should be in use at the same time. This is
especially true in Milan, because the lamps being chiefly
in public places, it really happens that in winter, at a
certain hour of the night, the greater portion of the
lamps are in use. Each lamp installed ought, then, to
pay
the interest and the cost of renewal of its share of
the capital invested, whether used during the whole
year or not at all. This constitutes, in consequence, an
annual constant that each lamp must pay, independent
of its consumption.
Then there remains to be fixed the tariff of consump-
tion, representing the cost of coal, labor, maintenance
and spare materials. As this cost is nearly propor-
tional to the time the lamp is used, this tariff is so
much per hour per lamp, or rather, so much per hour
and per ampere consumed by the lamp.
If the contract is by metre, the consumption is paid
by the readings of the meter, which registers the quan-
tity of current or the amperes consumed. If the con-
tract is per lamp, the total hours per year are calculated;
only, to check a consumption of light greater than that
agreed on or foreseen, the consumer must pay, besides,
for the renewal of the lamps. Up to the present time
the latter form of contract prevails; but for stores and
dwellings the tariff by metre is preferred and will be
applied on a more extended scale hereafter.
The following is the tariff adopted from the com-
Colombo--Milan Station --1885.
2179
mencement, and having proved convenient by experience,
is maintained integrally at present; it is based on the
normal lamp of 16 c. p.:
Francs. Dollars.
Annual constant for the 16 c. p. lamp. 35.00
Tariff of consumption :
Per ampere-hour..
Per lamp, normal-hour__
-
(7.)
0.0533 (.01)
0.04 ( .008)
For lamps of 100, 32, 10 and 8 c. p., the constant and
tariff of consumption are varied proportionately to the
quantity of current which they expend.
It is evident that this tariff favors the largest con-
sumers; not those who have the largest number of
lamps, but those whose lamps are used during the
greatest number of hours. Thus, for example, a con-
sumer whose lamps burn during 3,500 hours per year
(as in the case of street lighting), would pay annually
for a normal lamp of 16 c. p. (equivalent to at least 180
litres of gas), a sum of 175 francs ($35), which amounts,
per hour, to:
16 c. p. electric lamp-
Corresponding price per cubic metre of
gas.-
Centimes.
Cents.
5.0
1
27.8
5.5
Which demonstrates the possibility and even the
convenience of applying the electric light to public
lighting.
Cafes, restaurants, clubs, etc., have an average con-
sumption of 2,700 to 2,800 hours, which amounts to a
tariff per hour of:
16 c. p. electric lamp….
Corresponding price per cubic metre of
gas
Centimes. Cents.
5.25
1.5
29.2
5.8
2180
Colombo-- Milan Station--1885.
Stores closing at from 9:30 to 10 o'clock P. M., and
having an average consumption of 1,400 hours, would
pay per hour:
Corresponding price per cubic metre of
16 c. p. electric lamp--
gas. -
Centimes.
Cents.
6.5
1.3
36.1
7.2
The price of gas is that of the monopoly accorded to
the gas company of Milan, without counting 2 centimes
($.004) municipal tax.
Lastly, the dwellings and offices closed in the eve-
ning, counting the cost of the light on a basis of 700
hours per year, the tariff per hour would be:
16 c. p. electric light.
Corresponding price per cubic metre of
gas.
Centimes.
Cents.
9.0
1.8
50.0 10.0
The electric light is in this case dearer than gas, even
at the price assured by monopoly, except in small
towns, where gas costs, in Italy, 45 centimes (9c.), and
even 50 centimes (10c.) per cubic metre. This is also
the case with theatres having a small number of repre-
sentations per year. In Italy, for example, all the large
opera houses have a season of 40 to 60 representations.
These figures will suffice to give an idea of the con-
ditions in which an incandescent electric lighting enter-
prise can be established and compete with gas. They
certainly do not represent the last word that can be
said of electric lighting. In the future we are sure
that reductions will be made which will still further ex-
tend this grand application of electricity, which is still
in its infancy, since there are but two instances of its
exploitation on a large and important scale, viz., in New
York and Milan.
As the cost of canalization increases rapidly as the
distance between the central station and the furthest
Columbo-Milan Station-1885.
2181
outlying lamp increases, it is most economical to estab-
lish stations in thickly settled districts, so that this
distance shall not much exceed 300 metres (975 feet).
If this light is to be adopted generally, to the exclusion
of gas, a cheaper system of canalization must be de-
vised. There is more than one way in which a practi-
cal solution of this problem may be sought; and
although this solution may be reserved for the future,
there is already one point gained in a fact whose im-
portance surpasses that of all other accessory questions.-
This fact is the complete and practical success of pub
lic lighting by the incandescent lamp, together with the
admirable system of distribution devised by Mr. Edison
-a success which is hereafter assured by an experience
of more than two years in New York and of nearly two
years in Milan.
2182 Lungren-Electricity and Gas-1882.
Complainant's Exhibit "Electric and Gas
Illumination."
By C. M. LUNGREN.
[Popular Science Monthly, September, 1882, at page 577.]
The period of contest and denial over the question of
the possibility of producing a light of low intensity by
means of electricity, that would be suitable for the
general purposes of interior lighting, has about drawn
to a close. It is now pretty generally conceded—what
there has never been any reason for denying that the
known laws of electric transmission interpose no bar to
the successful solution of the problem, but that the
difficulties in the way are solely of a practical kind.
And it is, further, quite generally agreed that these
practical difficulties have been for the most part re-
solved, and the question reduced down to one of cost
simply; and while a good deal of discussion has taken
place upon this point, but little has been written that
will enable the general public to form a judgment upon
the subject, and arrive at a trustworthy opinion of the
relative cost of it and gas under actual commercial
conditions.
In estimating the relative cost of the two illuminants,
it has been common to compare simply the cost of the
materials consumed in their production, or when the
cost of the apparatus necessary to generate the elec-
tricity has been taken into account this has usually
been upon the basis of a limited production, and to this
extent unfair to electricity. A comparison to be of any
value should be between plants of a size sufficient to re-
duce the cost to the lowest point at which it can be
commercially maintained, and should include all of the
items entering into it. The attempt has been made in
the following pages to institute such a comparison, and
present the facts in the case as they are, so far as they
Lungren-Electricity and Gas-1882. 2183
can be obtained. The comparison is upon the basis of
works capable of producing a million feet a day, as in
such works gas can be made as cheaply as in any that
are larger. The figures for the electric plant are based
upon the work of Mr. Edison, as he is the only one
who has so far made any attempt to put in an electric
plant upon an industrial scale. And for that reason,
further, only his system of distribution is considered,
though it may be a question whether it is the one which
will prove most satisfactory in practice. An objection
to it of considerable force, in the opinion of some, is the
difficulty of handling engines and boilers with sufficient
rapidity to meet great and sudden variations of de-
mand, such as not unfrequently occur during the sea-
sons of the year in which the weather is changeable.
The variation that experience has shown takes place at
different periods of the day can be met readily enough.
On this account and on acccount of the greater freedom
secured in the matter of working various pieces of ap-
paratus without interference, it would seem that the system
of distribution which includes a storage battery would
be preferable, and may, perhaps, become the final form
adopted in electric installations. It cannot well enter
into the present calculation, however, as there are no
data with reference to the first cost and depreciation
available, and because the present secondary batteries
do not seem to have yet reached a satisfactory com-
mercial form.
The cost of such a plant for coal gas will vary in this
country from $2,500 to $4,000 for each million feet of
the yearly make, but $3,000 may be taken as a fair
average. Owing to the great variability in the demand
for light at different seasons of the year, a gas works of
this size will be called upon to furnish but 200,000,000
instead of 365,000,000 feet a year. The plant will
therefore cost $600,000. Of this $250,000 may be taken
as the cost of the mains, which in average conditions
will have for a works of this size a total length of fifty
2184
Lungren-Electricity and Gas-1883.
miles, covering a district of about three square miles.
To compare an electric with a gas plant, it is necessary
to know the number of five-foot burners that will be
maintained at the time of greatest consumption, as on
this depend both the amount of horse-power required
and the size of the mains to transmit the current.
The variation in the demand for light from hour to
hour as it would occur in average conditions on a bright
December day is exhibited in the following table in
percentages of the total make for the twenty-four hours:
ג
'
7-8 A. M.
14 per cent.
8-9
9-10
......
10-11 (6
11-12 66
12- 1 P. M
1- 2
2- 3
3- 4
HA HA HA Ho Ho Ho Ho Ho
7-8 P. M.
8-9
12 per cent.
12
((
9-10
"
10
((
......
10-11
6
11-12
5
12- 1 A. M...... .....
1,700
(C
1- 2
110
པ
3
2- 3
11%
<<
3- 4
•
...
11%
4- 5
7호
​(6
4- 5
10
5- 6
....16 to 20"
5- 6
1,8%
6-7
<<
.14
6- 7
17%
(C
This shows the time of greatest consumption to be
between the hours of five and six, and the demand as
high as twenty per cent. of the entire daily make. In
the case of the plant under consideration, the maximum
number of burners that will have to be maintained at
any one time is therefore 40,000.
Before proceeding to estimate the cost of the plant
to generate and distribute electricity sufficient to main-
tain this number of burners, a few words descriptive of
Mr. Edison's system will be desirable, especially as
there appears to be considerable misapprehension on
the subject. The distribution is what is known as in .
multiple arc-that is, the lamps are placed upon cross-
wires between the conductors. Imagine a ladder
erected upon an ordinary railway, so that it stands
across the track, each foot resting upon one of the rails.
Then these rails will represent the outgoing and re-
turning street conductors; the sidebars of the ladder,
Lungren-Electricity and Gas-1882. 2185
the house conductors, and each rung a lamp. The
dynamo machines generating the current are arranged
in exactly the same way with regard to the circuit, all
the positive poles being joined to one main conductor,
and all the negative ones to the other. The arrange-
ment is what is known, in the case of electric batteries,
as coupling for quantity, as opposed to coupling for in-
tensity, and is similar to that of a number of pumps
discharging water into a common main. This disposi-
tion of the electric-producing apparatus has the im-
portant advantage that the reserve plant, to meet con-
tingencies, needs to be but a fraction of the total one,
while if each machine supplied an independent circuit
the plant would have to be in duplicate. As is well
known, the steam-engines driving the dynamos are
coupled directly to the machines, without the interven-
tion of belts or gearing, the combination being termed
the steam dynamo.
The street mains consist of wrought iron tubes about
two inches in diameter, containing two half-round
copper rods imbedded in an insulating resinous cement.
A main of this kind is carried continuously around each
city block. At the intersections of the streets the con-
ductors are brought together and joined to a main
somewhat larger, termed a feeder, which supplies the
current to these four blocks. It will thus be seen that
the system of mains and the mode of production of the
electricity are as readily capable of expansion to meet
increased business as in the case of gas. The mains
can be tapped anywhere for new consumers, and to
meet this increased demand it is only necessary to run
a feeder to the place of enlarged consumption, and in-
crease the producing plant sufficiently.
What, then, will be the cost of such an electric plant
to do the same amount of lighting as the above gas
plant? If we take eight sixteen-candle lamps, main-
tained throughout the whole system for each actual
horse-power applied to the dynamo machine, engines
with a normal capacity of five thousand horse-power
2186
Lungren-Electricity and Gas-1882.
will be required to sustain the maximum number of
burners. This will include the reserve plant, as engines
of a normal capacity of forty-two hundred can readily
be forced to five thousand horse, or twenty per cent., to
meet this extreme demand, and, with the generators
arranged after Mr. Edison's plan, this per cent. is an
ample reserve. The maximum demand can, of course,
be met either by forcing or by running the entire plant
at its normal rate, and forcing only in case of accident.
To cover a district of three square miles, two distribut-
ing stations will be sufficient. The steam dynamos may
be taken as of two hundred horse each, working nor-
mally. The present steam dynamos are of but one hun-
dred and twenty-five horse, but they can be made two
hundred horse with but slight increase of cost, which
Mr. Edison contemplates doing in future installations.
This will give thirteen steam dynamos to one station
and twelve to the other. These may each be placed at
$8,000, making a total for the two stations of $200,000.
That this is a sufficient allowance will be evident upon
considering the machines in detail.
two hundred horse-power engines.
tion that these can be obtained by
per horse-power, or $3,600 each.* This leaves $4,400
to cover the cost of the dynamo. The material in these,
as now being constructed, is as follows:
a
There are first the
No one will ques-
large buyer at $18
Iron (wrought and cast) ..... 40,700 pounds at 33 cents = $1,425 00
Zinc (cast).....
Copper
....
680
3,440
44,820
6
28
40 80
963 20
$2,429 00
This leaves $2,071 for the cost of construction, which
* Mr. Edison informs me that engines of 200 indicated horse-
power are being purchased by him for $1,750 each, delivered in
New York. This estimate is, therefore, much too high, but, as the
comparison of plant in the text is based upon it, I have thought it
best to let it stand and point out the needed correction here.
Lungren-Electricity and Gas-1882. 2187
will be recognized as more than enough, when it is re-
membered that the cost of the iron as above given in-
cludes its shaping, and that the copper on the armature
is in the form of bars and disks, which, with suitable
tools, can be expeditiously constructed.
Adding twenty-five per cent. to the cost of material
for the 200-horse machine, there is still left $1,364 to
be expended in construction. It seems to me, there-
fore, that $8,000 is a safe estimate of the cost of such
steam dynamos. Regarding the boilers, the sectional
or water-tube boiler on account of its freedom from
dangerous explosions, the smaller space occupied by it,
its higher efficiency and less cost for repairs, is in every
way the best suited for a purpose of this kind. Such a
boiler set ready for use, including stack and apparatus
for handling coal and firing, will cost $20 per horse-
power. The total boilers would therefore cost $100,000,
making the entire producing portion of the plant, ex-
clusive of real estate, $300,000.
As the Edison mains are now being laid, they will
transmit a current sufficient to maintain from sixteen
thousand to eighteen thousand sixteen-candle lamps.
Taking the former figure, this is one and a quarter mile
per 1,000 lamps. Basing the calculation for mains
upon this mileage and the size of the present mains,
the same number of miles of electric mains would be
required as for gas. The present conductors are, as
stated, in the form of half-round copper rods, of vary-
ing sizes, diminishing, of course, as they proceed from
the station. They are, however, equivalent to round
rods with a uniform diameter of one-half inch. Such
rods weigh 755 of a pound per foot, and 3986.4 pounds
per mile, costing, at 28 cents per pound, $1,116 per
mile. As there are two rods in each main, the cost per
mile for copper would be $2,232. To this must be
added $1,200 per mile for wrought-iron tubes, boxes
at the joints and between the mains, and the
house wires and insulating material, and $1,000
per mile for laying, making the total cost of the
1000
2188
Lungren-Electricity and Gas-1882.
main per mile, laid ready for use, $4,432. Four-
fifths of the mains would be of this size, the other fifth
being feeders equivalent to round rod three-fourths of
an inch in diameter. These latter weigh 1.69 pound
per foot, and would therefore cost $2,340 per mile, and
taking the cost of inclosing tube, insulation and laying
the same as above, their total cost per mile would be
$7,196. The total cost of the mains, forty miles at
$4,432 per mile, and ten miles at $1,196 per mile, would
therefore amount to the same as the gas mains, viz.,
$250,000. If real estate be added at $50,000, which in
most cities requiring this size of plant would be ample,
the total cost of the electric plant would be the same as
one for gas.
*
The elements entering into the cost of the light to
the company furnishing it are in each case the interest
on the investment, depreciation, or the amount spent
each year in keeping the property in good condition,
the labor of all kinds-in the manufacture, distribution
and management--and lastly, the cost of the materials
used in its production. In the case of gas but a few of
these items as they occur in American works are obtain-
able, so that recourse must be had to the published re-
ports of foreign companies, and the like items estimated
for this country. Of these, the reports of the London
companies as analyzed by Mr. Field will best serve for
the purpose of the present comparison.t Taking first
the item of depreciation, we find that for the four
metropolitan companies this was, for the year 1880, on
* While this estimate seems to me not far from the expenditure
that would be actually required for this size of plant, it should be
stated that it is lower than any of those given by the electrical ex-
perts examined by the select committee of the House of Commons
in its consideration of the Electric Lighting Bill.
+ Having been unable to obtain a copy of Mr. Field's "Annual,”
I have taken the figures as quoted from this for the year 1880 by
Mr. Dowson, in a recent lecture before the Society of Arts.
Lungren-Electricity and Gas-1882. 2189
the producing portion of the plant 9.86, cents per 1,000
feet of gas sold, or about five and a half per cent. on
the cost of this part of the plant as it has been taken in
this paper. Calling this ten cents a thousand feet, we
have $20,000 a year as the expenditure under this head,
which is probably well within the actual figures of
most American works. In the case of the electric
plant four per cent. is a sufficient allowance for the
same item, which gives a yearly charge of $12,000 and
a cost of six cents per 1,000 feet.
Depreciation of this part of the plant varies but little
with different works, as the conditions upon which it
depends are relatively constant, but that of the mains
is, on the other hand, exceedingly variable. In a dry,
open soil gas mains will last a great length of time, and
even when they become entirely rusted through they
will still continue efficient if undisturbed. They do
not, however, remain undisturbed, so that in the most
favorable conditions some expenditure is necessary to
keep them in working condition. We shall probably
not be far wrong if we take this at two per cent. of the
entire cost of the mains, which includes, of course, that
of laying them. This item then becomes in the case of
our gas plant $5,000 per year, and 2 cents per 1,000
feet. In the case of the electric mains, this percentage
must be reckoned only upon their cost, exclusive of the
copper, as this latter is practically indestructible and
can be used again and again. The amount upon which
to reckon the two per cent. depreciation is, therefore,
$2,200×50=$110,000, and the yearly charge $2,200,
which gives 1.1 cent per 1,000 feet. The interest on
the investment is the same in each case, and amounts
to $24,000 a year at four per cent., and to 12 cents per
1,000 feet. These items include all that are properly
chargeable to the expense account of the plant save
taxes, which would be about the same in each case,
and which may be neglected for the present. The
plant account, then, stands in the two cases for each
thousand feet or its equivalent:
2190
Lungren--Electricity and Gas-1882.
Gas. Electricity.
Interest
12.
12.
Depreciation of producing works……… 10.
6.
((
of mains.
Total__
2.5
1.1
24.5
19.1
19.1
5.4
Balance in favor of electricity..
The items entering into the cost of coal gas are, ex-
clusive of management, rent and taxes, etc., the cost of
coal, of manufacturing and of distribution. Taking the
last first, we find 4.4 cents per 1,000 feet as the cost of
this item for the four metropolitan companies. Putting
this at 5 cents for American works, and deducting from
this 2 cents for the depreciation of mains, which is in-
cluded in this charge, there is left 2 cents for the cost
of the labor of inspection of meters, etc., which consti-
tutes the charge of distribution, and which would be
about the same in both systems.
As the depreciation of the mains is not given sepa-
rately, this item is liable to error, due to a wrong esti-
mate of such depreciation, but as it affects both systems
similarly, it will not vitiate the results. Under manu-
facturing, the English report includes purifying, salaries,
the wages for carbonizing and wear and tear, which
latter item has already been carried to the plant account.
The first of these amounts to 1.82 cent, the second .82
of a cent, and the third to 7.16 cents; making a total
of 9.8 cents per 1,000 feet. This is probably much be-
low the actual amount paid for these items in American
works, but I am assured, on excellent authority, that in
works constructed after the best modern models, puri-
fication should cost the gas company nothing, and that
all labor in the manufacturing department should be
covered by an outlay equivalent to one man's wages
($2.50 per day) for each 40,000 feet of gas made per
day. As the same amount of labor would have to be
paid for each day in the year as on the days of greatest
Lungren-Electricity and Gas-1882. 2191
demand, this would amount, for a daily make of
1,000,000 feet, to 25 men whose wages at $65 per month
(26×2) would be $19,500* a year, or 94 cents per 1,000
feet of the actual make. Including the cost of purifi-
cation and calling the amount 12 cents, we shall not be
far wrong, or at least shall not exceed the actual outlay
in the average works of this size. In the case of elec-
tricity the labor required at each station would be:
One chief engineer.
Three assistants (at $75).
Five firemen (at $60)
-
Total..
រ
1
1
$125 per month.
225
300 .
$650
(6
making $15,600 a year for the whole manufacturing
plant, 7.8 cents per 1,000 feet. To this may be added
1 cents to cover salary of electrician and incidental
labor, bring the item up to 9 cents.
There remains to be considered the cost of the coal
in the case of gas, and the expense of running the
engines in the case of electricity. The cost of coal per
1,000 feet of gas made was, in the case of the London
companies, 36% cents, corresponding to $3.51 per ton,
the make of gas being for this amount of coal 9,529
feet. This was offset by the sale of residuals, as below:
Coke and breeze.
Tar and products.
Ammonia and products-
Total____
1
1
1
1
11.16 cents.
7.18
5.72
24.06
(6
which leaves 12.8 cents as the net cost of the coal.
* The engineer furnishing the information on which this state-
ment is based informs me that this should be $12,500, or $2.50 per
40,000 feet of the actual yearly, instead of the maximum daily make.
This would reduce the item 93 cents to 64 cents per 1,000 feet.
2192
Lungren-Electricity and Gas-1882.
Compared with foreign companies both in England
and on the Continent, but very little is done with the
residual products in this country, and the amounts re-
ceived vary greatly between different works. Reliable
data on this point cannot be obtained, but under the
most favorable conditions this item cannot be taken as
amounting to more than one-half the cost of the coal,
while with most works it is probably inconsiderable.
The average price of the coal used may be placed at
$4.50 a ton, and the amount of gas produced 10,000
feet, making the cost 45 cents per 1,000 feet. This
make of gas can hardly be maintained with a produc-
tion of residuals equal to one-half the cost of the coal,
but assuming that it is, the cost of the coal becomes 22
cents per 1,000 feet.
In the foregoing estimate of the electric plant, it has
been assumed that eight lamps could be maintained
throughout the entire distributive system for each
actual horse-power expended upon the pulley of the
dynamo machine. That this is entirely feasible has
been proved by careful tests made by experts in no
way interested in any of the lamps, and their results
can therefore be accepted without question. For such a
use as electric lighting the cost of a horse-power may
safely be taken as not above the best results hitherto
obtained in practice. In general manufacturing the
item of power while important is not sufficiently so to
demand that constant and great care necessary to obtain
the very best results, and hence few engines and boilers
yield in practice the same results as in special tests.
With electric light companies this item, on the contrary,
is vital, and we may confidently expect to see them in
time obtaining their power at a considerably less cost
than is now common. Mr. Edison finds, as a matter of
of fact, confirmed by several months' test at Menlo
Park, that he is able to maintain a horse-power an hour
with five pounds of slack (one-third pea and two-thirds
dust), costing $2.45 a ton. For the purpose of the
present comparison, however, it is best to make a liberal
Lungren--Electricity and Gas-1882. 2193
allowance, and take for a 200 horse-power engine a con-
sumption of four pounds of coal an hour, the coal cost-
ing $4.50 per ton of 2,240 pounds, delivered. A horse-
power will then cost of a cent an hour, and we may
rightly abate our liberality sufficiently to include in this
the cost of the oil for lubricating the engine and
dynamo.
Τσ
The maintenance for an hour of 200 electric burners,
the equivalent of the 1,000 feet of gas, will therefore
cents for the gas.
cost 20 cents, as against 22
Summing up the results so far obtained the two ac-
counts stand as follows:
PLANT ACCOUNT.
Interest
Depreciation of producing works. 10.
Depreciation of mains.
Manufacturing expenses :
Labor
Coal....
Working expenses :
Distribution.
Total_..
1
1
1
PER 1,000 FEET.
Gas.
Electricity.
12.
12.
6.
2.5
1.1
24.5
19.1
12.
9.
22.5
20.
34.5
29.
2.5
2.5
61.5
50.6
Under this last heading there should be added rent
and taxes, management, law charges, bad debts and
various incidentals. These cannot be separately arrived
at with any closeness, but they may be taken in the
lump as about the same part of the total charges as in
the case of the London companies, which is 16 per
cent., exclusive of the interest on investment. This in
the present case would be 9.4 cents per 1,000, bringing
the total cost per 1,000 up to 71 cents with gas and 60
cents with electricity.
The promoters of the electric light would probably
2194
Lungren-Electricity and Gas-1882.
demur to this statement, so far as rent and taxes are
concerned, as they insist upon the much smaller real
estate required with the electric than with a gas plant.
This difference does not, however, seem to me sufficient
to be of any practical moment, as the real estate in the
case of electricity is in the district supplied, where the
price of laud is relatively high, while the gas companies
can readily place their works in such locality as to com-
pensate in lowered land value for the greater amount
required. Gas companies can, moreover, build within
much smaller limits than usual when, for any reason, it
is desirable, and closely approach the space requisite
for an electric installation.
An item of considerable amount which has been
omitted from the estimate for electricity is the cost of
the renewal of the lamps. With the general introduc-
tion of incandescent electric lighting, this is a charge
which would fall directly upon the consumer, but it is
one which would steadily diminish with improvement
in lamps. Assuming, however, that it is a legitimate
charge upon the company supplying the light, the item
amounts to 10 cents per 1,000, if the lamps have a life
of 600* hours and cost 30 cents. This brings the elec-
tric account up to 70 cents per 1,000.
So far as coal gas is concerned, then, these figures
show a slight advantage in favor of electricity, and
while they are only approximative they are near enough
to the truth, I think, to represent the actual relation of
the two illuminants. While very much, doubtless, re-
mains to be done in the improvement of coal gas manu-
facture, it does not seem probable that this will affect
its cost of production to the same extent as future im-
provements of electric apparatus may be expected to
decrease that of the electric light. Looking closely at
the two accounts, it does not seem probable that the
item relative to plant will be materially lessened in the
*I am informed by Mr. Edison that the average life of the lamps
is now 900 hours, including 3 per cent. breakage in handling.
Lungren-Electricity and Gas--1882. 2195
future. The cost of the plant has already been taken
at a figure very near the lower limit, so near that the
substitution of this in its place would make a difference
in the yearly plant account of but 2 cents per 1,000.
We may, on the other hand, expect improvements to
largely reduce the cost of the electric plant. On Mr.
Edison's system of distribution, the size of the con-
ductors varies inversely as the resistance of the lamps,
so that they may be materially reduced if the resistance
of these latter can be increased; while any improve-
ments affecting the number of lamps per horse-power
diminishes both the interest account by reducing the
plant, and the actual cost of production.
How far coal gas can go in a reduction of the cost of
production it is difficult to say, but I think the lower
limit may safely be taken at the point at which the sale
of residuals pays for the coal. Both of these items—
cost of coal and prices of residuals-are practically be-
yond the control of a gas company. The coal is
already purchased in the open market at the lowest
figures at which it can be obtained, and the market for
residuals depends chiefly upon the development of
chemical industries, which can hardly be hastened by
the action of a gas company. This market is a steadily
growing one, and it is not impossible that the residuals
will in time pay for the coal, though it is hardly prob-
able. The items of labor and distribution cannot prob-
ably undergo any considerable reduction. The limit,
then, below which it does not appear that there is any
probability of coal gas falling in this country is 46 cents
per 1,000, which is a figure that may be reached by
electricity without assuming anything less probable
than the above supposition respecting gas. It is only
necessary to get ten lamps per horse-power, and pro-
duce the latter with three pounds of coal an hour, to
bring the cost down to 47 cents, exclusive of the lamps.
As a present competitor, however, what is known as
water gas-gas produced by the decomposition of
steam in the presence of coal or oil-appears to be the
2196
Lungren-- Electricity and Gas--1882.
more formidable. This mode of gas manufacture has
the advantage of coal gas in a lessened cost of the pro-
ducing plant, a smaller labor account, and a decreased
depreciation of the generating apparatus. Its success-
ful competition with coal gas ultimately depends upon
what the latter can make of its residuals, as there is no
offset of this kind in its case, but with present condi-
tions it can go below it. The producing portion of the
plant costs but little more than half that for coal gas,
while the labor is about a third, and depreciation but
slightly more than this. A sixteen-candle gas will re-
quire three gallons of oil per 1,000 feet, and can be
made with oil at 5 cents a gallon and coal at $4.50 a
ton, at an expenditure of 28 cents per 1,000 feet for
materials. The total cost will not exceed 60 cents.
Such, then, appears to be the relation of these two
agents on the basis of illumination solely, but it must
not be forgotten that the amount of light which each
plant can furnish does not represent the actual relative
capacity of the two. The electric plant can be run not
only four hours a day for light, but any further num-
ber of hours for power, without any increase of the
machines. The gas plant, on the other hand, would
have to be increased to furnish both power and light.
That this advantage of electricity is liable to be a very
important one will hardly be questioned, when the ex-
tent of the field open to electro-motors is borne in
mind.
On these figures the cost of electricity is near enough
to that of gas to enable it to offer a very substantial
competition, and one which may be expected to grow
stronger with increased experience and future improve-
ments. That under the stimulus of this competition
considerable improvement will be made in lighting by
gas seems very probable. Already it has been shown
that in the matter of burners there is a wide field for
invention, and that the results now usually obtained
are much under what are possible. With the high-
power burners of Siemens the illumination obtained
Lungren-Electricity and Gas-1882. 2197
from sixteen-candle gas has been more than doubled,
and in others it has been carried up to from five to five
and a half candles per foot. How suitable burners
yielding such a great increase of light will be for the
general purposes of lighting, and whether they can with
advantage displace the simple flat tip, remains to be
seen, but the present indications are that it is chiefly
through the use of improved burners that gas must en-
deavor to resist the assaults of the incandescent light.
Competition on the basis of a gas of higher illuminat-
ing power simply, without a resort to improved burners,
does not seem very promising. The recently published
report of the sub-commission appointed to test the in-
candescent lamps at the Paris Exhibition, of which Mr.
Crookes was a member, shows that a thirty-two candle
lamp can be maintained with an increase of from 28 to
37 per cent. of the power required to sustain one of
sixteen candles, while with gas such an increase of
illumination will require an additional expense of fully
50 per cent. of the cost of one of the lower candle-
power. This is so with the Lowe gas, with which three
gallons of oil are sufficient to give sixteen candles, but
six are required for thirty-two, and it is not probable
that coal gas can be enriched any cheaper. Whether
the limit to progress in gas lighting, both in the matter
of improvement of manufacture and burners, is suffi-
ciently far off to give gas unquestioned possession of
the field of lighting or not, the result can alone deter-
mine. But if the figures presented in this paper can
be at all relied upon, they show that gas manufacturers
and those interested in gas property will do well not to
underrate the strength in their own domain of this
rising industrial power.
2198
Swan-" Electric Lighting "--1880.
Complainant's Exhibit "Electric Light-
ing.*
SCIENTIFIC AMERICAN SUPPLEMENT, NEW YORK, Nos. 264
AND 265, JANUARY 22 AND 29, 1881.
ALMOST two years ago I had the honor of delivering
a lecture in this place on electric light. To-night I
have undertaken to report the progress which has been
made since then in connection with the subject. At
the time of my last lecture the public mind was greatly
perturbed by the question whether or not gas lighting
was about to be superseded by electric lighting. It was
generally believed that a revolution-working discovery
had been made, and you may remember, as a conse-
quence, gas stock was much depressed in value. After
a while, when the supposed wonderful discovery dwin-
dled and paled in the daylight of scientific examina-
tion, the panic subsided, and then the current of feel-
ing drove the other way, and in place of the hasty
credulity which at first took possession of the public
mind, there is now, I think, an equally unreasonable
unbelief in the possibilities of electric lighting-the
idea now widely prevailing that electric light, as a sub-
stitute for gas, is after all a delusion.
[A brief résumé of the general principles was here
given, and the development of the dynamo machine
shown.]
On the whole the cost of producing electricity by
mechanical means has been diminished.
It is practicable to develop 1-horse power by the
combustion of 2 lbs. of coal per hour, and to produce
with this amount of motive power a current of elec-
tricity sufficient to give a light of over 1,000 standard
candles; that is to say, we can maintain for one hour
an electric light of more than equal to 1,000 standard
candles, or 66 large gas burners, by the combustion
* Abstract of a lecture delivered by J. W. Swan, at the Literary
and Philosophical Society, Newcastle-on-Tyne, October 20, 1880.
Swan "Electric Lighting "--1880. 2199
of 2 lbs. of coal. That is a much more economical re-
sult than can be obtained by the voltaic battery or any
other means of generating an electric current at present
known. [Reference was made to the voltaic cell, and
the question of storage was discussed as exemplified in
the secondary battery of M. Planté.] M. Planté was, I
believe, the first to put the idea of a secondary battery
into practice. The secondary battery of M. Planté
consists of plates of lead placed opposite each other
and very near together, but not touching. Here is a
Planté cell. It consists simply of two pieces of sheet
lead rolled up together, and separated by the space of
about one-eighth of an inch. You observe that in this
combination we have two plates of the same metal, viz.,
lead; and in this respect the combination differs from
an ordinary voltaic battery, inasmuch as the very es-
sence-so to speak-of the voltaic battery is the dis-
similarity of the two plates which in part constitute it.
It is zinc and copper, or zinc and platinum, or some
dissimilar combination of that sort that we are all
familiar with as characteristic of the voltaic battery.
Here, in the secondary battery, the two plates are alike,
therefore of themselves they cannot generate a current
of electricity like the ordinary voltaic battery. But if
these two lead plates are for a time connected by wires
with a generator of electricity, no matter of what kind
(it may be a dynamo-electric machine which supplies
the primary current), one of the lead plates is changed
on its surface-it becomes oxidized-and after under-
going this change it is, when detached from the gener-
ator, in such a condition as to be able to give out, at
any future time, a current of electricity on its own ac-
count; and when the charge has been expended the
plates are, like an empty gasómeter, just in the same
condition they were before receiving the charge, and
ready to be charged afresh. The secondary battery is,
therefore, an instrument of very great interest at the
present moment, and it is much to be hoped that it
may be improved, because, in the simple form which I
have described, it does not quite do all that would be
required of a secondary battery, applied as a store of
2200 Swan-" Electric Lighting "-1880.
electricity on a large scale for extensive practical elec-
tric lighting. I have here a modified form of a second-
ary battery, which, if it does not give us all that could
be desired, makes a very considerable contribution
toward it. This battery was charged this morning;
before being charged it was nearly inert. I will join
the poles together by this platinum wire, and if the
charge has been retained the wire will become hot.
[The wire is, you see, white hot. The want of a means
of storing electricity is a newly felt want; as yet it
cannot be said to have been fully supplied, but, as I
have shown you, it has been supplied to a certain ex-
tent, and research is still busy at work seeking its com-
plete fulfillment. There can be no doubt that what is
wanted will be found, and with the perfecting of the
secondary battery that great objection to electric light-
ing that you cannot store the power which produces
it as you can store gas-will be completely met.
[The thermopile was here briefly referred to.]
All the various means of producing light by electricity
that can make any pretension to practicability are di-
visible into two classes, namely:
1st. Lighting by the electric arc.
2d. Lighting by incandescence.
In lighting by the electric arc there is a break or gap
in the circuit which has to be bridged over by a sort of
electric flame. In lighting by incandescence there is
no break or gap at the point where light is produced,
but a thin, highly infusible, and badly conducting solid
substance is there interposed which becomes white hot,
and emits a light, bright in proportion to the degree of
heat produced in it.
Now, to fix in your mind precisely what I am talking
about, I will first show you what I mean by the elec-
tric arc. This will enable you more easily to follow my
remarks on the question of electric lighting by this
method.
Here is an enlarged view of the electric arc-here
are the two carbon points, and here-between them-
is formed the electric arc.
Swan" Electric Lighting "-1880. 2201
A powerful electric current, produced by a gas en-
gine and dynamo-electric machine, is supplied to these
two pencils of carbon through thick copper conducting
wires, and you see that a stream of flame is flowing or
rushing between them. If the points are too much
separated the light is lessened; by increasing the air
space between the points resistance to the passage of
the current is increased, and the current is consequently
diminished, and when this diminution of current passes
a certain limit the light is lessened. On the other hand,
when the points are made to approach too closely to
each other, the light becomes less for the opposite
reason.
A certain amount of difficulty or resistance must be
offered to the passage of the current in order to pro-
duce light, and to get the best effect the resistance must
neither be too much nor too little.
When the points are made to touch there is no longer
the resistance of the air space to be struggled through,
the light consequently goes out.
Observe the alteration in the points; they burn away,
and one faster than the other. Now, as the production
of a steady light demands that the points should be
maintained at a constant distance apart, it is evident
that under the complicated conditions of the case a
nice regulation of the distance of the points to each
other is a matter of extreme difficulty.
I will now ask for the current to be turned on to a
lamp hung up aloft, in order that you may see how very
nearly the difficulties of producing a steady arc light
have been surmounted.
The particular lamp I am using for the purpose of
my illustration is Crompton's lamp, of which here is a
diagram. Properly regulated it feeds the pencils to-
gether almost continuously and with great precision.
That, then, ladies and gentlemen, is par excellence the
electric light. That is the form and style of electric
light that inventors have for the last forty years strug-
gled and battled with difficulty upon difficulty to render
serviceable to the wants of man.
From the nature of the electric arc light you will
2202
Swan-" Electric Lighting"-1880.
readily perceive that it is a kind of light not suited to
the lighting of dwelling houses, nor shops, nor streets.
It does not lend itself kindly to division nor exten-
sive distribution. It will give you either a great deal
of light or none.
For certain exceptional uses it is excellent. If you
want a very brilliant illumination all centred in one
focus, for a lighthouse, or signal, for example, or for a
high-roofed railway station, or very large workshop, or
open space, it is unquestionably the most economical
and the best of all artificial lights.
It has already found for itself in England over two
hundred appropriate applications. Its use is continued
and increased on the Thames Embankment. It is used
in the reading room of the British Museum; in the
Picton Library, Liverpool; in a portion of the South
Kensington Museum; at the Liverpool Street Railway
Station; the Barrow Shipbuilding Works; the St.
Enoch Railway Station, Glasgow; on the Promenade
at Blackpool; and at the new Albert Docks, where, by
means of Siemens lamps, three miles of wharves and
quays are made almost as light by night as by day, and
at a very moderate cost.
As an illustration of the economy of lighting by
means of the electric arc under conditions suited to its
use, I instance the case of the Alexandra Palace, where
2,000 gas lights, which consumed 26s. worth of gas per
hour, are replaced by six of Mr. Crompton's lamps,
giving a greater aggregate amount of light than the
2,000 gas burners, at a cost of 6s. per hour. In some
instances the economy of the electric arc light is greater
by half than in the case I have mentioned. Not only
is it economical in such a case as that of the Alexandra
Palace, but it produces an effect of general illumina-
tion overhead as well as upon the ground not produci-
ble by any other means.
But the interest which attaches to electric arc light-
ing is much lessened by the fact that the purposes to
which that mode of lighting is suited are exceptional.
We do not, as a rule, want the light of 1,000 candles
Swan-" Electric Lighting "-1880. 2203
What we do generally want
steady lights, spread about in
or more all in one place.
is a number of small and
different rooms, and in different parts of those rooms.
For electric light of this description we must search in
another direction.
I said that there is another way of producing elec-
tric light, namely, by incandescence.
Lighting by incandescence is a branch of the subject
which has a special charm for me, because I have be-
stowed upon it much thought and labor; and it is, I
believe, the branch which will yield the largest crop of
fruit. Electric lighting by incandescence is just as
simple as arc lighting is difficult: all that is required is
a material which is not a very good conductor of elec-
tricity, highly infusible, and which can be formed into
a wire or lamina, and is either non-combustible in air,
or, if combustible, does not undergo change in a vacuum.
There are, so far as I know, just two substances that
possess, in any sufficient degree for the purpose in
question, the qualities I have specified.
These two substances are platinum, or an alloy of
platinum with iridium and carbon. Platinum has the
advantage over carbon that it is not combustible in air;
it does not, like carbon, burn away if you make it white
hot; but it is very inferior to carbon in the degree of
heat it will bear without fusion; and for producing
light by incandescence it is essential to economy that
the incandescent material should be capable of endur-
ing an extremely high temperature, because the amount
of light emitted by an incandescent substance incrcases
in a more rapid ratio than the temperature.
When, for example, you have a piece of platinum
wire or carbon red hot, it emits almost no light, but
double its temperature by sending a double quantity of
current through it, and it will yield much more than
twice the light it did before.
It is therefore evident that the hotter the incan-
descent material can be made the less the light will
cost per unit of power expended.
Iridio-platinum, comparatively with other metals,
2204
Swan" Electric Lighting"-1880.
may be called extremely infusible, but compared with
carbon it is nowhere. Carbon has, in fact, resisted
without fusion the very highest degree of heat brought
to bear upon it, and what that degree of heat is I can
hardly estimate, it is so enormous.
But carbon has been found so difficult to deal with
on account of its ready combustibility (and some other
troublesome properties which I will mention afterward),
that experimenters have bestowed much attention upon
platinum and iridio-platinum as the incandescent ma-
terial for electric lamps.
Mr. Edison was, I think, the last who attempted to
utilize platinum in an electric lamp, and I think there
can be no doubt that he obtained better results with
platinum, and came nearer making a useful platinum
lamp than any experimenter in the same track who had
gone before him.
Here is a view of Edison's platinum lamp.
This is the lamp of which so much was promised and
expected in October, 1878, and which led, you remem-
ber, to the panic in gas shares. This lamp did not
realize the hopes of the inventor.
(I will not rekindle Mr. Crompton's electric sun, be-
cause I hope presently to show you some small lamps,
whose light would be absolutely drowned in that fierce
radiance, as stars are by the light of day.)
While Mr. Edison was endeavoring to produce a
useful incandescent lamp by means of platinum, I was
endeavoring to obtain the same end by means of
carbon.
It had appeared to me for many years that if ever
electric light was to become generally useful it would,
most probably, be by means of the incandescence of
carbon. I had, long before the time to which I am re-
ferring, attempted to render this idea practicable.
As a matter of history, I will briefly describe an ex-
periment which I tried about twenty years ago.
I had a number of pieces of paper and card of various
forms and sizes buried in charcoal in a crucible. This
crucible I sent to be heated white hot in one of the
Swan-" Electric Lighting "--1880.
2205
pottery kilns belonging to Mr. Wallace, of Forth Banks.
From the pieces of carbonized card which I thus ob-
tained I selected a long spiral; the ends of this I
clipped between small blocks of carbon carried by up-
rights, and connected with conducting wires. A small
glass shade was cemented over this mounted carbon
spiral, and the air was exhausted by means of a very
good air pump, lent to me for the purpose of this ex-
periment by the Rev. Robert Green, of Longhorsley.
A good vacuum (according to the ideas that then pre-
vailed) having been produced, I applied the wires of
my battery (consisting of ten cells of Callan's modifica-
tion of Grove's battery) with great expectation of a
brilliant result; instead of this there was the most
absolute negative presented to me; not a vestige of
heat or light appeared in my long ringlet of carbonized
paper. It was evident, and I immediately recognized
the fact, that the electric current of the strength I was
using would not go in sufficient quantity through so
long a piece of carbon as I had taken. I therefore re-
peated the experiment with shorter carbon and a greater
number of cells, and I obtained, under these altered
circumstances, an extremely interesting result.
My carbon was in the form of an arch (this diagram
will help my explanation), about one inch high and a
quarter of an inch wide. The ends of the arch were
held in small clamps, with square blocks of carbon.
The air pump having been worked, I had the pleas-
ure of seeing that when contact with the battery of
forty or fifty cells was completed my carbonized paper
arch became red-hot, and it was evident that nothing
more was wanted than a still stronger current to make
it give out a brilliant light; but I had used up all the
battery power at my disposal, and having reached this
limit, I contented myself with watching the behavior of
the arch, the engrossing question being: How long will
it endure?
I noticed that the inner part of the arch was hotter
than the outer part, and that, perhaps in consequence
of this, the arch became bent on one side. This bend-
2206 Swan-" Electric Lighting "-1880.
ing gradually increased, until at last the arch had so far
curled down that the top was on a level with the clamps,
and on coming in contact with the sole of the lamp it
broke in two, and the experiment collapsed.
That, I confidently believe, was the very first instance
in which carbonized paper was ever used in the con-
struction of an incandescent electric lamp.
I am now speaking of twenty years ago, and at that
time the voltaic battery was the cheapest source of
electricity known, and the means of producing high
vacua were very much less perfect than they are now.
I laid my electric light experiments aside until about
three years ago, when two things concurred to lead me
to pursue the subject afresh.
The discovery of the dynamo-electric machine had
entirely altered the position of the question of electric
lighting, shifting it out of the region of things scientifi-
cally interesting into that of things practically useful.
The Sprengel air pump, too, had been invented, and
with its invention we had been provided with a means.
of producing much higher vacua than could be pro-
duced by the old form of air pump.
Mr. Crookes' radiometer experiments had shown us
what a really high vacuum was and how to produce it.
Mr. Stearn, of Birkenhead, an ardent scientific ama-
teur, was so attracted by the extraordinary results Mr.
Crookes had obtained by means of high vacua as to go
with great enthusiasm into the same line of experiment,
and he soon acquired such a knowledge of the Sprengel
pump, and such expertness in its manipulation as per-
haps was only equaled by Mr. Crookes himself.
I had the good fortune to make Mr. Stearn's ac-
quaintance, and that was the other one of the determin-
ing causes of my second attempt to solve the problem
of electric lighting by the incandescence of carbon.
In the interval between the first and second periods
I have mentioned many attempts had been made by
various experimenters to render practicable incandes-
cent carbon lamps, but none were entirely successful.
Here is represented a variety of the most notable of
Swan-" Electric Lighting "-1880.
2207
these attempts. Some are vacuum lamps, and some
have air admitted. Sawyer and Man's lamp is filled
with nitrogen. When the incandescent carbon is in
air it burns away, and must consequently be renewed
just as a candle must be renewed; it must also be
thicker than would be necessary in a vacuum, and,
being thicker, it requires a proportionally greater cur-
rent to render it incandescent; both these circum-
stances are obviously against economy.
(To be continued.)
2208 Swan-" Electric Lighting"-1880.
(Continued from Supplement No. 264, page 4207.)
ELECTRIC LIGHTING.*
In all the various attempts to utilize the principle of
the incandescence of carbon in vacuo two great diffi-
culties has stood in the way and baffled every attempt
to overcome them. One was the rapid wearing away
and consequent breaking of the incandescent carbon;
and the other the obscuration of the lamp by a kind of
black smoke. So uniformly did these phenomena pre-
sent themselves that the idea was propounded and
generally accepted that the blackening of the lamp
globes was due to volatilization of the carbon under
the action of the enormous heat to which it was sub-
jected.
In Fontaine's work on electric light this passage
occurs at page 180:
"Attentive examination of incandescent carbons
through a strongly colored glass has shown that they
are not uniformly brilliant. They present obscure
spots indicative of non-homogeneity, and the position
of cracks, which rapidly disintegrate the carbon. The
vacuum never being perfect in the receivers the first
carbon is in greater part consumed. It would appear
that, consequently upon the little oxygen contained in
the lamp being transformed into carbonic acid and car-
bonic oxide, the carbon should be preserved indefi-
nitely. But there is then produced a kind of evapora-
tion which continues to slowly destroy the incandescent
rods. This evaporation is, besides, clearly proved by
a pulverulent deposit of sublimed carbon, that we have
found on the interior surface of the bells, on the sev-
eral interior parts, rods, contacts, hammers, etc."
If this idea of the volatilization of carbon were
founded in fact, any further attempt to render incan-
descent carbon lamps durable by means of a vacuum
* Abstract of a lecture delivered by J. W. Swan, at the Literary
and Philosophical Society, Newcastle-on-Tyne, October 20, 1880.
Swan-"Electric Lighting "-1880. 2209'
were mere waste of time, and durable they must be if
they were to be of any practical value.
Fortunately, I did not accept as conclusive the ex-
periments which seemed to show that carbon was vola-
tile, and that the blackening of globes of incandescent
carbon lamps was an inevitable result of the carbon
being very highly heated. I knew that the conditions
under which, without exception, all previous experi-
ments had been tried, were such as did not allow to be
formed anything approaching a perfect vacuum within
the lamp. Screw fittings had invariably been em-
ployed to close the mouth of the lamp, and the ordinary
air pump to exhaust the air. Under such circum-
stances it was certain that a considerable residuum of
air would be contained within it, and also that it would
leak. Then, there had never been any thought given
to the gas occluded in the carbon itself, and which,
when the carbon became hot by the passage of the
current through it, would be evolved; nor had sufficient
care been taken to make the resistance, at the points of
fixture of the carbon, less than in the carbon to be
heated to incandescence.
It was evident to me that before any definite con-
clusion could be arrived at as to the question of the
volatility of carbon, the cause of the blackening of the
globes, and the wearing away of the incandescent rods,
we must first try the experiment of heating the carbon
to a state of extreme incandescence in a thoroughly
good vacuum (such as Mr. Crookes had taught us how
to procure), and under more favorable conditions as to
the contact between the incandescent carbon and the
conductors supporting it than had hitherto obtained.
Accordingly, in October, 1877, I sent to Mr. Stearn
a number of carbons, made from carbonized cardboard,
with the request that he would get thein mounted for
me in glass globes by a glass blower, and then exhaust
the air as completely as possible. This delicate opera-
tion Mr. Stearn very kindly undertook and very skill-
fully carried out.
In order to produce a good vacuum it was found nec-
2210
Swan-" Electric Lighting "-1880.
·
essary to heat the carbon to a very high degree by
means of the electric current during the process of ex-
haustion, so as to expel the gas occluded by the carbon
in its cold state, for, otherwise, however good the
vacuum was before the carbon was heated, immediately
the current passed and made it white hot, the vacuum
was destroyed by the outrush of the gas pent up in the
carbon in its cold state. In order to make a good con-
tact between the carbon and the clips supporting it, the
ends of the carbon were thickened, and, in some of the
early experiments, electrotyping and hard soldering of
the ends of the carbons to platinum was resorted to.
I will not weary you, however, with details, but
simply say that the prescribed conditions having been
rigorously complied with, it was found, after many
troublesome experiments,, that when the vacuum within
the lamp globe was good, and the contact between the
carbon and the conductor which supported it sufficient,
there was no blackening of the globes and no appreci-
able wasting away of the carbons.
Thus was swept away a pernicious error, which, like
a lying finger post, proclaiming, "No road this way,"
tended to bar progress along a good thoroughfare.
It only remained to perfect the details of the lamp,
to find the best material from which to form the car-
bon, and to fix this material in the lamp in the best
manner. These points, I think, I have now satisfac-
torily settled; and you see the result in the lamp
before me on the table.
It is a very modest looking affair, but its perform-
ance goes beyond its appearance. The carbon is ex-
tremely thin-a mere hair-and how wonderfully
strong and elastic it is I will endeavor to show you by
means of the lantern.
·
This carbon, unlike the carbon spoken of by Fon-
taine in the extract I read to you, is quite homogene-
ous and almost flinty in hardness, and it becomes
harder by the use in the lamp; the longer and the
hotter it is heated the harder it becomes. What
Swan-" Electric Lighting "-1880.
2211
degree of hardness it will ultimately arrive at is an
interesting question.
Here is a magnified view of the carbon ring in a state
of incandescence. Observe how absolutely uniform in
brightness it is; that proves it to be homogeneous, and
foretells its durability.
Now I will show you how easily lamps of this kind
are lighted, and how completely this form of electric
light can be divided and distributed.
Is it not a pleasant light? It is not so white as the
arc light, but yet a whiter light than gas. Colors are
correctly seen by it as this picture shows. But the
great merit of this light consists in its not being in
contact with air, and, therefore, there cannot possibly
be the slightest air pollution caused by it. The rooms
in which this light is used will be as pure by night as
by day.
It is essential to economy in lighting by incandes-
cence that the incandescent carbon should be
very thin.
The carbon I use is not one-twentieth of the thickness
of the thinnest of the carbons formerly employed, and,
therefore, one-twentieth of the current, costing one-
twentieth the price, will produce in my thin carbon the
same degree of luminosity as twenty times more cur-
rent will produce in such carbons as were used in those
ancient lamps.
You will notice that in my lamp leakage is very thor-
oughly guarded against. The wire which passes
through the glass not only having the glass fused around
it where the wire and globe meet-but in addition to
this, the wire is coated with glass almost up to the
carbon. In this way the vacuum is preserved very
effectually.
You have, of course. all heard that after Mr. Edison
abandoned his platinum lamp as impracticable, he in-
vented a new lamp in which carbonized cardboard is
used.
Here is a diagram of Mr. Edison's carbon lamp, with
its horseshoe of carbonized paper. It is in some
respects like mine, but latterly I have given up the use
2212
Swan--" Electric Lighting "-1880.
of carbonized cardboard, and am now using a material
as much better than carbonized cardboard as carbonized
cardboard was better than the material previously used.
In an article which appeared in the February number
of "Scribner's Magazine," authenticated by a letter
from Mr. Edison in the same publication, it is stated
that Mr. Edison was the first to use carbonized paper;
that is incorrect. And this also occurs after a descrip-
tion of the Sprengel pump used in exhausting these
lamps: "Mr. Edison's use of carbon in such a vacuum
is entirely new." Now, I daresay, there are many here
who will remember this little lamp, which I showed here
two years ago in action. This lamp has exactly the
same simplicity as my present lamp, being composed
entirely of three substances, namely, glass, platinum
and carbon, and it was exhausted in precisely the same
manner, and to the same degree, as that which Mr.
Upton-no doubt in good faith but still in error-
speaks of as "entirely new."
I do not mention these things in any way to dis-
parage Mr. Edison, for no one can esteem more highly
his inventive genius than I do. I merely state these
facts because I think it is right to do so in my own in-
terest and in the interest of true history.
The complete seclusion of the light in this lamp from
contact with air suggests its adaptability to coal mine
illumination, and I earnestly hope that this may prove
to be one of its uses.
But the great purpose to which a lamp of this kind
is applicable is the lighting of your houses. In view of
such an application two all-important questions present
themselves—one as to distribution, another as to cost.
Can this light be divided, distributed and measured
as gas
is divided, distributed and measured? And at
what cost? It is quite impossible in a brief lecture to
discuss these questions exhaustively, but as far as is
possible, in a few words, I will answer them.
First, then, as to division and distribution, it has
been asserted on very high authority that great loss
necessarily attends the division of the electric light.
Swan--" Electric Lighting "--1880.
2213
To a certain extent this is true of lighting by the electric
arc, but it is totally and absolutely erroneous of lighting
by incandescence. There is no loss in dividing the
electric light produced by this means. Faraday has
stated the law of the case in these words: "An electric
current which will heat one inch of wire white hot, will
also heat to the same temperature 100 inches, or an
infinite length of the same wire." There is no ques-
tion of the truth of this. Now, as it is only necessary,
in order to maintain a given current, to increase the
force which produces it in the same proportion as you
increase the resistance to its flow, it follows that the
cost of raising to a certain degree of incandescence a
longer or shorter length of carbon, or of maintaining a
10-candle light or 100-candle light, will be exactly pro-
portional to the light produced. You may even con-
template on this principle the economical production of
an electric light as small as a rush light. A certain
unit of light may be established in an indefinite num-
ber of places, with no greater aggregate expenditure of
power than that directly and simply proportional to
the number of lights.
With regard to distribution, I believe that it will
prove to be practicable to light any large town-all
Newcastle, for instance-by means of wires laid in the
ground as gas pipes are laid, and all branching from
one centre, and conveying the electric current to lamps
like this.
The lamps now lighted are supplied by a current
coming from generators working at the far end of
Mosley street (a quarter of a mile away), and it would
be just as easy by using a more energetic current-a
current as it were under higher pressure-to maintain
these several miles away, and for this purpose the con-
ductors need not be large, not so large certainly as to
make the distribution of electric current more costly
than the distribution of gas.
For supplying large towns with electric light, Mr.
Edison proposes to have a number of centres for the
supply of electric power, perhaps a quarter of a mile
2214
Swan--" Electric Lighting "-1880.
apart, whence wires would be sent out in every differ-
ent direction, distributing the current to the houses
round about. His plan of distribution is this. He
proposes to send out bundles of main wires from each
of the centres of supply, and from these main wires to
branch as many small wires into the houses as there
are lamps to be lighted, each branch wire proceeding
from a main wire to the place where the lamp is
situated, and from thence to a return main wire.
Now, although this plan has the great merit of sim-
plicity, I do not think it will answer, except for very
short distances.
When a number of lamps are grouped together in
that manner, it is necessary that the individual lamps
should offer a very high resistance to the current, for
if each lamp does not offer an extremely high resistance ·
to the passage of the current there must be great waste,
a large proportion of energy being in that case spent
in heating the conducting wires, instead of the carbon
in the lamps.
Mr. Edison accordingly proposes to make his lamps
of a very high resistance; he proposes to use for the
incandescent material a form of carbon which offers a
higher resistance than simple carbon in its compact
state; but if carbon pure and simple is used, then I
submit it had better be in as stable and condensed a
state as possible, because in process of use it tends to
consolidate, and it is undesirable that any change
should take place in the lamp during use.
The resistance offered by a filament of carbon in its
best state for incandescent lamps, as thin as it is safe
to use in a lamp, and of a length sufficient to give, say
a light equal to one burner, or ten standard candles (a
unit of light which I think we must not go beyond in
planning an extensive system of town lighting) will not
offer so high a resistance as that which Mr. Edison has
made the basis of his scheme of distribution.
With lamps of this resistance, the result would be
that before many were bridged across from one main
wire to another, as much or more work would be done
Swan-" Electric Lighting "-1880.
2215
in the conducting wire as in the lamp. The only way
of avoiding this waste of energy, without abandoning
the idea of small units of light, would be either to em-
ploy enormously thick conductors, or have a very lim-
ited area supplied from one works.
I think the difficulty is capable of being surmounted
in this way: Instead of grouping the lamps as Mr.
Edison proposes, each lamp being as it were a loop or
bridge between two mains, I propose to string them in
series—10, 50, or perhaps 100 lamps being all inter-
posed in one and the same line. In this way every
lamp would add to the resistance of the line instead of,
as in Mr. Edison's plan, diminishing its resistance.
The waste of energy in the conducting wire would thus
be avoided.
A copper wire, less than one eighth of an inch thick,
would supply current for one such series of, say from
10 to 100 lamps, at five miles distance, with a very
small percentage of loss; while to supply at the same
distance a corresponding series on Mr. Edison's plan
would demand copper conductors of such thickness as
would certainly make the plan far too expensive, or, if
such thick conductor was not used, there would be an
impracticably extravagant waste of energy in the wire.
If even 50 per cent. of the energy were expended in
the wire, the size of the conductor required to transmit
the current, say even two miles, would be far too great.
There is no way of escape that I know of from this
dilemma, viz.: that either we must make our unit of
light larger than necessary for a very great many pur-
poses, and so give up the idea of extensive division and
extensive distribution, or, in order to gain these points,
we must group the lamps in the manner I have pro-
posed.
There are, no doubt, difficulties in the carrying out
of my plan, but none that are not easily surmountable.
For example, if 20, 50, or 100 lights were in a series,
a break in any part of the line would extinguish all the
lights. This danger can be met in two ways:
I would have only one lamp belonging to a given line
2216 Swan-" Electric Lighting"-1880.
in one house, so that the extinction of such a line of
lights as we are contemplating would not be a very
serious mishap; but I would make such a mishap ex-
tremely unlikely to occur, by placing along with each
lamp an automatic circuit closer. This would so act as
to bridge over the gap made by the accidental breaking
or failure of a lamp, and so prevent the extinction of
the rest of the lamps in the series, while a fresh lamp
was put in the place of the broken one-a thing no
more difficult, and probably not more costly, than the
replacement of a broken gas chimney or globe.
There is another difficulty occasioned by the varia-
tion of the current in proportion to the number of
lamps in action.
What is required in this case is to maintain a uni-
form current in the line of lamps, whether 1 or 100 are
alight. This can be accomplished by self-acting ap-
paratus somewhat on the principle of the governor of
the steam engine, and which would automatically raise
or lower the potential or pressure by steps of one-hun-
dredths, according to the number of lamps in use.
I have also considered the question of measuring the
current, and, if time allowed, I could show you that
that could be done as easily as the measuring of gas.
Similarly, all other practical difficulties arising out
of this method of distribution' can be met, and being
met, we are at liberty to contemplate a great central
works producing electricity by large steam engines, and
distributing it by means of wires to a whole town, ex-
actly as gas is now distributed by gasworks.
I have already referred to the cost of electric light
produced on the arc principle, and shown that when
the circumstances are favorable to the employment of
that method it is much more economical than gas-
light.
The economy of lighting by incandescence has not
been exemplified by so many instances of actual practi
cal use. One thing is, however, quite clear, and that
is, that electric lighting by incandescence is an econom
ical process—it will be less costly than gas lighting.
Swan-" Electric Lighting "-1880.
2217
That is conclusively demonstrated by the fact that the
1,000 feet of gas employed in working a gas engine to
develop an electric current, and used in my lamps, will
yield more light than 1,000 feet of gas consumed in the
ordinary way in gas burners.
burners. This room is now lighted
by twenty of my electric lamps, and to produce the
current which feeds them 160 cubic feet of gas per
hour are being burnt in a gas engine; before my lamps
were kindled the room was lighted by 70 gas jets, con-
suming, I am told on good authority, 280 feet per hour.
It is very evident that we have got more light out of
the gas through the medium of electricity than was got
from the larger quantity of gas which those burners
consumed. Our conditions here are somewhat unfa-
vorable to my light for a fair comparison, but from
measurements carefully made, both of light produced
and current required to produce it, I am warranted in
saying that at least twice as much light will be pro-
duced by a certain quantity of gas used to generate an
electric current employed in my lamps as would be ob-
tained from this quantity of gas burnt in gas burners
in the usual manner.
If that is so, then it is evident that when, instead of
the motive power of gas, that of steam produced in the
most economical manner is employed, this method of
electric lighting will be very much less costly than gas
lighting. I reckon that 40 lb. of coal employed in
raising steam to generate electricity is capable of pro-
ducing in my lamps the effect of 1,000 feet of gas burnt
in gas burners in the ordinary manner.
The economical view of the question is therefore, in
my opinion, very favorable to electric lighting, and I
think fully warrants me in anticipating an extensive
substitution of electric light for gas light.
The great difficulty which till now has completely
blocked the way to any general use of electric light was
the difficulty of division. That difficulty is now com-
pletely overcome, by the method of producing electric
light by the incandescence of carbon in vacuo of which
I have given you a practical demonstration to-night.
2218
Swan-" Electric Lighting "-1880.
•
Now, ladies and gentlemen, if I have not exhausted
my subject I certainly have exhausted your patience.
I will weary you no more.
Eighty years ago science gave us enlarged means of
turning night into day; since then not a little of our
lifetime has been spent in gas-lit rooms, and it has been
somewhat of a reproach to science that she has not
provided us with this larger measure of light without
at the same time imposing on us the necessity of
breathing a vitiated atmosphere.
To-day science vindicates herself; henceforth we
may make the long nights of our northern winter bright
without any such sacrifice.
Swan-Incandescent Lighting-1881. 2219
Complainant's Exhibit “Electric Lighting
by Incandescence.”*
BY J. SWAN.
SCIENTIFIC AMERICAN SUPPLEMENT, NEW YORK, No. 307,
NOVEMBER 19, 1881, p. 4891.
EVER since Sir H. Davy showed that a brilliant and
continuous light could be produced by causing the cur-
rent from a voltaic battery to pass between two points.
of charcoal, the application of electric light to useful
purposes has been one of the chief aims of electrical
experimentalists. But it is within the last twenty
years, or since mechanicians and electricians combined
to make it possible to produce electricity by mechan-
ical means, that the idea of useful electric illumination
has been brought within the scope of practicality.
The difficulty of producing electric light with car-
bon points was to make it steady and to moderate its
excessive brilliance. By dint of improvements in the
form and quality of charcoal points, and ingenious
mechanism for maintaining the points of these pencils
at a constant distance from each other, the first of these
difficulties has to a very large extent been overcome.
But the second one has remained, and from the very
nature of the case must remain, as an insuperable
obstacle to the application of this form of electric light
to the general purposes of artificial illumination.
I do not intend to convey the opinion that the form
of electric light to which I am referring is not in some
cases a useful form. It would be absurd to express
such an opinion in the presence of those who have
witnessed the splendid illumination of the railway sta-
tions and streets of London, and by these means.
* A paper read before the British Association, York meeting,
1881.
2220
Swan-Incandescent Lighting—1881.
What I say is this, that that form of electric light is
only exceptionally applicable; that it leaves the
greater number and the more important of our wants
in respect of artificial light unprovided for. It is, in
my opinion, quite inapplicable to domestic lighting,.
and it is there that we experience the most keenly the
evils of the existing modes of artificial illumination by
means of gas and oil lamps. In order to adapt electric
light to house illumination it is necessary to entirely
change the method of producing it.
Starr was the first to conceive the idea that it might
be possible to produce an electric light both small and
steady by heating to a white heat a thin piece of car-
bon. Starr's proposal was to put a thin plate of car-
bon in the vacuum of a mercury barometer, and to
keep it in a state of white heat by passing an electric
current through it.
The difference between the two systems I have men-
tioned is this: In the first, iu which light is produced
by a disruptive electric discharge between points of
carbon, there is a break in the circuit, so far as solid
material is concerned, at the place where the light
occurs.
In the other the solid conductor is quite continuous,
but at the place where light is produced the con-
ductor has a high degree of resistance. At that place
the conductor is carbon, and as carbon is compara-
tively with metals a bad conductor it happens that
when an electric current is forced through this circuit
a certain amount of electricity is converted into heat
in the carbon. If the quantity which passes in a given
time is large enough in proportion to the mass of car-
bon it becomes white hot and emits light.
Electric light produced on this principle of incan-
descence has many good properties which electric light
produced by the disruptive discharge between carbon
points, commonly known as the "arc," has not.
If the electric current which produces the incandes-
cence is quite constant, the light emitted by the white
Swan-Incandescent Lighting-1881.
2221
hot carbon is absolutely constant. There is not the
slightest flicker or variation in it; it is, moreover, quite
under control as to its brilliance, and may be made as
yellow as gas-light or as white almost as sunlight. It
communicates no noxious vapors to the air, and is not
too costly.
But the crowning merit of electric light produced on
the principle of incandescence is that it is indefinitely
divisible without sacrifice of economy. You may have
a lamp so constructed as to give a light of ten candles,
or you may construct it with larger conductors so as
to obtain a light of 100 candles from your incandescent
carbon, and the smaller lamp will be almost as econom-
ical as the larger-light for light. That is, the ten-
candle lamp will only use one-tenth of the power, and
therefore cost one-tenth of the amount to maintain it
that is required by the lamp which gives ten times the
light.
This property of divisibility into as many small
centres of illumination as are required-which is in-
herent to this method of electric lighting by incan-
descence to fully the same extent as in gas light-
combined with the steadiness of this species of light,
its good color and its wholesomeness gives it a char-
acter of general applicability which is not possessed
by any other kind of electric light. It is forty years.
since Starr, through his agent, King, took out his
patent for producing light on this principle. It is only
within the last two or three years that the many prac-
tical difficulties that beset the utilization of this
method have been surmounted. Nothing can well be
simpler than the ideal incandescent lamp. A slip of
carbon in a vacuum, that is all. To realize this idea
much experimentation had to be gone through and
much disappointment to be suffered.
Starr did not make his lamp practical. Lodyguine,
Konn and Sawyer and Mann tried long and patiently
to render it practical, but they did not quite succeed.
The first difficulty was with the vacuum. In the
2222
Swan-Incandescent Lighting-1881.
vacuum lamps of earlier date it was neither possible to
produce nor to maintain a perfect vacuum; there were
always screws and washers about them, and these, and
the carbon itself in a cold state, formed a reservoir of
air quite sufficient to cause the disintegration and rup-
ture of the carbon after a few hours' ignition. Besides
this difficulty of the carbon soon breaking, there was a
further difficulty in the blackening of the glass in-
closed.
From elaborate experiments made by M. Fontaine,
and published in his work on electric lighting, the con-
clusion was arrived at that the blackening of the lamp
bells was due to the volatilization at C, and that the
breakage was also a consequence of this action, objec-
tions, if valid, quite final to the practicability of this
method. In short, at the period of these experiments,
four or five years ago, electric lighting by the incan-
descence of C in vacuo was completely discredited by
by the crudity of all the attempts that had been made
to apply the principle, and by the fallacies which had
grown out of these unsuccessful attempts, and which
obtained general acceptance, so much so that in the
report of the Select Committee of the House of Com-
mons on Electric Lighting, issued June, 1879, and in
connection with which evidence was given by all the
highest electrical authorities of that time, there is no
mention whatever even of the possibility of producing
light in this way.
I saw reason for doubting the soundness of M.
Fontaine's conclusions with respect to the cause of the
breakage of the carbons in incandescent lamps, and
years ago I proceeded to test them by experiment.
My main idea was to employ in a good Sprengel pump
vacuum a form of carbon made by carbonizing paper
at a high temperature, with which I had experimented
many years before. By means of this form of carbon I
hoped to obtain economy in the light, because, as it
was very thin, a small current would make a strip of it
white hot.
Swan-Incandescent Lighting-1881. 2223
The carrying out of my idea was made easy by the
assistance I received from Mr. Stearn.
Mr. Stearn undertook to mount some of my paper
carbons in a good vacuum, and after many failures
from carbons breaking he at last succeeded in making
some bulbs, very highly exhausted, contain my paper
carbons attached by electrically deposited copper to
platinized strips, which carried the current in and out
of the lamp.
I had the pleasure, in February, 1879, of showing to
the president of this section (Sir W. Thomson) a lamp
made in this way. In making these experiments I did
not confine myself exclusively to the use of paper car-
bon. The lamp, as constructed for me by Mr. Stearn,
was extremely simple. It consisted merely of a highly
exhausted glass bulb, into which were sealed, by fusion
of the glass, two platinum conductors supporting the
carbon.
This simple form of lamp I showed lighted at a lecture
which I delivered before the Philosophical Society of
Newcastle in February, 1879. The final result of our
experiments was that when the vacuum was good the
carbon did not appreciably wear away, and that when
the contact between the ends of the carbon and the
metallic conductors was good the globes did not
blacken. Henceforth it was possible to produce a
durable electric lamp that emitted a steady light of
moderate power.
Very soon after this, and I am quite sure without
knowing what I was doing, Mr. Edison produced a
lamp identical with mine in all essential particulars.
It, too, consisted of a simple bulb from which the air
had been exhausted by the Sprengel pump, and which,
like mine, had no screw-closed openings nor complica-
tions of any kind, but contained simply the in-going
and out-coming wires sealed into the glass with the
carbon attached to them.
Since then the manufacture of lamps on this prin-
2224 Swan-Incandescent Lighting-1881.
•
ciple, with slight modifications in the material out of
which the carbon is made and the manner of making
it, has been established on an extensive scale, both in
England and America, and in the electrical exhibition
now open in Paris, electric light produced by incan-
descence occupies an important position. Already in
this country the method has been put to actual use in
house illumination and for lighting the saloons of pas-
senger steamers. It has also been tried experiment-
ally in coal mines.
The success which has attended these applications is
such as to render the subject one of great interest to
mechanical engineers, for until that great discovery is
made, of the possibility of which the President has
spoken in his inaugural address, when electricity shall
be produced by direct conversion of heat into elec-
tricity with smaller loss of energy than it involved in
its conversion into motive power through steam—until
that revolutionary change is made we shall have to
look, perhaps not entirely, but mainly, to motive power
and to mechanical engineers for the apparatus where-
with to produce the electricity required for electric
lighting.
REMARKABLE PROPERTIES OF PREPARED CARBON.
Here is a view of one of my lamps. Here is a bulb
of glass made as nearly as possible vacuous.
Here are
the wires which carry the current in and out of the
lamp through the carbon, which is here. The carbon
is made from cotton thread treated with sulphuric
acid, and then carbonized at a high temperature out of
contact with air. Here is a piece of paper which has
been treated by the process I have mentioned, and
here is a piece of the paper before treatment. You
will observe that the treatment has welded the fiber
together. The difference in the carbon produced from
the treated and the untreated paper is as great as the
difference in the paper before carbonization. Let fall
Swan-Incandescent Lighting-1881. 2225
ou some hard surface, this carbonized parchment
paper rings like metal, while the carbonized blotting
paper is soft and porous. An additional advantage of
this process of parchmentization is that it facilitates
the thickening of the ends of the carbon filament,
where good and extensive contact with the metal con-
ductor is essential. Carbon made in this way is hard
and elastic to a degree quite wonderful. Filaments
0.01 inch diameter and 2 or 3 inches long can be bent
double, and on release spring back like steel. After
being heated for some time to an extreme temperature
by the electric current, the carbon develops qualities of
hardness and incombustibility which place it in an
altogether exceptional position and which give promise
of great durability for incandescent lamps.
The hardening process is accompanied by a change
in conductivity, the carbon in its hardened condition
offering less resistance to the passage of the electric
current than before. This at first sight may seem to
be a disadvantage, inasmuch as the intensity of light
depends on the amount of heat developed in a given
mass, and this reduction in the resistance of a given
filament implies a lower temperature and less light for
a given current passing, but this is compensated by the
less electro-motive force required to overcome the
resistance. To develop the same temperature and
light in the extremely hard form of carbon which
I have aimed at producing, more current and less
E.M.F. are required, as the two are equivalent to each
other. There is no loss of economy by this change of
condition, and mechanically there is an advantage, for
the harder C is less liable to rupture. It is, in fact,
more nearly in a state of utmost consolidation and
stability. The amount of light that can be obtained
from one of my lamps obviously depends on the super-
ficial area of the C and the temperature to which it is
heated, but the amount of light emitted by a hot body
increases in a greater degree than the temperature.
Evidently, therefore, the hotter it can be made the
better for economy.
2226
Swan-Incandescent Lighting-1881.
By sending enough current through the carbon its
temperature can be raised to such a point as produces
a light rivaling in intensity the arc light. So much as
500-candle light has been obtained from one of my
small lamps when pushed to its utmost limit of endur-
ance, but the lamps are not durable at the enormously
high temperature that produces this light. The lamp
that would, if pressed with current to the breaking
point, give a light of 500 candles, would be durable
while giving a light of 50 candles.
A very much larger return of light for power ex-
pended can be obtained if the durability of the lamp
is disregarded than if durability is considered. Sir
W. Thomson and Mr. Bottomley have made careful
measurements of the energy expended in the produc-
tion of light in my lamps. Some of their results are
shown in this table, from which it appears that with
one of my small lamps, when rather less than 1-6th
h.p. was expended on it, a light of 42 candles was
emitted, or an aggregate of 270 candles per h.p. With
a higher E.M.F., and therefore a larger current, 102-.
candle light was obtained from the same lamp. This
amount of light was produced by the expenditure of
rather more than h.p., i. e., the h.p. under these cir-
cumstances yielded 390 candles.
By producing light in this manner and employing
the gas engine as the motor to drive a dynamo-electric
machine, the very interesting result is arrived at that
more light is obtained from a given quantity of gas
exploded in the gas engine than can be obtained in the
usual way to produce the light directly.
An important point in this method of illumination,
and one of particular interest to engineers, is the neces-
sity for regularity of speed in the motor, unless some
regulating device, such as a secondary battery, inter-
vene between the dynamo-machine and the lamps.
Without such assistance the slightest irregularity in the
speed of the dynamo makes itself apparent in the fluc-
tuation in the light. The light is so sensitive to varia-
Swan-Incandescent Lighting-1881. 2227
tions of speed that the overlap of a driving belt is quite
sufficient to make the light wink at every passage of the
joint over the pulley.
But I do not apprehend a continuance of this slight
difficulty, for it is quite certain that the secondary bat-
tery, in which so great an improvement has recently
been made by M. Faure, used in the manner described
by Sir W. Thomson on Friday last, will come into use,
to do away with it entirely, and at the same time do
away with many other difficulties and inconveniences of
supplying current to lamps directly from the dynamo-
electric machine.
The extremely rapid alterations of direction which
occur when incandescent lamps are lighted by alternat-
ing current machines do not produce any unsteadiness
in the light. The lamps which have been kept lighted
during several nights past in one of the picture galleries
of the exhibition here, and which some of you have
probably seen, are worked by Siemeus' alternating cur-
rent machine. You would notice they have been per-
fectly steady. It is a question which time alone can
answer whether the lamps will prove more durable with
an alternating or with a continuous current. There is,
perhaps, some slight ground for surmise that they will
last longer with the alternating current.
Referring back for a moment to the use of my lamps
in mines. So far the mine lamp, defended by a suit-
able lantern, has been detached by flexible conducting
wires to main conductors. The limited portability this
arrangement allows is inconvenient, and the main con-
ductors are expensive, and their retention does not per-
mit the total elimination of the element of danger in
connection with the accidental breakage of a wire. I
have, therefore, thought that a completely self-con-
tained and portable mining lamp would be an advantage,
and I have here a specimen of such a lamp, for the
construction of which I am indebted to the skill of M.
Gimmingham. This lamp can be kept lighted for six
hours by two cells of Faure's secondary battery, weigh-
2228
Swan-Incandescent Lighting-1881.
ing ten pounds, and will give the light of one or two
candles during that time. To charge the battery afresh
it will only be necessary to place it for a time in con-
nection with the wires of a dynamo near the pit's
mouth. The lamp and its attached battery need never
come out of the pit.
Now that we can look to the method of electric light-
ing by incandescence as a perfectly practicable method,
and now that we have the means of combining the
economy of the mechanical generation of electricity
with the constancy and many conveniences of voltaic
accumulation, it is clear that the time is now ripe for
the almost unlimited application of electric light to
general purposes, and that engineers may, with much
advantage, give their immediate attention to the many
details which fall within their province in connection
with the mechanical production and distribution of
electricity on a large scale.
Trant--Divisibility--1879.
2229
Complainant's Exhibit “The Divisibility
of the Electric Light.”
BY WILLIAM TRANT.
SCIENTIFIC AMERICAN SUPPLEMENT, NEW YORK, January
11, 1879, p. 2514.
The English and American periodicals devoted to
electrical science now announce, "on authority," that
the electric light discovered by Edison is a light by in-
candescence. If this be true there is nothing new or
startling either in the discovery of the light or of its
divisibility. Lighting by incandescence has been
studied for a long time; indeed, it has been studied
much more thoroughly than any other kind of electric
lighting. Thirty-three years ago a method of produc-
ing and subdividing the light was patented in England
by a Mr. King. The light was produced by heating to
white heat in a vacuum, by means of the electric cur-
rent, either platinum or carbons; and, the specification
adds, "when the current is of sufficient intensity, two
or a larger number of lights may be placed in the same
circuit." For some years after this discovery several
improvements on King's invention were patented in
America, France and England; "but," says M. Fon-
taine, "none of these appear more complete, more ex-
plicit, and more practical than King's; it is, then, use-
less to continue our nomenclature." The principle of
lighting by incandescence, although not neglected or
forgotten, seems to have made but little progress until
1871, when M. Lodyguine showed an experiment in the
Admiralty Dockyard in St. Petersburg, when he di-
vided the circuit into no less than two hundred lights.
This naturally made a great sensation at the time-as
great a sensation as that caused by Mr. Edison's tele-
gram of Nov. 7th. The Academy of Science awarded
to M. Lodyguine the large Lomonossow prize of 50,000
roubles. A company was formed in St. Petersburg
2230
Trant---Divisibility---1879.
with a capital of 200,000 roubles, and the excitement in
Europe was then almost as great as has been witnessed
in England lately. It was soon found, however, that
Lodyguine's discoveries, like those of his predecessors
in the same field, were, after all, impracticable, and that
his illumitable division of the light, however ingenious,
was only a fanciful experiment. Every penny sub-
scribed to the company referred to was lost, and Lody-
guine's great discovery is now, where it was then-in
his laboratory.
It has, however, been urged that the early inventors
of the electric light knew only of the galvanic battery
as a generator of a powerful current, and that had they
known of the Gramme machine, or other dynamo or
magneto-electric machine, the results might have been
different. The remark, however, only applies to King
and the improvers who immediately succeeded him.
The great division of the light by Lodyguine, to which
reference has just been made, was in a circuit produced
by two "Alliance" machines. Even, however, if such
were not the case, there are at present before the world,
in more or less detail, four recent inventions for the
production of a divided light by incandescence. These
are the inventions of M. Reynier, of M. Arnaud, of Mr.
Edison, and most recent of all, M. Werdermann. From
the way in which these discoveries-if they are dis-
coveries have been ushered into the world, it is found
that great claims are made on their behalf, and there
are, therefore, naturally great expectations on the part
of the public in regard to them. It cannot be urged
now in mitigation of the shortcomings of the incandes-
cent light, as it has been urged in the past, that it has
not had a fair trial, on the ground that the lamps in ex-
istence were imperfect in conception and ccmplex in
construction. The lamp of M. Reynier seems admirable
in its way, and if light by incandescence were to be the
light of the future, the claims of this lamp would have
to be very carefully considered, and, in any case, it will
certainly hold an important place in all investigations
Trant-Divisibility-1879.
2231
into the subject. The lamp of M. Werdermann appears
to be identical in principle with, and only slightly
different in detail from that of M. Reynier, and we may
fully expect that these inventors will have to come to
terms with each other-so much alike are their inven-
tions. Of the details of Mr. Edison's inventions-if
there are any, nothing is known beyond the fact stated
in the "Scientific American," that it is a light produced
from a spiral of incandescent platinum; while the re-
ports in the American daily press show such an effer-
vescent ignorance of the fundamental principles both of
electricity and of dynamics, that no reliance whatever
can be placed upon them.
Experience, then, has shown that a light by incan-
descence comes before us in a very questionable shape,
and it is essentially a light which discourages the notion
of its practical application. The question indeed may
be very properly asked: How is it that light by incan-
descences has always proved such an utter failure?
It has had a period of thirty-three years in which to de-
velop; it has been divided into various lesser lights, num-
bering from two to two hundred; and it has arrested
the attention and taxed the skill of the greatest electri-
cians in the world. How is it that it is obliged to give
way to light by the voltaic arc? The answer is at hand.
The light by incandescence can only be obtained and
divided by a great sacrifice of light and power. This is
imperative from the fundamental principles of electrical
science. The diminution, according to the "square,
and not according to simple proportion, applies to
electricity just as it applies to light, heat, sound, gravita-
tion, and other physical phenomena. Thus, if a circuit
be divided into two branches whose resistances are
equal, a current of half the strength passes through
each branch, producing at the point of resistance, not
half the light, but only a quarter, because the effect fol-
lows the square of the current strength. If the current
had been divided into three equal branches, each
""
2232
Trant-Divisibility-1879.
branch only one-ninth part of the original light would
be obtained, and so on; so that if an electric light of
1,000 candles were divided into ten equal lights, the
result would be ten lights of ten candles each, instead
of 2,000 candles. When this law is borne in mind, and
when it is also remembered that to produce the electric
light by incandescence at least one-half of the current
is lost, it will easily be imagined what a wasteful light
it is. Recent experiments prove this. It was recently
stated, in reference to M. Werdermann's incandescent
light, that he produced two lights of 320 candles each
(total, 640 candles), with a prime mover of 2 horse-
power; and this was considered a great result-as in-
deed it was for an incandescent light. But how this
sinks into insignificance when compared with the re-
sults of lighting by the voltaic arc. A few days ago
M. Rapieff, with two of his regulators and a small
Gramme machine known as the M machine, and which
M. Gramme says requires only 1 horse-power, pro-
duced two lights, which, when carefully measured by
the photometer, were found to be each equal to 1,150
candles, or a total of 2,300 candles, while with one of
M. Gramme's A machines, requiring 24 horse-power, a
light of 6,000 candles can be obtained from one of M.
Rapieff's regulators. Some experiments detailed in M.
Fontaine's book on "Electric Lighting" gave a similar
result. M. Fontaine's experiments with an incandes-
cent light show that under the most favorable circum-
stances, with a Bunsen battery of forty-eight cells, eight
inches high, the diminution of the subdivided light was
so great that, where he put five lights in one circuit, he
only obtained a total illuminating power of a quarter of
a burner, with four lamps only three-quarters of a
burner, with two lamps six-and-a-half burners, and
with one lamp fifty-four burners. These numbers give
the following ratio: 1, 3, 8, 26, 216, thus showing how
rapidly the light diminishes when divided. With the
voltaic arc, however, and with the same battery, he was
able, by a Serrin lamp, to obtain a light of 105 burners.
Trant-Divisibility—1879.
2233
It will be seen, then, from what has been above
stated, that the production and the divisibility of the
light by incandescence is a very wasteful process—so
wasteful, indeed, as to render its practical application
impossible for general lighting. If, therefore, all Mr.
Edison has to announce to the world is that he has suc-
ceeded in dividing an incandescent light-and the an-
nouncement that such is so is made on authority—his
discovery amounts to very little. Both the light and
divisibility were discovered long ago. It will easily be
seen that it is not in that direction that any great prac-
tical results can be obtained. The voltaic arc supplies
the only divisible light of any utility and economy, and
it is in its development that any real progress must be
looked for.-WILLIAM TRANT, in "Nature."
2234 Preece-In Philosophical Magazine-1879.
Complainant's Exhibit “The
Light."
BY
Electric
W. H. PREECE, Memb. Inst. C. E., V. P. Soc. T. E.,
Electrician General Post-Office, &c.
LONDON, EDINBURGH AND DUBLIN PHILO-
SOPHICAL MAGAZINE AND JOURNAL
OF SCIENCE.
Vol. VII.-Fifth Series.
January-June, 1879.
1. The theory of the electric light cannot be brought
absolutely within the domain of quantitative mathe-
matics, for the reason we do not yet know the exact rela-
tion that exists between the production of heat and the
emission of light with a given current; but we know
sufficient to predicate that what is true for the produc-
tion of heat is equally true for the production of light
beyond certain limits.
The work done in a battery, or any source of current
electricity, is expended outside the battery in a closed
circuit in the form of heat. When this heat acquires a
certain temperature per unit mass, we have light. If the
heat be confined to a mass of metal wire like platinum,
we have light by incandescence; if it be expended in
the transference of minute particles of incandescent
matter like carbon across an air space we have the elec-
tric arc.
The exact relations between current, heat,
temperature, mass, and light have yet to be determined
by experiment.
2. The arc is thus a form of energy developed in one
point of a circuit, which is the exact equivalent of
another form of energy expended in another point of
the circuit. Thus, if we produce light by galvanic
battery, it is the equivalent of chemical work done in
he battery. If it be produced by a dynamo machine
Preece-In Philosophical Magazine-1879. 2235
driven by a steam engine, it is the equivalent of coal
consumed in the furnace. The object to be obtained in
any economical utilization of this energy is to convert
the greatest possible portion of it into light.
3. Now the relations that exist between the work
done, the current flowing, the resistances present, and
the heat developed are easily demonstrated. The work
done (W) in any circuits varies directly with the elec-
tromotive force (E) in that circuit, and with the quan-
tity of electricity (Q) that passes through it, or
W=E Q;
but by Ohm's law the electromotive force is equal to the
product of the resistance (R) of the circuit into cur-
rent (C) flowing, or
E=CR;
and by Faraday's law the quantity of electricity passing
depends upon the strength of the current (C) and the
time it flows (t), or
Q=Ct.
Therefore, substituting these two values in the above
equation, we get
W=C2 R t;
in which we have what is known as Joule's law, which
gives us the work done (W), or its equivalent, the heat
generated (H) in any circuit. By regarding the time
as constant, we can put the equation
H:==C2R.
(1)
4. Now let us take the case of a battery whose elec-
tromotive force is E and whose internal resistance is p.
Let the resistance of the connecting wires be r. Let
us also have a particular resistance 7, which may be
a wire to be heated to incandescence, or a lamp to be
lit by the arc; then by Joule's law (1),
but by Ohm's law
H=C² (p+r+l);
E
C=
p+r+1
E2
.. H=
p+r+1
2236 Preece---In Philosophical Magazine-1879.
5. Confining our attention for the present to the heat
generated (H), this will be distributed throughout the
circuit; and that in the resistance (7) will be
1
E2 1
HX
p+r+l
(p+r+1)²
2
(2)
Now, if we suppose n resistance in circuit joined up
in series, then the total heat generated will be
E2nl.
H'=
(p+r+nl)2
(3)
·
If we differentiate this fraction with respect to nl
and put it equal to nothing, we can find when the heat
generated in these resistances becomes a maximum;
that is,
dH'
1
·[(p+r+nl)² E²—2E²nl(p+r+nl)]=0,
dnl
(p+r+nl) 4
whence
p+r+nl=2nl ;
that is,
p+r=nl;
or the greatest heat is generated in the resistances when
the value of the latter equals the resistances of the rest of
the circuit.
6. Let us now assume the n resistances to be con-
nected up in multiple arc; then the joint resistance
will become
1
n
and the heat generated will be
H"=
1
E2
-
n
1
(p+r+-)²
n
(4)
Preece-In Philosophical Magazine-1879. 2237
and the maximum amount of heat will occur, as before,
when
1
p+r=-,
11
7. Now, in the first case, if the internal resistance of
the battery and of the connecting wires be very small
compared with nl, we may neglect them; so that by
putting p+r=0, equation (3) becomes
E2
H':
nl
or the total amount of heat generated in the resistances
will vary inversely as the number of the latter in circuit.
8. In the second case we cannot neglect p+r, for here
1
the greater we make n the smaller becomes with
-
n
1
respect to p+r; so that if eventually becomes very
n
small, we may neglect it in the denominator of the frac-
tion. Then
1
E2
E21
n
H"=
(p+r)²
n(p+r)²
(5)
so that in this case also the total heat generated in the
resistances will vary inversely as the number of the latter
in circuit.
9. Now, it must be observed that in each one of these
cases the total heat is distributed over n resistances;
and, therefore, as compared with one resistance, the
1
heat generated in each is only - of that generated in
n2
one. So that, joined up either in series or in multiple
arc, the heat generated in each of a number of resistances
varies inversely as the square of their number.
2238 Preece-In Philosophical Magazine-1883.
10. With respect to the light emitted, if the amount
of heat generated represented exactly the amount of
light emitted then the above equations would indicate
the effects produced by multiplying the lights or sub-
dividing the current when a constant battery is
employed. But this is not so. The light obtained is
not proportional to the heat generated. Below a cer-
tain limit the production of heat is not accompanied
by light at all. In the case of incandescence, if the
heat be distributed over two wires instead of one, inas-
much as the mass to be heated in the one case is double
that in the other, the actual temperature to which each
of the wires will be heated will be only one-quarter of
that obtained with one wire, and the total light emitted
will be half of what it was before. In the case of the
arc a similar result probably takes place; the incan-
descent matter, which is heated by the current and
which gives out the light, is increased by the addition
of each lamp, and therefore diminishes the actual tem-
perature of each arc, and consequently diminishes the
light given out in direct proportion to the number of
lights.
11. Moreover, in the arc the actual disintegration of
the carbons and the transference of matter across the
air-space, represent an amount of work done which
must be deducted from that converted into heat, and
which again tends to diminish the amount of light
emitted. If, therefore, the lamps be joined up in a
series or in multiple arc, the light emitted by each lamp
will vary inversely in a greater ratio than the square of
the number in circuit.
12. We have assumed E to be constant; but if the
current be produced by a magneto, or dynamo-machine
worked by a steam-engine consuming a given amount
of coal per unit time, E is no longer constant, for it
varies with the resistances in the circuit. The constant
in this case is the work done in the steam-engine in
unit time. Calling this W₁, the total heat generated
in the circuit when the lamps are joined up in series
will be
Preece-In Philosophical Magazine-1879. 2239
H₁=W₁xnl
p+r+nl;
(6)
and since the light varies inversely as n (§ 10), the
light emitted
nl
L₁=W₁X
1
(7)
n (p+r+n)
and when joined up in multiple are,
1
n
L₂=W₁×
(8)
1
n (p+r+—)
n
1
Or by putting p+r=Olin equation (7) and—-0 in the
denominator of equation (8), we get
n
and
W₁
L₁
n
W₁1
L₂ =
2
(p+r)n2
So that beyond certain limits, when the current is pro-
duced by dynamo-machine, if n lamps be joined up
in
1
series, the total light becomes diminished by —, and
n
the light emitted by each lamp becomes diminished
by
1
n 2
If they are joined up in multiple arc, the total light
1
1
is diminished by — and the light emitted by each lamp—.
n 2
n3
2240 Preece-In Philosophical Magazine-1879.
In the latter case the rapid diminution in the light
emitted is due to the fact that the heat is developed in
the machine itself instead of in the resistances external
to it.
13. We have assumed W, to be constant; but this is
only the case when a certain limit is reached, and when
the velocity of the rotating coils in the dynamo-machine
has attained a maximum. This limit will vary with each
dynamo-machine and each kind of lamp used. With
the Wallace-Farmer machine the limit appears to be
reached when six lamps are connected up in series.
With the Gramme alternating machine and Jablochkoff
candles the limit appears to be five lamps. Beyond
these limits the above laws will be true. It is this
partial success in multiplying the light that has led so
many sanguine experimenters to anticipate the ultimate
possibility of its extensive subdivision-a possibility
which this demonstration shows to be hopeless, and
which experiment has proved to be fallacious.
Scientific American-1882.
2241
Complainant's Exhibit "General Incan-
descent Electric Lighting in New York."
Scientific American, September 16, 1882, p. 176.
While the lighting of detached buildings by incan-
descent electric lamps is a familiar sight in this city,
the inauguration of a general system of incandescent
electric lighting from a central station may fairly be
regarded as marking the beginning of a new epoch in
social economy.
To those who had critically followed the development
of the multiple arc system of Mr. Edison there was no
apparent cause for doubting its entire practicability
when applied to general public lighting. Still, to the
multitude the final demonstration of actual service
throughout a considerable area under the complex con-
ditions encountered in a city district, covering many
streets and blocks of houses, was necessary to give as-
surance that the whole matter was not more or less
speculative.
The great steam dynamos at the central station of
the first district were started in concert on the after-
noon of Monday, September 4, and from that evening
the new system of interior lighting has been one of the
established institutions of the city. To a large extent
gas light has been supplanted throughout the district,
and there is no reason for doubting the extension of the
new light to other districts as rapidly as the requisite
central stations and systems of electric conductors,
lamps, meters and other appliances can be produced.
At any rate, the new system has passed three of the
four essential stages of progress toward commercial
permanence and success.
When Mr. Edison first attacked the problem of in-
candescent electric lighting he was met with the gen-
eral objection of electrical authorities that a durable
incandescent electric lamp could not be made. When
2242
Scientific American-1882.
he proposed to subdivide the electric current, so as to
multiply small lamps economically, he was warned on
all sides that he was in pursuit of an impossibility;
the thing could not be done. Having produced the
desired lamp and subdivided the current experiment-
ally, his critics not less confidently asserted that a lab-
oratory experiment was one thing, the practical appli-
cation of a theory to a complex system of public service
was quite another, and he was bound to fail. It was a
question of economy, and admitting that an incandes-
cent electric lighting system could be furnished under
the conditions required, it would not pay. On this
point the company which have furnished the means
for the inauguration of the system in the district now
lighted by them are probably better qualified to judge
than the opponents of the system. It is certainly to be
hoped that their expectation of profit in supplying a
better light than gas affords at the same or less cost
will be amply justified.
As the plan of the central station and the general
application of the system in the first district have been
so recently described in this paper (August 26, 1882),
it will not be necessary to dwell upon them here.
Assuming the new light to cost the same as gas light
—and it is not reasonable to expect that those who
have assumed the cost and risk attending the develop-
ment and introduction of the new light will set the
price of it below what competition with gas may make
necessary—the question is, How are the public to be
benefited ?
The first and most obvious advantage arises from the
quality of the light. It is more nearly like sunlight
than any other artificial illuminant. It is free from
flickering and unsteadiness-faults which make both
the electric are light and the ordinary gas jet so pain-
ful and injurious to the eyes. It does not vitiate the
air, as gas does, by consuming oxygen and loading the
air with products of combustion. Its heating effect is
very much less than that of a gas jet of the same illu-
Scientific American-1882.
2243
minating power. It is not a source of peril from fire,
the lamp proper being incapable of firing the most com-
bustible fabric; while the low tension of the current
makes the formation of arcs and the overheating of con-
ductors altogether unlikely.
Fears as to the continuity of the service have been
expressed, but the grounds for them are not apparent
after an examination of the plant of the central station.
It is true that no system of storage is provided, as in
the case of gas. None is needed, since the electricity
is supplied by a battery of steam dynamos, which de-
liver their several currents into a circuit common to all,
with a large surplus available, so that the stoppage of
any of them by accident or for repairs would not dimin-
ish the illumination of the district. Of course, a gen-
eral fire about the central station might stop its opera-
tion and leave the district in darkness, but the same
risk obtains with gas; and after the establishment of
two or more centres of distribution this hazard may be
obviated by means of connecting mains to be used in
such emergencies.
The experience obtained in the running of Station
No. 1 will no doubt lead to the introduction of consid-
erable changes in the plan and engineering of subse-
quent stations; the company are none the less to be
congratulated for the wisdom with which they have
brought into successful operation an enterprise involv-
ing so much of magnitude, complexity and novelty.
2244
Wheeler-Harper's Weekly-1889.
Complainant's Exhibit "Electric Lighting
in New York."
BY SCHUYLER S. WHEELER, Sc. D.,
Electrical Expert of the Board of Electrical Control,
New York.
[Harper's Weekly, July 27, 1889; pages 586, 601 and 602. |
A peculiarity of electricity, in which it differs from
water and steam, when forced through pipes for giving
power, is that it does not flow or act at all until it has
a completed path in which to circulate. Such a path
is therefore appropriately called a circuit. In this re-
spect it is more like a moving belt, which comes to the
wheel, passes around it and returns, and, like the cur-
rent which, after passing through the lamps, returns
without pressure, the belt has no pulling power on the
side which is returning to the driven wheel. This
peculiarity of electric circuits, though very important,
is often overlooked, and is mentioned to explain, further
on, how electric shocks are received.
The series system is that upon which all are lights
are operated. All of the wires from the Brush arc light
station, shown in figures 2 and 4, are connected in this
way to the arc lamps.
The multiple arc system is used exclusively for sup-
plying incandescent lights. Every light is connected
directly to two main conductors, figure 13, and draws
current from one and discharges it into the other, each
lamp using a small portion of the whole quantity of
current that is supplied to the upper conductor. The
quantity of current in the main wires therefore varies,
and must be increased in proportion to the number of
lamps supplied, there being always in the conductor
enough in quantity to supply the demand of every
Wheeler-Harper's Weekly-1889. 2245
lamp that is lighted. As each divided portion of the
current has to pass through only one lamp, the pressure
maintained on the main wire and from the dynamo is
only that required for a single lamp, and therefore the
whole electro-motive force in this system is equal only
to as much as is required by one lamp in the series
system-about forty volts or a little more. In this
plan the pressure is kept constant at just enough to run
a lamp, and it cannot, therefore, give a severe shock;
but the quantity of current drawn through the main
wire increases as lamps are connected to it; it is there-
fore called the constant potential or pressure system,
while on the same basis the other is called the constant
current system, because with it the amount of current
in the wire is invariably the same. The multiple arc
system is used exclusively for incandescent lights, and,
until the invention of the alternating system, was the
only way of connecting them. As the supplying of
many lamps requires current of great volume, the main
wires are always very large. For this reason the Edi-
son Company, who were the first to introduce incan-
descent lights, constructed their lines underground, as
they were too heavy to be hung overhead. They laid a
large amount of copper rods, connected together simply
in multiple arc, on the plan just described. This work,
executed with a quality of workmanship which has been
very creditable to them, was done several years before
the invention of cheaper systems, but the plan is not
adapted to long distances, because the conductors must
be large enough to carry current for each lamp, instead
of the same current being used again for the next lamp,
as in the series system.
There are two other plans which are important
modifications of the multiple arc and of the series.
systems respectively. One of these, the "three-wire
system," is really two ordinary multiple arc circuits.
with two of the conductors, one of each circuit, merged
into one, so that there are only three conductors, which
supply two full sets of lights as if the circuits were en-
2246
Wheeler--Harper's Weekly-1889.
tirely separate. This arrangement permits a consid-
erable saving of wire, but not as much as is saved by
the method of the alternating current. It is now used
by the Edison Company in place of the simple multiple
arc circuit of two main wires.
The multiple series system is a device for connecting
incandescent lights into an arc light circuit. A num-
ber of incandescent lamps, sufficient when combined to
stand the strong current of the arc circuit, are con-
nected to the wire at the required location, in place of
one of the regular arc lamps. This arrangement has
several disadvantages, of which one is that a single
lamp cannot be turned off, because the remaining ones
will not be able to carry the entire current. In the
multiple arc system, the current of each lamp being
entirely independent of the others, any number of
lamps can be turned off and on at will without affecting
the rest. This is one of the most important facts
about the multiple arc method of connection.
But the heavy wires required for running lamps in
multiple arc are too costly to permit lights being sup-
plied economically at long distances through them.
If the lights could be connected to a short wire in a
simple multiple arc, and this wire could be charged by
the power of the arc circuit current without touching
that circuit, we should have the advantage of the arc
circuit for bringing the power to the place, and at the
same time be able to turn each light off and on inde-
pendently. This is precisely what is accomplished by
the alternating system.
In this system the power is carried on small wires by
means of high pressure to the locality of the lights,
and is there absorbed by an induction coil, which
generates a low-pressure current in a separate wire, to
which the lamps are connected in multiple arc, and
from which they are supplied. As the only way of
carrying the power long distances economically is by
using high pressure, it was very desirable to have the
lamps run by power from a high-pressure wire; at the
Wheeler-Harper's Weekly-1889. 2247
same time it was desirable to have them not connected
to it, to avoid danger of shocks. Attention was there-
fore given to the problem of obtaining from a high-
pressure current another current which could be of low
pressure in a separate wire, and by which the lights
could be supplied without being connected with the
main line, it was known that such a transfer or recrea-
tion of a new current from an old one could be made
with an ordinary induction coil by connecting the main
line to one part of the coil and the local lamp wires of
the house to its other part. The coil would then gen-
erate the current required in the house-wiring; but the
principle on which it generates the current required
that the main line current be rapidly interrupted and
reconnected. And though this interrupting could not
be done without complicated machinery, a number of
attempts were made to do it, on account of the desira-
bility of operating incandescent lights cheaply from
long circuits; finally the idea was hit upon of making
the current itself intermittent before it was sent out on
the wire, in order to do away with this machinery, and
then the problem was solved.
THE ALTERNATING CURRENT.
To appreciate properly the importance of the alter-
nating current and the inventions to which it is likely
to lead, we must review the ways in which electricity
produces its effects. A current passing through a wire
may produce either heat or chemical decomposition,
and at the moment of starting it shoots out into space
invisible lines of force and energy which will generate
a brief current in any neighboring conductors which
they meet. But this effect, which we call induction, is
only momentary, and the induced current ceases imme-
diately. When the inducing current is stopped, a
similar but reversed action takes place, the lines of
force returning into the wire, and inducing in the
neighboring conductor another momentary current
2248
Wheeler-Harper's Weekly-1889.
•
flowing in the opposite direction. This induction is
the means by which all currents are generated in a wire.
As the currents so produced are only momentary, it is
necessary to again start and stop the acting or inducing
current to produce other momentary currents in the
separate wire. When such interruptions are made to
succeed each other with great rapidity, the momentary
currents generated succeed each other with equal
rapidity, and even become a constant vibratory flow of
current in the second wire, without its being connected
in any way with the inducing wire.
The effect of the induction due to the interruptions
of a primary current may be increased, in fact, exactly
doubled, hy sending the current instantly in the oppo-
site direction, and then reversing it, and so on, instead
of simply stopping it at each pulsation, since the elec-
trical changes in the wire will then be twice as great
and sudden as if the current were simply interrupted
and then restored without there being a reversed cur-
rent in the interval.
The power of the electricity transferred by this means
to the second wire is proportional to the lengths of the
first and second wires, which must be placed parallel,
as that is the position required to produce the action.
To get a suffinient length of the wires in proximity to
each other, they are usually wound together in large
coils, which are called induction coils. If in such a
coil the secondary wire is wound many times around
the other, the current produced in it will have great
penetrating power with but little volume, while if it is
wound only a few times around, and is made of large
wire, its current will have correspondingly small pene-
trating power, but great volume, in consequence of
having a large wire through which to flow. The former
winding for coils is common in medical batteries for
converting the low current of the chemical cell into a
high current which can be felt without having enough
volume to do harm. When these coils are being used,
the humming noise of part of the instrument is always
Wheeler-Harper's Weekly-1889. 2249
noticed. This noise is caused by a mechanism which
interrupts the exciting current rapidly for the purpose
of producing the induction. Electricians started with
this device as a means of converting a high-pressure
current, by which power could be carried a long dis-
tance economically, into a current of low pressure,
which would be safe and manageable for every-day
use; but the vibrating mechanism accompanying the
coil could not be left at every house to take care of
itself. This difficulty was overcome by substituting
for the continuous current, which required interrupters
at each coil, a current which was itself vibratory, or
"alternating," and constructing the dynamos so that
the current generated would alternate as it came out of
them. This invention permitted the interrupters to be
dispensed with entirely. The induction coils thus
simplified were also doubled in power by the substitu-
tion of the current which alternated instead of merely
stopping and starting. The number of alternations
was increased to about 300 per second, an immense
rate of vibration, by which the effects of the coils were
made still greater. The two coils of wire in each in-
duction instrument were then made to have more
powerful effect upon each other by interlocking them
with magnetic iron, by means of which a portion of the
inductive influence of the main or exciting coil,
which had always before been wasted, was concen-
trated upon the other coil, thereby increasing the effect
upon it. The principle of the whole device is shown
in figure 14, which will serve to explain its construc-
tion. A portion of the current from the main line flows
from a branching connection through a coil wound
around a bundle of iron, which becomes magnetic
every time a current surrounds it. Upon this magnet
is another coil of wire of larger size, connected to the
lamps in the house, in multiple arc, in the usual manner,
as explained in figure 13. The alternating current pass-
ing from the main line through the first coil magnetizes
and demagnetizes the bar at each alternation, and gen-
$
2250
Wheeler-Harper's Weekly-1889.
erates brief but powerful currents in the second or
lamp coil, the magnet serving merely to carry the ex-
citation from the primary coil into the centre of the
secondary coil to add to the effect. The magnet is
always made of very thin sheets of iron, separated by
tissue-paper, for the reason that, were it not cut up, the
alternations would induce currents in it instead of in
the secondary coil, to prevent which it must be broken
up or laminated, so that no current can circulate in it.
The induction coil thus simplified and improved is
known as a converter, because it serves to convert the
electrical energy of one line into new energy in another
line.
An important feature of the converter is that its
magnet reacts upon the primary coil, and prevents any
currents being drawn from the main line except when
the magnet is weakened by doing work in generating
current in the secondary coil. A current can flow from
the secondary coil only when lamps are connected to it,
no current is drawn from the main line unless some is
being actually used on the lamp circuit. When a small
current is drawn it produces a corresponding effect
upon the magnet, and a proportionate current is taken
from the line.
By using a very large wire having but few turns for
the secondary coil, the current derived may be made.
to have great volume, while its pressure or penetrating
power depends upon the number of turns of wire that
are used in the secondary coil. By selecting a suffi-
ciently large size of wire the apparatus can be made to
give any desired quantity of current, suitable, for in-
stance, to run a large or small number of incandescent
lights, while its pressure may be very low compared
with that of the main line. The range of the converter
is not limited to this, however, for by varying the size
of wire used in the coils it may be built to produce a
still lower pressure from a high one, or vice versa, as in
changing a low-pressure current into one of very great
pressure. This arrangement has been used for chang-
Wheeler--Harper's Weekly--1889. 2251
ing the current of a dynamo into a more intense cur-
rent, in order that it may be carried a long distance
economically for special purposes. There seems to be no
limit to the use which can be made of these simple coils
when employed in conjunction with the alternating cur-
rent, on account of the means which they furnish of
exchanging any given kind of current for one of any
other desired dimensions.
The efficiency or perfection of converters is quite re-
markable. It will be remembered that dynamo gene-
rators produce in electricity ninety per cent. of the
power they receive. The yield from the secondary coil
of a converter has over ninety-five per cent. of the
power of the current supplied to the primary coil.
This transformation or exchange with almost no loss.
is not equaled nor approached in any machinery used
in the other arts.
The converters are usually incased in cast-iron
boxes. Figure 15 shows the appearance of one com-
plete and ready to be fastened up in a building. The
two ends of the two coils are seen projecting through
the case at the top, ready to be connected to the main
line and to the lamps in the building respectively.
The introduction of the alternating method opens up
an entirely new field in electricity, and presents a fresh
supply of possibilities. As the most important trans-
formations of electricity into useful products are facili-
tated by its ready transfer into separate currents of dif-
ferent volumes that are convenient for different pur-
poses, and as this change can be made only by the use
of constant interruptions to operate the transformer,
the invention of a form of electricity in which the pul-
sations are self-contained gives us practically a new
force. It is owing to the fact that half of the uses
which are made of electricity depend upon the effects
which it produces only at the moments of its starting
and stopping that the alternating current is of such im-
portance. It contains in a condensed form all of the
active powers of electricity, while the continuous cur-
2252
Wheeler--Harper's Weekly--1889.
rent contains only half of them, namely, the power of
heating and of effecting chemical action. Perhaps an
illustration will explain this better. Motion and power
are derived from electricity through its power of at-
traction; but, after the electrified wire has attracted the
moving part of the apparatus to it, the motion will con-
tinue no further unless the attraction is stopped long
enough for the moving part to be put back so that it.
can be attracted again. This must be done during an
interval in the attraction, which can be obtained only
by interrupting or switching off the current, unless the
current is of itself vibratory or alternating. With a
current of this kind the part which had been attracted
can move back when the current reverses, and be at-
tracted again by the next current in the right direction.
A continuous motion to and fro will then be kept up
in the movable piece without any switch.
The alternating current, which possesses the inter-
vals and reversals required to produce additional ef-
fects, may be looked upon, then, as a higher kind of
electricity, possessing greater powers than those of the
ordinary current.
The original object of the introduction of this
energy-radiating current was to generate currents for
electric lighting in separate wires from one main line,
by means of simple coils in each building, to which the
local wires are connected without being connected to
the main line. The main line might then be safely
charged at high pressure, for the purpose of reaching
long distances, without danger from the local wires. It
might be interesting to mention here that the same
thing is being done in Boston, for the same reasons,
with steam, or rather superheated water, which is car-
ried in strong pipes through the streets at very high
pressure, and converted at the houses into low-pressure
steam, which is easier to handle. The same object has
now been completely accomplished with electricity,
which affords a better means of generating the low
pressure sought for, and lighting is now done on this
Wheeler-Harper's Weekly-1889. 2253
plan on a very large scale, while the examination of
the properties of the new current possessing the new
feature of a surrounding region of intense energy has
led to remarkable inventions, and to discoveries as to
the nature of electricity. It has been found, for ex-
ample, that electricity, magnetism and light are very
much alike, if not exactly the same thing.
*
In New York electric lights are supplied by alternat-
ing currents over wires six and eight miles long by the
Manhattan Electric Light Company, who, by means of
this system, are enabled to establish their generating
station at a distance on the outskirts of the city, where
the operating expenses are a minimum. The ma-
chinery used is known as the Slattery Induction
System. The station is on the East River, at
Eightieth street, where coal and supplies can be
brought by barges at considerably less expense than if
they had to be unloaded and carted across the city.
The current is generated by a large number of dyna-
mos, which are placed on strong foundations on the
second floor of the building, and are driven by five
powerful engines situated on the floor below, and simi-
lar to those shown in the illustration of the Brush
station.
These dynamos are quite large, but are somewhat
simpler than those used in generating continuous cur-
rents. Fig. 16 gives a view of one of the kind used,
* It should be stated that the claims urged on behalf of various
patents for the alternating current system as applied to electric
lighting are still under adjudication by the Courts. Judge Colt, of
Boston, has already decided that the Gaulard & Gibbs patent, held
by the Westinghouse Company, does not affect the use of the Slat-
tery apparatus in the United States. A suit is now pending in the
United States District Court of Indiana to test the question whether
the Slattery patent does not cover all forms of the present alternat-
ing current system for electric lighting. The plaintiff in the suit is
the Fort Wayne Jenney Electric Light Company, and the defendant
is the Evansville Gas and Electric Light Company, which uses
the Westinghouse alternating current system.-Ed. " Harper's
Weekly."
2254
Wheeler-Harper's Weekly-1889.
which supplies a thousand lights. It contains twelve
powerful magnets, which are supported by its frame,
and surround a central space which they keep highly
magnetized. These magnets and the circular space be-
tween them may be seen in the drawing. Within this
space is a revolving drum or wheel, which has a great
length of wires wound upon it in such a way that as
the wheel rotates the wires are passed close to each
magnet in succession. As the wires approach, a cur-
rent is generated in them; and as they pass away from
the magnets this current ceases and a current of the
opposite direction is generated.
One such alternation will be produced as each mag-
net is passed. All that remains is to provide a con-
nection from the wires on the wheel to the line outside.
This is made by a stationary spring connected to the
line and bearing on the wheel as it revolves.
This part is much simpler than the corresponding
part in continuous current machines. In these the
generating operation is the same, and the current is
alternating until it leaves the machine, but is made
continuous as it passes out by a rapid automatic
changing of the connections, which sends the currents
to the right and to the left, in harmony with and cor-
recting the alternations as fast as the armature re-
volves. Fig. 17 gives a view of one room of the Man-
hattan Company's station and shows how the machines
are arranged. This building is the latest and largest
that has been put up for electric light purposes. It
has a capacity nearly double that of any other station,
having accommodations for engines of 5000 horse-
power and dynamos for 70,000 lights. It was built
upon the most approved plan, with the aid of the ex-
perience gained with former stations. It is fire-proof
and very substantial, and is the best arranged station
in the city. The wires from each machine are led to
switches placed on the wall, which can be seen in the
background of the picture, and above these are meters
which show constantly the amount of current being
Wheeler-Harper's Weekly-1889.
2255
supplied over each wire. All of the electricity gene-
rated here is carried down to the centre of the city in
comparatively small wires over a well-built line of
poles five miles long. From this line, part of which is
shown in Fig. 18, the wires are turned off at conven-
ient corners and carried across town on other poles to
the terminals of the subways, where they are con-
nected to the corresponding cables underground, which
in turn are connected by branches to numerous the-
atres and stores. A great many public places are
lighted from these wires, the current which can be car-
ried by each one of them, when transformed by the
converters into currents of low pressure, being suffi-
cient to light a large number of lamps.
2256 Parliamentary Report-C. W. Siemens-1879.
Complainant's Exhibit Extracts from
Report of Parliamentary Committee
on Electric Lighting, 1879.
ORDERED BY THE HOUSE OF COMMONS TO BE PRINTED,
13TH JUNE, 1879, BLUE BOOK COPY.
TESTIMONY OF MR. C. W. SIEMENS, P. 20.
150. I suppose it would generally follow from that, that
not subdividing the electric light, but taking one elec-
tric light which your experiments refer to, you would
contend that the electric light is economical in regard
to the amount of energy obtained from the fuel ?-It is
a very economical mode of producing light.
151. It would be considerably more expensive if your
light were subdivided into various lights ?—The con-
sumption of energy increases in a very rapid ratio, in-
versely as the concentration of the light. In dividing
the light into two lights each will probably not give
more than one-fourth of the effect.
152. Very nearly according to the squares or more
than the squares ?—I think it is more than the squares.
Exact experiments are wanting on this subject; but so
far as observations have led me to come to a conclusion,
I should say that it increases in a more rapid ratio
than the squares.
190. What does your central light in the Albert Hall
produce ?—Thirty thousand candles. There are five
lights of 6,000 candles each, and those 30,000 candles
are produced with a consumption of say 24-horse power,
which would make the light in the Albert Hall still four
times less expensive in power than the light on the Em-
bankment.
191. Of course it is not applied yet I am only re-
ferring to a letter which I have received to-day; then a
subdivision of the light presents no insuperable diffi-
Parliamentary Report-C. W. Siemens-1879. 2257
culty, but is a question of cost ?—It is a question of
cost.
192. You have made an apparatus for subdivision,
which I think you described at the Royal Society, if I
remember rightly ?—I read a paper not long ago on an
apparatus which subdivides a light perfectly well. There
is no insuperable difficulty about it, and I believe that
the time will come when, if the light is used in large
centres, and sent into districts, it will be necessary to
subdivide it; although that subdivision should, in my
opinion, not be carried beyond the limit of absolute
necessity.
193. With regard to the question of having central
stations of electric energy, how would you think that
this is likely to be brought into practice in the future?
-I believe that if central dynamical stations were es-
tablished in populous neighbourhoods, the current
could be divided within a circle of, say two or
three miles diameter without any serious loss of en-
ergy.
194. Would you not require very large conductors ?
-You would require large conductors, but these large
conductors would be capable of transmitting very large
amounts of electric energy. I may here mention, per-
haps, that two years ago I suggested, as a mere thought,
the possibility of carrying power from a large waterfall
to a distance of some 20 or 30 miles for distribution
and I then came to the conclusion that it would prob-
ably require a conductor or copper rod of three inches
in diameter to convey the energy of 1,000 horses. But
further consideration has led me to the conclusion that
a much smaller conductor would be sufficient for that
purpose. In fact, the only limit to the transmitting
power of a long conductor is its liability to become
heated, for in transmitting an electric current through a
conductor a portion of the dynamical effect of the en-
ergy is lost and converted into heat, which heat accu-
mulates in the conductor and has to be disposed of by
radiation or conduction. If the resistance of the con-
2258 Parliamentary Report-C. W. Siemens-1879.
ductor is made equal to that of the dynamo machine it-
self, it follows from Dr. Hopkinson's recent experiments
that the loss does not exceed the equivalent of 10 per
cent. of the power employed. One-tenth of the total
power employed at the central station would therefore
go to heat the conductor, and if that conductor is ex-
posed to the cooling action of the atmosphere, it will
be capable of transmitting a vast amount of electrical
energy before it would become heated to any consider-
able extent; so that I now believe that a conductor of
two inches would probably suffice to convey electric
energy equal to 1,000-horse power to a distance of 30
miles.
195. You would only require, would you not, one
radial conductor of that kind, and you might use the
water pipes and the gas pipes for the return current?—
Yes.
196. So that you would not require to have another
wire for the return current ?-No; I think the gas and
water pipes would be excellent return conductors, and
if a number of central stations were to connect with
these large masses of metal under the streets, the re-
sistance of the return circuit would really become nil ;
and they would not only be available, but they would
be extremely economical, in an electric point of view, as
return conductors.
197. You would require to convert the gas companies
into amiable friends, would you not, before you would
get permission to use those pipes for the return cur-
rents? There would be the water companies to set-off
against them.
198. Of course, your engine might work only at
night to produce the electric light; but, supposing that
your engine was working day and night, could you find
any use for the electric energy during the day?—I be-
lieve it could be used advantageously for the distribu-
tion of power, and especially for the smaller uses of
power in a populous district.
199. Going into a dressmaker's shop and turning the
Parliamentary Report-C. W. Siemens-1879. 2259
sewing machines, and such things as that?-Turning
sewing machines, turning lathes, and light machinery
of various descriptions. I may here mention that, in
consequence of a conversation that I had with Sir Will-
iam Armstrong some time ago, he has made an appli-
cation upon a small scale at his place at Craigside, of
the power of a waterfall for lighting his library during
the evenings, and working, I think, light tools, such
as lathes or swing machinery during the day time.
200. Power transmitted in that way, I suppose, would
sustain much less loss in its application to small ma-
chinery than the ordinary transmitted power of a steam
engine ?—I believe it would be the cheapest mode of
transmitting power to à considerable distance. The ex-
periments which we have made give a result of a loss
of 50 per cent., that is to say, five-horse power applied
to a dynamo-machine produces, roughly speaking, 24-
horse power at a distant point. The results lately ob-
tained in the experiments by Mr. Schwendler and Dr.
Hopkinson would lead me to hope for better results
than that; but still, taking the loss at 50 per cent., it
would follow that, say 100-horse power engine at a cen-
tral station, which could be worked with a consumption
of 2 lbs. per horse power per hour, would produce at
a number of points power at the rate of 5 lbs. per horse
power per hour, which would still be an economical result
for a small application of power.
201. For instance, our friends across the Atlantic
might some day make use of the Falls of Niagara,
and take the power 30 miles into the interior; is
that what you mean ?-That could be done, but there
are many cases not quite so imposing, but where
natural forces might be used; in Scotland for in-
stance.
220. Speaking of the question of the subdivision of
the light, you said that there was no practical difficulty,
except the cost; supposing that we had 10 lights in
2260 Parliamentary Report-C. W. Siemens--1879.
series at work in different rooms say, and a certain num-
ber of those lights were not required, there would have
to be an interposition of an equivalent resistance for
each light put out; would not that be the case, sup-
posing that the remaining lights were not to be increased?
-Yes, that would be so.
221. And, consequently, the lights which were put
out would cost as much as though they were lighted?
-That would be the case if several lights were put on
the same electric circuit; but hitherto we have put
central lights upon special circuits and the putting out
of a light would mean the breaking of the circuit, or the
stoppage of a machine.
222. But could that practically be done for domestic
illumination; you would have your main conductor in
the street would you take a special branch wire for
each room off the main conductor ?-In making a large
application of electric light, it would be necessary to put
a succession of lights upon the same circuit; but those
would probably branch off a main conductor, and each
branch would be provided with a current regulation, so
that each branch would work under all circumstances
with a given amount of current. If the electro-motive
force or the current increased in consequence of a di-
minished resistance, through the stoppage of some of
the branches, an extra resistance would have to be put
into each branch circuit.
223. So that, in point of fact, a resistance equivalent
to the action of the light is put in, whether it is burning
or not, otherwise you have an increase of light in your
other lights if they are on the same circuit ?—There
would be a certain amount of electric energy lost.
224. And, therefore, the cost is the same, whether
the light is burning or not? -Nearly the same.
258. Then, as to its application to dwellings, it would,
I suppose, be a work requiring some further experiment
and a work of some difficulty, before you could hazard
an opinion as to its being used in dwellings generally
Parliamentary Report.-C. W. Siemens-1879. 2261
instead of gas. For instance, the expense of keeping
the carbons and all the machinery in order would al-
most prohibit its being used generally in dwellings,
would it not?-There would not be much machinery if
central pumping or power stations were adopted. The
consumer would only have his electric candle or his
electric lamp to keep in order, and that would not in-
volve any very serious difficulty. But if you subdivided
the electric light, I think it perhaps would become an ex-
pensive light.
259. Has your attention been called to some of the
more recent experiments of Mr. Edison, and to the suc-
cess which he is stated to have achieved in subdividing
the light, and making it applicable for rooms and dwell-
inge, and so on, with great ease and cheapness ?—I
have, and I think Mr. Edison can, no doubt, produce by
his means a very steady and possibly an agreeable
light.
260. And a cheap light, he claims, I believe ?—Dy-
namically speaking, I think, he has to prove his case as
yet. Our experience, as far as I can judge from my
own, leads me to an opposite conclusion.
261. That is, to a conclusion opposite to that which
is said to have been the result of Mr. Edison's recent
experiments ?—Yes. The dynamo-machine which Mr.
Edisod proposes, I think, is not promising.
*
276. Earl Percy.] You said that the electric light is
cheaper the more it is concentrated; am I right in un-
derstanding that the loss of power depends upon the
sub-division of the light rather than upon the distance
which the current has to travel?-Both of these con-
ditions have their effect. The distance to which a cur-
rent has to travel would only increase the resistance if
the conductor was not increased; but if I had to increase
my distance to, say, twice the distance originally exist-
ing between the source of power and the electric
light, and I made a long conductor of twice the area,
then the electric resistance would be the same in both
2262 Parliamentary Report.-C. W. Siemens-1879.
Distance does
cases, and the loss would be the same.
not a priori imply loss of power; it implies weight of
conductors; but sub-division of the electric light im-
plies a loss which cannot be obviated. In dividing the
focus of light into two foci, each of these two foci would
not give half the amount of light produced by the original
focus.
277. They would give considerably less than half the
amount of light, would they not?-Considerably less;
probably one-fourth.
295. With reference to the application of the light to
theatres, with regard to which one of the last questions
was put to you, at the present moment, at any rate,
there is a great difficulty in reducing the volume of the
electric light, and suddenly turning it up or down, as
you can in the case of gas; it would not be suitable,
for instance, for such purposes as footlights and side-
lights on the stage, which require constant changes ac-
cording to the action of the piece ?-It would, at any
rate, have to be differently managed. To a certain ex-
tent the intensity of the current would modify the light,
but it would not be so thoroughly under control
as gas in that respect. It is very easy to put it out
and to put it on again, but it is not so easy to modify its
intensity.
296. It is not at present easy, whatever it may be in
the course of future experiments, greatly to modify the
brilliancy of the light ?—It does not offer the same fa-
cilities as gas.
297. You would say that for such purposes as foot-
lights and side lights, which require constant modifi-
cation of the light, at present at any rate, whatever your
experience may lead you to in the future, the electric
light is hardly a suitable light ?—Such a light, for in-
stance, as Mr. Edison proposes now, I think, would be
much more controllable in that respect than the elec-
tric arc.
The electric arc cannot be varied in its in-
tensity and brilliancy so readily as gas; but if the light
Parliamentary Report-C. W. Cooke-1879. 2263
is produced by igniting a piece of irridium or platinum
wire, then it is easy enough to modify the cur-
rent so as to give only a small amount of radiated
light.
298. But up to the present, at any rate, lighting with
platinum and irridium has hardly gone beyond the ex-
perimental stage ?-Certainly not.
299. And, as far as we know at present by practical
experience, it has, for different reasons, proved unsuit-
able. One reason is that it is too expensive; and I un-
derstand that if you use two platinum points you would
get the arc passing between them in the same way as
you do between the carbon points; but as you would
not get the particles of carbon passing between them
you would not get anything like the same intensity of
light. I do not know whether that is correct ?—I do
not think metals could be used in that way for produc-
ing the electric arc at all; they would waste away very
rapidly.
:
300. At any rate, shall I be justified in putting it as
high as this that lighting with platinum and irridium,
and such metals, has not got beyond the experimental
stage ?-Certainly not.
301. And therefore this invention of Mr. Edison's
may turn out to be perfectly satisfactory; but until we
have seen it, it is difficult to judge from it whether a
light has yet been found suitable for such things as the
footlights and sidelights of a theatre ?-I think there
are a great many applications remaining for gas; but
for large applications I believe the electric light is quite
ripe for practice.
TESTIMONY OF CONRAD W. COOKE; PAGE 36.
338. I do not know whether, from your study of the
question, you are prepared to give an opinion as to
whether the application of these systems to the produc-
tion of the electric light is in a sufficiently advanced
state just now to bring it within practical and indus-
2264 Parliamentary Report-C. W. Cooke-1879.
trial uses, either in
ment to the use
competition with, or as a supple-
of gas ?-I think the electric
light might be used as a supplement to gas
in most cases, and also as a perfect substi-
tute for gas in certain special cases, while in a third set
of cases it cannot compete with gas at all, and gas must
hold its own, without any opposition from elec-
tricity.
339. Would you explain how ?-I think the electric
light is applicable for the illumination of the interiors
of large buildings, such as the Albert Hall; for such
large passages as the lobbies of this House, or the
House itself; for open spaces, such as Charing Cross,
and large squares, such as the Place de l'Opera, in Paris,
and similar places; and again for lighthouse illumina-
tion; for any large space, in fact, that is not very much
cut up with obstructions to give shadows; and even in
cases where there are obstructions, of such a nature as
a common factory, where there is no decoration, so that
you could whitewash everything; even a factory full of
driving belts and gearing of every sort. I have been
in factories where, by whitewashing every part that
could be whitewashed, hardly any shadows could be
noticed. In those cases the electric light may be ap-
plied. In other cases, where there is decorative work,
the light may be thrown through a skylight or on to a
white ceiling or a white screen. In those cases I think
it cannot be met at all by gas. There are cases in which
the electric light is supplementary to gas. Take the Albert
Hall as a building; the inside of the hall is perfectly
lighted by the electric light; and I will say more than that;
it would be more perfectly lighted if the gas were put out
in the hall, for reasons which I shall be prepared to
give, if necessary. But for the rest of the building, for
passages and for the corridors, I do not think that elec-
tric illumination would be of much use; the passages
are so curved and twisted and bent that the electric
light would be very costly, and a great many separate
lights would be required.
Parliamentary Report-C. W. Cooke-1879. 2265
340. Whereas gas is very easy of application under
such circumstances ?-Excessively easy, and it is more
convenient. Then there is a third set of cases in which
electric lighting could not be applied at all; that is to
say, in the poor and narrow streets, and in small shops
and buildings generally. When I say that it could not
be applied, of course I mean in its present aspect, ac-
cording to the systems at present in use. I cannot see
that it can be applied to small houses, or to domestic
purposes, except in libraries or palatial houses, or large
rooms. But there must be an enormous number of
places of small area which cannot be lighted by the
present system of electric lighting.
341. Supposing that electric lighting became at all a
general source of street illumination, have you consid-
ered whether it might not interfere with the telegraphic
communication of the country ?—I think that if some
provision were not made for protecting telegraph lines
from the effects of induction, it would have a very injuri-
ous effect indeed if the lines carrying the electric cur-
rents for the light ran at all in a parallel direction with
the lines carrying the telegraphic circuits. In the first
place, we have the induction going on between line and
line on telegraph wires from the feeble currents pro-
duced by telegraphic batteries, and if you were to carry
the tremendously powerful currents for producing the
electric light, they would have a proportionately greater
effect upon the telegraph wires; but, at the same time,
there are means for getting over that entirely by com-
pensating it; one way would be to have a return wire
for the electric light instead of using the earth.
342. Instead of gas pipes and water pipes ?— Instead
of using the gas pipes and water pipes, unless the line
for the electric light were carried round by another
route; but if there is a return wire, and that wire be
twisted with the other, either in the form of a cable, or
simply twisted in its direction as it is hung on the in-
sulators, it need not twist more than one turn in a mile,
or one turn in half a mile, or one turn in a foot, or any-
2266 Parliamentary Report--C. W. Cooke--1879.
thing you like, provided that it has as many portions of
the return wire as there are those of the outgoing wire
opposed to the main line of the telegraph, which would
get over the difficulty; but even in those cases it would
only affect those places where the electric circuit runs in
a parallel direction to the other; it would not affect the
telegraphy of the country which goes along the railways,
because I do not take it that it is at present the idea to
light the railways by electric light, having a central
power station at one end of a great railway. If they
lighted railways they would probably have their ma-
chines at each station, or at every two stations; and in
that case they must not carry the electric light wire
parallel with the telegraph lines without compensat-
ing it.
352. Have you any information in regard to the rela-
tive cost of the two different systems of lighting ?-I
have. The most accurate document that has yet ap-
peared in connection with the cost of street illumination
is the report of Monsieur Cernesson to the Municipal
Council of Paris. Trials were made with the greatest
possible care of the Jablochkoff system, extending over
some months, and everything was taken into considera-
tion that could possibly influence the result, and really
a very magnificent report in a scientific sense
has been produced. I have some of the particulars
here.
353. Will you be kind enough to state those par-
ticulars to the Committee ?-It has always been re-
ported that the Jablochkoff system absorbed one horse
power per light. The experiments at Paris show
that it was 20 horse power for 16 electric candles.
354. What is the value of the electric candles ?—The
photometric value of the electric candles as they stand
with their globes on (and the globes absorb a very large
amount of light, something like 60 per cent.) as meas-
ured in a horizontal plane by Monsieur Allard, is 18
carcels, equal to 167-4 candles. A carcel is about 9.6
Parliamentary Report-C. W. Cooke-1879. 2267
candles. Of course the horizontal plane is the most
brilliant, because there is no shadow at all from the tip
of the carbon; but when the light was measured at the
level of the pavement, it was reduced to 12.1 carcels,
or 112.5 candles. That gives a total mean illumination
for the 62 lights, of 6,975 candles, and the cost of that
came out to be 1 l. 9 s. 9 d. per hour, distributed over
62 lights. The cost of the lights in the Avenue de
l'Opera, including the Place de l'Opera and the Place
du Theatre Francais, including wages, steam power,
oil, and candles, at 50 centimes per light per hour, aver-
ages 1 7. 19 s. 4 d. per hour, or 7½ d. per light per hour.
At midnight the lights are put out, and then the streets
are illuminated by 344 gas jets; each of which gives
a light of 10-2 candles, producing an aggregate of
illumination, equal to 3,519 candles as against 6,975,
less than half. The cost of these 344 gas jets is 5 s.
9 d. per hour, or a little over one-fifth of a penny per
light per hour.
355. As against 7 d. ?-As against 7 d.; so that
the illumination of the Avenue de l'Opera to a given
photometric degree costs for the two sets of lamps as
there installed (because they are placed not at the best
advantage) more than two and a half times more when
effected by electricity than by gas. But the Jabloch-
koff system is a costly one, because it is one of the di-
viding systems; and although it is excessively conven-
ient for certain purposes, there is an enormous loss in all
systems of divisions.
356. In this case you have got very much the same
as a single light in the Albert Hall divided into 62 dif-
ferent lights?-Yes, you have.
357. That is to say you have a 6,000 or 7,000 light
power, divided into 62 lights ?—Yes, and at the Albert
Hall it is far cheaper than gas, because there you have
a central light; and you are not losing the enormous
amount which you do by all systems of division. It is
the system of division which makes the Jablochkoff
system a costly one; and I think that the same must
2268 Parliamentary Report-C. W. Cooke-1879.
apply to all systems of division of which the Jabloch-
koff is decidedly a convenient one.
358. Will you explain to the Committee what is the
cause of the great diminution by the system of division?
-It is the great resistance thrown into the circuit at
each lamp by the arc itself. Of course the electric light
is caused by placing a resistance at a small spot, and
compelling the electricity to pass it, thereby being con-
verted into heat and into light; and if you multiply
those on a circuit you reduce your current, and you
might go on multiplying them until your resistance
brings your current down to nothing. With a given
current you have only to go on multiplyfng your di-
vided lights, and at last your current will not pass at
all; you have reduced it to nothing.
359. The very essence of the light is the resistance
to the current which it passes ?—I think that it is safe
to say that the very essence of all electric lights is due
to resistance at a certain spot.
*
388. Have you given attention to the question of ob-
taining light by means of incandescence, necessitating
a closed circuit ?—I cannot speak with any practical
experience of that. My view of it is that you would
have a far greater loss; it could not be done so econom-
ically, but it would probably be applicable in cases where
economy was not so much an object, and where there
was some special reason for dividing it.
389. Lord Lindsay.] Assuming a street to be worked
on this method, the street being joined up in a series,
and supposing that the occupier of one house wished to
put out his lights, how would this be effected ?—In that
case, if you throw out a lamp, or throw out a house,
you must throw into the circuit a resistance exactly equal
to what you cut out. If you do not do that you will affect
every lamp in the series and the machine as well. If
you put out your lights by breaking the circuit, you put
out every light in the series, and the engine will run
Parliamentary Report-C. W. Cooke-1879.
away if it is not properly controlled; and if you put
them out simply by short-circuiting them you will make
the others brighter.
390. It would seem that the cost of a lamp working
and one at rest would be the same, with the exception
of the carbon which was not consumed ?- The cost to
the supplier would be the same, certainly. It would not
affect the main current.
391. Supposing that this were done, is there any
means of learning the quantity of electricity which
would be used in a given space of time by the occupier
of a house?—I think that a contrivance might be made
for the purpose, although it would be somewhat diffi-
cult to meet all the peculiar circumstances, for instance,
of a man shutting off the whole of his house, or shut-
ting off one light, or shutting off two lights, and so on.
You would probably have to have a meter at each light,
I think, in a case of that sort, because you must, if you
shut off one light, put in an equal resistance. It might
be done by shunting in a certain variable resistance at
each lamp. In that case you could diminish your light
due to the amount of leakage through the variable re-
sistance. Certainly a meter would be a very compli-
cated thing to arrange; you would have, I suppose, to
have some little electric motor. Then, again, I think
it would be very difficult to arrange for a variation in
the speed.
399. I suppose we may assume that the lighting of
large areas can be done satisfactorily, and without ex-
cessive cost, by means of the electric light ?--Yes, I
think that the lighting of large areas, such as squares,
and buildings, and large halls, by the electric light,
would give a decidedly economical result.
400. But your answer would not be so decided with
regard to small places, and with regard to domestic
illumination?--No, not in the present state of the
science.
*
*
2270 Parliamentary Report-C. W. Cooke---1879.
420. Dr. Siemens in his evidence, stated that the
light should be centralised rather than subdivided; do
you concur in that view ?-That is what I meant.
421. Is it not desirable that it should be subdivided?
-It is very desirable for illuminating purposes that you
should distribute your lights in a great many places,
but the moment you divide your current, at each point
of division you lose a certain amount. In fact, you
might almost compare it to changing money where you
have to pay commission at each change.
422. I suppose that the fact that it cannot be subdi-
vided is one of the difficulties in its practical use now?
-That is one of the great difficulties in street illumina-
tion, and it is the insuperable difficulty at present as re-
gards domestic illumination; but, for the illumination
of large halls and large areas, I think that centralisation
is better than subdivision.
423. Do you remember the experiments that they tried
in Billingsgate Market ?—Yes.
424. What was the cause of the failure there ?-A
great many causes were given. Those who were in favour
of the gas said that it was an imperfect light; that it
was unhealthy; that it made the fish look bad, and a
great many other things. Those, again, who were in
favour of the electric light, said that the Billingsgate
people did not like their bad fish to be shown up. It
is impossible to get at the real truth in a case of that
sort where there were so many divided interests.
425. Dr. Siemens, in referring to Mr. Edison, who is
credited with having recently invented a machine for
subdividing the light, expressed some doubt on the sub-
ject and stated that he thought that it was not as prom-
ising as the reports indicated; do you know anything
about that ?-We really know very little at all about it.
A few newspaper paragraphs have appeared on the sub-
lect, and I have been very much interested, as every-
body has. His nephew told me, himself, that he has
seen, I think, over 200 lights on one circuit. I must say
I should like to see it myself, and that is all that I
can say.
Parliamentary Report-W. H. Preece-1879. 2271
TESTIMONY OF W. H. PREECE; PAGE 66:
510. I think you have both considered and made ex-
periments upon the subdivision of the electric current
for the production of various lights?—I have; I have
examined the questions theoretically from a mathemat-
ical point of view, and I have also examined it experi-
mentally.
511. Did you not publish a Paper upon the subject in
the January number of the "Philosophical Magazine?"
-I did.
512. What was the result that you came to ?—In
that Paper, I showed first of all, that there are two
ways of subdividing the light. Supposing that this
piece of string which I hold in my hands were a wire
conveying the current, we might insert in that one string
several lamps, or we might take these several lamps and
join them up in what is called a parallel arc.
You may
have your wires arranged parallel with each other, with
one lamp in each. The result of my inquiry was to
show, that when lamps are joined up in series, the in-
tensity of light in each lamp diminishes with the square
of the number inserted; and when they are joined up
in this parallel arc, the intensity of the light diminishes
as the cube of the number, showing, that when you at-
tempt to subdivide the light beyond two or three, the
intensity of the light diminishes in a marvellous
ratio.
513. In other words, that means, that the economy of
the light diminishes in as great a ratio as the square in
the one case and as the cube in the other; and that if econ-
omy is important that is a very wasteful mode of pro-
ducing the electric light ?-Certainly. I might give
you an illustration of that, taken from the case on the
Thames Embankment. From the experiments that
have been made, one-horse power economically ap-
plied, ought to give a light equivalent to about 1,250
candles. The lights on the Embankment are produced
by what is called a Gramme alternating machine, which
2272 Parliamentary Report-W. H. Preece—1879.
is practically four machines, using altogether 20 horse-
power, each machine being worked by five horse-power.
Now each of those machines ought to give 6,250 can-
dles; but they are joined up in series, and in each wire
there is a series of five candles. The square of five is
25, and if we divide 6,250, which ought to be the can-
dle light, by 25, the result is 250, which ought to be the
light per candle on the Embankment if it were naked.
But it is obscured by a globe which diminishes the light
about 40 per cent., the result is that by calculation the
light on the Embankment ought to be 150 candles; and
by the photometrical measurements of Professor Keates,
it agrees very well with that figure, for it is about 160
candles. However, by calculation based on my investi-
gation published in the "Philosophical Magazine,"
those lamps ought to give 150 candles.
514. What does the naked light give ?—I do not know
the measurement, but by calculation it ought to give
250 candles, and I should say, judging by the eye, it is
not far out. So that 20 horse-power on the Thames
Embankment ought to give an illuminating power of
25,000 candles, and it only gives an illuminating power
of 3,200 candles, showing a terrific waste.
515. Then, according to your view, the electric light
is really very economical when it is used for giving cen-
tral lights, but not when it is used in a subdivided
form?—It is only economical when one machine is used
to produce a single light.
516. And any departure from that means waste,
economically speaking ?-Certainly.
517. What is your opinion as to the application of
the electric light for general street lighting ?-I do not
think that the electric light for street lighting is at all
applicable; and for this reason, that if you have a long
street with an electric light you may have it in the mid-
dle; but we will say, for the sake of argument, that you
have it at one end, and you have that light sufficiently
powerful to light efficiently the extreme end. Then at
the near end you must have an enormous waste of light;
Parliamentary Report-Geo. F. Deacon -1879. 2273
because as the light diminishes with the square of the
distance the amount at the one end of the street to give
light at the other end must be largely in excess of the
requirements at the near end. From that point of view,
I am at the present moment occupied in preparing
another paper on the subject, for the "Philosophical
Magazine," in which I bring out such an extraordinary
result that I am not inclined to believe it is true; but
the result is this: that you can light a street of 1,000
feet with 40 lamps of 15-candle power better than if
you use one single electric light of 6,000 candle
power.
518. That is to say a long street ?-A long street;
showing that the ordinary gas lamps of 15-candle power
are better adapted for street lighting than a single
electric light.
519. But supposing that you have symmetrical spaces.
like squares, how would the electric light answer in
such cases?—There the electric light comes out right.
For symmetrical spaces for such a space, for instance,
as the Albert Hall, for spheres, for square spaces, one
single centralised light is the same in effect as a largely
distributed light; and practically, for economical pur-
poses, it is better.
TESTIMONY OF GEO. F. DEACON, P. 99.
949. Have you considered the effect of the division
of the electric current into various lights as occasioning
a large loss in illuminating power?-I have; the loss
is considerable; and, probably, so far as practice has
gone up to date, the loss in each light is nearly as the
square of the number of lights; but the exact deter-
mination of the question is beset with practical difficul-
ties of many kinds, and I do not think that the theoret-
ical determinations which have been made will necessa-
rily be exactly borne out in practice. Part of the loss
attributed to sub-division is probably due to the alter-
nate currents necessary in the only sub-divided system
which has been largely used.
2274 Parliamentary Report-Geo. F. Deacon--1879.
950. Will you explain what are some of the occasions
of the loss; I suppose the resistance of numerous car-
bons instead of the resistance of two carbons
would be one cause ?-Yes, the moment you begin
to increase the points of resistance you must increase
the electro-motive force; and that is an undesirable
thing on many accounts. There would be greater loss
through the insulators to begin with; and the machines,
working at high tension, would, on many accounts, be
more costly to maintain than machines working at low
tension.
951. At the present moment, in the illumination for
public purposes, the lights are divided into series, are
they not?—Yes, in all cases, except one that I have
seen. I believe that there is an American invention di-
vided in multiple arc.
952. Lord Lindsay.] What system is that; the Brush
system ?—No, I was speaking of Edison's.
953. Chairman.] There have not been many experi-
ments, have there, in the sub-division into parallel cir-
cuits ?--The only ones that I have seen are those of M.
Werdermann; and I understand now that his lamp has
been used in series with better effect, but I have not
seen it so used.
954. From your experience as engineer to a large cor-
poration, do you think that, whether you have a con-
centrated system of light or a divided system, the elec-
tric light is likely to be useful for public purposes, either
in illuminating thoroughfares or in illuminating public
buildings ?— Certainly for illuminating public buildings,
and I think that for many public thoroughfares there
is an indication that the cost will come very closely
down to that of gas, if not a little lower. I think, for
instance, that directly the gas companies begin to con-
centrate their gaslights, to which there is a tendency at
the present time, they will be beaten by electricity. I
find by calculation that the 200-candle burners, for in-
stance, if taken at the same rate of cost as the smaller
burners, which perhaps is rather unfavourable to the gas,
Parliamentary Report--Geo. F. Deacon--1879. 2275
and not quite fair, would be 31 d. per hour; but you
may allow 14 d., and that still leaves 2 d. That comes
very close to the cost of even a partially subdivided
electric light of the same power.
992. Those lamps in the street, I suppose, would be
in series, would they not?—I think that up to five or
six lights on one circuit there is a possibility of divis-
ion in series being accomplished with moderate econ-
omy; and it may be that division in multiple arc will
also be carried to somewhere about the same extent.
But beyond that, I think either of them will be so
costly as to put a stop to much further division on any
system which has yet been tried.
993. Then, practically, it comes to this, that we can
only use six lights in a series, and that would carry
you over what distance of ground?—That depends upon
the intensity of the light.
994. If you put the lights 100 yards apart, at the end
of 600 yards you would require another engine and
another generator, would you not ?—Quite so.
I am
speaking entirely in the light of practical results up to
this time. I know that certain mathematicians have
attempted to show that it is impracticable to go further
theoretically, but that is certainly not an universal opin-
ion; there are very high authorities for the belief that
there are modes of overcoming the present difficulties
of subdivision.
995. Do you know the length of the circuit that was
used on the Embankment a little while ago ?—No, I do
not know the length.
996. I think I have seen it stated that it was more than
3,000 yards?—If so it is very much longer than anything
in the Avenue de l'Opera.
997. Chairman.] With a central station ?—Yes.
998. Lord Lindsay.] Have you considered at all the
possibility of the electric light being applied to domestic,
that is to say, to chamber lighting in houses ?-I think
it is quite possible that it will be applied as a luxury;
2276 Parliamentary Report--Geo. F. Deacon--1879.
but so far as I can see at present, again in the light of
experience up to the present date, I do not think it is
likely to be applied economically.
999. Then you think it would not damage the gas
companies in any way ?-I do not think it will damage
the gas companies, even if it is applied very largely for
public lighting.
1000. Would the same remark apply to street light-
ing ?-Quite so.
1001. Supposing that you had your lamps in a house
in series, how would you effect the reduction of a single
light without affecting the others?—Theoretically there
is no difficulty in doing that as a matter of electricity;
but, practically, so far as I can see at the present time,
I fear that the difficulty would be considerably greater
than the mere turning of a stopcock, or regulating it by
a stopcock.
1002. You would interpose a resistance, in fact, would
you not? Yes.
1003. And, therefore, that light would cost the same,
whether it was burning or not, with the exception of
the carbons ?-Yes, with the exception of the carbons.
That is, of course, in the case of lights in series only.
But those inventors who have attempted to go further
in subdivision, have placed their light in multiple arc
and then other conditions come in which render it less
economical on other accounts.
*
1029. You referred just now to Mr. Edison; have you
had your attention called to the more recently reported
inventions of Mr. Edison, by which he claims to have
sub-divided the light so as to make it applicable for do-
mestic purposes ?--Yes, I have, but there appears to be
a doubt whether those reports contain the last patents
of Mr. Edison, upon which he bases his statements and
his hopes.
1030. I believe it was in contemplation some time
ago by the Corporation of Liverpool to purchase the
gas companies in Liverpool, was it not ?-It has been
Parliamentary Report-Geo. F. Deacon-1879. 2277
talked about; and a committee of the Corporation did
sit for some time for the purpose of investigating the
whole subject.
1031. And then about that time a Bill was promoted
to give the Corporation power to use the electric light?
That was so. The Corporation thought that if the elec-
tric light was at all likely to be used, they ought to
have the power to use it themselves.
1032. That was notwithstanding your report ?—Yes,
about the same time, if I remember right.
1033. Did that have the effect of seriously depreciat-
ing the apparent value of the gas companies for the pur-
pose of purchase ?-I do not think it had any effect on
the gas companies' shares.
1034. Have you seen the new system of using gas in
Regent-street and Queen Victoria-street?-In Waterloo-
place I have, and in one or two places on the Embank-
ment. I have already remarked that I think is is a mis-
take to attempt to concentrate gas. Directly the gas
companies begin to concentrate gas, they enter into di-
rect competition with electricity, and they will be losers,
I think. One of the great advantages of gas is, that it
is so easily sub-divided with scarcely any loss; there is
a slight loss, but it is so trifling as to be unimportant.
I think also, with respect to these lamps of 200 candle
power, that they are made for the production of a great
effect on the pavement below; but neither the reflectors nor
the jets are so arranged as to throw the light to a dis-
tance, which is what you want.
1035. Did the Corporation of Liverpool, in promoting
this Bill, contemplate the adoption of any system of
electric lighting, supposing that they got their powers?
-I think they would have made experiments in the
open spaces opposite St. George's Hall. Of course they
would have acted tentatively; and if it had been
successful there, they might have tried it in other
places.
1036. Mr. Arthur Moore.] Do you think, then, that
the time has come when it would be wise to permit cor-
2278 Parliamentary Report-Geo. F. Deacon-1879.
porations to light their own streets by electricity ?—
Yes; I think there are many open spaces in large towns
which might be illuminated by electricity with great ad-
vantage, and that corporations should have the power
to light such places. I do not think that it will be at
present applied to streets. The Avenue de l'Opera in
Paris is quite an exceptional street, and we are not likely
to have many like it in our towns.
1037. Do you not think that if you had one or two of
the wider streets lighted in this way, the shadows
thrown on the side streets would be very great, and that
they would be at least apparently in much greater dark-
ness than they are at present ?--I am inclined to think
that the electric light, if largely used, will have the ef-
fect of making the public demand a higher standard of
illumination; and for that reason, if for no other, the
gas companies will profit by it.
1038. I think I understood you to say that you
thought that the system of electric lighting was going
on so rapidly, that probably in a short time there might
be some better means of sub-dividing the light found?
-I think there will be better means of sub-dividing the
light; but I cannot see my way to any result approach-
ing those that have been proposed from America, Mr.
Edison's, for example.
1039. Has your attention been drawn to the evidence
given by one of the French promoters, I think Monsieur
Vivarez, who said that there was no additional cost in
dividing the light ?—No, I have not seen that evi-
dence.
1040. They said that they could divide the light
simply and make two lights instead of one at half the
cost of each ?—I have seen nothing in practice to bear
that out, and, theoretically, I do not think it is pos-
sible.
1050. With regard to the expense of the electric
light, I suppose you would say that, in a general way,
all the tendency of modern improvement and investiga-
Parliamentiary Report--Sir William 2279
Thomson--1879.
tion is to reduce that expense and to render the electric
light cheaper?—I do not think that the concentrated
lights will be very much reduced in cost, because I do
not see where the diminution of cost is to come from.
It cannot be in the machine, because we know that al-
ready a very high efficiency of the machine has been
obtained. It can scarcely be to a very great extent in
the lamp; but in the sub-divided system I think
there will be a very great increase of efficiency.
*
1061. Have you any experience of the use of iridi-
um ?—I cannot say that I have any practical expe-
rience of the effect of iridium for incandescence.
1062. Is it not understood that most of Mr. Edison's
patents and inventions have reference to the use of
iridium ?-An alloy of platinum and iridium, I under-
stand.
1063. Then no one in this country is justified in ex-
pressing an opinion as to the possibility of dividing the
light in opposition to Mr. Edison's statement until it
has been tried; is not that so ?-No; but I think that
if all that Mr. Edison had said, or rather all that has
been said of Mr. Edison's inventions, had been literally
correct, we should have heard a great deal more about
it before now, because the time has passed when pat-
ents would have been secured.
1064. Is it not the case that his last patent has only
just been sealed ?-I do not know how many patents
there are. I have seen one or two of his French pat-
ents.
"New
1065. Chairman.] Are you aware that the
York Herald" of last week (which I have this morning
received from Mr. Edison himself) describes fully, with
drawings, Mr. Edison's inventions for which patents
have been recently taken out ?—No, I have not
seen it.
TESTIMONY OF SIR WILLIAM THOMSON, P. 177.
1753. If, then, the electric light is such an economical
producer of the waves that we call luminous rays, do
2280
Parliamentary Report--Sir William
Thomson--1879.
you consider that the electric light has a great future
before it or not ?-A great future. In the immediate
future I anticipate a great extension of the practical
usefulness of the electric light. In a future somewhat
less near, I anticipate the use of the electric light for
every case of fixed lights, whether in large rooms or in
small rooms, or in great public halls or in passages and
staircases leading to them, and even in fixed lights in
the lobbies and staircases of private houses.
1754. Then you think that the use of the electric light
is not the dream of a savant, but a practical possibility in
the future ?-Certainly. The electric light has been in
dreamland for 60 years, and it has now come into the
world of realities.
1755. And it is now rapidly progressing ?—It is now
rapidly progressing, and in good hands. A great deal
of good work is spent upon it at this time, and there is im-
mense promise in the work that is now being carried on
by practical men upon the electric light.
1756. Your reason for supposing so is, that there
is now a prodigiously greater economy in the trans-
formation of mechanical force or energy into light
than there formerly was ?-That is my reason.
*
1779. Would you allow me to ask you about the di-
vision of the electric light into various small lights;
scientifically do you agree with calculations the result
of which have been put before us, that the effect of a
division must be, in some cases, to decrease the light so
divided, according to the squares, or according to the
cubes of the distance ?-We have no scientific law of
the economy of the electric light in different degrees of
division and concentration; but practice and theoretical
guesses seem to agree in making the economy much less
when we spend the same quantity of energy, for example,
in ten feebler lights than when we spent it in one strong
light; when we do this we do not get nearly one-tenth
part of the whole light by any of the plans hitherto in
use.
Parliamentary Report-Sir William 2281
Thomson-1879.
1780. But there is nothing in the mathematical dis-
cussion of the question that should render that reduc-
tion necessarily by the square or the cubes ?—No; it is
quite possible that a plan of using electric energy for
light might be found and may yet be found, in which teǹ
feebler lights will give a sum of light equal to
that obtainable by the same energy in one concentrated
light.
1781. In one of the early answers that you gave, you
seemed to look to electric lighting as suitable for the
interior of houses and for domestic purposes; has in-
vention progressed so far that it is at all fit for that just
now ?—I think it is almost fit for it now. I believe that
almost every drawing-room in London, in large houses
at all events, might now be lighted economically,
and in all respects advantageously, by the electric
light.
1782. That is for the large rooms of a house?—Yes.
1783. But the ordinary methods, of which we have
heard, of dividing the light, do not seem to be very much
advanced, except in the case of the Jablochkoff can-
dle ?—No ; I believe that is the most advanced sub-
division of the electric light which we yet have.
1790. Then, so far as I gather your views, whilst you
think that the electric light is now applicable to large
halls or public rooms, such as drawing-rooms, it is not
physically very economical by the processes just now
used for general distribution throughout a house ?-I
would not be prepared to say that it is not economical
now. I think with proper mirrors, lenses, prisms, and
screens, it could be economically used throughout a
house at present.
1791. I mean in bedrooms and such places as that?
-Not perhaps in bedrooms. Small movable lights may
be preferred there.
1792. But even if it is not at present available for
general domestic use, according to what you have told
us about the wonderfully economical transformation of
2282
Parliamentary Report-Sir William
Thomson-1879.
energy into light, there is a large margin for future im-
provement ?-A large margin.
1793. Have you taken into consideration what was
suggested to us in evidence by Dr. Siemens, viz., that
for a practical realisation of the electric light, it would
be necessary, in cities, to associate it with the distribu-
tion of power?—It would be advisable, certainly, to as-
sociate it with the distribution of power, because the
same means that are used for giving electric light
would be perfectly available for the distribution of
power.
1794. For example, in the daytime, you might distribute
power by large engines, and you might turn your power
into light at night ?-Quite so.
1795. That might be very advantageous, might it not,
where there was a natural source of power, such as a
river or a waterfall ?-Very advantageous. I look for-
ward to the Falls of Niagara being extensively used for
the production of light and mechanical power over a
large area of North America.
1796. In fact the energy which is wasted in the
Falls of Niagara might be conducted to a considerable
distance, and make a manufacturing town ?-Certainly,
it might be advantageously conducted hundreds of
miles.
1797. But in such a case as that, how are you to con-
duct your electricity, and how are you to conduct your
power; supposing that you had a thousand horse power
engine in a town, would you not require an immense
conductor to conduct away its energy?-You would re-
quire powerful copper or iron conductors. I have rec-
ommended a tubular form with water flowing in the
tube to keep it cool. [Subsequent consideration has
shown this to be unnecessary; see deferred Answer,
page 1931.
1798. Is that to carry off the heat, and keep off its
conductive properties ?--Yes, and to prevent it from
fusing. The heat so carried off is waste heat. Some
waste is necessary, but the proportion of waste may be
made practically very small.
Parliamentary Report-Sir William 2283
Thomson-1879.
1799. Of course where you have such a tremendous
waste of power, as at present in Niagara, one can con-
ceive that being used for large manufacturing purposes;
but would the power that you would send from a thou-
sand horse power engine be more than you could use for
slight things like lathes and sewing machines and such
things?—Yes; there is no limit to the application of it
on a great scale. It might drive great turning lathes in
engineers' works. It might do all the work that can be
done by steam engines.
1825. You speak as having great faith in the
future of the electric light, so far as its application to
domestic lighting and to street lighting goes ?—Yes.
1826. Do you consider that such an application of
the electric light is calculated to do damage to gas com-
panies in the depreciation of their stock, or do you think
that the increased demand for gas, as a motive power,
would counterbalance the loss for lighting power?—I
think that is very probable in the present state of
things; but, in the state of things that I look forward
to, of great central engines working in the most econom-
ical way possible, burning not more than 2 lbs. of coal
per horse-power per hour, this function for gas would
be superseded. Still there may be many other pur-
poses for which gas can be advantageously used. Gas,
as a direct heating means, will probably have many ap-
plications, so that I do not think it probable that it will
be ever found that less gas will be wanted than at pres-
ent.
1827. But, in view of what you said about the heat-
ing power of gas, the gas companies would gradually
come to modify the present chemical constituents of
their gas, in order to produce more hydrogen and less
carbon, I suppose ?-No doubt an improvement may be
made in that way; as, for instance, in a meteorological
observatory, where gas is used for photographic regis-
tration, it undergoes a process of naphthalising, I be-
lieve, which I understand adds illuminating power
to it.
2284
Parliamentary Report-Sir William
Thomson-1879.
1828. I believes it adds nearly 30 per cent.; do you
consider our means of producing electricity to be greatly
in advance of our means of utilising it ?—I think they
are.
1845. So that my objection would, of course, not hold
good, if you had unconcentrated rays. With regard to
street lights, supposing that you have a street lighted
with a certain number of these high lights, would they
be in series, or in multiple arc, according to your sug-
gestion ?—I have not attempted to work that problem
out. I see a way of doing it in series and also ways of
doing it in multiple arc. I would rather leave it to prac-
tical inventors to find out what was the best way. I
have thought of the subject, but I have not thought of
it as to its practical bearing. I think that probably
having the lights in series would be the best way with
proper means of preventing the current from being
stopped when any one of the lights accidentally goes
out for a moment.
1846. Leaving that and going to domestic lighting,
you said that you considered it possible, with advan-
tage and with economy, to light any rooms now in any
houses, with the exception, say, of bedrooms, where
small handlights are required; would you also say that
that should be done in series ?-It would depend very
much upon the mode of supply. I could scarcely an-
swer that question, because there is so much to be done
before it can really be made practicable; I think it
would be too expensive at present in private houses,
ordinarily, to have separate engines for the electric
light, unless in a very large house. In large drawing
rooms, perhaps, it might be advantageous even now. I
look forward rather to a time when a block of houses
may be lighted by a central engine; then I think it
would be economical with only such electric lamps as
we have at present, supposing that the lamps perfectly
get over the difficulty about unsteadiness. I think prob-
ably series would be the best arrangement.
Parliamentary Report-Sir William 2285
Thomson-1879.
1847. Then supposing that we had a block of houses
lighted from one station the current will enter that
house, pass through the different lamps in that house,
and go into the next house ?--Yes, it would not do to
have very many in series, because the electro-motive
force would rise too high.
1848. Supposing that we had a lamp in a dining-room,
and that after dinner I did not want that lamp any
more, how should I put it out ?—If there are other
lamps in series you would do it by short-circuiting it.
It may be short-circuited through a resistance, but then
there will be a waste of light.
1849. Then there is the same cost for that lamp as
when it was burning with the exception ot the carbon ?
—Yes, but with proper regulators by inventions not yet
made, the machine will have a governor according to
which, when you short circuit without resistance any
one of the lights, the machine will not give more cur-
rent than you want for the other light or lights, whether
in the same circuit or in parallel circuits.
1850. Such a machine as you mention is now being
made, I believe, is it not ?—I have not heard. I have
scarcely thought of this subject, myself, except in a very
general way.
1851. As to the production of this electricity, you
think it might be done by each person, if he desired
individually, having an engine of his own ?-It might,
certainly.
1896. Mr. Hardcastle.] I understood you to say that
drawing-rooms might even now be economically lighted
with the electric light; in saying that, do you mean
that certain houses might be furnished with steam-en-
gines and electrical apparatus, and that still the light
would be economical ?-Yes, I think so. The first cost
of a gas-engine, or a steam-engine, is considerable ; but
the quantity of gas used in a gas-engine to get a certain
amount of illumination by the electric light would be
very moderate. On the other hand, if the power could
2286
Parliamentary Report-Sir William
Thomson-1879.
be supplied from a central steam-engine, the cost would
be reduced almost to the expense of the carbons. Now,
carbons more than powerful enough for a drawing-
room, would be only 3 d. an hour at the most, and that
would not be a large expense for a large drawing-room,
or for a conversazione, where there were a large num-
ber of guests. The expense of the carbons only goes on
during the time that the illumination is wanted. Then
I look at the expense of the carbons, which is at pres-
ent the greater part of the expense of the electric light,
as quite a transient phase of the economical question.
The carbon itself is not thicker than two or three quills;
and the value of the material is not more than a twen-
tieth part of a farthing. I cannot but think that the
cost of the carbons will be reduced to an exceedingly
small fraction of the present amount, and that will re-
duce the cost of the electric light immensely below what
it is at present.
1897. But, in the case of the engine for the
supply of a single house, you would be obliged to have
an engineer, and all the appliances of that kind,
would you not ?—If it be a gas-engine there is no diffi-
culty.
1898. Is that automatic ?-Any man-servant, or even
in a house where no man-servant is kept, the servants
of the house could start the engine and stop it, and keep
it going perfectly.
1899. Have you ever paid attention to the use of irid-
ium instead of carbons ?-I have not.
*
1903. You suggested a very grand scheme for utilis-
ing the power of the falls of Niagara, or other water-
power at a distance; without going into detail at all,
was your idea to make use of that power to produce
enormous magnetical force, and to convey that force to
a distance by wires ?—Yes, to drive magneto-electric
machines by water-power applied in the neighbourhood
of the fall; and to use conductors to transmit the cur-
rent produced by those machines to the places where
Parliamentary Report-Sir William 2287
Thomson-1879.
illumination is to be produced, or where the develop-
ment of mechanical power is wanted. The light would
be produced by the electric lamp wherever it is needed;
the power would be produced by electro-magnetic en-
gines driven by the current.
1904. Would there not be some danger from such
a terrific power being engendered of those shocks which
you described as being possible ?—I think not, because
it would not be an alternating current; it must be a con-
tinuous current.
1913. You spoke of the use of large copper tubes con-
taining water, of what diameter would those tubes be?
-I have not made an estimate; it would depend alto-
gether upon the quantity of power to be transmitted
and upon the distance. In the Report of the Institution
of Civil Engineers, for February, 1878, a discussion
upon the subject is reported, and some estimates as to
quantities are there given; but I am afraid that I could
not repeat any just now.
1914. In a general way, what size of tube have you
thought of; would it be estimated by inches ?—By
inches. It would be very moderate indeed in com-
parison with water pipes, for instance. Perhaps the
tubes might be three or four inches in diameter and of
moderate thickness. A moderate amount of copper
would certainly carry a great deal of electric energy.
[See deferred Answer below.]
1915. Do you consider that there would be any
practical difficulty in the insulation of those tubes
under ground ?-I think there would be no dif-
ficulty in giving them sufficient insulation for this pur-
· pose.
Deferred Answer to Questions regarding the Quantity of
Metal required for the Electric trans-
mission of Energy.
The answer is best given by aid of a formula.
Let A be the work done per unit of time by the prime
2288
Parliamentary Report-Sir William
Thomson-1879.
mover in maintaining the electric current through the
circuit of the main conductor and receiving machines;
p the proportion of work lost in transit, in virtue of
the resistance of the main ;
R the resistance of the main ;
E the electro-motive force maintained by the prime
mover between the sending end of the main, and the
earth ;
y the strength of current through the main. The elec-
tro-motive force between the two ends of the main is p
E. Hence
y =
pE
R
And, by the elementary formula for work done in main-
tenance of electric current, we have
Hence
A = E y.
p E2
R
A =
Ρ
Let now d be the diameter of the main conductor,
supposed to be solid copper of circular section, in 10ths
of an inch, and L its length in British statute miles. Its
resistance, in ohms, is (Clark and Sabine's Electrical
Tables and Formula, ed. 1871, p. 105)
5.5 × L
;
de
Hence, in absolute centimetre-gramme-seconds measure;
and therefore,
5.5 × L × 109
R =
A =
de
p E2 d²
5.5 x L x 109
Parliamentary Report--Sir William 2289
Thomson-1879.
The power transmitted is (1 - p) A, and this must be
divided by 736 x 10" to reduce to horse power. Hence,
if H denotes the horse power transmitted to the remote
end, we have,
E2 d²
(1 - p) p E² de
H =
4·05 × 1019 × L
or approximately
(1 - p) p E² de
d²
H=
4 × 1019 × L
Take now, for example, L = 300, and d = 5, we have,
(1 − p) p E2
H =
48 × 1019
Suppose, now, 20 per cent to be allowed to be lost in
transit: we have p =. And suppose the whole electro-
motive force E to be equal to that of about 71,000 Dan-
iell cells, that is to say, E = 80,000 volts, or 80,000 × 108
absolute: we have.
X 64 x 1024
H:
48 × 1019
21,000.
That is to say, a copper wire of half an inch diameter
suffices to transmit 21,000 horse power to a distance of
300 statute miles, with an expenditure of 26,250 horse
power at the sending end. The 20 per cent. loss, being
5,250 horse power, is spent in generating heat all along
the 300 miles of conductor, which is at the rate of 17.5
horse power per mile, or one horse power per 300 feet.
The heat generated by one horse power is the equiva-
lent of 736 × 1010 (centimetre-gramme-seconds) ab-
•736 × 1010
solute units per second, or
980
or say, 75 × 107
gramme-centimetre gravitation units per second, or
75 × 107
42400
177 gramme-water-centigrade thermal units
per second. Now the surface of 300 feet of wire of
half an inch diameter is about 33,000 square centi-
2290
Parliamentary Report-Sir William
Thomson-1879.
metres. Hence the generation of heat in the main con-
ductor is at the rate of about of a thermal unit per
square centimetre of surface per second. The rate of
loss of heat by radiation and convection from an unpol-
ished surface of copper (or other solid material) is about
4000 per square centimetre per degree of excess of tem-
perature above that of the surrounding medium. Hence
if the main conductor is freely exposed in the air, its
temperature will be raised only 20° centigrade by the
heating effect of the current. Hence the complication,
which I formerly suggested, of tubular form, with
water flowing through it to carry off waste heat, is un-
necessary.
The weight of a statute mile of round copper wire of
half an inch diameter is 4,000 lbs., of which the cost is
about 200 7. Hence the cost of the copper required to
transmit 80 per cent. of 26,250-horse power to a dis-
tance of 300 statute miles (say from Niagara to Montreal,
or Boston or New York, or Philadelphia) is 60,-
000 l., or less than 3 7. per horse power actually trans-
mitted.
:
Briggs-Comparative Economy-1879. 2291
66
Complainant's Exhibit Comparative
Economy of Electric and Gas Light."
BY ROBERT BRIGGS.
[American Gas Light Journal, January 2, 1879.]
In the London Engineering of October 18 there is a
communication relating to this question, where the
results of the most recent developments of the electric
light in comparison with gaslight, are fully presented.
A summary of the paper, which is necessarily of
much length, exhibits that for absolute economy in the
force expended, taken on the basis of the converti-
bility of heat into mechanical effect; the electric light
is at least one hundred times more efficient than the
gaslight. And this estimate is based on the light pro-
duced per horse-power expended, as found by some
experiments made at the Franklin Institute, in Phila-
delphia, while all the European makers of dynamo-
electric machines claim nearly five times the quantity
of light per horse-power.
Again, if the cost of producing the coal gas—that is,
the heat which would proceed from the coal needed
to make the coal gas-be taken in place of what the
coal gas itself would evolve when burned, the above
ratios are made over twice (2.3) more unfavorable for
the efficiency of coal gas.
From all of which it is evident that the possibility
of electric lighting, as compared with the reality of
gas lighting, is enormously in favor of the former.
But as the source of electricity is found in the dy-
namo-electric machine, which derives its motion from
a steam engine, and as the steam engine is, even in its
most approved form, probably the most wasteful utiliza-
tion of natural force; the expenditure of heat, as de-
rivable from the coal to be burned under the boiler of
2292
Briggs-Comparative Economy-1879.
a steam engine (of such size as is suitable for driving
dynamo-electric machines) when compared with that
derivable from the coal demanded to make coal gas, is
2.2 times less for electric than for gas light, if the
Franklin Institute values for electric light be taken,
and 11 times less if Siemens' or Gramme's results for
their machines be adopted.
According to the Franklin Institute experiments, to
produce a given quantity of light by the two systems,
there must, for electric light, for each pound of coal
burned under the boiler of a steam engine, be five and
one-fourth pounds of gas coal distilled in a retort;
and the question is whether the apparatus in either
case is more or less expensive originally, or in repairs;
and whether the operating of the same will demand
greater or less skill or time of workmen ?
It is stated that the result of 380 candles per horse-
power, representing the power demanded to produce
the light of the best spermaceti candle by the electric
system, is that of ninety pounds weight falling one
foot per minute. A man ascending a flight of stairs
at a very moderate rate will have expended a force
equal to three candles. The results claimed by the
makers of electric machines are five times as good as
this.
The electric light, wherever it is desirable to
illuminate from one point, either at considerable dis-
tance or by great volume of light, therefore is greatly
more economical than gas light at the present time,
with a promise of yet higher relative efficiency. And
the adaptability of the electric system to smaller, or
even domestic uses, would seem to be only a question
of time for research and ingenuity to mature.
The enormous advantage of the electric light as re-
gards comfort, health and safety, when compared with
illumination by combustion of any substance whatever,
are obvious, and the attainment of much less success
than has been already reached would warrant the sub-
stitution of the new light for the old.
Briggs-Comparative Economy-1879.
2293
The complete absence from flickering, so objection-
able in all gas light, being only partly relieved by the
argand burner (an objection which causes many to
resort to the student's lamp, using petroleum as a sub-
stitute for gas light, when reading or sewing), consti-
tutes a great superiority for the electric light. The
blinking of some of the exhibited electric lights is a
fault of the apparatus not incident to the system
at all.
An observation of particular electric lights for a long
time showed that the light from a good apparatus did
not vary to the eye oftener than once in a quarter hour
at the most frequent, to even longer times at the less
frequent, disturbances, while the effect of the instan-
taneous cessation or aberration on a reader was less
than that of a summer cloud which should obscure the
sun for the same length of time only. In fact, readers
cannot but rarely discern the diminution of light. Of
course a perfect light for illuminating purposes would
never vary, and the perfectibility of the electric system,
and of any other will, and in the nature of things must,
be relative.
ROBERT BRIGGS.

2295
2
Complainant's Exhibit, Prof. Morton's Lecture.
American Gas Light Journal.
LECTURE UPON THE ELECTRIC LIGHT.
DELIVERED OCT. 17, 1878, BEFORE THE AMERICAN GAS-LIGHT ASSOCIATION,
By Prof. HENRY MORTON, Ph.D.,
PRES. STEVENS INST, HOBOKEN, N. J.
GENTLEMEN OF THE GAS-LIGHT ASSOCIATION:-I purpose this even-
ing to show you what the electric light now is in the various forms in which
it has been developed up to the present time, and also to give some account
of its history, and to point out, from a study of the latter, what are the
reasonable prospects of its future development.
Jan. 2, 1879.
from the positive to the negative pole, carrying with it particles of the
carbon, as well as filling the space between with vapor of the same. The
both the poles between which they fly, so that all becomes intensely lum-
particles thus torn off are exceedingly heated by this action, as also are
inous. The intensely hot and luminous poles constitute the "electric
light" of this form.
I now cause the image of the electric arc to be projected upon the screen,
and you there see (Fig. 1) what I have described. If we place a piece of
silver in a carbon cup, arranged as the positive pole, it is, as you see, in-
stantly fused into a luminous white-hot globule, from which springs a
tongue of emerald green flame, and also a cloud of silver smoke, or vapor-
globule and negative pole of carbon.
In the first place, evidently au electric ligut is some source of light de-ized silver, forming a swaying curtain or veil around the brightly luminous
veloped by electricity, and as there are three distinct methods by which
electricity may be caused to develop light, we have naturally three distinct
sorts of electric light:
Naming these in the order of their intensity, they are-
The Electric Arc,
Ignited Conductors,
Incandescent Gases.
These I will show you and explain in their order.
THE ELECTRIC ARC.
Beautiful and intense as is this electric arc, it is evident that, in order to
become useful, it must be rendered constant and uniform in its action.
Now, to render this electric arc in any degree constant and reliable, a va-
riety of conditions must be provided for.
Thus, in the first place, as I have already noticed, a part of the carbon is
actually vaporized. This causes a wearing away of the poles. Again, the
carrying of particles of carbon from one pole to another changes the form
of each. If the action goes on in the air, there will also be an actual com-
bustion of the carbon poles. To counteract these sources of irregularity
regulators of various sorts, operated by clock-work or by gravity, and con-
trolled by the current and the consumption of the carbons, have been devised
by Duboscq, by Foucault, by Gaiffe, by Serrin, by Deleuil, and many others.
The difficulty with all these, is that, however well they may reg-
ulate everything else, they cannot regulate the minute accidental varia-
tions in the structure of the carbon poles during their consumption, by rea-
son of which these sometimes become very thin near their extremities, which
60000
K+
B
Fig. 1.
Fig. 2.
The electric arc may be said to have made its first appearance on this diminishes the amount of light produced, and at others change their shape
planet in the laboratory of the Royal Institution, in London, when Sir
Humphrey Davy, in 1808, made his famous experiments with the galvanic
battery of two thousand pairs of plates, with which he decomposed soda,
potash, etc., and discovered their metallic bases.
The experiments of Davy were repeated and extended by various conti-
nental investigators, and in this country by the elder Silimán, of Yale, who
first noticed and described many of the characteristic phenomena of this
electric discharge, or "Voltaic arc," as it is called.
Its image was first projected on a screen by Foucault, and "electric
lamps" or regulators were, at an early period, devised by him, by Deleuil,
by Duboscq, and by many others; and efforts to improve these in the way
of rendering them more efficient in producing a reliable and steady light,
have continued down to the present day, and are by no means at an end now.
In order to understand these, it will be necessary to consider a little what
this "electric light," "electric arc," or "electrio discharge," is, or con-
sists in.
When two pieces of dense charcoal, retort carbon, or the like, are con-
nected each with one pole of a galvanic battery, consisting of fifty or more
pairs of plates powerfully excited, and, after being brought into close con-
tact, are slightly separated, a stream of electric fluid, as we call it, rushes
so as to allow the main discharge to pass more to one side than another, so
shifting the source of light from side to side of the poles, the side furthest
from the discharge always emitting much less light, and being shaded by
the pole itself from the greater light produced on the other side.
Thus, for example, with an electric arc springing, as shown in the cut
Fig. 2, from the left side of the poles, a b, many times as much light will
be emitted towards the left as will come towards the right, and as the arc
flies around, this direction of maximum of emission will, of course, change
with it.
So immense are the fluctuations produced in this way that, in the experi-
ments which I have myself made, I found the same light, measured from a
given direction, to change, within a few minutes, back and forth between
400 and 2,000 candles.
The use of reflectors and shades tends to equalize these irregularities,
but they are present to a marked degree in all arrangements which have
ever come under the notice of the present writer, notwithstanding the con-
trary assertions of all their respective inventors or promoters. Thus, only
a few days after I had first noticed the electric lights used in the basement
hall of the Equitable Building, and had remarked their exceptional irregu-
larity, I saw in one of our mechanical journals a long article on the very
2296
Jan. 2, 1879.
American Gas Light Journal.
3
regulator there used, describing it as the succesful solution of the problem same time, on the circuits being opened or closed. The light is as white
of a perfectly steady electric light. Again, a few days since I was visited, and pure as Gillard's gas, with which it has one point in common, namely,
within a few hours, by one of the prominent promoters of electric lights, its production by the incandescence of platinum. The gas pipes are replaced
who described to me the universal satisfaction expressed by every one with by simple wires, and no explosions, bad smells, or fires can take place.
his regulators; and by one of our largest mill owners, who was anxious to "The trials that have been hitherto made, with the object of producing
introduce electric lights into his mills, but having examined this same light | an electric light by means of heated platinum, have failed on account of the
in a place where a number were in constant use, found that that regulator, melting of the wires. This difficulty has been overcome by M. de Changy's
at all events, was entirely too unsteady to answer,
dividing regulator. The cost of the light is estimated to be half that of gas.
A lamp placed at the mast head of a ship would form a permanent signal
for about six months without the necessity of changing the platinum. With
several such lights, placed in tubes of colored glass, it would be easy to
telegraph by night, as they could be extinguished and relighted rapidly
from the deck.
All things, of course, have their degrees, and there are undoubtedly
numberless places where the best regulators are quite steady enough to do
all that is required. But certainly the problem of an electric light steady
enough for all uses has not approached a solution in the direction of what
are known as "electric light regulators."
Many years ago elaborate experiments were made to overcome this diffi- "For lighthouse purposes considerable amplitude can be given to the
culty by employing a stream of mercury, falling in successive drops from tight. I also saw a lamp so arranged, in a thick glass globe, that it could
one reservoir to another, as the source of the electric light. This was be immersed to considerable depths without being extinguished by any move-
known as the Way light, and extensive experiments, with massive and ment. This lamp has already been used in the taking of fish, which were
costly apparatus, were carried on to test its efficiency. The volatilization attracted towards the light.
|
and oxidation of the mercury, the want of constancy in the light, and other
like causes, however, led to the abandonment of these experiments, after a
large sum had been expended.
To dispense with the costly machinery of those mechanical regulators,
M. Jablochkoff has recently carried out the ingenions plan of making a
sort of electric candle, in which two parallel rods of carbon, separated by a
narrow band of fusibie porcelain, are supported vertically and made the
poles of an electric circuit. The current, leaping between their ends, melts
down the barrier of porcelain as the rods are consumed, and thus the
"candle" burns down. This arrangement has, without doubt, the merit
of simplicity, but it has found little favor in this country, because it has
proved to be less reliable than the "mechanical lamps" or "regulators,"
and to involve a great waste of power, expended in overcoming the resist
ance of the interposed porcelain.
In this department of electric lighting, the case stands, I believe, at the
present day thus:-Improvements in electro-motors (that is, machines for
producing electricity, of which we shall speak further on) have given us
relatively cheap electricity, obtainable with convenience wherever steam
power is at hand; but the electric light regulators of to-day are not essen
tially different from, or much in advance of those of fifty years ago; and,
while they will furnish a light reliable enough and steady enough for a
vast number of uses, they are by no means fit for universal application, nor
does the progress which they have made in the direction of improved
steadiness hold out any strong encouragement to hope that much more can
be done in this direction, unless some radically different method can be
discovered.
"
The questions of economy, efficiency, and practical application of the
"electric aro,
as a source of illumination, as well as the proper basis of
measurement by which to determine its actual performance, I will discuss
further on after we have considered other departments of the subject which
must be included in such consideration.
We will turn now, therefore, to the next form of electric light-that
mainly produced by
INCANDESCENT CONDUCTORS.
In some of the early experiments of Sir Humphrey Davy, we find mention
of the henting to luminosity of wires of various metals, as tests of the com-
parative power of different batteries; and, in 1858, so great an advance had
been made in the practical utilization of this means of lighting, that M.
Jobart, in a report to the Academy of Sciences in Paris, was able to speak
as follows:
“I hasten to aunouuce to the Academy the important discovery of the
dividing of an electric current for lighting purposes. This current, from a
single source, traverses as many wires as may be desired, and gives a series
of light ranging from a night lamp to a lighthouse lamp.
years,
I saw
"The above slight description will suffice to show to what a variety of
applications this discovery can be put. The communication which I have
had the honor of laying before the Academy is founded upon no illusion; a
lamp was, to my astonishment, lit in the hollow of my hand, and remained
alight after I had put it in my pocket with my handkerchief over it.”
In looking the matter up in the Comptes Rendus, or minutes of the
French Academy, I find that the communication of M. Jobart was
received at the meeting held March 1st, 1858, and was referred to M. Bec-
querel. At the meeting of April 5th, M. Becquerel reported that he did
not find anything sufficiently definite to warrant the Academy to express an
opinion as to the importance of this discovery. "All that was desirable at
present was fuller information." At the meeting of April 19th M. Jobart rê-
sponds to this request by stating that "he could not give more precise de-
tails without exposing the author to see another profit by his discovery.”
Familiar as is the fact that history repeats itself, we cannot but be struck
by the many points of resemblance between the above and what we read in
the newspapers of to-day, concerning the wonderful doings of Menlo Park,
and must hope that Mr. Edison's inventions will escape that permanent ob-
souration which seems to have finally shrouded M. de Changy's.
It would appear as if this brilliant and complete success described by
Mr. Jobart as achieved by M. de Changy in Paris, in February, 1858, was
very rapidly followed up in this country, for I learn from a letter in the
Salem Obscrver of Nov. 2, 1868, that Mr. Moses G. Farmer, or some friend
of his in Salem, lit their parlor for every evening during July of 1859 with
electric lamps operated on a like principle.
It is true that nineteen years have not sufficed to render this admirable
arrangement successful in practice, but what is that to the prophetic mind
which, foreseeing what is to happen in the "near future," naturally over-
leaps distinctions between past and future, theory and practice.
For us, however, who only know the past and the present, it may be well
to look a little closer at the means actually used, and the results obtained,
in these and other experiments.
In the first place, let me show you what this light by incandescence ac-
tually is.
There is a coil of platinum wire, through which I pass the current from
a battery. It grows first red, then yellow, then white, and nɔw it gives
out a beautiful soft, and steady light; but we must be cautious; if I allow
the current to become a little stronger, the wire fuses and drops asunder,
and our experiment is at an end.
It is, as I understand, just here that Mr. Edison has made his much an-
nonuced but carefully concealed iuvention. He has devised some simple
and ingenious arrangement by which the solid conductor can be brongh
up to the highest point of incandescence, without risk of fusion.
ago.
True, this achievement was claimed for M. de Changy, and seems to bo
implied in Mr. Farmer's description; but somehow, as with the famons
perpetual motion machine, "the little screw which makes it all go" does
“The luminous arc between the carbons produces, as is well known, a not appear to have been forthcoming in either case; aud in this present
very intense, flickering, and costly light. M. de Changy, who is a chemist, year of 1878 we still look to the "future, ," "near" or remote, for the
mechanician, and physicist, is thoroughly conversant with the latest dis-"practical success" so confidently announced nineteen or twenty years
coveries, and has just solved the problem of dividing the electric light.
"In his laboratory, where le has worked alone for the past six
a battery of twelve Bunsen elements producing a constant luminous arc be-
tween two carbons, in a regulator of his own invention—this regulator be-
ing the most simple and perfect I have ever seen. A dozen small miner's
lamps were also in the circuit, and he could, at pleasure, light or extinguish
cither one or the othor, or all together, without diminishing or increasing
the intensity of the light through the extinction of the neighboring lamps. This apparatus consists of a glass vessel provided with a metal cap and
The lamps, which are enclosed in hermetically-sealed glass tubes, are in-packing box below, by means of which it can be closed air-tight.
tended for the lighting of miues in which there is fire damp, and for the A connector at K allows of the exhaustion of air from the interior, and
street lamps, which would by this system be all lighted or put out at the the filling of the interior with any inactive gas,
The first electric lamp operating by incandescence of which we have
any actual record seems to be that invented by the American, Starr, a
putent for which was taken out in England by his agent, King, in 1845,
and which has thus come to be known as the King`lamp. This lamp has
been modified in details until it has reached the form shown in Fig. 3,
known as the Koun lamp.

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Fig. 3.
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American Gas Light Journal.
B
K
Two upright metallic conductors, connected respectively with the two
poles of the electric circuit, pass up through this glass vessel and at their
upper ends support, as shown, two or more rods of carbon or other conduc.
tors. The electric connection with these rods is made from C by means of
the lever I, which communicates first with the longest rod, F, and when
that is burned up, falls upon the next iongest, and so on. The light is pro-
duced by the rod of carbon heated white hot by the current.
Various slight modifications of this lamp have been made and elaborately
experimented with; but they all show the same essential characteristics.
The first of these is that, as long as any oxygen remains in the vessel, the
carbon rods consume rapidly, the first one generally lasting only twenty
minutes. The second carbon will, however, last two hours if the light
does not exceed forty burners; but even when all active gas has been re-
moved, the carbon suffers a sort of vaporization.
The second characteristic of these incandescent lamps is that, with the
same current, they develop much less light than is obtained from the elec-
tric arc. Thus, a battery of 48 elements, with a Serrin lamp, gave an
electric arc equal to 100 burners; but with one of these lamps gave a light
equal only to 80 burners, and when divided between three lamps, gave
only the light of 10 burners each.
Jan. 2, 1879.
In another case a given battery with one lamp gave the light of 9 burn-
ers: with two lamps, 2 burners; and with three lamps, one-third of a
burner each. Another battery with one lamp gave a light of 65 burners;
with two lamps, 7 burners; with three lamps, 1 burners; with four
lamps, three-fourths of a burner; and with five lamps, one-half burner
each.
In this connection it is curious to notice that the latest accounts from
Mr. Edison show that he gets a light equal to about 18 candles, or three
argand gas burners, per horse power with his new device, and with similar
machines for producing the electric current and the electric arc, from 1,000
to 2,000 candles per horse power; thus showing remarkable agreement
with these earlier experiments as to the loss of effect resulting from the
subdivision of the light.
Another modification of this Starr or Koun lamp is found in that which
has been recently exhibited in New York as the Sawyer-Mann lamp.
This differs from the former apparatus in no important feature except
that the interior of the vessel is said to be filled with pure nitrogen at the
ordinary pressure. The carbon rods are said not to waste away in these
lamps. Without knowing anything positively on the subject, my opinion
is that this is only because they have not been subjected to strong currents,
but have only been heated to the extent of yielding the light of one or two
burners. Under these circumstances, the carbons of the Koun lamp will
last a long time, but on the other hand, the light so obtained is not
economical, as we see above.
When exhibited in New York recently, we understand that five lamps
only were operated by a magneto machine of Arnoux & Hochhausen,
driven by a three-horse power steam engine, said to be developing only one
and one-half horse power.
It is certain that none of these lamps have yet demonstrated anything
like such practical success as can enable us to see that they can take the
place of gas in ordinary illumination. They have, of course, many advan-
tages in certain respects over the electric arc, but these are combined with
compensating drawbacks on the part of economy; and it is only by turning
our eyes to the as yet unrevealed possibilities of the future that we are able
to see the electric light us a successful substitute for gas and other methods
of illumination.
Another method of electric illumination by ignition is that suggested by
Jablockkoff some time since, but which seems to have been abandoned
practically on account of the costliness of the apparatus, not to mention
other difficulties.
This consists in causing the main current to pass in a series of inter-
cepted or reversed pulses through the primary circuits of numerous induc-
tion coils, and then to pass the induced sparks, obtained from the secondary
coils of these instruments, across or around little rods of porcelain, which
thus become heated to whiteness.
Fully to understand this it will, however, be necessary to explain the
structure and operation of an "induction coil," and this comes naturally
now in order in connection with the third method of obtaining light from
electricity, namely,
ELECTRIC LIGHT FROM INCANDESCENT GAS.
In order to obtain electricity in such a state that it will pass through a
gas and thus heat it to luminosity, we must, in practice, make use of an in-
duction coil.
One of these instruments is shown in Fig. 4, as seen outside, and in sec-
A
B
I
G
C
T
E
Fig. 4.
D
The third characteristic is the manner in which the light-producing power
of the current diminishes as it is distributed between a number of lamps.
Thus, the current from a given battery, acting on one lamp, produced a
light between 4 and 5 burners; on two lamps, a light of 14 burners each;
on three lamps, one-third to two-thirds of a burner each. From another tion in Fig 5; its structure and mode of operation may be described as
battery, the current on a single lamp gave a light of 11 to 12 burners; with follows:
two lamps, one-half burner each; and on three lamps, one-ninth of a
burner each.
Beginning from the interior of the structure we have in the first place a
core A B, formed of a bundle of soft iron wires. This is surrounded by a

2298
Jan. 2, 1879.
Fig. 5.
American Gas Light
Gas Light Journal.
If the cross section of the vessel is smaller, the light
is brighter, and thus, by the use of tubes with wire
let into them, very brilliant effects can be produced.
Such tubes are called, from their first manufacturer,
a glass blower of Bonn, Geissler tubes, and some of
the ordinary forms are shown in Fig. 8.
By using different gases, and employing various flu-
orescent substances, in the surrounding jackets, very
beautiful combinations of colored lights are obtained.
I now show you a number of these tubes arranged
on a screen, and illuminated at once by the discharge
from my large coil.
Some of these tubes you will notice not only emit a
bright light while the electric discharge is passing,
but continue to glow for some minutes after it has
coil of thick copper wire so arranged that an intermittent current of elec- ceased. This introduces us to a new phenomenon of
tricity from a galvanic battery may be passed through it. This interrup-light.
tion is effected as follows: The current from the battery enters at the bind-
ing screw and passes by a brass strip to the column C and thence to the
brass spring, which rests against the screw D, thence by the column D into
the coil indicated in section around A B, and out again to the battery by the
binding screw. When the current is to be interrupted, a hammer, omitted
in the figure. falls upon the spring between C and D, so striking it away
from the screw D. When the current passes, it powerfully magnetizes the
core, and when it censes, the core rapidly (we may say instantly) loses its
magnetic properties.
Outside of this coil thus carrying the battery current, aud which is known
as the "primary coil," or "primary circuit," is another coil, E F, usually
of very fine copper wire of great length, varying from hundreds of feet to
hundreds of miles in different instruments. This is known as the "second-
ary coil," or "secondary circuit," and in it is produced, by magneto-dy-
namic induction, a momentary current at the instant when the iron wires of
the core become magnetic, and another momentary current in an opposite
direction at the moment when the core loses its magnetism. This gaining
and losing of magnetism is, of course, the result of the passing and stop-
ping of the primary current, and thus, in this sense, the secondary or in-
duced current is caused by the primary one. If in place of simply inter-
rupting the primary current, as above, rapidly alternating currents, in op-
posite directions, are sent through the primary coil, the practical result will
be the same. These momentary induced or secondary currents have as we
say, high intensity, being able to leap over distances and pass through re-
sisting materials.
Thus the coil shown in Fig. 6, constructed some years ago for the present
writer, and which contains, in its outer or secondary coil, 50 miles of wire,
will throw a spark 21 inches through air, or through a block of solid glass
5
When light falls upon certain bodies its vibrations
cause changes in the relative positions of their parti-
cles, somewhat like the changes which heat vibratious
produce in solids when they cause them to melt; for
example, ice melted by the sun's rays. When, how-
ever, these vibrations cease to act, the changed sub-
stance falls back into its previous condition (as when
the melted ice again congeals), but in so doing, emits again vibrations like
those expended in the former change, but of lower "pitch," or greater
wave-length. Just as water in freezing emits heat, of low "pitch," and
thus cold, compared with our bodies, but nevertheless heat compared with
G
E
B
GW
E
Fig. 7.
H
D
Fig. 6.
three inches thick. These instruments are, however, on account of the
amount of wire used, and the careful insulation needed, very expensive.
Thus the one shown in Fig. 4 cost $275, and that shown in Fig. 6 $1000.
To employ one of them wherever a single gas burner was to be replaced
would, therefore, be out of the question on this ground of cost, without
considering any other objection.
This same discharge from an induction coil may also be used as a source
of light in another way.
If an exhausted vessel, or one only containing highly rarefied gas, is ar-
ranged with conductors running into it, as in Fig. 7, and these conductors
are connected by wires with the ends of the secondary of an induction coil,
then the electricity will pass through the rarefied gas, producing light which
will be often arranged in strata, or layers, in the manner indicated in the
drawing, Fig. 7.
Fig. 8.
a zero of temperature. So these phosphorescent bodies exposed to strong
light suffer a change which, in reversing itself, causes the emission of light
again, fainter, it is true, and lower in "pitch," that is, of a color nearer
the red or lower end of the spectrum, than the exciting light, but neverthe-
less very appreciable light. Thus violet light, by phosphorescence, becomes.
blue, green, yellow, or red; blue light becomes green, yellow, or red, and
80 ou.
Such gases as are contained in these tubes are, however, not alone in
possessing this property. I have here several solid substances-sulphides
of barium, strontium, and calcium-which behave in the same way. We
illuminate them by an electric spark, and then they continue to glow in the
dark. Superior to them all, however, I find the dial of this clock.
I expose it for a moment to the electric light, and now you see it in the
dark from the furthest corner of the hall.
I have analyzed the material with which this clock dial is coated, and I
find that it is a sulphide of calcium ("Canton's phosphorus," discovered
in 1768), attached by some resinous medium or varnish. Though the sub-
stance is therefore in composition, only the old and familiar one above
mentioned, its present manufacturers have found out some method of
wonderfully increasing its efficiency. One of these clocks exposed for a
moment to direct sunlight glows so brightly as to be easily seen in a room
which is darkened. This phosphorescence is, moreover, readily excited by
lamp or gas light, and one of these clocks will continne to glow during an
entire night with no other excitement than that which it gets by the dif
fused light in a room during the day. Toward morning the glow is faint,
but is still sufficient to show the position of the clock hands.
The substances required to make this compound-i, e., lime and sul-

2299
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American Gas Light Journal.
phur-are very cheap, and the French savant, Becquerel, who has elabor
ately investigated this subject, describes methode of preparing it so that it
shall emit light of various colors-orange, green, blue, and violet. If a
further advance in brilliancy and duration should be made at all equal to
that shown by the clock dials as compared with all former specimens, it is
not improbable that this may become a very important substance. If we
could paint our walls with such a body it would, as it were, absorb light
during the day and then emit it during the night, and it would only be
necessary to have curtains to draw over our luminous walls at night to shut
out their light when necessary, just as we now draw curtains over our win.
dows in the daytime.
In face of such an arrangement as this, even Mr. Edison's new "electric
burner" would be costly and unnecessary. By painting the outside of
houses with the same material, all need of street lamps would be avoided.
It is true that "some practical difficulties remain to be overcome," but
what are those in these days of intentive power? Should one of our great
inventors take the matter in hand and organize a stock company, it will, of
course, be merely a question of time and expense in preliminary experiments.
Seriously however, this new form of phosphorescent sulphide of calcium
is a wonderful substance, which may well suggest strange possibilities for
the future.
ELECTRO-MOTORS, OR INSTRUMENTS FOR PRODUCING ELECTRIC CURRENTS.
In whatever way electricity is to be used as a source of light, there is, of
course, no question that a cheap source must be found in order that it may
compete with other sources of illumination. As long as the galvanic battery
was the only source of electricity, we were met at the very start by the fol-
lowing state of facts.
Jan. 2, 1879.
forces are distributed in certain dircotions, known as "lines of force,"
Some-notion of these is obtained if we place a plate of glass over a mag-
net and then sprinkle iron filings on the former, when on tapping the glass
the filings will arrange themselves in certain lines.
A very beautiful method of arranging and permanently fixing such lines
has been devised by Prof. A. M. Mayer, and from a plate so arranged by him
Fig. 9 has been produced by a process of photographic engraving.
Now it was discovered by Faraday, in effect, that whenever a condcuctor
was so, moved in the vicinity of a magnet as to pass through or "cut" these
lines of force, a current was developed it the conductor. The greatest
effect was obtained when the lines were cut at right angles, and when the
greatest number of lines are cut in the same time, either by passing
through a denser "field of force" as near the poles of the magnet, or by
moving more rapidly. When the conductor moved along the lines of force
no current was produced.
As the conductor passed into and through the "field" of one pole a
current was developed in one direction, and as it passed out of the same
field into and through the field of the other pole, a current in the opposite
direction was developed. Between the two fields there would, of course,
be a neutral point where no current was developed. Indeed, if we turn to
Fig. 9 we will see that a conductor, while passing the centre of the magnet,
would be moving along the lines of force, and ought, therefore to develop
no current, while near the poles it would pass at right angles to the lines
of force, and so give a maximum current. At other parts of its path the
conductor develops currents of more or less intensity, according as it finds
the lines of force more or less oblique to its path.
While the above basis of explanation is very commonly employed in
connection with our present subject, it does not seem to me as satisfactory,
Fig. 9.
The source of energy in the battery is practically the zinc consumed.
Weight for weight, coal has almost six times the available energy of zinc;
while, moreover, the price of zinc is about 25 times that of coal. In the
race between the two, therefore, zinc starts with this enormous disadvantage
that an equal amount of energy obtained from it will cost about 150 times
as much as if obtained from coal. To make gas from coal, and burn it for
light will then be cheaper than to obtain electricity from zine and turn it
into light, unless the loss in the former case is 150 times greater than in the
latter.
nor as clear and direct in its relations to the entire subject of electrical in-
duction, as another which I shall now proceed to state.
In the first place, it will be desirable to state the relations between mag-
nets and electric currents first pointed out by Ampere.
According to this theory, a magnet owes its characteristic properties to
the presence in the molecules of electric currents all circulating in the
same direction.
In other words, if Fig. 10 is supposed to represent a short magnetic bar
with its south end toward us, the little arrows would represent the direc-
Batteries, therefore, as sources of electric force for lighting purposes, are tion in which the currents of positive electricity were flowing in its molecules.
out of the question from an economic standpoint.
The possibility of economic lighting by electricity came first to exist
when, in 1831, Faraday discovered that the motion of a magnet in relation
to a conductor would develop a current of electricity in the latter, and thus
that electricity might be developed by the expenditure of mere mechanical
energy.
Then, to the coal distilled in the retort was born as a rival (as yet help-
less as an infant and unknown), the coal burned under the boiler of the
steam engine.
This child has grown slowly or rapidly ever since, and if the reign of the
gas coal is to end, it will be only to its near relation, the steam coal, that
it will yield its throne.
It is therefore eminently proper that we should trace the progress of this
development in the present connection.
The first principle involved in this subject is this:-
Magnets exert forces in all directions around them, but in such a way
that they may be said to be surrounded by "felds of force," in which the
Fig. 10.
Fig. 11.
Fig. 12.
The general effect of such currents could evidently be expressed by
single currents passing in the entire bar, as indicated in Fig. 11, and the
practical effect of such a series of parallel currents would very evidently
coincide with that of a current passing through a helix, as indicated in
Fig. 12.
As a matter of fact, we find that a helix of wire, through which an elec-
tric current is flowing, will exhibit all the properties characteristic of a
magnet. Thus, it will attract iron, if freely suspended point north and

2300
Jan. 2, 1879.
American Gas Light Journal.
7
south, and if two of such helices are brought together their like ends will on the withdrawal of the same, this will be equivalent in effect to the sud-
repel and their unlike ends attract each other.
den insertion and withdrawal of a maguet.
This attraction and repulsion, moreover, appears to come under a still
wider law, for it may be readily shown that any parallel electric currents,
if going the same way attract, and if going opposite ways repel.
The first attempt which was made to utilize the above-described princi-
ples in producing a current of electricity from a magnet by the expenditure
of mechanical energy was that by Pixii, of Paris, who, in 1832, produced
the apparatus shown in Fig. 16.
B
B'
Fig. 13.
Fig. 13 shows how this explains the attraction of unlike and repulsion of
like poles in magnets.
In A and B, the north and south poles being opposite, the magnetic or
electrio currents flow parallel and in the same direction, and thus attract
in A' and B', the two north poles being together, the currents flow in oppo-
site directions, and thus repel.
Another general law must next be stated, namely: Whenever a conduc-
tor approaches a parallel current, a mometary flow of electricity is estab-
lished in the said conductor, opposite in direction to that of the current to.
wards which it is moving; as the same conductor recedes from the current
a momentary flow in an opposite direction is produced.
Fig. 16.
Here two coils of wire, with soft iron cores, are supported at the upper
Let us see how this applies in such a case as we have now to consider.
Let NS, Fig. 14, represeut a magnet in which the magnetic currents are part of a frame, while below them a strong steel magnet is made to rotate
flowing as indicated by the arrows on the bar; if, then, we bring a conduc- by appropriate machinery. As each pole of the magnet in turn comes op-
tor, like the loop of wire to the right, towards the south end of this mag-posite the iron core of either coil, it renders it instantly magnetic, and thus
net, a current will be developed in the loop opposite to the currents in the develops a current in the surrounding coil. These currents of course are
N
alternately in opposite directions, and to correct this a "cummunicator" is
placed below on the moving shaft, which, by reversing the connections at
the right moment, sends the currents always in the same direction through
the exterior wire.
Saxton, in Philadelphia, made, in 1833, a modified form in which the
steel magnets were placed horizontally, and remained at rest while the coils
with their soft iron cores were rotated opposite their ends. Various small
modifications followed. Thus, in 1836, Clarke, in London, made a machino
represented in Fig. 17, in which the steel magnet was made of several single
Fig. 14.
magnet, because the loop is approaching all of them. If now the loop con-
tinues to be moved forward over the S end of the magnet, when it comes
over, say the point n, it will still be approaching many of the magnetic cur-
rents, but will be receding from a few, those, namely, which it has already
passed. There will, therefore, be an interferenco between the opposite
currents due to the approach to the magnetic currents to the left, and the
recession from those to the right, and the resulting current will, therefore,
be feeble, although still in the first direction.
When, however, the loop comes over m the number of magnetic currents
it is leaving is just equal to that of those it is approaching, and the two cur-
rents will, therefore be exactly neutralized.
Beyond m, towards N, however, the current due to the withdrawal from
the magnetic currents will predominate and increase until the North end of
the magnet is passed.
The horizontal lines with vertical arrows, at the lower part of Fig. 14,
represent the directions and relative intensities of the currents developed as
the loop moves over the magnet from right to left.
It will be readily understood that it is quite immaterial whether the con-
ductor is moved over the magnet or the magnet is moved through the
conductor.
Fig, 451
Thus, if the conductor is wound into a coil, as in
Fig. 15, and the magnet is pushed into or drawn out
of it, we shall have a like production of currents.
Or again, if the coil should have in its centre a bar
of soft iron, and this should be magnatized by the
Approach of a magnet, and then losh its maguatiam
Fig. 17.
magnets united, and the coils were rotated opposite the poles, but at right
angles with the plane of the magnets.
Again, Breton wound coils on the poles of the magnet, and then rotated
an armature in front. This armature, by its approach and withdrawal,
caused movements in the lines of force, or in the magnetic currents which
developed momentary currents of electricity in the coils of wire. The re-
lation of this action to Breguet's apparatus for exploding mines, and to the
Bell telephone, is worthy of notice.
Duchenne combined this last plan with the preceding one by winding
coils both on the magnet and the armature, and using one or other of the
circuits for his induced eurrent.
To pa sentiased.
2301
Jan. 16, 1879.
American Gas Light Journal
LECTURE UPON THE ELECTRIC LIGHT.
DELIVERED OOT. 17, 1878, BEFORE THE AMERICAN GAS-LIGHT ASSOCIATION,
By Prof. HENRY MORTON, Ph.D.,
PRES. STEVENS INST., HOBOKEN, N. J.
[Continued from page 7.]
The first attempt to make a magneto-electric machine of such a size as to
be available for industrial purposes, was made in 1849, by M. Nollet, Pro-
fessor of Physics at the Military School at Brussels.
27
limited their use to a very narrow field, and they could hardly be said to
have carried the subject of electric lighting beyond the range of an interest
ing scientific experiment on a large scale.
The next important step in the development of the mag
neto-electric machine consists in the application by Dr.
Siemons of his peculiar armature to these instruments.
This armature is shown in longitudinal section in Fig. 19,
at E, and in cross section at F.
The armature is in fact a rod or bar of soft iron, with deep
grooves out lengthwise along it, reducing its section to an H
form, as is shown in F. Insulated wire is then wound length-
wise in these grooves, as shown in E. Such an armature as
this, mounted with caps, as shown in Fig. 19, may then be
rotated in a very narrow and dense magnetic field, and its
reason of their rapidity of angular movement, being close to
the axis of rotation.
The original intention of those first engaged in developing this machine
was not, however, to produce with it an electric light, but to employ it to
decompose water in order that the hydrogen so liberated might be used as
an agent of illumination. If we were in want of an illustration of the ex-wires will out many lines of magnetic force in a short time by
travagance and irrationality of expectation which so often exhibits itself in
enterprises entering upon new fields, we surely need go no further than
this. M. Nollet died before his designs were entirely carried out; but they
were elaborated by an intelligent workman who had assisted him in the
construction of his machines, M. Joseph Van Malderen, who, under the
auspices of a company composed of French and English capitalists, and
named the "Alliance Company," developed the apparatus into an efficient
generator of electric currents for the direct produétion of light by means of
the electric arc.
The apparatus, as thus constructed, was, in general principle, only an en-
largement of the Clarke machine (already shown), and consisted of a large
number of compound steel magnets, between the adjacent sides of which
cores of soft iron, surrounded with coils of insulated wires, were made to
revolve. An appropriate connection of these various coils with each other,
and with commutators on the axis, enables the current to be taken off in a
constant direction. When it was afterwards discovered that, for an electric
light, the current need not be constant in direction, but was even more
convenient when rapidly alternating, this was of course yet more easily pro-
vided for. Fig. 18 shows one of these Alliance machines, which really
This armature was first used in magneto-electric machines
employed for telegraphing by Siemens, in 1857.
The next advance, and this a very marked one, was made in
1866, by H. Wilde, of Manchester, who, on April 13, commu-
nicated to the Royal Society the result of a series of experi-
ments with magneto-electric machines, of which Fig. 20 is a
good representative.
Fig. 19.
E
In this machine a number of small horse-shoe magnets are
so arranged that a Siemens' armature may be rotated between their poles.
The coils on this armature have developed in them, by moving in this
highly concentrated magnetic field, a very powerful current. This current
is then passed through heavy coils of wire surrounding the sides of a large U
magnet, made of massive plates of wrought iron. Between the poles of
this rotates another Siemens' armature of larger size, from which a current
of immense power is obtained.
•
While the electric current developed by this machine far exceeded any-
thing which had ever been obtained before, it was only secured by a large
expenditure of power-something between a five and a twenty-horse power
engine being required to drive it.
The important fact developed by Mr. Wilde in this machine was that a
magneto-electric machine could develop a current whose magnetizing power
C
Fig. 18.
Fig. 20.
was vastly greater than that of the magnets from which it was derived.
Thus, if the small magnets above would lift a weight of 50 pounds, the
large electro-magnet below, when excited through their instrumentality,
would lift 500 pounds or more. This possibility of a sort of magnetic accu-
mulation or growth was a demonstration of immense value to the progress
of magneto-electric science.
A practical difficulty which first showed itself in a conspicuous degree in
these very powerful machines was the heating of the armature. Foucault
needs no further description, but is rendered perfectly clear in its structure had first shown, long before, that when a conductor was rotated or moved
and operation by the cut.
in a magnetic field it became strongly heated.
""
Many of these "Alliance machines were made and used in different His apparatus to illustrate this is shown in Fig. 21, where a copper disc.
places in France for lighting works of construction at night, such as the is rotated between the poles of a powerful magnet, and becomes very
Cherbourg docks, and on some vessels as the Lafayette and the Jerome Na-hot.
poleon, and in some lighthouses; and, as modified slightly in arrangement Tyndall, by similarly rotating a copper tube, melted the fusible metal
of parts by Mr. Holmes, in England, notably in the South Foreland light-with which it had been filled.
house.
The heat developed in the armatures of Wilde's large machines was so
The great cost of these machines, the large amount of power required to great as to cause serious inconvenience, and of course involved a great loss
run them, and the cost and trouble of keeping them in repair, however, of effect or waste of power.
•

2302
28
American Gas Light Journal.
In 1867 Siemens proposed a very obvious modification of this machine of
Wilde, by dispensing with the smaller machine and connecting the coils of
the large one with its own armature through the commutator of the same.
Jan. 16, 1879.
that devised by Dr. Antonio Pacinotti, in 1860, and constructed by him for
the physical and technological cabinet of the University of Pisa. A des-
cription of it, however, did not appear till several years later in the June,
1864, number of the Italian scientific periodical, "Il Nuovo Cimento."
This number, which was published during the month of March, 1865, con-
tained an extended illustrated description of the machine.
As a special feature of the apparatus he pointed out the peculiar form of
the movable electro-magnet-a circular iron ring in which, contrary to the
I
Pig. 21.
Fig. 23.
The residual magnetism of the iron of the electro-magnet was found suffi- case with the armatures previously in use, the magnetic poles did not re-
cient to start the action, which then increased by self-development.
main stationary, but could be moved within the ring-that is, made to
This, however, occasioned what was at first regarded as a serious diffi- assume in it successively all possible different positions.
culty.
If the magnetism of the electro-magnet was thus made to depend on
the current of the machine itself, any interruption in the flow of the same
in the exterior circuit at once cut down or destroyed this magnetism, and
so reduced the whole action.-
To obviate this, Lado, of London, first made a machine with an armature
wound with two coils of wire, one being connected with the magnet of the
machine, and the other with the exterior circuit.
Afterward he made a machine in the form shown in Fig. 22, where two
armatures were used-one connected with the coils of the machine itself,
and thus supplying what is often called the "field of force," the other
supplying the exterior circuit.
Subsequent experiment has, however, shown that the arrangement is
very far from economical in the conversion of energy, and all the machines
now in use include the exterior circuit and the field of force in one continu-
ous connection.
This, of course, greatly complicates the relations, and makes the fluctua-
ions during running greater and more numerous; but for the sake of
This movable ring of iron had the shape of a spur wheel of 16 teeth, and
was firmly secured to the axis of the machine by means of four strips of
brass. Small wooden wedges were placed upon the teeth of the ring, and
the space so formed between each two of the wedges filled up regularly
with insulated copper wire. These spools were all wonnd in the same
direction, and the terminal end of each was soldered to the beginning of
the one succeeding it, so that the whole system of 16 spools virtually
formed a single coil of wire surrounding the ring in a regular manner, and
returning upon itself.
Wires were soldered to the separate points of juncture and were led,
parallel to the axis of rotation, to an equal number of insulated pieces of
brass, mounted in two rows upon, and slightly projecting from, the surface
of a disc firmly secured to the axis.
The iron ring, with the bobbins wound upon it in the manner already
described, was mounted in a horizontal position between the two legs of a
powerful upright electro-magnet, the distance of which from the
ring could be adjusted at pleasure by means of a set screw and a slot in
the lower connecting cross-piece. Contact rollers, kk, were made to press,
one on each side of the axis, against the lower wooden disc carrying the
strips of brass, so that during the rotation of the ring all of the latter were
brought successively into contact with them. When, therefore, the terminal
posts, hh', are placed in connection with the poles of a galvanic battery,
B
992
KO
HON
Fig. 22.
Fig. 24.
e ficiency or the economy of expended power, it has been found essential to the current will pass, supposing it to enter at h (+), by way of the binding
a lopt this arrangement.
PACINOTTI'S RING MACHINE,
The first magneto-electric machine for the prouction of an electric cur-
rent continuous in character and constant in direction and intensity, was
post, 7, to the roller, k, and through the strip of brass on the diso against
which the roller may happen to press at the time, up to the two wire coils
of the armature whose point of juncture is in connection with this strip of
brass.
The current here divides, each portion passing in an opposite direction
through the spools surrounding each half circumference of the ring, to

2303
Jan. 16, 1879.
American Gas Light Journal.
meet again to form one current at the left contact roller, k, from where the
reunited current passes to the second binding post, l'. From here the cur-
rent proceeds to the leg A of the electro-magnet, circulates around it, and,
after acting similarly with regard to the other leg, B, passes back by way
of the binding post h' to the negative pole of the battery. Magnetic poles
thus became developed in the iron ring at the points NS, the position of
the contact rollers having been so chosen as to bring about this effect, and
the actions of attraction and repulsion taking place between them and the
poles of the stationary electro-maguet gave rise to the rotation of the
ring.
In order to turn the action of the electro-magnet upon the magnetized
iron ring to the greatest possible account, Pacinotti provided the two poles
with armatures, AAA, BBB, of soft iron, which were made to surround the
ring very closely for over two-thirds of its circumference. Strips of brass,
EE, FF, attached, served to give them greater security. In the elevation
of the machine here given these armature have been omitted in order not
to conceal the ring and its surrounding spools.
The foregoing description of the ring of Pacinotti and its action has more
especial reference to its application in an electro-magnetic machine, but
toward the end of his article Pacinotti clearly indicates in what way, by the
use of the same annular armature, the electro-magnetic may be converted
into a magneto-electric machine, capable of producing, by the proper use
in connection with it of a permanent or electro-magnet, a continuous cur-
rent of a constant direction.
29
drum through the magnetic field of the exterior magnets in the magneto-
electric machine just described, these currents are not to be avoided,
though they may be diminished to some extent by constructing the arma-
ture of coils of iron wire instead of massive iron. In such machines, how-
ever, which are built for the purpose of producing very large quantities of
electricity, and which for this reason are constructed in accordance with
the dynamo-electric principle, these Foucault currents would be attended
by a considerable increase in the temperature of the machine, in addition
to which considerable power would be required in order to rotate the iron
armature, owing to its becoming so strongly polarized by the powerful
electro-magnets developed, for which power there would be no equivalent
return in useful effect.
"These considerations must have determined the inventor to secure the
iron armature inside the drum, and so prevent it from taking part in the
motion of the latter in such dynamo-electric machines, like those to be
used for illuminating purposes, for instance, as are intended for the pro-
duction of large quantities of electricity. As a matter of course, this
renders the construction and mode of arrangement of the drum much more
complicated, and all the more so when it is considered that the long drum,
with its surrounding coils of wire, has to be moved through the narrowest
possible space between the pole armatures of the electro-magnets and the
stationary inner core.
"Figs. 25 and 26 represent the construction, in detail, of such a dynamo-
electric machine on the v. Hefner-Alteneck system. A horizontal section
of the drum and a side view of the complete machine are there given.
abcd is a thin German silver drum upon which, in the manner already de-
On substituting for the electro-magnet AB a permanent magnet, and on
rotating the ring armature, the poles induced in the ring by the proximity
of the magnet will always be found at the extremities of the diameter pass-
ing, when produced, through the poles of this exterior magnet; so that we
may come to consider the spools as alone partaking of the rotary motion,
while the two semi-circular magnets produced by the induction remain at
rest. The current induced in any particular spool will, in the motion of
the latter from N to S, preserve the direction it has on leaving N until it c
reaches a, a point midway between N and S. Here a reversal in direction
of the current takes place, which new direction is preserved until the spool D₁
arrives at b, a point midway between S and N, where a reversal to its form-
er direction of the current occurs, and so the action continues. The cur-
rents developed in the different spools will therefors add to each other's
effect, and are hence most properly collected at the points A and B, the
collecting brushes coming thus to act upon the commutator at right angles
to the magnetic axis of the rotating armature.
Pacinotti did actually obtain an uninterrupted current of constant direc-
tion on causing the opposite poles of permanent magnets to approach the
ring during the rotation of the latter. He also obtained the same effect by
magnetizing the stationary electro-magnet by means of a current, though
he deemed the former method preferable.
The claim of Pacinotti to priority in the invention and application in
magneto-electric machines of the annular armature has already been fully
established. and is daily becoming more generally recognized.
SIEMENS-HALSKE MACHINE,
The following description is translated from the admirable treatise en-
titled "Die Magnet und Dynamo-elektrischen Maschinen," by Dr. H.
Schellen, just published:
Fig. 25.
m1
We have already drawn attention to the fact that when metallic bodies
are caused to move in a magnetic field, such motion develops in them in-
duced, or so-called Foucault currents, which, if not conducted away, be-
come transformed into heat, and thus, according to the circumstances of
the case, give rise to a considerable heating of the metallic bodies in
motion. As long, therefore, as the iron core revolves with the coiled
Fig. 26.
D₁
scribed, the wire is wound in many circumvolutions, and in eight separate
coils. Each terminal face carries a short tube, which tubes form the trun-
nions of the drum, and which lie in boxes, F, and F2, provided with oil cups.
An iron shaft, CC, secured by means of screws in the pillars, D, and D,,
passes through these tubes into the interior of the drum, where the core,
nn, 881, held together by two discs bolted to each other, is fastened upon it.
The drum is surrounded on the outside at two opposite places for about two
thirds of its circumference, and over its entire length, by two curved iron
armatures, NN, and SS,. These are placed as closely as possible to the wire
drum, and form, with the stationary hollow interior core, nn, 881, a narrow
annular space, the magnetic field, through which the drum abcd, with its
surrounding wires, must be able to pass in its rotation with all possible
freedom.
"Inside of the front hollow truunion of the drum which rests in F, there
passes another hollow tube, which is secured to the end face of the drum,
and between which and the trunnion the ends ec, of the separate wire coils,
are led through to the commutator, pp,, attached to its front end.
"The two curved iron armatures, NN, and SS, terminate in flat plates, No
Sm, and N101, Sim,, which constitute the cores of the electro-magnets, EE,
E, E,, and through which the armatures are rendered magnetic. These
cores are united at their ends by strong soft iron connecting pieces, om and
o,m, which also serve the other purpose of forming the side portions of the
cast iron framework of the machine. Here also the wires of the two horse-
shoe-shaped electro-magnets, E and E, are wound in such way that the
poles of the same name are opposite each other, so that all portions of the
iron arch uniting each set of these poles exhibit the same kind of polarity.
In this way the drum and the interior iron core are surrounded for about
two-thirds of their circumference, and over their entire length, by the sta-
tionary exterior magnetic poles, NN, and SS, and a very extended magnetic
field formed by this means, the intensity of which will be the greater the
more powerful the induced currents developed, and, in consequence, the
poles of the electro-magnets, become.
"In order to carry out the dynamo-electric principle, the coils of the two
electro-magnets, EE, and E, E, are connected with the commutator brushes,
or the contact rollers, in such a way that the current generated by the ma-
chine traverses successively the wire surrounding the drum, the coils of the
electro-magnets, and the electric lamps placed in the circuit. The two sys.

2304
30
American Gas Light Journal.
Jan. 16, 1879.
tems, the induced currents of the drum and the poles of the electro-mag- connected with each other and led to the radial pieces of the drum shaft in
nets, exert, up to a certain maximum limit, a mutual strengthening action
upon each other, which limit is determined by the wires upon the drum,
the velocity of rotation of the latter, and the mass of iron in the cores of the
electro-magnets.
"In order to drive so powerful a machine, a steam engine, or other uniform
source of power will be required. As long as the circuit remains unclosed,
and the two binding screws are not in metallic connection with each other,
the rotation of the drum may be effected by the expenditure of sufficient
force to overcome merely the friction in the journal boxes, F,F,. If, how
ever, the external circuit is closed, by the introduction of an electric lamp,
for instance, the induced currents will at once be developed in the drum, if
but a trace of magnetism exist in the armatures, NN, and SS.. These cur-
rents, by adding to the strength of the electro-magnets, exert a strengthening
action upon the armatures, and thereby become themselves strengthened. The
quantity of electricity generated by the machine, as well as the mechanical
power expended in running it, will thus rapidly become greater, since every
increase in magnetism is attended by a corresponding increase in the inten-
sity of the current. It is for this reason that, for certain purposes, for pro-
ducing a steady electric light, for instance, a uniform action of the driving
engine is absolutely necessary; and all the motors designed to be used in
driving dynamo-electric machines must, on this account, be provided with
reliable regulating contrivances, in order to secure such uniformity as
much as possible.
a somewhat similar manner to that obtaining in the Gramme machine,
which has already been described. These radial pieces are insulated from
each other by means of asbestos paper. Contact rollers are no longer em-
ployed, their place being taken by flat elastic bands (brushes), made of
silver-plated copper wires.
"The smaller size of these machines is 698 mm. in length, 572 mm, wide,
and 233 mm. high; the drum alone is 388 mm. long, and carries 28 wire
coils and a commutator divided into 56 parts. Its weight amounts to 115
kilogrammes; the maximum velocity of the drum, 900 revolutions per min-
ute; and the intensity of the light produced, 1,400 standard candles. One
and a half horse power are required to run it.
The medium size differs in construction but slightly from the one just de-
scribed. It is 757 mm. in length, 700 mm. wide, and 284 mm. high; the
drum has a length of 456 mm., and is also wound with 28 coils; the com-
mutator is, therefore, also composed of 56 pieces against which wire brushes
are made to press. The machine weighs 200 kilogrammes, and produces,
with its maximum velocity of 700 revolutions per minute, a light of 4000
candles. It requires 3 horse power."
To be continued.]
[From the "Chemical News."]
The Nature of the Elements.
"In using the machine for the production of the electric light, it may
happen that, through any external cause, impurities in the carbons, for in-
stance, the arc becomes extinguished and the current interrupted. In such At a crowded meeting such as is seldom witnessed of the Royal Society,
a case the consumption of power on the part of the machine suddenly falls on Thursday evening, December 12th, 1878, Mr. J. Norman Lockyer,
almost to zero, and a considerable (even dangerous) increase in the velocity F.R.S., read a lengthy paper, in which he discussed the evidence derived
of rotation of the drum would be the consequence thereof, were the driving from spectroscopic observation of the sun and stars and from laboratory ex-
engine to continue working at the same rate without having a correspond-periments, which has led him to the conclusion that the so-called elements
ing resistance to encounter. In order to meet any such danger Siemens of the chemist are in reality compound bodies. In order that the line of
and Halske have provided their machine with an automatic switch, which
Fig. 27.
throws into the circuit an artificial resistance when, through any cause what-
ever, the circuit is interrupted in the lamps.
*
*
*
"The machine represented in Figs. 25 and 26, has a length of about 10
centimetres, a height of 32, and a width of 461 centimetres, and yields,
when the drum revolves at the rate of 450 per minute, for which six horse
power are required, an electric light of 1400 standard candles. The current
produced by it is capable of heating to redness a copper wire one metre
long and one millimetre in thickness.
In the machines of medium and smallest size, in order to secure the ne-
cessary simplification in construction, the iron cylinder is firmly united with
the wire coils, and rotates with them. The fixing of this inner armature,
on the contrary, is rendered necessary in such cases in which there occurs a
very frequent change of polarity, and in which the utmost utilization of the
driving power is called for, which is usually only the case with the larger
machines.
"Fig. 27 represents in perspective a Siemens-Halske machine (system of
v. Hefner Alterneck), of the latest construction. The electro-magnets have
the flat shape of those nsed in Wilde's machine. The current is taken off
by means of metallic brushes, and the large number of radial pieces in the
commutator shows that the drum carries a larger number of separate
coils.
argument followed by Mr. Lockyer may be understood, it will be necessary
briefly to refer to the results of previous researches. As a rule, in observ-
ing spectra the substance to be examined is volatilized in a gas flame or by
means of sparks from an induction coil, and the light is allowed to fall on
the slit of the spectroscope; the spectrum is then generally one in which
the lines run across the entire field, but by interposing a lens between the
spark apparatus and the slit of the spectroscope, Mr. Lockyer was enabled
to study the various regions of the heated vapor, and thus to establish the
fact, already noted by some previous observers, but to which little attention
has been paid, that all the lines in the spectrum of the substance volatilized
did not extend to equal distances from the poles. He then showed by the
aid of this method that in the case of alloys containing different proportions
of two metals, if the one constituent were present in very small quantity its
spectrum was reduced to its simplest form, the line or lines longest in the
spectrum of the pure substances alone appearing, but that on increasing
the amount of this constituent its other lines gradually appeared in the or-
der of their lengths in the spectrum of the pure substance. Similar obser-
vations were made with compound bodies. It was also noticed that the
lines furnished by a particular substance varied, not only in length and
number, but also in brightness and thickness according to the relative am-
ount present. Armed with these facts and with the object of ultimately as-
certaining more definitely than has hitherto been possible which of the ele-
ments are present in the sun, Mr. Lockyer about four years ago commenced
the preparation of a map of a particular region of the spectra of the metallic
elements for comparison with the map of the same region of the solar spec-
trum. For this purpose about 2000 photographs of spectra of all the various
metallic elements have been taken, and, in addition, more than 100,000 eye
observations have been made. As it is almost impossible to obtain pure
substances, the photographs have been carefully compared in order to elim-
inate the lines due to impurities; the absence of a particular element as
impurity being regarded as proved if its longest and strongest line was ab-
sent from the photograph of the element under examination. The result of
all this labor, Mr. Lockyer states, is to show that the hypothesis that iden-
tical lines in different spectra are due to impurities is not sufficient, for he
finds short line coincidences between the spectra of many metals in which
the freedom from mutual impurity has been demonstrated by the absence
of the longest lines. He then adds that five years ago he pointed out that
there are many facts and many trains of thought suggested by solar and
stellar physics which point to another hypothesis-namely, that the ele-
ments themselves, or, at all events, some of them, are compound bodies.
Thus it would appear that the hotter a star the more simple is its spectrum;
for the brightest, and therefore probably the hottest stars, sach as Sirius,
furnish spectra showing only very thick hydrogen lines and a few very thin
metallic lines, characteristic of elements of low atomic weight; while the
"In the latest machine of this form the commutator disc is done away cooler stars, such as our sun, are shown by their spectra to contain a much
with, and the ends of the separate wire coils surrounding the drum are larger number of metallic elements than stars such as Sirius, but no non-

2305
Feb.
3, 1879.
American Gas Light Journal.
LECTURE UPON THE ELECTRIC LIGHT.
DELIVERED OCT. 17, 1878, BEFORE THE AMERICAN GAS-LIGHT ASSOCIATION,
By Prof. HENRY MORTON, Ph.D.,
PRES. STEVENS INST., HOBOKEN, N. J.
[Continued from page 30.]
In 1871 M. Z. T. Gramme, a cabinet maker, of Paris, presented to the
French Academy the description of a new form of magneto-electric ma-
chine, possessing several new and remarkable features. Its general
structure can be well understood from the accompanying figure, which
represents one of its simplest forms as constructed with permanent mag-
nets, and to be driven simply by hand power.
51
Now let R indicate such a coil, and suppose it to move toward the right;
it will evidently leave more magnetic currents in a given direction in the
left hand semi-annulus than it approaches, and will therefore acquire a
current in the direction shown by the arrow, to which will be added the
effect due to approaching the opposite currents in the upper part of the
Fig. 28.
The large U magnets terminate in heavy end pieces, which constitute
massive north and south poles, almost surrounding the armature, which
constitutes the peculiar feature of this machine.
This armature consists of a ring made of a coil or hank of soft iron wire,
around which are wound a series of coils of copper wire, in the the manner
shown in Fig. 29, which represents such an armature partially dissected.
The ring made of a hank of iron wire is shown cut across and spread out
to some extent, the cut ends appearing below B and at A. The several
coils of wire are also represented partly in place above and spread apart in
the lower part af the figure. The wire of these coils passes continuously
from one to another, but between each makes a loop, which is hooked into
a copper conductor, RR, constituting part of the commutator.
The general principle on which this machine acts can best be explained
by reference to the diagram (Fig. 30). Let S and N represent the poles of
the permanent magnet, and the divided ring between them stand for the
ring of iron wire.
This ring, under the influence of the poles S and N, will always have a
north pole at n and a south pole at 8, the parts p and p. being neutral, or,
Fig. 30.
right hand semi-annulus. At n, and also at s, this action will reach a max-
imum, as the coil will be (at n, for example) approaching all currents of
the right hand semi-annulus and leaving all those of the left, and vice versa
at 8. At p and at pi, however, the effect will be nil, as the coil would
there appoach and leave equal numbers of currents of like direction.
Now if we consider a number of coils all moving around from left to
right, on the upper part of the ring the currents in them will have the
same direction; and if they are all connected together these currents wi
aid each other, and may be taken off by conductors pressing on the com-
mutators at p and p. Let us suppose that the current is such as to mak
P, positive and p negative. As the coils pass p, the direction o 1the cur-
rents in them is reversed, but so also is their relation to the conductor or
commutator. Thus, a coil which was coming toward p, from above was
sending its positive current forward toward p.; as it leaves p., going on-
ward below, its current being reversed, it no longer sends its positive
current forward, but sends it back to p₁, which it has passed. Thus pi
gets not only the positive current from the coils on the upper half of the
ring, but from those also on the lower half.
first place no rapid reversal of magnetism in the iron core of the armature,
By reason of the action which has thus been described, there is in the
as in the Wilde machine, but only a continuous and progressive change as
the ring rotates; and in the second place there is a continuous current of
electricity in a constant direction, with only one reversal for each revolu-
tion of the entire set of coils.
B
B
R
Fig. 29.
Fig. 31.
Of course the method of passing the current of one machine through the
coils of an electro-magnet replacing the permanent magnets shown in Fig.
28, could be carried out with this machine just as with Wilde's; or the
in other words, will correspond with two semi-annular magnets with their
north poles together at n and their south poles together at . The magnetic
currente in the various parts of this ring will then be represented by the
arrows drawn on it. As the ring rotates these poles will always maintain machine itself, being made with electro-magnets, these could be excited by
essentially the same position in space, and therefore, in relation to the
coils wound on this ring, we might assume that this inner ring was at rest,
and that the coils above were carried round-over it.
its own current, as with the machines of Ladd and of Siemens, which we
have already described. This lust plan was, in fact, at once adopted, and
the standard Gramme machine was made in the form shown in Fig. 31,

2306
52
American Gas Light Journal.
Feb. 3, 1879.
Here the electro magnets consist of the large horizontal cylinders seen constituting a double series of coils. These armature coils (Figs. 33 and
above and below, so wound with wire as to produce a combined north pole
at the centre above, where the extension piece is attached, and a corre-
sponding south pole below.
Within and between these extension pieces is the armature or bobbin,
consisting of the iron ring wound with its numerous flat coils. The con-
nections in this case are carried out on both sides of the axis, and thus
several pairs of brushes can be applied, and numerous currents taken off.
With all these machines, however, the best effects are obtained by em-
ploying only one circuit, or passing the whole current from the bobbin
34) being connected end to end, the loops so formed are connected in the
same manner, and to a commutator of the same construction as that of the
Gramme. As the armature rotates, the cores pass between the opposed
north and south poles of the field magnets, and the current generated de-
pends on the change of polarity of the cores. It will be seen that this
constitutes a double machine, each series of coils, with its commutator,
being capable of use quite independently of the other; but in practice the
electrical connections are so made that the currents generated in the two
series of armature coils pass through the field-magnet coils, and are joined
in one external circuit. This form of armature also presents considerable
uncovered surface of iron to the cooling effect of the air, but its external
form, in its fan-like action on the air, like that of the Brush, presents con-
siderable resistance to rotation. In the Wallace-Farmer machine there was
7000
Fig. 32.
RRIS ENG
Fig. 35.
through the electro-magnet coils and the exterior circuit, where it is considerable heating of the armature, the temperature being sufficiently
used.
In 1873 Wilde described a new form of magneto-electric machine, in
which he abandoned the use of the Siemens armature, and returned, in
general structure, very much to the form of the old Alliance machine.
Two sets of electro-magnets, 16 in each, were arranged in such a way that
they formed two hollow cylinders opposite each other, with the poles of the
magnets of each cylinder facing each other, but having space between
for another cylinder of 16 electro-magnets, mounted parallel with the
others, and carried by a disc of iron, from which they projected at each
side. In fact, there were three cylinders of magnets, all having a common
horizontal axis; the outer ones fixed and the inner ones radiating, so as to
carry its magnets between the poles of the others.
Good effects were obtained with this machine, and the heating of the
armatures was avoided, but it was not found to equal the improved Siemens
or the Gramme in efficiency or economy of power.
In 1875 a patent was taken out in the United States by Mr. Moses G.
Farmer for a machine essentially like that of Wilde, just described. This,
with some modifications of details, is now manufactured by Wallace & Sons,
of Ansonia, and has come into very general use.
high to melt sealing-wax.
Another machine made and used in this country to a considerable extent
is that of Mr. Brush, manufactured by the Telegraph Supply Co., Cleve-
land, O. This is shown in Fig. 35.
The Brush machine has for its magnetic field two horseshoe electro-mag-
nets, with their like poles facing each other, at a suitable distance apart,
the circular armature rotating between them.
In this machine the currents are generated in coils of copper wire wound
upon an iron ring, constituting the armature. This ring is not entirely
covered by the coils, as in the Gramme armature, but the alternate uncov-
ered spaces between the coils is almost completely filled by iron extensions
from the ring, thus exposing large surfaces of the armature ring for the
dissipation of heat, due to its constantly changing magnetism, as in the
Pacinotti machine.
The ring revolves between the poles of two large field magnets, the two
positive poles of which are at the same extremity of the diameter of the
armature, and the two negative poles at the opposite extremity, each pair
constituting practically extended poles of opposite character.
The coils on the armature ring are eight in number, opposite ones being
In the experiments made by the present writer, as well as those conduct-connected end to end, and the terminals carried out to the commutator.
ed by the Franklin Institute, this machine seems to be inferior in "duty" Figs. 36 and 37 show this arrangement, only one pair of coils, however,
to some others; but the conditions of such trials are so difficult to establish,
in adapting the nature of the exterior circuit, including the lamp, to the
Fig. 33.
n
Fig. 34.
Fig. 36.
Fig. 37.
peculiarities of each machine, that I should not regard these conclusions as being shown in Fig. 36 as connected. In order to place the commutator in
absolutely final.
a convenient position, the terminal wires are carried through the centre of
In the Wallace-Farmer machine (Fig. 32) the magnetic field is produced the shaft to a point outside the bearings.
by two horseshoe electro-magnets, but with poles of opposite character The commutators are so arranged that at any instant three pairs of coils
facing each other. Between the arms of the magnets, and passing through are interposed in the circuit of the machine, working, as it were, in multi-
the uprights supporting them, is the shaft, carrying at its centre the rotat-ple arc, the remaining pair being cut out at the neutral point; while in the
ing armature.
Gramme machine, the numerous armature coils being connected end to end
This consists of a disc of cast iron, near the periphery of which, and at throughout, and connections being made to the metal strips composing
right angles to either face, are iron cores, wound with insulated wire, thus the commutator, two sets of coils in multiple arc are at one time inter-

2307
Feb. 3, 1879.
American Gas Light Journal.
posed in the circuit, each set constituting one-half of the coils on the
armature.
The commutator consists of segments of brass, secured to a ring of non
conducting material, carried on the shaft. These segments are divided
into two thicknesses, the inner being permanently secured to the non-con-
ducting material, and the outer ones, which take all the wear, are fastened
to the inner in such a manner that that they can be easily removed when
required.
The commutator brushes, which are composed of strips of hard brass,
joined together at their onter ends, are inexpensive and easily renewed.
The high speed at which these machines are run, together with the form of
the armature, cause the rotation of the latter to be considerably resisted by
the air, and producing a humming sound, but otherwise they run smoothly,
the heating of the armature being inconsiderable-not exceeding 120° Fahr.
after four and three-quarter hours run.
53
If all the coils marked a are connected together, it is evident that at any
moment the currents in all of them will be in the same direction. Thus,
suppose the electro-magnet spoke 2 to have a north pole at its outer end,
and 3 to have a south pole similarly situated; then us 2 moves over a it
will produce a current alike in direction to that produced by the oppo-
site pole of 3 moving over the oppositely wound wire of the next coil
marked a.
Of course, as the magnet 2 leaves a and the oppositely polarized magnet
1 approaches, this current will be reversed in the first coil marked a, and
also likewise in the second coil a, for a like reason.
It has been stated that these machines worked one Jablochkoff candle for
each horse power consumed, but several who watched their actual running
say that very much more power was actually consumed.
THE LONTIN MACHINES.
When the Jablochkoff candle came into vogue it became highly impor-
tant to go back in one of the directions in which improvement had been
Among the machines for generating electricity that have commanded
made in most of the recent machines, and produce a machine which should more or less of general attention, may be included the magneto and
yield alternating or reversing currents, in place of those passing continu-dynamo-electric machines devised by Lontin. In their mode of construc-
ously in one direction. This was necessary to equalize the consumption of tion and arrangement these machines possess features which recall the
the two parallel carbons of the Jablochkoff, and also even with other lamps, Alliance and Holmes magneto machines on the one hand, and the Siemens
for purposes which we will explain further on.
and Gramme dynamo machines on the other.
To meet this requirement Gramme has arranged a machine which not
only produces alternating currents, but operates readily, at the same time,
a number of separate circuits. It is these machines which were recently
There are two styles of Lontin dynamo machines, the one yielding con-
tinuous currents of one direction, and the other producing alternating
currents.
In the machine of the first form, a number of bar electro-magnets are
disposed radially about a central shaft of soft iron, and the star-shaped
wheel thus formed is made to revolve between the poles of an ordinary
powerful U-shaped electro-magnet. The wire of the electro-magnet wheel
R
S
Fig. 38.
Fig. 39.
used during the Exposition to light certain streets and public places in forms one complete circuit, and is connected at the several point of june-
Paris. The general appearance of this machine is shown in Fig. 38.
This machine, it will be observed, differs radically from the continuous
current machine of Gramme.
In the first place, it is, as it were, turned inside out. Thus there is a
magnetic ring wound with successive coils, but this, in place of revolving
within the field of fixed electro-magnets, is stationary on the outside, while
a series of eight electro-magnets, excited by a separate machine, rotate in
the interior of this fixed armature ring.
The principle of the machine will be readily understood from the dia-
gram (Fig. 39).
ture of each two successive magnet coils, with the appropriate section of
a commutator, placed upon the axis of the machine. On revolving the
wheel between the poles of the stationary upright field magnet it will
readily be seen that, considering any individual radial electro-magnet,
there will be induced in the coil of the latter, during its motion away
from one pole and its consequent approach to the opposite pole, a current
which, though varying (first diminishing and then increasing) in intensity,
will still maintain a constant direction until the coil has arrived at the
opposite pole, where a reversal of the current will take place. The current
will continue flowing in this new direction until the revolution of the wheel
The interior system of electro-magnets is so wound that the polarity of brings the coil back to the pole from which we have considered it to start,
each spoke is reverse to its neighbors. These magnets, therefore, by in- when and where the current will be restored to its former direction. At
duction develop eight consecutive poles in the soft iron of the surrounding any moment, therefore, during the revolution of the wheel, all the electro-
ring, and as they revolve the poles of this ring move with them. Thus, magnet coils in the upper half of the wheel will be traversed by a current
while in the older Gramme machine the actually moving ring had poles flowing in one direction, and all those in the lower half by one in the oppo-
stationary in space, over which the coils passed, in this case the actually site direction. Elastic strips, one on each side, bear against the commu-
stationary ring has moving poles which pass through the stationary tator in the line where the reversal takes place, and lead away the currents
coils.
to the proper binding posts. The mode of generation and direction of the
currents in this form of the Lontin machine is thus seen to be exactly sim-
ilar to that obtaining in the Gramme machine.
These coils are wound in eight sets, each alternate set being wound in an
opposite direction, and each set is made up of several separate coils, to
facilitate the making of all sorts of combinations, which are most easily
arranged in this machine, as no commutators are used, and all the coils
are fixed,
The stationary electro-magnets are included in the main circuit, in
accordance with the dynamo-electric principle. By mounting several of
these wheels of electro-magnets, with separate commutators and field
2308
54
American Gas Light Journal.
magnets, on the same central shaft, an equal number of independent our
rents may be obtained, which by appropriate means may of course be
combined in any desired mauner.
By winding the alternate electro-maguots on each wheel in opposite
directions, the machine may be made to produce currents constantly vary-
ing in direction. The Lontiu machine proper, for alternating currents,
has, however, a more elaborate form, bearing a rather close resemblance to
the machine devised by Holmes.
Feb. 3, 1879.
this case must be constant in direction, a special commutator is provided to
secure this result. The alternating currents obtained from the remaining
coils are conducted away from the machine by means of collars and brushes
in the ordinary manner.
The great resemblance of this machine to a machine of the Brush form,
in which eight sets of electro-magnets are employed, instead of the usual
two, nced scarcely be pointed ont.
Several forms of the machine above described are manufactured by
Siemens and Halske, the details varying with the purposes to which it is
intended to apply any particular machine. The larger machines possess
one important distinctive feature, in that no iron is made use of in the con-
struction of the revolving disc, the cores of the coils being formed of wood,
or some other non-magnetic material. By this mode of arrangement tho
hurtful inductive effects, the production of Foucault currents, the loss
of power by conversion into heat, and the like, attendant upon the use of
iron in this connection, come to be entirely avoided.
This Lontin machine consists essentially of an electro-magnet wheel, like
that in the first described form of the machine, only that the magnets are
much more numerous, amounting in number to 24 and over, and are wound
in the manner just referred to—that is, the alternate magnets are wound in
opposite directions; and of a large stationary soft iron ring surrounding
this wheel concentrically, to which ring there are secured, at equal dis-
tances apart, a number of short electro-magnets, equal in point of number
to the electro-magnets on the inner wheel. Tho electro-magnet coils of the
revolving wheel are connected together, so as to form one circuit. The
current necessary for the saturation of these magnets is obtained from an
auxiliary machine (a Lontin machine of the first form, for instance),
mounted upon the same axis, connections being so made, by means of
brushes and collars, that the rotation of the large wheel does not interfere
with the circulation of this current. The ends of the electro-magnets,
during the rotation, pass very closely by the cores of the outer stationary
magnets, and as the successive magnets on the wheel present opposite poles By THOMAS NESHAM KIRKHAM, M.I.C.E., & F.C.S., and THOMAS HERSEY,
to these cores, constantly alternating currents are induced in these outer
(To be continued.]
GAS LIGHTING ». ELECTRIC LIGHTING.
J
LATE OF THE IMPERIAL gas-light COMPANY, LONDON.
magnets. One series of terminals of the coils of these magnets is led to The gas scare continues, and is likely to do so, while day after day the
one binding post, while the other passes to a set of circuit-closing devices, newspapers insert fresh pieces of news as to the progress of electric light-
by means of which all of the currents, separately or together, or any indi-ing, each new thing, if only true and practicable, sufficient to considerably
vidual one or ones, may be conducted away from the machine.
injure the gas companies.
The great merit of this second form of the Lontin machine lies in the
facility with which currents varying in number and intensity may be de-
rived from it, so that quite a number of electric lights may be produced at
the same time, and also in. the fact that in the conducting away of these
currents contact brushes are entirely dispensed with; so that the great loss
in electricity attendant upon this mode of collection, besides the frequent
attention required by its use, are entirely avoided.
With a velocity of rotation of 320 turns per minute, the machine being
arranged so as to yield 12 separate currents, the outer magnets being con-
nected together two and two for this purpose, 12 lights were obtained, each
equivalent to 740 candles. Three series of 8 magnets each gave 3 lights,
cach having an intensity of 1,480 standard candles.
It is said that to prevent any detriment to the machine arising from the
conversion into beat of any currents that may not be required, while the
remaining ones are being applied to some special purpose, these superflu-
ous currents are made to pass through appropriate resistance coils, and
thus become in a manner absorbed.
A large Lontin machine of the kind last described was used at one time
for lighting the railway depot at Lyons, where it fed 31 separate lamps,
each giving out a light of about 340 candles. The power needed to run
this machine is not stated. Another machine of this form, giving 24 lights
of 1,480 candles, required from 20 to 22 horse power to drive it. Smaller
machines, of from 2,000 to 3,000 candles, demand somewhat more than
5-horse power.
SIEMENS' NEW MACHINE.
Siemens and Halske have lately devised a new dynamo-electric machine,
for the production of one or several independent currents, which may be
made at pleasure either intermittently unidirectional or rapidly alter-
nating in character.
As, however, there is not at present much real data as to the cost and
value of the electric light from experiments in England open to the public
we, as experienced gas engineers, have investigated for ourselves the data
furnished by M. Hippolyte Fontaine as to the results of using the electrio
light in France, and we have personally examined the Jablochkoff system
as shown at Messrs. Wells & Co. in Shoreditch, that of Mr. Werdermann
in the Euston Road, the Rapieff system at the "Times" office, and the
Lontin light at the "Gaiety" Theatre.
But, before going into the cost and value of the electric light, we, as hav-
ing a considerable knowledge of the management of the Metropolitan Gas
Companies, desire to say that we are utterly at a loss to understand the
reason for the cry raised against them by the newspapers, which, almost
without exception, appear to have a grievance, and to represent that the
public in general have great cause for complaint; and as we know this to
be without adequate foundation, we think it right to say so, and to point
out that it is almost impossible for any producers of an article for sale to be
more stringently kept from going wrong-even if they desired to do so-
than are the Metropolitan Gas Companies, and especially those of them
that are under the more recent legislation, which represent share and sharo
and loan capital amounting to £9,570,571 out of a total in the Metropolis of
£11,845,749.
The new legislation binds the companies under it to give au illuminating
power of 16 candles, and that they do give this, and more, is proved by the
official testing of the Metropolitan Board of Works and the Corporation of
London, who would be ready enough to enforce the penalties if there had
been default, as has been proved by the enforcement on two or three occa-
sions of the severe penalties for slight excesses in the sulphur impurity
which the companies are compelled to keep as low as the Referees appoint-
ed by the Board of Trade can reasonably call upon them to do.
As regards pressure, the Act of Parliament has prescribed a minimum,
but it is very seldom that it is even approached, so desirous are the compa-
nies that a full supply of gas should be afforded to all their customers; but
with the enormous business of the companies there must necessarily arise
defects from time to time, and all they can do is to have a sufficient staff of
In one form of this machine the two sides of an upright iron frame carry
each a series of 8 circularly disposed electro-magnets, the cores of which
stand out at right angles to the sides, and carry at their ends, where they
face the corresponding cores of the opposite series, large flat plates of soft inspectors and workmen ready to remedy them without unnecessary delay.
iron. The plates of each set are alternately of opposite polarity, while
those facing each other exhibit the same polarity; and as the space between
them is made as small as the mode of construction will permit, magretic
fields of high intensity and of alternately opposite polarity will come to be
formed.
It should, however, be understood that much the larger number of com-
plaints arise from the defects in fittings or burners belonging to the consu-
mers for which the companies are not in any way responsible.
As regards the meters, the companies supply them at a rental to almost
all their customers, although they are not compelled to do so except as to
Upon a shaft running through the centre of the frame there is secured a the smaller sizes of meters; but the consumers of gas can, if they please,
diso, carrying on its circumference an upright iron ring, oblong in section, purchase meters for themselves from any maker, and, so long as they are
made either of wire or plates, sometimes also of massive iron. This ring is good enough to obtain the official stamp for correctness of registration, the
"Correctness," however, means
surrounded at eight (or more, in some forms of the machine) equidistant companies must allow them to be used.
places by flat coils of insulated copper wire, which, with the ring, are that meters may be stamped as correct if they register three per cent.
carried by the rotation of the shaft throngh the magnetic fields formed by against the companies, but they are not allowed to pass if they register
So even in this the consu-
the electro-magnets. Two of the coils on the rotating ring are devoted ex-more than two per cent. against the consumer.
olnsively to the purpose of keeping the field magnets saturated, in accordance mer is favored at the expense of the companies.
with the well-known dynamo-electric principle; and since the current in We are quite at a loss to understand what the sins of the companies are,
2309
74
American Gas Light Journal.
LECTURE UPON THE ELECTRIC LIGHT.
DELIVERED Oor. 17, 1878, BEFORE THE AMERICAN GAS-LIGHT ASSOCIATION,
By Prof. HENRY MORTON, Ph.D.,
PRES. STEVENS INST., HOBOKEN, N. J.
[Concluded from page 54.]
In addition to the other forms or modifications of magneto-electric ma-
chines-by which name I intend to designate all that I have already
described, as I do not think that the term dynamo-electric machines, to
designate those in which electro-magnets, excited by the machine itself, are
used as producers of the "field of force or magnetic field in which the
revolving magnets move, as distinguished from the earlier sort, using per-
manent magnets or the like, is at all necessary-there are some others
which should not be passed over without notice.
"
In the first place, Mr. Edward Weston, of Newark, is manufacturing a
machine resembling exactly in appearance, and, as far as I can see, in all
essentials of construction, that which I have already described and shown
as Siemens' later form. (See Fig. 27.) With several of these machines I
have made numerous trials lately, and find them to ruu well for as much as
ten hours at a time, and to give a higher efficiency in light per horse power
than any of the other machines with which I have experimented. This
result seems to agree with the general result of experiments made in Europe
with the machines of Siemens, and with a general verbal statement which
Feb. 17, 1879.
1849. Nollet-Van Malderen—Alliance machine.
1852. Holmes introduced electro-magnets.
1857. Siemens introduced peculiar armature.
1864. Pacinotti, the first continuous current machine.
1866. Wilde made his first form of machine.
1866. Siemens & Halske, same principle as Ladd.
1867. Ladd, self-exciting principle
1867. Wheatstone developed same principle.
1871. Gramme first described his continuous current machine.
1878. Wilde describes his second form.
1875. Siemens describes his machine. (Fig. 27.)
1873. Farmer patented machine like Wilde's second.
1874. Lontin machine, for many circuits.
1878. Gramme's alternating machine.
In considering the practical application of the electric arc as a source of
light, it becomes very important to notice with accuracy just what is the
chief location of light in the ignited poles, and how this may be affected
by various conditions.
Thus, in the first place, if we are using a machine with a current of uni-
form direction, we will find that the upper or positive pole, as they are
generally arranged, soon acquires a cup-shaped form, as shown in Fig. 40,
and that the most intensly luminous portion of the carbon is the interior of
this positive cup. The edges of this cup will evidently cut off this light
from spreading upward for a very considerable angle, while on the other
hand all the light from this interior luminous area will pass freely down-
ward. From this it will of course follow that very different results would
be obtained if, with such machine and arrangement of the carbons, the
lights were measured from below, or on a level, or from above.
Fig. 40.
was made to me as to the result of experiments at the U. S. Torpedo Sta-
tion at Newport, R. I., where they have one of these Siemens machines.
There is also a very efficient machine manufactured by Messrs. Arnoux &
Hochhausen, of New York. Some of these were used very successfully last
summer for lighting the bathing beach at Coney Island, and for lighting
several points in New York during the holiday season.this winter, and the
new State House at Albany during its inauguration.
One of these was kindly loaned to me on the evening of the address here
reported, but as it was soon afterward required for use by its manufacturers
I have not had an opportunity to make any examination of, or experiments
with it. It much resembles the second form of Wilde, or the Farmer ma-
chine in general arrangement.
·
In describing the various forms and modifications of these machines I
have not attempted in all cases to follow the chronological order of each
step, as this would sometimes have involved the skipping about from one
type of machine to another. I will now, therefore, give an abstract of the
chronology of the subject, following Dr. Schellen's book as an authority
for a part of the list:
1831. Faraday discovered magneto-electric induction.
1832. Pixii made first magneto-electric machine.
1833. Saxton made magneto-electric machine.
1836. Clarke made magneto-electric machine.
Fig. 41.
If the two carbon points are not placed truly in line with each other,
then we have such a state of affairs as is shown in Fig. 41.
Here, evidently, while the light from the hollow positive pole would
radiate freely in front, it would be largely cut off behind, and escape only
with a medium degree of facility at either side; in fact, measurements
made with such arrangement show the following figures:
Representing by 100 the light emited, in a horizontal position, when the
points are in line, we have for the various directions, when they are dis-
placed as shown in Fig. 41:-In front, 287; laterally, 116; backward, 38.
In the report of experiments made by a committee of the Franklin Insti-
tute (see Journal of that Society, vol. 75, p. 301) I find the record of a
similar set of measurements, as follows:
Front...
Side...
·
•Back.
2,218 candles.
578
578
<
C
111
3,485÷4=871
"The light produced by the machine, under the same conditions, except
the carbons being adjusted in one vertical line, was 525 candles. This
would seem to indicate that nearly 66 per cent, more light was produced
by this adjustment of the carbons; but a close study of the conditions sat-

2310
Feb. 17, 1879.
American Gas Light Journal.
isfied us that such is not the case, and that there is no advantage to be de-it, by means of the lifting finger, will raise one edge
rived from such adjustment, except when the light is intended to be used of the washer h, which, by its angular impingement
in one direction only."
against the rod, f, clamps and lifts it to a distance
This shows us, among other things, how very great a difference of re-coutrolled by the adjustible stop, x, but separating
sult in candle power may be obtained with the same apparatus, if a differ-
ence occurs in the arrangement of the points; and it also explains why an
are which gives a very high candle power when measured, may quite fail to
exhibit anything like au equal degree of actual illnminating power when
put to some practical use.
Thus, in the case just cited, while the candle power, measured from the
front, would be 287, the average for all directions would be only 189, or
about one-half as great.
In this connection a certain advantage is found in the use of machines
with alternating currents. Here the carbons both burn away alike to
pointed ends, and the light is thus much more equally distributed on all
sides. (See Fig. 42.)
the carbon points far enough to produce the light.
As the carbons burn away, the increased length of
the electric arc increases its resistance, and weakens
the magnetism of the helix, and therefore the coil,
rod, and carbon move downward by the force of grav-
ity until, by the shortening of the arc, the magnetism
of the helix is strengthened, and the downward
movement arrested. When, however, the downward
movement is sufficient to bring the clutch-washer, h,
to the support, g, it will be released from the clamp-
ing effect of the lifting finger, and the rod, f, will
slip through until arrested by the upward move-
ment of the core, due to the increased magnetism of
the helix.
In most of the machines now in use the current which produces the light
is the same which passes around the coils of the stationary magnets, by
which the field of force is developed; hence there is the most intimate re- The normal position of the clamp-washer is with
lation between the machine and the lamp, and any fluctuation in the the edge under the adjustible stop, just touching the
resistance offered at the latter is at once felt at the machine. To eliminate support, g, the office of the core being to regulate the
this source of uncertainty and irregularity, in some experiments which I slipping of the rod through it. If, however, the rod,
have lately conducted with various machines I have employed a simple, from any cause. falls too far, it will instantly and au-
substantial holder for the carbons, with means of adjustment from time to tomatically be raised again, as at first, and the carbon
time by band. This requires, of course, the frequent attention of an assist-points thus continued at the proper distance from
ant during the experiments, but by this means I have obtained more each other.
constant and favorable results, from all the machines tried, than with any
of the automatic lamps.
d
K
k
75
Fig. 43.
In the lamps used in these experiments, the helix was composed of two
separate insulated wires wound together, so that, by means of suitable pin
Next to this I have found the Brush lamp to be most satisfactory, when contacts, shown at the top of Fig. 10, they could be connected either in
used with its own machine.
Fig. 42.
Fig. 44.
couples or end to end, thus varying the intensity of the magnetism of the
helix. Thus, in connection with varying the weight to be lifted by the
magnetism of the helix, either by loading the core or increasing the upward
thrust of the springs, enabled us to adjust the lamp to suit the varying
qualities of the currents dealt with.
Several new methods of arranging the carbons, and rendering them more
or less adjustable automatically, have been, recently suggested or put in
practice.
Thus, in Nature for Dec. 19th, 1878, I find a plan described by Wilde,
which consists in placing two carbon rods beside each other, as in the Jab-
lochkoff candle, but without any insulating material between them. Under
As the structure of this lamp is very simple, I will give a description of it these circumstances the author states that the arc will keep to the extremi-
here.
This lamp is shown in Figs. 43 and 44, in which a is a helix of insulated
copper wire, resting upon an insulated plate, b, upheld by the metallic
post, c. Loosely fitted within the helix is the core d, partly supported by
the adjustable springs e. The rod, f. passes freely through the centre of
the core, d, and has as its lower end a clamp for holding the carbon pencil,
A washer, h, of brass, surrounds the rod, f, just below the core, d, and has
one edge resting on the lifting finger attached to the latter, while the other
edge is overhung by the head of an adjustable screw stop, x.
The metal post, r, is supported and guided by a tubular post, i, secured
to a suitable base plate. Attached to the lower end of the post, c, and
passing out through a slot in i, is the arm, y, supporting an insulated
holder for the lower carbon.
If now one conducting wire from the machine be connected to the base
plute, and the other to the lower carbon holder, the current of electricity
will pass up through the posts, i and c, through the helix a, rod, f, and
the carbons, kk, thus completing the circuit.
The axial magnetism produced in the helix will draw up the core, d, and.
ties of the rods, or will run to them if established elsewhere.
To provide against extinction, and secure automatic relighting, one of the
holders is hinged so as to allow its carbon to fall against the other unless
pulled away by an electro-magnet in circuit. This arrangement is certainly
very simple, and free from many of the objections offered in connection
with the Jablochkoff candle. It will be seen here, however, that the maxi-
mum light will be developed between the two rods, or, in other words, on
their respective inner surfaces where it will have the least facility for pro-
ducing useful effect.
A very curions modification of this candle has been made by Mr. Edward
Weston, in which he places a strip of some relatively volatile matter on the
backs or outer sides of the parallel carbon rods. The arc then forms across
from these parts, and the incandescent vapor assumes much the appearance
of a gas flame.
Among the recent forms of lamp described in Dr. Schellen's recent work,
"Die Magnet- und Dynamo-Elektrischen Maschinen," are several announc
ed by the Siemens-Halske firm.
In one of these, two carbons inclined towards each other, aro allowed
2311
76
American Gas Light Journal.
Feb. 17, 1879.
to descend, and thus bring their upper ends together by the with- Houston, of Philadelphia, which they have themselves described as fol-
drawal downwards of a non-conducting interposed rod, whose motion is lows:
controlled by an electro-magnet in the circuit.
In another, which, however, looks like a suggestion rather than a practi-conductor of considerable length, is suddenly broken, a bright flash, called
"As is well known, when an electrical current, which flows through a
cable machine, the carbons are arranged so that the lower one is constantly the extra spark, appears at the point of separation. The extra spark will
vibrating up and down, and the upper one simply rests upon it, except in
so far as it is being constantly knocked away by the motion of the lower appear, although the current is not sufficient to sustain an arc of any ap-
one, which motion is effected by an electro-magnet in the circuit.
A much more complete apparatus, on the same general principle, we will
describe presently.
Among the latest developments in electric lamps may be reckoned the
plan of Mr. Werdormann, which may be described as follows:
C
I
Fig. 45.
Mr. Werdermann makes one electrode to consist of a disc of carbon, ta-
pering in thickness from the centre to the circumference on one side, and
flat on the other. The other electrode is a very fine and thin rod of carbon,
with one end pointed. The disc is placed horizontally with the rounded
side downwards, and the thin rod vertically, and in contact with the disc,
the current being supplied via the metal collar by which the rod is sur-
rounded near the top. On passing the electricity the fine point of the car-
bon rod above the collar becomes incandescent, and a very small electric
arc is produced between the two carbons. Referring to the diagram (Fig.
45), the upper carbon is shown at o, and the rod carbon at c. The former
is supported by means of an adjustable jointed bracket B, attached to the
wood stand. The rod carbon is guided by the spring collar on the top of
the stand, and to which the. connection is made, and is supported by the
This cord is attached to the clasp D
fine cord, running over the pulley P.
at the bottom of the rod and to the balance weight w, by which the rod is
maintained in constant, practical, though not absolute contact with the
disc. Round the upper part of the disc is a metal band A, to which the cir-
cnit wire is attached, and the current thus passed on to the next lamps.
preciable length at the point of separation.
"In our system, one or both of the electrodes, which may be the ordinary
carbon electrodes, are caused to vibrate to and from each other. The
electrodes are placed at such a distance apart that in their motion toward
each other they touch, and afterward recede a distance apart, which can be
regulated. These motions or vibrations are made to follow one another at
such a rate that the effect of the light produced is continuous; for, as is
well known, when flashes of light follow one another at a rate greater than
25 to 30 per second, the effect produced is that of a continuous light. The
vibratory motions may be communicated to the electrodes by any suitable
device, such, for example, as mechanism operated by a coiled spring, a
weight, compressed air, etc.; but it is evident that the current itself fur-
nishes the most direct method of obtaining such motion, as by the use of
an automatic vibrator, or an electric engine.
"In practice, instead of vibrating both electrodes, we have found it nec-
essary to give motion to but one, and since the negative electrode may be
made of such size as to waste very slowly, motion is imparted to it, in pre-
ference to the positive. The carbon electrodes may be replaced by those of
various subtrances of sufficient conducting power. In this system, when
desired, an independent battery circuit is employed to control the extinction
and lighting of each lamp.
"The following is a description of one of the forms of electric lamp
which we have devised, to be used in connection with our system of electrio
lighting:
"A flexible bar, b, of metal is firmly attached at one of its ends to a pil-
lar, p, and bears at its other end an iron armature, a, placed opposite the
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"This lamp, (says the Ironmonger of Nov. 9), "was tried on October 28,
and again on November 6, on the works of the British Telegraph Manufac-
tory (Limited), Euston Road, London, the current being derived from a
small Gramme machine of two-horse power. At the commencement two
lights were maintained equal to 640 candles, and the light was perfectly
steady. Subsequently the current was sent through a row of 20 lamps, the
light of each being equal to 40 candles; still the light was steady. Mr.
Werdermann asserted his ability to distribute the current from the small
machine then at work so as to divide it among 60 lights. In that case the
light would inevitably be small; but enough is apparent to prove that, so adjustable pole-piece of the electro-magnet, m. A metal collar, c, supports
far as a current will bear division, Mr. Werdermann will be able to utilize the negative electrode, the positive electrode being supported by an arm, j,
it."
It will be noticed that here, as with all other lamps working by incandes-
cence, there is great loss, which increases with the subdivision. A Gramme
machine utilizing two-horse power should give, with an ordinary lamp, a
light of from 1,000 to 1,500 candles, in place of the 640 here claimed from
two lamps, or the 400 candles claimed for ten lamps.
A yet more recent system is that developed, or, we might rather say,
now in course of development, by Profs. Elihu Thomson and Edward
Fig. 46,
attached to the pillar, p. The pillar, p, is divided by insulation at i into
two sections, the upper one of which conveys the current from the binding
post, marked +, to the arm, j, and the rod, 7, supporting the positive
electrode.
“The magnet, m, is placed as shown by the dotted lines, in the circuit
which produces the light. The pillar, p, is hollow, and has an insulated
conducting wire inclosed, which connects the circuit closer, v, to the
binding post, marked — The current is conveyed to the negative eleo-
2312
Feb. 17, 1879.
American Gas Light Journal.
trode through b and the coils of the magnet, m.
When the electrodes are
in contact, the current circulating through m renders it magnetic and at
tracts the armature, a, thus separating the electrodes, when, on the weak
ening of the current, the elasticity of the rod, b, again restores the contact.,
During the movement of the negative electrode, since it is caused to occur
many times per second, the positive electrode, though partially free to fall,
cannot follow the rapid motions of the negative, electrode, and therefore
does not rest in permanent contact with it. The slow fall of the positive
electrode may be insured either by properly proportioning its weight, or
by partly counterpoising it. The positive electrode thus becomes self-
feeding.
"The rapidity of movement of the negative carbon may be controlled by
means of the rigid bar, l, which acts, practically, to shorten and lengthen
the part vibrating. In order to obtain an excellent but free contact of
the arm, j, with the positive electrode, the rod, r, made of iron or other
suitable metal, passes through a cavity filled with mercury, placed in
electrical contact with the arm, j. Since the mercury does not wet the
metal rod, r, or the sides of the opening through which it passes, free
movement of the rod is allowed without any escape of the mecury. We
believe that this feature could be introduced advantageously into other
forms of electric lamps.
"In order to prevent a break from occurring in the circuit when the elec-
trodes are consimed, a button, v, is attached to the upper extremity of
the rod, R, at such a distance that when the carbons are consumed
as much as is deemed desirable, it comes into contact with a tripping lever,
t, which then allows two conducting plugs, attached to the bar, v, to fall
into their respective mercury cups, attached, respectively, to the positive
and negative binding posts by a direct wire. This action practically cuts
the lamp out of the circuit."
“PHILADELPHIA, Sept. 19, 1878."
In a later publication (Journal of the Franklin Institute for January,
1879), the same inventors describe a further modification and extension of
their system, as follows:
"The following apparatus was devised by the authors for the purpose of
obtaining induced reversed currents for use in electric illumination. These
currents we use with a vibrating lamp, a de-
scription of which has already been pub-
lished.
F
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Fig. 47.
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77
With this notice of the newest, or, as we may say, youngest system of
electric lighting, which has its birthday with the new year, I may well
conclude this hastily prepared and imperfect notice of this very interesting
subject, and if what I have here thrown together may supply at least ma
terial for a fuller treatment, or a skeleton on which a completely organized
structure may be constructed, I shall have accomplished all that I could
hope.
Before concluding this address I should draw attention, in a more direct
manner, to something which has been developed indirectly in the course of
my remarks; and that is that the loss of efficiency in the electric force as a
means of producing light, when it is divided, is not a unique phenomenon,
but is exactly paralleled in the case of ordinary combustion.
If gas.is burned in very small flames we may get almost no light from it,
and, on the other hand, if we burn it in very large flames, the amount of
light developed will increase in a much higher ratio than will the amount of
gas consumed.
Thus I have here a new burner made by Sugg, of London, with three con-
centric argand rings which burns 30 feet of gas, and yields a light equal to
1964 candles. The same amount of the same gas burned in six standard
five foot burners yielded a light of 114 candles. Here is a gain of over 70
per cent. in the total light produced, by simply concentrating the combus-
tion in one large flame in place of dividing it into six small ones.
In the case of the ordinary lime-light we have another instance of yet fur-
ther concentration.
Here, with a consumption of about 71 feet of gas an hour, in a burner
with three jets heating a cylinder of lime from all sides, we obtain a light
equal to 260 candles in every direction.
This shows very clearly the illogical character of the comparisons so often
made between the concentrated light of the electric arc and the divided
light of the ordinary gas burner.
concentrated form, and it certainly has not yet been shown that, when di-
Heretofore electric lights have only been practically developed in their
vided there will be an enormous loss of efficiency. Gas, on the contrary,
has heretofore only been practically used in its divided form, and there can
be no doubt that its efficiency is capable of much increase when it is burned
in a concentrated manner.
It is here where the actual contest will come in, and the relative succEBS
of the two sources of light in each field will depend upon what it will ac-
complish in that field and not in some other. In other words, we must com-
"Our method of operation is as follows: pare the divided electric lights (say Mr. Edison's, when they become visi-
A reversed primary current is caused to in-ble) with ordinary burners, and the electric-arc light with the lime-light, or
duce reversed secondary currents in second-some such concentrated form of gas burning.
ary coils provided therefor. These secondary
currents are caused to give vibrations to
to carbon electrodes, and thereby at the
same time produce a partial arc between
them. With sufficient strength of primary
current, a considerable number of secondary
currents are obtained, each of which is able
to operate one of our vibrating lamps.
THE END,
[From Translation in " Van Nostrand's Magazine,”]
The Gas Engines at the Paris Exhibition.
By M. Armengaud, Jr.
ABSTRACT OF THE AUTHOR'S ADDRESS AT THE CONFERENCE DU TROCADERO.
“The use of a vibrating lamp admits of a
wide range in the size of the carbons em- The attention of most of those in attendance at this Conference has
ployed. When a light of very moderate been drawn at the Exposition to certain machines, which, in their general
intensity is desired, the carbons are made of appearance and mode of working, resemble steam engines. But upon
very small size, and are placed in a closed approaching them it is readily seen that the similarity is only apparent;
glass vessel for protection from the atmos- the movements of these motors are accompanied by a series of slight deton-
phere. To moderate the brilliancy opales-ations, and a near inspection reveals the fact that attached to each is a
cent glass is used. To obtain the highest efficiency of inductive action perforated chamber, within which burns a flame which seems to give life to
from a set of primary coils, the following form of induction of coil was de- the machine. These are the gas motors. The motive power is derived
vised: -the primary coil, P, surrounding the core, C, is provided with a from illuminating gas, not from steam.
secondary coil, S, adjacent to it. The ends E and F of the bobbin are
made of disks of iron concentric with the core, C, and slit from centre to
circumference. The outer extremities of these disks are connected by
wires or sheets of iron, L, to one another, forming in this manner an in-
duction coil encased in iron, or one whose core has its north and south
extremities magnetically conected. The strength of the current developed
in the secondary coil is greatest when the core, C, which is movable, is
inserted so that both of its extremities are in contact with E and F. By
withdrawing this core, the currents in the secondary coil may be weakened
to almost any desired extent. This coil is best adapted to the use of
primary currents whose direction is constantly changing. All the wire
being completely surrounded by iron, whose direction of magnetic polari-
zation if rapidly changed, the highest inductive effect is thereby produced
in the secondary coil.
.
"The variations in the intensity of the induced currents will, of course,
be followed by variations in the intensity of the light emitted by the lamp.
The movement of the core may therefore be made to increase or decrease
the intensity of the light."
It is proposed to present to the conference some explanations of the
structure and mode of working of the different engines of this class exhib-
ited at the Champ de Mars, and to consider the possible future achieve-
ments of these engines if they continue the progress so clearly made
manifest by this exposition.
Such a progress would hardly seem to possess sufficient interest to hold
the attention of an audience not composed exclusively of engineers. But
it is proposed to relieve the subject of its technical character as far as pos-
sible, and present the more general form of discussion. The task is
rendered easy by the very happy circumstance that in the working of a gas
engine we find a summary of the most beautiful applications of scientifio
principles.
A gas motor possesses the essential organs of the steam engine; the
cylinder which receives the gaseous fluid; the piston which, by aid of a
rod and crank, transmits the pressure to the shaft; the fly-wheel which
regulates the motion; and the pulleys and belts by which the power is
conveyed to the machines to be driven.
The gaseous fluid is a mixture of gas and air, in such proportions as is
2313
(No Model.)
T. A. EDISON.
2 Sheets-Sheet 1.
Regulating the Generation of Electric Currents.
No. 239,374.
Fig. 1.
Patented March 29, 1881.
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2314
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T. A. EDISON.
2 Sheets-Sheet 2.
Regulating the Generation of Electric Currents.
No. 239,374.
Fig. 5.
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2315
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATING THE GENERATION OF ELECTRIC CURRENTS.
SPECIFICATION forming part of Letters Patent No. 239,374, dated March 29, 1881.
Application filed January 11, 1881. (No model.)
To all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Method and Means for Regulating the
Generation of Electric Currents; and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to
Io the letters of reference marked thereon.
•
When a number of generators are used to
furnish the current for a system of generation
and translation-such, for instance, as shown
and explained by me in a prior application for
15 a patent by me made-it is necessary to pro-
vide some means for controlling the genera
tion, so that it may be in accord with the de-
mand of the translating devices, which, of
course, must vary. Several methods and means
20 for accomplishing this I have shown in prior
applications; and the present invention con-
sists in another method and arrangement for
accomplishing it.
In the present case the invention consists
25 in combining, with a battery of generators and
the main circuit thereof, an electric engine con-
nected in the field-of-force circuit, and arranged
to give a counter electro-motive force to that
of the current energizing the fields. In such
30 arrangement, as the number of translating de-
vices in circuit lessens, diminishing the work
to be done, the generators tend to run at a
higher speed. The engine, however, also runs
at a higher speed, throwing an increased
35 counter electro-motive force into the field-
circuit, weakening the current therein, which,
in turn, lessens the magnetic intensity of the
field - magnets, causing a diminution of the
generated current. If the work to be done
40 increases, the contrary effect is produced.
45
In the drawings, Figures 1, 2, 3, and 4 rep-
resent diagrammatically different arrange-
ments, all, however, containing the arrange-
ment noted.
In these drawings, P represents the engine.
In Figs. 1 and 2 its field-coils are in a multiple-
arc circuit 3 4 to the main circuit 1 2.
A A'A" are the generators, with their arma-
tures.connected to the main circuit in multiple
50 arcs by the conductors a a'.
In Fig. 1 the engine P is connected by mul-
tiple arcs 6 7 8 through the fields of the gen-
erators. In Fig. 2 it is connected by 9 through
them in series. In either case P is energized
as an engine from the main circuit, and the 55
fields of the generators are energized from the
same circuit, and the counter electro-motive
force which P sends through the fields in op-
position to the current therein from the main
circuit will be proportioned to the rate of 60
speed given P, which will be proportionate to
that of the generators, as all are energized
from the same circuit, which is fed by the cur-
rent from the generators. As the rate of speed
of the generators depends upon the resistance 65
in the exterior circuit, as such resistance less-
ens, the machines tend to run at a higher speed;
but the engine P also tends to run at the same
increase of speed, sending a greater electro-
motive force back through the fields of the gen- 70
erators, thereby weakening the current around
the fields and lessening the generation. By
this method a perfect balancing of forces may
be effected.
If desired, the engine itself may be adjusted 75
by increasing or decreasing the work which is
given it to do, one method thereof being shown
in Fig. 1, where a friction-brake, L, with au
adjustable weight, is shown.
In Figs. 3 and 4 the same general arrange. 8
ment is shown, except that in Fig. 4 P is shown
as a pure dynamo, its own current passing
through its own field. In these latter arrange-
ments adjustable resistances R are included
in the field-circuit, to aid in the regulation when 85
desired.
What I claim is—
1. The method of regulating the generative
force of a battery of generators, by causing the
current energizing the field-of-force magnets 90
to energize an electric engine whose counter
electro-motive force regulates the strength of
the current energizing the field-of-force mag-
nets, substantially as set forth.
2. The combination, with a battery of dy- 95
namo or magneto electric generators, of an
electric engine arranged to throw a current
of counter electro-motive force through the
field-circuit of the generators, substantially as
and for the purpose set forth.
IOO
2316
2
239.374
3. The combination, with the engine ar-
ranged to give the counter electro-motive force,
as described, of a brake or other mechanism,
giving the engine a definite but adjustable
5 work to perform, so that the electro-motive
force may be regulated, substantially as set
forth.
This specification signed and witnessed this
16th day of December, 1880.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
ERNEST J. BERGGREN.
2317
A.
Fig. 1.
Attest:
James A. Payne
John C. Schmider
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
d.
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Fig. 2.
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Inventor:
I. A. Edison
Joer Dyer & Wilber
This Atty's.
Fig. 5.
T. A. EDISON.
Method of Manufacturing Electric Lamps.
No. 230,255.
Patented July 20, 1880.
2-
D.
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2318
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY,
METHOD OF MANUFACTURING ELECTRIC LAMPS.
SPECIFICATION forming part of Letters Patent No. 230,255, dated July 20, 1880,
Application filed February 5, 1880.
To all whom it may concern:
now complete, it is attached, by the neck before
Be it known that I, THOMAS A. EDISON, a mentioned, to the air-exhausting pump. When
citizen of the United States, resident at Menlo a proper vacuum has been attained the end of 55
Park, State of New Jersey, have made cer- the tube is softened and sealed, after which
5 tain new and useful Improvements in Elec- the lamp is removed from the pump. The
tric Lamps and the Method of Manufacturing tube is then softened and sealed near its point
them, of which the following is a specification. of juncture with the globe, as the neck was
My electric lamp consists, essentially, (as before sealed at the tip. There is the same 60
shown in prior applications of mine for pat-degree of vacuum upon both sides of this last
10 ents,) of an incandescing conductor of high re- seal-i. e., within the globe and in the tube
sistance hermetically sealed in a glass vacuum- between it and the tip. The vacuum in the
chamber.
neck is then destroyed by fracture of the neck,
and the neck is again softened and sealed im- 65
mediately above the, seal which was formed at
the juncture of the tube and globe, and the sur-
plus portion of the tube removed,
Great difficulty has always been experienced
in so sealing a glass vacuum globe or chamber
15 that complete union of the parts was had and
danger of opening or separation avoided, in
order that a stable vacuum might be main-
tained when the parts forming the seals were
in vacuo when the sealing was done. In fact,
20 the maintenance of a stable vacuum has been
pronounced impossible by many scientists.
The object of my invention is to furnish a
method of manufacturing electric lamps so
that a stable vacuum may be maintained there-
25 in.
In carrying out my method of manufacture,
a glass bulb, of the size desired for the inclos-
ing-globe of the lamp, is formed with a sup-
porting-neck extending in, one direction, of a
30 diameter sufficient to permit the passage of
the incandescing conductor through it. Pref-
erably a piece of tubing, of the size of the neck,
has the bulb blown in it. Upon a point on
the bulb, preferably exactly opposite the cen-
35 ter of the neck, is formed a long tube for at-
tachment of the bulb to the air-exhausting ap-
paratus. Upon the end of a smaller piece of
tubing a small bulb is formed, and the body
of the tube, a little below the bulb, is enlarged
40 for a small space to about the size of the sup-
porting - neck. This portion forms the arc-
supporting part, wires, terminating in clamps
for holding the conductor, being passed there-
through and hermetically sealed therein. Af
45 ter the conductor has been secured on the sup-
porting portion it is passed up through the
neck of and into the bulb until the further
passage of the supporting portion is stopped
by the enlargement thereon taking against the
50 end of the neck of the bulb, when the two are
sealed together at that point by fusion. The
mechanical construction of the lamp being
For a more particular description reference
is to be had to the drawings accompanying and 70
forming part of this specification, in which—
Figure 1 is a view of the globe, the neck,
and the tube as first formed. Fig. 2 is a view
of the same ready to receive the incandescent
conductor and its support. Fig. 3 is a view 75
of the incandescent conductor and its support
ready for union with the globe. Fig. 4 is a
sectional view of the parts of the lamp joined
together and sealed; and Fig. 5 is a view of
the completed lamp.
80
A piece of tubing, the size of C, is taken, on
which is blown or otherwise formed the bulb
B, whose upper portion is drawn out into the
tube A, curved so that several bulbs may be
attached to one air-exhausting pump. The 85
part C is left unchanged, in order to form a
supporting-neck for the lamp. In forming
this tubing, however, the lower end is often
drawn out, as shown in Fig. 1. This small end
is removed on the line xx, leaving the globe, 90
neck, and tube as shown in Fig. 2.
F is a piece of glass tubing of the size some-
what less than C. Upon its upper end is
formed the bulb D, on whose top are drawn
out the two wire seals p p. Below D the en- 95
largement E is formed in the tube F, its exte
rior diameter being the same as that of C.
Platinum wires ww, joined to conductors 1 2,
are passed through openings in the projections
pp, which are then fused by heat around the 100
wires w w, so as to seal the wires hermeti-
cally in the glass by seals extending around the
wire above the general surface of the bulb D,
as clearly shown in the drawings. Clamps ce
•
2319
2
230,255
are then attached to the wires, and the incan-
descing conductor fastened in the clamps.
•
It is to be here remarked that the clamps or
wires within the globe must be of some mate-
5 rial not so affected by any influences existing
within the globe, where the proper vacuum has
been attained, as to interfere with the light or
its proper dissemination. If iron be used, it
is so acted on that it is gradually destroyed,
10 with an ensuing deposit on the glass, obscur
ing the transparency of the globe, and, also
acting on the carbon, uniting with it, and finally
destroying it. In order to prevent this and
to guard against any injurious influences what-
15 ever, the clamps c c and wires within the globe
should be of platinum or some metal or-met-
als of the platinum group, treated by the pro-
cess described by.me in an application for a
patent now pending.
20 The arc I and bulb D are inserted in the neck
Cuntil the end x x of the neck C rests upon
the enlargement E, when the two are securely
and hermetically there joined by fusion of the
glass at that point. The lamp is then attached,
25 by the tube A, to an exhaust-pump. When
the proper degree of exhaustion has been
reached the tube A is sealed by fusion of glass
at il and removed from the pump, whereupon
a seal, b, is made in the tube A, immediately
30 above the globe B. This last sealing is made
entirely in vacuo, and the degree of vacuum
in B and in A,between b and d, is the same. I
have found, however, that a perfect seal cannot
be made when all the portions of the glass
35 which unite to form the seal were in a vacuum
when the seal was made. Hence the seal d of
the tube A is now broken off, admitting air in
❤
A above b. A is now sealed by fusion at e, or
A may be broken off at e, and a drop of molten
glass placed thereon to form the seal. The 40
seal a, Fig. 5, is now the resultant of two seal-
ings-one at b in vacuo and one at e in air. I
have found that such a seal is lasting under
all conditions, and that by the method here
indicated a globe is so constructed and sealed 45
that a vacuum perfectly stable is maintained
therein.
The wires 1 2, for attachment to devices for
completing the circuit, pass out of the end of
the tube F, in order to prevent their accidental 50
crossing or displacement. A plug, G, of cork,
plaster-of-paris, or other insulating material, is
put in the end of F, securing the wires therein.
What I claim is-
1. The method of forming electric lamps, 55
substantially as set forth, consisting in sepa-
rately forming the inclosing- globe and the
supporting-bulb for the incandescent conduct-
or, attaching the wires and incandescent con-
ductor thereto, and then hermetically uniting 60
the parts prior to the formation of the vacuum,
substantially as herein described.
1
2. The method of hermetically sealing a
vacuum-chamber, substantially as described,
which consists in first sealing in vacuo and 65
then sealing in air, substantially as described.
In testimony whereof I have hereunto af-
fixed my signature this 28th day of January,
A. D. 1880.
Witnesses:
C. P. MOTT,
S. D. MOTT.
THOS. A. EDISON.
2320
No. 223,898.
Figh.
T. A. EDISON.
Electric-Lamp.
Patented Jan. 27, 1880.
Fig. 1.
m.
α.
px
d
**** 96
C'
Fig. 3.
a
C'
d
Witnesses
Charst Smith
Gto. Pickny
eTTe
Inventor
Thomas A. Edison
for Lemuel W. Serrell
Burrell
}
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
alty
2321
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
ELECTRIC LAMP.
SPECIFICATION forming part of Letters Patent No. 223,898, dated January 27, 1880.
Application filed November 4, 1879.
To all whom it may concern:
·
Be it known that I, THOMAS ALVA EDISON,
of Menlo Park, in the State of New Jersey,
United States of America, have invented an
5 Improvement in Electric Lamps, and in the
method of manufacturing the same, (Case No.
186,) of which the following is a specification.
The object of this invention is to produce
electric lamps giving light by incandescence,
10 which lamps shall have high resistance, so as
to allow of the practical subdivision of the
electric light.
►
The invention consists in a light-giving body
of carbon wire or sheets coiled or arranged in
15 such a manner as to offer great resistance to
the passage of the electric current, and at the
same time present but a slight surface from
which radiation can take place.
The invention further consists in placing
20 such burner of great resistance in a nearly-
perfect vacuum, to prevent oxidation and in-
jury to the conductor by the atmosphere. The
current is conducted into the vacuum-bulb
through platina wires sealed into the glass.
25
The invention further consists in the method
of manufacturing carbon conductors of high
resistance, so as to be suitable for giving light
hy incandescence, and in the manner of secur-
ing perfect contact between the metallic con-
30 ductors or leading-wires and the carbon con-
ductor.
Heretofore light by incandescence has been
obtained from rods of carbon of one to four
ohms resistance, placed in closed vessels, in
35 which the atmospheric air has been replaced
by gases that do not combine chemically with
the carbon. The vessel holding the burner
has been composed of glass cemented to a me-
tallic base. The connection between the lead-
40 ing-wires and the carbon has been obtained by
clamping the carbon to the metal. The lead-
ing-wires have always been large, so that their
resistance shall be many times less than the
burner, and, in general, the attempts of pre-
45 vious persons have been to reduce the resistance
of the carbon rod. The disadvantages of follow-
ing this practice are, that a lamp having but
one to four ohms resistance cannot be worked in
great numbers in multiple arc without the em-
50 ployment of main conductors of enormous di-
mensions; that, owing to the low resistance of
the lamp, the leading-wires must be of large
dimensions and good conductors, and a glass
globe cannot be kept tight at the place where
the wires pass in and are cemented; hence the 55
carbon is consumed, because there must be al-
most a perfect vacuum to render the carbon
stable, especially when such carbon is small in
mass and high in electrical resistance.
The use of a gas in the receiver at the at- 60
mospheric pressure, although not attacking
the carbon, serves to destroy it in time by "air-
washing," or the attrition produced by the
rapid passage of the air over the slightly-co-
herent highly-heated surface of the carbon. I 65
have reversed this practice. I have discovered
that even a cotton thread properly carbonized
and placed in a sealed glass bulb exhausted to
one-millionth of an atmosphere offers from one
hundred to five hundred ohms resistance to the 70
passage of the current, and that it is absolutely
stable at very high temperatures; that if the
thread be coiled as a spiral and carbonized,
or if any fibrous vegetable substance which
will leave a carbon residue after heating in a 75
closed chamber be so coiled, as much as two
thousand ohms resistance may be obtained
without presenting a radiating-surface greater
than three-sixteenths of an inch; that if such
fibrous material be rubbed with a plastic com- 80
posed of lamp - black and tar, its resistance
may be made high or low, according to the
amount of lamp-black placed upon it; that car-
bon filaments may be made by a combination
of tar and lamp-black, the latter being pre. 85
viously ignited in a closed crucible for several
hours and afterward moistened and kneaded
until it assumes the consistency of thick put-
ty. Small pieces of this material may be
rolled out in the form of wire as small as seven 90
one-thousandths of a inch in diameter and
over a foot in length, and the same may be
coated with a non-conducting non-carbonizing
substance and wound on a bobbin, or as a spi-
ral, and the tar carbonized in a closed cham- 95
ber by subjecting it to high heat, the spiral
after carbonization retaining its form.
All these forms are fragile and cannot be
clamped to the leading-wires with sufficient
force to insure good contact and prevent heat- 100
ing. I have discovered that if platinum wires
are used and the plastic lamp-black and tar
material be molded around it in the act of car-
bonization there is an intimate union by com-
2322
2
223,898
bination and by pressure between the carbon
and platina, and nearly perfect contact is ob-
tained without the necessity of clamps; hence
the burner and the leading-wires are connect-
5 ed to the carbon ready to be placed in the vac-
uum-bulb.
IO
When fibrous material is used the plastic
lamp-black and tar are used to secure it to the
platina before carbonizing.
By using the carbon wire of such high re-
sistance I am enabled to use fine platinum
wires for leading wires, as they will have a
small resistance compared to the burner, and
henee will not heat and crack the sealed vac-
15 uum-bulb. Platina can only be used, as its
expansion is nearly the same as that of glass.
By using a considerable length of carbon
wire and coiling it the exterior, which is only
a small portion of its entire surface, will forin
20 the principal radiating-surface; hence I am
able to raise the specific heat of the whole of
the carbon, and thus prevent the rapid recep-
tion and disappearance of the light, which on
a plain wire is prejudicial, as it shows the
25 least unsteadiness of the current by the flick-
ering of the light; but if the current is steady
the defect does not show.
35
I have carbonized and used cotton and linen
thread, wood splints, papers coiled in various
30 ways, also lamp-black, plumbago, and carbon
in various forms, mixed with tar and kneaded
so that the same may be rolled out into wires
of various lengths and diameters. Each wire,
however, is to be uniform in size throughout.
If the carbon thread is liable to be distorted
during carbonization it is to be coiled between
a helix of copper wire. The ends of the car-
bon or filament are secured to the platina
leading-wires by plastic carbonizable material,
40 and the whole placed in the carbonizing-cham-
ber. The copper, which has served to prevent
distortion of the carbon thread, is afterward
eaten away by nitric acid, and the spiral soaked
in water, and then dried and placed on the
45 glass holder, and a glass bulb blown over the
whole, with a leading-tube for exhaustion by
a mercury - pump. This tube, when a high
vacuum has been reached, is hermetically
sealed.
-
With substances which are not greatly dis- 50
torted in carbonizing, they may be coated with
a non-conducting non-carbonizable substance,
which allows one coil or turn of the carbon to
rest upon and be supported by the other.
In the drawings, Figure 1 shows the lamp 55
sectionally.
sectionally. a is the carbon spiral or thread.
cd are the thickened ends of the spiral, formed
of the plastic compound of lamp-black and tar.
d d' are the platina wires. h h are the clamps,
which serve to connect the platina wires, ce- 60
mented in the carbon, with the leading-wires
xx, sealed in the glass vacuum-bulb.
copper wires, connected just outside the bulb
to the wires x x. m is the tube (shown by
dotted lines) leading to the vacuum-pump, 65
which, after exhaustion, is hermetically sealed
and the surplus removed.
e e are
Fig. 2 represents the plastic material before
being wound into a spiral.
Fig. 3 shows the spiral after carbonization, 70
ready to have a bulb blown over it.
I claim as my invention-
1. An electric lamp for giving light by in-
candescence, consisting of a filament of carbon
of high resistance, made as described, and se- 75
cured to metallic wires, as set forth.
2. The combination of carbon filaments with
a receiver made entirely of glass and conduct-
ors passing through the glass, and from which
receiver the air is exhausted, for the purposes 80
set forth.
3. A carbon filament or strip coiled and
connected to electric conductors so that only
a portion of the surface of such carbon con-
ductors shall be exposed for radiating light, 85
as set forth.
1
4. The method herein described of securing
the platina contact-wires to the carbon fila-
ment and carbonizing of the whole in a closed
chamber, substantially as set forth.
90
Sigued by me this 1st day of November, A.
D. 1879.
Witnesses:
THOMAS A. EDISON.
S. L. GRIFFIN,
JOHN F. RANDOLPH.
l l l l l l l l l l l l l l l l l l lllllllllllllllllll O O O O O O O O O O O O O O O O O C
[Second Edition."
1
DI
ON DROIT
A.D. 1880, 11th FEBRUARY. N° 602.
SPECIFICATION
OF
THOMAS ALVA EDISON.
UTILIZATION OF ELECTRICITY FOR LIGHT,
HEAT, AND POWER.
PRINTED BY ORDER OF THE COMMISSIONERS OF PATENTS FOR INVENTIONS.
LONDON:
PUBLISHED AND SOLD AT
THE COMMISSIONERS OF PATENTS' SALE DEPARTMENT,
38, CURSITOR STREET, CHANCERY LANE, E.C.
Price 8d.
1882.
O O O O O O O O O O O O O O O O O O O JO V ð ð O ð ðŸ O
O O O O O O O O O O O O O O O
2324
[Second Edition.]
A.D. 1880, 11th FEBRUARY. N° 602.
Utilization of Electricity for Light, Heat, and Power.
LETTERS PATENT to Thomas Alva Edison, of Menlo Park, in the State of
New Jersey, United States of America, for an Invention of "IMPROVEMENTS
IN THE UTILIZATION OF ELECTRICITY FOR LIGHT, HEAT, AND POWER, BEING
AN IMPROVED SYSTEM AND MEANS FOR THE GENERATION, REGULATION,
DISTRIBUTION, MEASUREMENT, AND TRANSLATION OF ELECTRICITY INTO
LIGHT, HEAT, OR POWER."
PROVISIONAL SPECIFICATION left by the said Thomas Alva Edison at the
Office of the Commissioners of Patents on the 11th February 1880.
THOMAS ALVA Edison, of Menlo Park, in the State of New Jersey, United States
of America. “IMPROVEMENTS IN THE UTILIZATION OF ELECTRICITY FOR LIGHT,
5 HEAT, AND POWER, BEING AN IMPROVED SYSTEM and MEANS FOR THE GENERATION,
REGULATION, DISTRIBUTION, MEASUREMENT, AND TRANSLATION OF ELECTRICITY
INTO LIGHT, HEAT, OR POWER."
The object of this Invention is to so arrange a system for the generation, supply,
and consumption for either light, heat, or power, or either or all, of electricity that
10 all the operations connected therewith requiring especial care, attention, or know-
ledge of the art shall be performed for many consumers at stations, leaving the
consumer only the work of turning off or on the supply, as may be desired; in other
words to so contrive means and methods that electricity may be supplied for
consumption in a manner analogous to the system for the supply of gas and water,
15 without requiring any greater care or technical knowledge on the part of the
consumer than does the use of gas or water, in order that economy, reliability,
and safety may be insured.
In carrying the Invention into effect a city, town, village, or locality may form
one district, or if the extent of territory makes it desirable may be divided into
20 several districts.
In each district I provide a central station, at which are grouped a suitable prime
motor or several motors, dependent upon the amount to be supplied, generators
or means for converting the prime motive power into electricity, means for
determining and regulating the amount of electricity generated and supplied, in
25 order that a constant pressure of electricity (so to speak) may be kept up.
The prime motors are any suitable engines, steam or water, and one or a series
of two or more are provided as may be necessary, each of which is provided with
[Price 8d.]
2325.
2
A.D. 1880.-N° 602.
Provisional
Specification.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
its own system of shafting and belting driving a number of magneto electric
machines, the number actuated by one prime motor being hereinafter termed a
battery.
•
•
It is to be noted, as is also shown in previous applications for Patents made by
me, that I make my field of force magnets exceedingly long, and of an extremely 5
large mass of metal in proportion to the mass of metal in the revolving armature
carrying the generating coil. By this extra length, as the magnetic tension
at the poles increases with their distance apart, there is secured at the polar
extensions acting upon the coils in the field of force a much greater magnetic
intensity, or so to speak, a greater motive force or pressure, causing consequently 10
the generation of a greater amount of energy in the coils operated on than would
result from the use of shorter magnets, even though the same mass of metal were
used therein. By this elongation of the cores I am enabled to dispense with
numerous convolutions or layers, one layer of wire being sufficient, whereby the
resistance of the machine is largely diminished. The large mass of metal in these 15
magnets is magnetically saturated by a weak current passing around them. It
takes this weak current a long time to bring this mass of metal up to the point of
practical maximum magnetic intensity, but once brought to that point the weak
current readily keeps them there, while with a shorter magnet a stronger current
would more speedily magnetically saturate them; this stronger current would still 20
be required to keep them so saturated.
If the coils of the field of force magnets and the generating coils were included
in one circuit, and all the currents generated were passed through the field magnet
coils, a very much greater amount of current than necessary for the maintainance
of a practical magnetic maximum in the field of force magnets would be passed 25
around them, and the coils acting as resistances to the energy in excess of that
required to magnetise the magnet to its practical maximum would cause a great
waste of electric energy; hence I prefer to keep the field of force magnets and the
generating coils separate, and that one machine in each battery (which machine
may be termed the battery field of force generator) be used to supply the requisite 30
energy to the field of force magnets of the other machines in such battery (which
may be termed the supply generators).
•
The coils of the field of force magnets are connected as a series in a multiple arc
in one circuit, while the generating coils of the supply generators of each battery
are all connected in a multiple arc to the main conductors (though for special 35
purposes they may be connected as a series).
This will give great economy, as the per cent. of the entire current generated in
each battery absorbed in keeping up the magnetic maximum in the field of force
magnets, when it is furnished by one special machine of the battery, the number
given it to feed being properly calculated, being less than when a portion of the 40
current generated in each machine is absorbed in its own field of force magnets.
Where a single battery of machines is used it is preferable, in view of what has
been herein before stated, that the current for the coils of the field of force magnets
of the field of force generators of the battery be supplied by a small galvanic
battery, but if more than one battery of machines be used the field of force 45
generators of all the batteries are fed from one or more prime field of force
generators connected in a multiple arc or in a series, the field of force magnets of
the prime field of force generator or generators used being kept magnetically
saturated by a weak galvanic battery current, as before set forth. For instance,
a weak galvanic current supplies the field current necessary for one prime field of 50
force generator, which in turn feeds the field of force magnets of the field of force
generators of ten batteries of twenty or thirty machines, the ultimate effect in the
generation of currents depending upon (as one important factor) the tension of the
galvanic current sent through the field of force coils of the prime field of force
generators.
This prime field of force generator may however be a dynamo electric machins
55
2326
Provisional
Specification.
A.D. 1880.-N° 602.
3
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
instead of a magneto machine, its field of force being kept up by the current
generated in the machine instead of by a galvanic current.
At the central 'station. all the supply generating coils or batteries thereof are
connected to conductors on the multiple arc system, and from these conductors at
5 the station main conductors (which for convenience may be called simply the
mains), connected thereto on the multiple arc system, lead in any and all desired
directions, conveying the energy to the points where work either by translation
into light or motive power is to be done.
In order to give a better understanding of the method of regulating what for
10 convenience may be called the pressure of the current through the entire system,
I will here state that all the devices for transmission of electricity into work
are arranged on the multiple arc system, each device being in its own derived
circuit, the effect being in substance to give each a circuit from the generating
source independent of the circuit of all the other devices; as a resultant it follows
15 that the greater the number of transmitting devices brought into circuit, the less
the total resistance of the current.
For instance, I prefer my lamps should be of about 100 ohms. resistance, then if
one lamp only be in circuit there is a resistance of 100 ohms. ; if another lamp be
put in circuit, two circuits of 100 ohms. are provided for the current, making the
20 net total resistance to the current 50 ohms.
Although the resistance in each derived circuit remain unchanged, this effect is
ordinarily opposite to the effect produced by the addition of lamps when they are
connected in an ordinary straight circuit, each one then adding to the resistance of
the circuit. The bringing into operation successively of numbers of the devices,
25 and thereby making more patlis or circuits for the currents, does not appreciably
lessen the pressure or diminish the effect upon the devices in use, the active force
at the central station, viz., prime field of force generators and motive power,
remaining unchanged until the net resistance of the devices in circuit exterior to
the battery of machines is so diminished as to approach in a degree the resistance
30 of the battery and main conductors, it being remembered that as the machines of
a battery are connected in multiple arc the net internal resistance of a battery is
as many times less than one as there are machines in the battery.
í
To avoid any appreciable variations and insure uniformity it is essential that
any lessening of pressure be immediately indicated, in order that just sufficient
35 energy be generated and sent out to keep up an equal flow through the circuit of
each translating device, that is, that the pressure be kept up uniform whether
more or less translating devices be in circuit.
This is obtained by providing at the central stations means for constantly
indicating the pressure and for regulating the production of appreciable variation
40 be indicated at each station test lights are arranged, so that an approximate
visual test of the effect of pressure upon the circuit of any translating devices in
use may be shown.
From what has been said it is evident that as more or less translating devices
are brought into circuit the total resistance of the circuit, or all the circuits thereof,
45 to the flow of all the current generated varies. To indicate this electrodynamo-
meters, galvanometers or electrometers are placed across the main conductors at
the central station, or by return wire at any point in the circuit, with a zero mark
placed to correspond with the deflection consequent upon the maintenance of the
proper amount of pressure.
50
55
It may be advisable (and I have so done) to place at the central station a series
of standard" Daniell's " batteries, connected by a switch circuit to the galvanometer
or dynamo galvanometer, in order that they may be frequently tested for any
inaccuracy occurring from any cause whatever. By these means any error what-
ever therein is readily detected.
To correct variations in the pressure various means may be employed. Each
supply generator may be connected into the circuit through a switch, and each
series may be likewise so connected, so that the current of one or more of a series,
R 1664. Wt. 1145.
:
2327
4
A.D. 1880.-Nº 602.
Provisional
Specification,
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
or one or more entire series, may be cut out or thrown into the circuit; or each
machine may be arranged so as to be disconnected from the prime motor, or when
needed the prime motor of an entire series may be disconnected.
The plan I prefer however is to arrange in connection with the circuit of the
battery feeding the field of force magnets of the prime field of force generator before 5
referred to a series of resistances so that the energy of the battery current may be
varied, this variation causing in turn a variation in current induced in prime field
of force generator, and in all the generators directly or indirectly controlled thereby.
When a dynamo machine is used these resistances are to be used in same manner
in connection with the circuit including the coils around the field magnets.
For distributing the current thus generated and regulated at the central station,
I prefer to use conductors within insulated pipes or tubing made water tight and
buried in the earth, provision being made at suitable intervals for house or side
connections.
10
While this plan is preferable for many reasons it is evident that conductors may 13
be carried in the air or over house tops. While only one pair of conductors may be
laid on each street, I prefer, especially where streets are wide, to lay a pair of
conductors along each side of the street near the curb. At proper intervals street
lamps may be connected thereto by derived circuits.
From main conductors on principal streets subsiduary main conductors are laid 20
through side streets; from the street conductors, wherever desired, derived circuits
are led into the houses, one of the conductors passing through a suitable meter,
preferably one which measures the amount of electricity passing through, as set
forth in my Patent, No. 4226, of October 23, 1878.
In the house each translating device is placed in a derived circuit, the entire 25
system of means for generation, conduction, and translation being one great
multiple arc system. The translating device in each house may be either for light
or power, or both. For light, the electric lamp consisting of an incandescing
material hermetically sealed in glass is preferred.
This lamp is made of high resistance in comparison with that of any electric 30
lamps which to my knowledge have been proposed. In lights heretofore proposed
the endeavour seems to have been to lessen the resistance of the carbon, none
having been suggested of higher resistance than, say, 10 ohms., but I have discovered
a very much higher resistance, say, 100 ohms., must be used in order that a number
may be economically and successfully used in a system.
The motor used should be so constructed that each with a constant flow or
pressure of current will give the exact power required.
35
This requires that each motor should be wound with finer or coarser wire, and
with more or less convolutions which determine the maximum effect of the motor.
In addition, as the motors may be run with variable loads or amount of work to 40
perform, and as irregularity of speed would be a consequent thereof, it is preferable
to provide each motor with a governor, which on excessive speed would operate to
break the circuit of the motor or otherwise control it. A preferable form of
governor, therefore, will form the subject matter of an application for Patent to be
filed by me.
A system arranged as thus described provides for all the conditions precedent to
an economical and reliable utilization of electricity as a lighting or motive power
agent.
45
As within certain ascertainable limits the greater the horse power of an engine
the less the proportionate cost per horse power, by consolidating at one station the 50
prime motive force necessary to the generation of a supply for many consumers, a
great economy as to production occurs.
As ordinarily proposed, each electric light requires its own regulator, which
usually is either thermostatic or magnetic, breaking the circuit or bringing in
resistances, in any case making a cumbrous lamp requiring delicate management 55
and constant attention.
By regulating at the central station entirely I am enabled to use a small separate
2328
Specification.
A.D. 1880.-N° 602.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
5
lamp, which may be used with the exercise of no more than ordinary care or
attention.
The distribution is so provided for that tampering therewith is guarded against,
and that connections from the mains to localities of translation are readily made.
5 The means for measuring insures accurateness, and in furnishing a basis for
equitable charges for the amount used by one particular consumer.
10
15
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Alva Edison in the Great Seal Patent Office on the 11th
August 1880.
THOMAS ALVA EDISON, of Menlo Park, in the State of New York, United States
of America. “IMPROVEMENTS IN THE UTILIZATION OF ELECTRICITY FOR Light,
HEAT, AND POWER, BEING AN IMPROVED SYSTEM AND MEANS FOR THE GENERATION,
REGULATION, DISTRIBUTION, MEASUREMENT, AND TRANSLATION OF ELECTRICITY
INTO LIGHT, HEAT, OR POWER."
The object of this Invention is to so arrange a system for the generation, supply,
and consumption for either light or power, or both, of electricity that all the
operations connected therewith requiring special care, attention, or knowledge of
the art shall be performed for many consumers at central stations, leaving the
consumer only the work of turning off or on the supply, as may be desired; in
20 other words, to so contrive means and methods that electricity may be supplied for
consumption in a manner analogous to the system for the supply of gas and water,
without requiring any greater care or technical knowledge on the part of the
consumer than does the use of gas or water, in order that economy, reliability, and
safety may be ensured.
25
In carrying the Invention into effect a city, town, village, or locality may form
one district, or if the extent of territory makes it desirable may be divided into
several districts. In each district I provide a central station, at which are grouped
a suitable prime motor or several motors, dependent upon the amount to be supplied,
generators or means for converting the prime motive force into electricity, means
30 for determining the amount of electricity generated and supplied, in order that a
constant pressure of electricity (so to speak) may be kept up. The prime motors
are any suitable engines, steam or water, and one or a series of two or more are
provided as may be necessary, each of which is provided with its own system of
shafting and belting driving a number of magneto electric machines, the number
35 actuated by one prime motor being hereinafter termed a battery. It is to be noted
that I make my field of force magnets exceedingly long and of an extremely large
mass of metal in proportion to the mass of metal in the revolving armature carrying
the generating coil. By this extra length, as the magnetic tension at the poles
increases with their distance apart, there is secured at the polar extensions acting
40 upon the coils in the revolving armature a much greater magnetic intensity, or so
·
2329
6
A.D. 1880.-N° 602.
Specification.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
to speak a greater magneto motive force or pressure, causing consequently the
generation of a greater amount of energy in the coils operated on than would result
from the use of shorter magnets, even though the same mass of metal were used
therein. By this elongation of the cores I am enabled to dispense with a number
of layers of coils, as one layer of wire is usually sufficient, whereby the resistance of 5.
the machine is largely diminished. The large mass of these magnet cores is
magnetically saturated by a weak current passing around them. It takes this
weak current a long time to bring this mass of metal up to the point of practical
maximum magnetic intensity, but once brought to that point the weak current
readily keeps them there, while with a shorter magnet a stronger current would 10
more speedily magnetically saturate them; this stronger current would still be
required to keep them so saturated.
If the coils of the field of force magnets and the generating coils were included in
one circuit, and all the current generated was passed through the coils of the field
magnet, a very much greater amount of current than necessary for the maintenance 15
of a practical magnetic maximum in the field of force magnets would be passed around
them, and the coils acting as resistances to the energy in excess of that required to
magnetize the magnet to its practical maximum would cause a great waste of
electric energy; hence I prefer to keep the coils of the field of force magnets and
the generating coils separate, and that one machine in each battery (which machine 20
may be termed the battery field of force generator) be used to supply the requisite
energy to the field of force magnets of the other machines in such battery (which
may be termed the supply generator.)
The coils of the field of force magnets are connected as a series or in multiple arc
in one circuit, while the generating coils of the supply generators of each battery 25
are each and all connected in a multiple arc to the main conductors (though for
special purposes they may be connected as a series).
This arrangement ensures great economy, as the per cent. of the entire current
generated in each battery absorbed in keeping up the magnetic maximum in the
field of force magnets when it is furnished by one special machine of the battery, the 30
number given it to feed being properly calculated, being less than when a portion
of the current generated in each machine is absorbed in its own field of force
magnets.
Where a single battery of machines is used it is preferable, in view of what has
been herein before stated, for the current to the coils of the field of force magnets 35
of the battery generators be supplied by a small galvanic battery, but if more
than one battery of machines be used the field of force generators of all the batteries
are fed from one or more prime field of force generators connected in a multiple arc
or in a series, the field of force magnets of the prime field of force generator or
generators used being kept magnetically saturated by a weak galvanic battery 40
current, as before set forth. For instance, a weak galvanic current supplies the
field current necessary for one prime field of force generator, which in turn feeds
the field of force magnets of the field of force generators of ten batteries of twenty
or thirty machines, the ultimate effect in the generation of current depending upon
(as one important factor) the tension of the galvanic current sent through the field 45
of force coils of the prime field of force generators. The prime field of force gene-
rators may however be a dynamo electric machine instead of a magneto machine,
its field of force being kept up by the current generated in the machine instead of
by a galvanic current.
At the central stations all the supply generating coils or batteries thereof are 50
connected to conductors on the multiple arc system, and from these conductors
at the station main conductors (which for convenience may simply be called the
mains), connected thereto also on the multiple arc system, lead in any and all
desired directions for conveying the energy to the points where work either by
translation into light or motive power is to be done. In order to give a better 55
understanding of the method of regulating what for convenience may be called the
pressure of the current through the entire system, I will here state that all the
2330
Specification.
A.D. 1880.-N° 602.
Edison's Impts, in the Utilization of Electricity for Light Heat, and Power.
7
devices for translation of electricity are arranged on the multiple are system, each
device being in its own derived circuit, the effect being in substance to give each a
circuit from the generating source independent of the circuit of all the other
devices. As a resultant it follows that the greater the number of translating
5 devices brought into circuit the less the total resistance of the circuit. For instance,
I prefer that my lamps shall each be of about one hundred ohms. resistance, then
if one lamp only be in circuit there is a resistance of one hundred ohms. ; if another
lamp be put in circuit two circuits each of one hundred ohms. are provided for the
current, making the net total resistance to the current fifty ohms. Although the
10 resistance in each derived circuit remains unchanged, this effect is the opposite of
the effect produced by the addition of lamps when they are connected in an
ordinary straight circuit, each one then adding to the resistance of the circuit.
The bringing into operation successively of numbers of the devices, and thereby
making more paths or circuits for the current, does not appreciably lessen the
15 pressure or diminish the effect upon the devices in use, the active force at the
central station, viz., prime field of force generators and motive power, remaining
unchanged until the net resistance of the devices in circuit exterior to the battery
of machines is so diminished as to approach in a degree the resistance of the battery
and main conductors, it being remembered that as the machines of a battery are
20 connected in multiple arc the net internal resistance of a battery is as many times
less than one machine as there are machines in the battery.
To avoid any appreciable variation and ensure uniformity it is essential that any
lessening of the pressure be immediately indicated, in order that just sufficient
energy be generated and sent out to keep up an equal flow through the circuit of
25 each transmitting device; that is, that the pressure be kept up uniform whether
more or less translating devices be in circuit.
This is attained by providing at the central station means for constantly indicating
the pressure and for regulating the production. If appreciable variation be indicated
at such station test lights are arranged, so that an approximate visual test of the
30 effect of pressure upon the circuit of any translating devices in use may be shown.
From what has been said it is evident that as more or less translating devices are
brought into circuit the total resistance of the circuit, or all the circuits thereof, to
the flow of all the current generated varies.
a
To indicate this electro-dynamometers, galvanometers, or electrometers are placed
35 across the main conductor at the central station, or by return wire at any point in
the circuit, with a zero mark placed to correspond with the deflection consequent
upon the maintenance of the proper amount of pressure. It may be advisable (and
I have so done) to place at the central station à series of standard Daniel batteries,
connected by a switch circuit to the galvanometer or dynamo galvanometer, in order
40 that they may be frequently tested for any inaccuracy occurring from any cause
whatever. By these means any error is readily detected. To correct variations in
the pressure various means may be employed. Each supply generator may be
connected into the circuit through a switch, and each series may be likewise so con-
nected, so that the current of one or more of a series, or one or more entire series,
45 may be cut out or thrown into the circuit; or each machine may be arranged so as
to be disconnected from the prime motor; or, when needed, the prime motor of an
entire series may be disconnected.
The plan I prefer however is to arrange in connection with the circuit of the
battery feeding the field of force magnets of the prime field of force generator before
50 referred to, a series of resistances so that the energy of the battery current may
be varied, this variation causing in turn a variation in current induced in the
prime field of force generator, and in all the generators directly or indirectly
controlled thereby; where a dynamo machine is used these resistances are
to be used in the same manner in connection with the circuit including the
55 coils around the field magnets. For distributing the current thus generated and
regulated at the central station, I prefer to use conductors within insulated pipes
or tubing made water tight and buried beneath the earth, provision being made au
2331
8
A.D. 1880.-N° 602.
Specification.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
suitable intervals for house and side connections. While this plan is preferable
for many reasons it is evident that a conductor may be carried in the air or over
house tops.
While only one pair of conductors may be laid on each street, I prefer, especially
where streets are wide, to lay a pair of conductors along each side of the street near 5
the curb. At proper intervals street lamps may be connected thereto by derived
circuits. From the main conductors on principal streets, subsidiary main conductors
are laid through side streets. From the street conductors, wherever desired, derived
circits are led into houses, one of the conductors passing through a suitable meter,
preferably one which measures the amount of electricity passing through. In the 10
house each translating device is placed in a derived circuit, the entire system of
means for generation, conduction, and translation being one great multiple arc
system. The translating device in each house may be either for light or power, or
both. For light, the electric lamp consisting of an incandescent material hermeti-
cally sealed in glass is preferred. This lamp should be of a high resistance in 15
comparison with the resistance of any electric lamp which to my knowledge has
hitherto been proposed. The endeavour seems to have been to lessen the resistance
of the carbon, but I have discovered that a very high resistance, say, one hundred
ohms., must be used in order that a number may be economically and successfully
used in a system.
The motor used should be so constructed that each with a constant flow or
pressure of current will give the exact power required. This requires that each
motor should be wound with finer or coarser wire, and with more or less convolutions
which determine the maximum effect of the motor.
20
In addition, as the motor may be run with variable loads or amounts of work to 25
perform, and as irregularity of speed would be a consequent thereof, it is preferable
to provide each motor with a governor which, on excessive speed, will operate to
break the circuit of the motor or to otherwise control it.
A system arranged as thus described provides for all the conditions precedent
to an economical and reliable utilization of electricity as a lighting or motive power 30
agent..
Within certain ascertainable limits the greater the horse power of an engine the
less the proportional cost per horse power; so in my system by consolidating at one
station the prime motive force necessary to the generation of a supply for many
consumers a great economy is attained.
เ
35
As ordinarily proposed, each electric light requires its own regulation, which usually
is either thermostatic or magnetic, breaking the circuit or bringing in resistances, in
any case making a cumbrous lamp, requiring delicate management and frequent
attention. By regulating at the central station entirely I am enabled to use a
small separate lamp which may be managed with the exercise of no more than 40
ordinary care or attention. The distribution is so provided for that tampering
therewith is guarded against, and that connections from the mains to the translating
devices are readily made. The means for measuring ensure accuracy, and furnish
a basis for equitable charges for the amount used by any particular consumer.
In the Drawings accompanying and forming part of this Specification an arrange- 45
ment of means is shown for carrying my Invention into effect, although it is to be
particularly noted that the Invention is not dependent upon the specific means
and their arrangement described and shown, but that they may be varied without
departing from the spirit of my Invention. In these Drawings Fig. 1 is a plan of a
central station.
Fig. 2 is a modification of Fig. 1.
>>
"
3 is a plan illustrating the street mains and house connections, with trans-
lating devices properly introduced.
60
4 is a plan showing a locality divided into four districts. In Fig. 1 three
batteries of generators C, Č¹, C², are shown, which may be increased or diminished 55.
as circumstances may demand. One generator c of each battery is used to generate
the current feeding the field of force magnets of the machines in its battery, the
2332
Specification.
A.D. 1880.-N° 602.
9
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
circuit from such field generator through the field of force coils in each battery
being shown by the dotted lines 2, 2, 2.
For actuating the rotary parts an engine D is used with each battery connecting
by belt d to line of shafting E, from which belts e pass to each generator. The
5 coils of each magneto battery in which currents are generated are connected, as in
C¹ and C², in multiple arc to conductors 3, 3, 3, 3, which in turn are connected in
multiple arc to main conductors, 6, 6, from which lead in multiple are the street
conductors or mains 7, 7, or, as is shown in part of battery c, each machine may be
directly connected in multiple arc to the station conductor 6, 6. F is the prime
10 field of force generator supplying the battery field of force generators c, c, c, its
circuit being shown in, dotted lines 1, 1. The field of force magnets of F are
magnetized by a current from the galvanic battery G, in whose circuit is arranged
the series of resistances H provided with the cut out K, by which more or less of
the resistances are put in or out of the circuit feeding the field magnets of F. This
15 arrangement forms a very effective and simple method of regulating the production
of electric current or the pressure at the central station, for the current generated
by F being dependent upon the intensity of the magnetization of its field of force
magnets which in turn depends upon the current transmitted around the magnets
by the battery G. As the resistance varies such current, it follows that by varying
20 the resistance in the circuit of G the current generated by F varies, which in turn
varies the current generated in c, c, c, which in turn varies the current generated in
the supply machines of the batteries, proportionate increase of current and rise of
pressure in the latter following increase of current around the magnets of F, and
vice versa. One or more test lamps T L are placed at the central station in
25 derived circuits to serve as a photometric test of the pressure in the line. For more
accurately indicating variations in the pressure one or more electrometers,
galvanometers, or electro dynamometers E D are placed in derived circuits with
scale marks indicating the deflection caused by the electric pressure so as to compare
the same with the standard pressure to be maintained. By the proper use of these
30 indicating devices and the regulating devices described, a uniform pressure may be
readily and easily maintained through all the mains. It is preferable to connect
all circuits from the generating machines to the main conductors 6, 6, through
switches I, I, I, so that an entire battery or any portion thereof may be thrown in
or out of circuit as the demand upon the station may indicate. It is to be noted also
35 that the belt to the pulley of each machine is to be so arranged by any well known
plans that it may be disconnected from the motor when desired, and in this manner
the number of machines in operation may be controlled, and the effective force of
each machine while in operation is regulated by the resistance in the circuit G.
The engine may be of any desired pattern or power, the number of machines in any
40 one battery being limited by the power of the engine.
45
In Fig. 2 c, c, c, c, are the generators for the field of force magnets in batteries
not shown, and o¹ is the field of force generator of a battery of which three supply
generators c², c2, c², are shown connected to station conductors 6, 6, as before
explained.
>
The prime field of force generator F is in this case a dynamo-electric machine
instead of a magneto electric machine, as shown in Fig. 1, all its coils being included
in one circuit 8, 8, which passes around the field of force magnets of the battery
generators c, c, c, c, cl. The same principle of regulation is used however, the
resistance H and cut out K therefore being arranged in connection with the circuit
50 through F1 so as to cause variation in the tension of the current therein, as and
with the result before explained. In this Figure there is shown what may be used
also in connection with the plan shown in Fig. 1, viz., means of testing the electro-
dynamometer E D or other indicating instrument used. From a standard Daniel's
battery, D B a circuit te may be formed through E D by means of the switch L
55 when moved to the position shown by dotted lines, so that the correctness of E D
may be ascertained periodically, and any inaccuracies which might arise be guarded
2333
10
A.D. 1880.-Ѻ 602.
Specification.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
against; usually the switch L remains as shown in full lines, and E D is in a
branch between the main conductors 6, 6.
The main conductors 7, 7, Fig. 3, are to be connected with the corresponding
wires at central stations (see Fig. 1), and lead down each side of the street M S.
The conductors 7, 7, also branch off into intersecting streets I S. The small 5
circles o in this Figure indicate electric lamps. For street lighting they are placed
as shown in derived circuits from the street mains. From the mains derived
circuits 9, 9, lead into houses, in which are placed at suitable spots the meters M,
through which one of the house conductors passes, and by which the amount of
electricity supplied to the house is accurately determined. Upon these house 10
circuits are arranged lamps o, on the multiple arc system, in such number, position,
and grouping, as may be desired. In these circuits I also propose to introduce
electro-motors E M, wherever desired for furnishing light motive power. From the
motor a belt i leads to a line of shafting h and pulleys a, a, for any needed dis-
tribution of the power, or the belt i may pass directly to a sewing or other 15
machine, a separate motor being used for each power driven machine.
Where motors are desired each preferably should be made of a power propor-
tionate to the maximum work to be done. While the electrical tension in each
machine is regulated at the central station, yet if the maximum load or work be
diminished at any particular motor its speed would necessarily be increased; it 20
also might be desired at times to diminish the normal speed of the motor. In
order, therefore, that some determinate speed may be maintained irrespective of
load or work, each motor should be furnished with a governor to regulate the
electric circuit and the speed.
In Fig. 4 is shown a locality divided into four supply districts; each is provided 25
with its own central station marked CS', CS2, CSS, and CS4. From each station
the mains 7, 7, lead out, as before described. At convenient points, however, say
P, P, connections between the mains of the stations may be made, as shown in
dotted lines, the effect then being to merge the entire locality into one large district
with four supply stations, the pressure through all being uniform, and each station 30
doing its own quota toward maintaining the uniform pressure. The use of four
stations and districts in this diagram is arbitrary, and for illustration only, as the
number actually employed in any one locality depends upon the area of the district
and the number of lights to be maintained
What I claim as my Invention is,-
First. A system for the generation and application of electricity consisting in
the combination of means at a central station for generating the electricity and
for indicating and regulating its pressure, means for distributing the electricity,
and devices for translating it into light or motive power, substantially as set
forth.
Second. A system for the generation and application of electricity consisting in
a combination of means at a central station for generating the electricity, and for
indicating and regulating its pressure, means for distribution, means for translating,
and means for measuring the amount used by each consumer, substantially as set
forth.
35
40
45
Third. The method of regulating the electro motive force or pressure in the main
conductors by regulating the strength of the field of force magnets of the main
magneto electric machines, so that variation of pressure upon the connection or
disconnection of translating devices may be prevented, substantially as set forth.
Fourth. The method of regulating the amount of effect at the translating devices 50
by regulating the field of force current of the generators, substantially as set
forth.
Fifth. The method of regulating the generative capacity of one or a battery of
magneto electric or dynamo electric machines by regulating the current passing
through the field of force magnets; substantially as set forth.
Sixth. The method of regulating the generative capacity of one or a battery of
55
2334
Specification.
A.D. 1880.-N° 602.
Edison's Impts. in the Utilization of Electricity for Light, Heat, and Power.
11
magneto electric or dynamo electric machines by varying the resistance of the
circuit passing around the field of force magnets, substantially as set forth.
Seventh. The method of operating a battery of magneto electric machines by
using the entire current of one machine of the battery to supply the field of force
5 current of the remainder, and throwing the entire current of the latter into a circuit
for use, substantially as set forth.
Eighth. The combination with one electrical circuit of a number of separate
translating devices, substantially as set forth.
Ninth. The combination with one main electrical circuit of a number of separate
10 translating devices arranged therein upon the multiple arc system, substantially as
set forth.
Tenth The combination with a number of translating devices of one regulator
placed at a central station and regulating all the said devices, substantially as set
forth.
15 Eleventh. The combination with one or a battery of generators and a number of
translating devices of means for constantly indicating the electric pressure upon the
translating devices, substantially as set forth.
Twelfth. The combination of a number of generators and a number of trans-
lating devices, all arranged upon derived circuits or multiple arcs, substantially as
20 described.
25
Thirteenth. The combination with means for constantly indicating the electric
pressure of a battery for testing the indicating means, substantially as described.
In witness whereof, I, the said Thomas Alva Edison, have hereunto set my
hand and seal, this 29 day June, A.D. 1880.
Witnesses,
S. L. GRIFFIN.
FRANK MCLAUGHLIN.
THOMAS ALVA EDISON. (LS.)
LONDON: Printed by GEORGE EDWARD EYRE and WILLIAM SPOTTISWOODE,
Printers to the Queen's most Excellent Majesty.
For Her Majesty's Stationery Office.
[1145.-100.—4/82.]
A.D.1880. FEB.11. No. 602.
SHEET 1.
2335
EDISON'S SPECIFICATION.
(2nd Edition.)
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2336
EDISON'S SPECIFICATION.
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SHEETS2337
Complainant's Exhibit, Forbes' Cantor Lectures.
SOCIETY FOR THE ENCOURAGEMENT
OF
ARTS, MANUFACTURES, AND COMMERCE.
}
CANTOR LECTURES
ON
DISTRIBUTION OF ELECTRICITY.
BY
PROFESSOR GEORGE FORBES.
DELIVERED BEFORE THE SOCIETY, FEBRUARY 2, 9, AND 16, 1885.
LONDON:
PRINTED BY W. TROUNCE, 10, GOUGH SQUARE, FLEET STREET, E.C.
.
1885.
Price One Shöllina.
2338
SOCIETY FOR THE ENCOURAGEMENT
OF
ARTS, MANUFACTURES, AND COMMERCE.
CANTOR LECTURES
ON
DISTRIBUTION OF ELECTRICITY.
BY
PROFESSOR GEORGE FORBES.
DELIVERED BEFORE THE SOCIETY, FEBRUARY 2, 9, AND 16, 1885.
LONDON :
PRINTED BY W. TROUNCE, 10, GOUGH SQUARE, FLEET STREET, E.C.
1885.
Price One Shillina.
2339
DISTRIBUTION OF ELECTRICITY.
BY
PROFESSOR GEORGE FORBES.
LECTURE I-DELIVERED FEBRUARY 2, 1885.
INTRODUCTORY.
When asked to give a course of lectures on
the distribution of electricity, I was very
pleased to accept the task, because I felt that
such a work was much needed. Numbers of
engineers have worked out very fully numerous
problems in electrical distribution for their
own wants, but no classification of systems
has been attempted, and no work has been
published to assist the engineer in drawing
out specifications and selecting between
systems.
I also felt that a principal reason why public
electric lighting had made so small progress
was the difficulty of planning a system of dis-
tribution, and the probability that an expen-
sive system proposed to-day would be super-
seded by a more economical system next year.
The low pressure system called multiple
arc distribution is enormously expensive, and
necessitates the engine-house being in the
centre of the populous district lighted, and
this is seldom feasible. A high pressure
system gets over this difficulty, but we can
hardly say that any such system has yet been
brought to practical perfection. This is what
is wanted for large central station lighting,
although much can be done even on the ex-
pensive low pressure plan.
At first I proposed to make these lectures
extremely popular. But as I progressed, I
found that I should sacrifice too much by
avoiding technicalities, and I felt that the
time I have spent on their preparation would
have better fruit if I addressed myself more
directly to brother engineers, but still in
language clear enough to be understood by a
non-technical audience.
sure
I shall use the Parliamentary term " pres-
in these lectures, signifying difference
of electric potential between the two con-
ductors. Those who have had mcst to do
with large practical installations know best
what serious items are the cost of conductors
and the purchase of a site. The latter would
be enormously diminished if the works could
be at a distance. It is my duty in these
lectures to see how far in each system of dis-
tribution the cost of conductors can be di-
minished; and wherever economy clashes with
other facts, and introduces new engineering
difficulties, it will be my duty to show how
these engineering difficulties may be removed.
One thing I must insist upon. If the econo-
mical considerations lead us to a large con-
ductor, we must recommend that large con-
ductor. No financial questions of a difficulty
in raising the money may be allowed to in-
fluence the engineer in recommending a
smaller conductor than his calculations have
proved to be the most economical in the
end.
You all know the different systems which
have been proposed for lighting. You know
how arc lights have been distributed in series,
and how incandescent lamps have been put on
multiple arc in large stations. More especially
you are acquainted with what has been done
in America in this matter. In some cases
only has a special system been thoroughly
worked out; and in very few cases, I fancy,
2340
have different systems been relatively com-
pared and pursued so as to bring out the most
economical conditions possible.
Besides these different systems I have spoken
of the series and multiple arc systems-you
are aware that the latter, the multiple arc, is
divided into a number of different modes of dis-
tribution. You have all heard people talking
about the network system, the system with
three mains, and also of lines-of-centres
distribution. These are different modes of
multiple arc system. And so also we have
another one, which is called the multiple series
system, which has been used to a certain
extent, and very successfully used, but which
has very radical defects in it which have pre-
vented its general adoption; at the same time,
many distinguished engineers believe that, in
the future, there may be a possibility of making
this system efficacious, and of removing the
defects which are in the way. The objection
to the ordinary multiple system, where all the
lamps are connected to two massive mains, or
to a number of wires which are so connected
together as to make two massive mains, is the
enormous cost of the conductors.
Besides the difficulty that the Electric
Lighting Act is unworkable, as every unpre-
judiced person must admit that it is, there is
no doubt another fact which has largely
hindered electric lighting, and that is the
enormous cost of the mains. And not only
that, but the multiple arc system introduces
another serious expense. It becomes essential
with such large mains to have our central
station and our engines in the centre of the
district which is being supplied. Now, in a
thickly populated neighbourhood, such as it
would be economical to light on the multiple
arc system, it is very difficult to get a site for
your engine and dynamos, and this has been
acknowledged by those who have tried to under-
take the system in London to be one of the
most serious objections to the multiple arc
system. Thus at every point we see that it is
of the utmost importance that engineers should
devote their attention to economy in the con-
struction of their mains, to enable us to have a
good supply after the most economical system
of mains which is possible, whether that system
be multiple arc or multiple series, or any
other of the modifications which have been
proposed. It is at present the earnest hope
of thousands and thousands of the inhabitants
of our great towns that they may have elec-
tricity supplied to their houses from central
stations, just as gas is at the present time.
4
They have been prevented hitherto from ob-
taining such a supply, partly by the cost of
production and supply, and partly by the
jealousies of municipal authorities acting
through Parliament, and who have undertaken
gas speculations. The public who want the
electric supply will not endure this much
longer, and it becomes a matter of importance
for electricians to see how far they are able to
reduce the cost of production and supply.
PRODUCTION.
The question of production is one which
has been very fully discussed. The dynamo
machine affords the most economical means
of production, and will probably continue to
do so.
If ever it be superseded, it can only
be by a step in our knowledge entitled to the
name of a great scientific discovery. Such
discoveries do not come at our bidding. They
are evolved in the laboratory of the patient
scientific inquirer, and seldom in the workshop
of the speculative inventor. In selecting our
dynamo, cost of manufacture and maintenance,
and cost of production of electrical energy,
are the chief items to be considered. For a
central station with 10,000 lamps, we want to
have about 1,000 electrical horse-power in the
circuit. We may use high-tension machines
in parallel, or low-tension machines in series,
until we get in the external circuit 7,500
ampères and 100 volts (if such be the class of
lamp we are using), or we may use a single
machine to produce the same effect. It is
better to use a large number of machines, so
that they may be each removable and able to
be replaced by another when repairs are
necessary. But it is a matter of indifference
what class of machine we employ (high-tension
in parallel, or low-tension in series), except so
far as cost is concerned. We have simply to
choose the machine which gives the greatest
output of energy in the circuit at the least
expense.
I have drawn attention to this because it is
important, and because few people have
thought of combining low tension machines in
series. And I have confidence that the sim-
plicity of construction of these machines, their
cheapness and economy of maintenance, and
their infinitesimal internal resistance, will lead
them to be generally adopted.
The question of primary batteries must be
laid on one side as being quite too costly. If
a battery were made practical in which coke
or charcoal should be consumed instead of
zinc, we might discuss the matter. In 1880, I
2341
made a number of partially successful experi-
ments in this line, but with no very definite
result. If, on the other hand, the residual
products of a battery were valuable, and there
was unlimited demand for them, some progress
might be made. As yet we have no reason
for hope in this direction. Secondary batteries
being dependent entirely upon the dynamo,
are connected with the supply rather than with
the production of the current.
There are other systems, such as that which
utilises alternate currents combined with the
induced current distributors on the plan
perfected by Messrs. Gaulard and Gibbs.
This also is rather a question of supply
and distribution, and will be left to a later
stage for discussion.
Leaving now the question of the production
of electricity on one side, the next point to be
considered is its distribution and supply. But
before attacking this problem directly, I should
like to make a comparison of it with the similar
problem with respect to gas.
COMPARISON WITH GAS DISTRIBUTION.
The production of gas is a somewhat ex-
tensive laboratory experiment enlarged to a
commercial scale. The distillation of coal,
and the subsequent treatment of the gas by
condensers, scrubbers, and lime purifiers,
previous to its admission through the regu-
lator and station meter to the gas holder, is
really a complicated process compared with
the production of electricity. In its distribution
through mains to the houses of individuals,
the problem is very similar to the problem for
electricity. A certain pressure is given to the
gas at the central statica. With this pres-
sure it must be forced through the mains, and
must be delivered to the gas-jets of con-
sumers at a definite pressure. The pressure
must not vary seriously with the number of
jets in use, nor with the position of a house in
the district. There must be no leakage in the
pipes, or as little as possible. In all these
points electricity has its analogue. More-
over, a difference of pressure will establish
itself if the flow of gas and the resistance of
the pipes to this flow are large; and the
larger the pipes the less is this resistance.
Hitherto, the analogies are very striking.
There are, however, two points of difference.
First, in gas-distribution the resistance to the
flow of gas is not proportional inversely to the
area of the pipe, so that while with electricity
the resistance of 100 parallel wires is the same
as that of one wire 109 times the section, this
5
is not the case with gas, where the hundred pipes
have much more resistance than the simple
pipe of 100-fold section. Secondly, the cost
of gas mains is not proportional to their
sectional area, and still less is it proportional
to the current of gas it has to carry. With
electricity, on the one hand, the cost of mains
always increases at least in proportion to the
current. The consequence of these facts is,
that the cost of mains is an incomparably more
important matter in the case of electricity than
in that of gas. This is what renders the dis-
tribution of electricity so important and worthy
of study by the electrician. Upon the arrange-
ments made under this head depends very
largely the question whether or not electricity
is as cheap a means of lighting as gas.
While comparing gas and electricity, it is
surprising to see how great difficulty has been
met in introducing the latter. When gas was
introduced, the public had no experience of,
nor occasion for confidence in, a general
supply, and the laying of pipes was a leap in
the dark. There was no knowledge of the
size of pipes required, there was little means
of even guessing at the probable consump-
tion. At the present time a public supply of
light is well understood and appreciated, and
we know well what currents our wires will
carry. Moreover, from the known gas con-
sumption, we can form a more accurate esti-
mate of the probable demand for electricity.
Then, at the same time when gas was intro-
duced, the burners were infamous (merely a
hole in the top of a closed tube), and the flame
was smoky and sulphurous, consumed the
oxygen, poisoned the air, and blackened sur-
rounding objects, while its smell was odious
and unwholesome. It was not known how to
prevent leaks, and leaks meant explosions.
The inexperience of the public was certain to
leave cocks turned on-hence explosions
again, and deaths from suffocation by gas.
Gas gave a naked flame which is a constant
source of danger, while to-day the incan-
descent light cannot set light to anything.
Yet, in spite of all these advantages, the diffi-
culty of introducing electricity has been far
greater than was that of introducing gas. The
electric light must contend against a mono-
poly. Gas had a fair and open field. Our
Legislature has favoured the monopolists; the
legislators for gas encouraged its develop-
ment. Gas met with financial speculators
just as electricity has done. The monopolists
who have sprung into existence are the one
deterrent cause.
2342
DISTRIBUTION OF ELECTRICITY.
Passing now to the subject of these lectures,
it will be well if we give a general survey to-
day of the various points with which we have
to deal, and of the different plans of distribu-
tion, which must afterwards be considered in
detail.
6
0'0024 of an ohm. Now, the energy which is
used up is given you by the calculation R
divided by 746. That is equal to 3·2 horse.
power used up in every 100 yards of our con-
ductor for every 1,000 ampères. Now, what is
the cost of this electrical horse-power per
annum? It is usually considered safe to say
a horse-power costs £10 per annum, but,
owing to the period in which electricity would
be used, this is not a safe figure. Let me
begin by considering £20 as the cost of horse-
power. £64 is the cost of the total horse-
power. We have wasted in four years in every
hundred yards £256; in twenty years £1,280
is wasted in that conductor. Now, if I double
the size of my conductor, I have the quantity
of power wasting reduced to £640. The
The first thing to be noticed is that, in order
to give electricity a fair chance in competing
with, or supplementing, the gas supply, the
cost of one of its most expensive parts, i. e.,
the conducting mains, must be reduced as low
as possible. Various schemes have been pro-
posed with one advantage or another. Some
systems have been devised whose speciality
is that they do not allow the potential to vary
much. Other systems have specially in view
the avoidance of total darkness if an accident.question comes to me, would it cost more than
should occur at any point. At present it is
essential that these considerations should be
second to economy. Let us first get the most
economical system, and all things else shall
be added hereafter. Now, in attempting to
reduce the size of our conductors, we meet
with three difficulties:- 1. With small con-
ductors, energy is wasted in heating them,
and this may become very considerable. Thus,
while capital outlay on copper is saved by
small conductors, the annual consumption of
coal is increased, and large engines and
dynamos are required. 2. With large currents
this heat may be sufficient to injure the insula-
tion. It also increases the resistance of the
conductors; and if the conductors be under-
ground, the heat may become unpleasant to
foot-passengers. Clearly, the conductors must
be large enough to prevent such troubles.
3. There is a loss of potential in the mains,
which is greater where these are smaller.
This loss is also greater in proportion to the
number of lamps fed by the main. The fall
of potential with one lamp might be one-tenth
of a volt, and with 100 lamps it would be ten
volts. So large a variation under varying
conditions of consumption cannot be permitted,
and the conductors must be large enough to
prevent any such variations.
I propose now to say a, few words on each of
these heads, in order to prepare the way for
criticising different systems of conducting
mains.
Now, let us first look at the problem with a
few figures before us, to see on what scale we
are dealing. Suppose that we are using a
conductor of a square inch section to carry
1,000 ampères. The resistance of 100 yards
of that conductor of pure copper would be
£640 of capital to lay down an extra hundred
yards of a similar section? No, it would not;
and, therefore, it is economical to double my
conductor. And so we go, step by step, until
we find that the gain is just equal to the extra
expenditure of capital in the laying down of
conductors, and then we have arrived at a
satisfactory arrangement. You will easily see
if you work this out. Now this is an important
point, in fact one of primary importance. It
was first approached by Sir William Thomson
in an address to the British Association, in
1881, in which he read a paper on
Economy of Metal Conductors of Electricity,"
and, in that most interesting paper, he arrived
at the conclusion that the interest spent upon
the capital of the conductors should be equal
to the value of the energy which is wasted
annually in these conductors.
"The
The first question which becomes a trouble
is, what are we to consider the cost of elec-
trical horse-power? There are two ways of
looking at this problem, and we will just
glance at them independently. First, let us
take the case of an installation which has
been carefully estimated for; and let us
see there, after the whole of the buildings,
distributing and supply plant, and everything
has been laid down, what is the cost of each
horse-power of electricity, if you like to call
it so.
To give you a perfectly unbiased
example, I have taken the figures, kindly
furnished me by Mr. Crompton, of a large
installation for which he carefully prepared
estimates. I find, on looking into this, that
in this case the cost of electrical horse-power-
of course depending on the number of hours
used during the year-if it was for 1,000 hours,
the cost of horse-power came to about 5d.;
•
2343
ས
for 2,000 hours in the year, 3'5d.; and for
3,000 hours only 3d.; and that means for the
year in these three cases, it would be 5,000
pence, 7,000 pence, and 9,000 pence. Now,
the next question that comes before us is,
what is the number of hours we are supposed
to use our electricity? There is very little
doubt that about 1,000 hours is probably a fair
average consumption for people in a town;
but I think it very likely that, at any rate in
the first installation set up, a certain selection
will be possible, which will raise the average
a little higher. For my own purposes at
present, I am going to assume 1,500 hours; if
you prefer another value, you can work it out
yourselves to suit it. That will be the average
cost of those two, which comes almost exactly
to £25 a year. Now, if you work out the cost
of the energy wasted in a 1,000 yards con-
ductor, you will find, I think, that the follow-
ing figures are energy wasted in the conductor
for 3 in., 4 in., 41 in., 5 in., 5§ in., 6 in., and
6 in.; the amount is £228, £20, £17·8,
£16, £145, £132, and £12. Therefore, the
gain in passing from any one to the next is
2·8, 2'2, 1·8, 1°5, 1*3, and 1'2. These are the
gains which there are in increasing the size of
the conductor.
Up to this point it is all plain sailing, a
matter of plain calculation. The next thing
is, What is the interest on the capital which
is expended? This, of course, depends on the
way in which the mains are laid, and different
people have different ideas about how they
should be laid. Many people lay mains at
present with stranded cables. For my own
part, I cannot see what is the object of doing
this; it is the most expensive form in which
you can produce your copper, and really
nothing is to be gained. It seems to me
simply to arise from the fact that cables we
used previously were submarine cables, and
certainly they are of great advantage there;
but why they should be used on land, where
there is no strain, I see no earthly reason.
Others think they should be laid in massive
bars of semicircular shape, covered with
bituminous compound: others, in flat sheets
laid in troughs. At any rate, every person
differs from every other, and consequently
every person must have a different value
for his cost of copper. But I have taken
it as an example, simply, and you need not
take the value I use. Take the £100 a ton as
the cost of adding an additional amount of
copper to our mains, after the troughs and so
on have been laid. In that case the interest
7
|
upon it depends upon the per-centage which
we allow. Now, what are we to allow? Ought
it to be 5, 7, or 10? That, again, is a ques.
tion for the engineer to determine for himself,
But allow me to point this out, that when we
are increasing the size of our mains, really we
ought to be diminishing the per-centage allowed
for maintenance. The wear and tear is less,
heating is less, the danger to insulation is
less; everything leads us to believe there is a
less cost of maintenance with a large conductor
than with a small one. This is a very important
point. Each one must judge for himself
whether to take 5, 7, or 10 per cent. He will
find with 5 per cent. the annual cost is £127,
at 7 per cent. £1.91, at 10 per cent. £2'55; so
that what we have to do is to find that size of
conductor which should equal the interest
which we happen to consider the right interest.
Supposing 5 per cent., then we have £127
settled, which gives 6 inches; 7 per cent.,
£1'91, about 4 or 4 inches; and 10 per cent.,
£2.55; between 3.5 and 4 inches for a thousand
ampères, I have gone through this example
carefully just to give you a clear conception of
the way in which the problem is to be worked
out, but I think you may very safely say that
the consumption I have taken is too large. It
is perfectly true that this estimate to which
I have alluded includes the cost of buildings,
dynamos, boilers, and other machinery, the
mains, and also the annual cost of coals at
18s. per ton. Well, all these points do come
in, therefore it is a question for each one
to consider for himself how far these things
are to be divided in this way. It may be said
by some, however, that it is desirable only to
look upon our plant as being fixed, and sup-
posing we want to carry extra current on the
same size of conductor, would it be wise to do
so or not?
We may ask, "With a working station,
what would be the extra cost for energy wasted
if we increased the current for the same section
of wires?" The answer might be given that
everything is in place and paid for, except an
extra engine and dynamo, and the cost of coal,
oil, waste, and petty stores for the extra energy.
The cost of a mechanical horse-power so
reckoned is, say, o'75d. per hour with coal at
21s. the ton, say I'ood. for an electrical horse-
power per hour, including loss of trans-
formation, besides the cost of the dynamo, i.e.,
1500d., or £6.250 per horse-power per annum of
1,500 hours. The cost of dynamos is £20 per
1,000 watts of maximum output, or £7 18s
per horse-power, which, at 15 per cent., is
2344
£1 2s. 6d. per annum. Thus the whole annual
charge per horse-power, in this way of looking
at it, is :-
Power..
Dynamo
Total charge....
£6.250
I'125
7'375
Now, we have seen above that when a con-
ductor of one square inch section carries a
current of 1,000 ampères, the loss of energy
per 100 yards is 3.2 electrical horse-power,
which is £23.599 per annum. Our Table now
becomes the following:-
Section in Cost of waste Gain for 1-10
sq. in.
inch increase.
energy.
Extra cost of
mains at 5 per
cent.
0.635
0·635
£
£
£
2.50
9 440
0.863
2.75
8.577
0.711
3:00
7·866
0.605
}
3'25
7.261
3.50
6'743
0518
0.635
0.635
It is not fair to allow more than 5 per cent.
on the extra copper, as there is no extra atten-
tion required, in fact probably less attention,
owing to the smaller development of heat.
This gives the maximum economy at 3 to 3°25
inches the 1,000 ampères. Where the cost of
an electrical horse-power is 0.8d. in place of
a penny (exclusive of interest and depreciation
in the dynamo) the economical size comes out
2.5 square inches to the 1,000 ampères.
I have now gone very fully into the question
of the most economical size of conductors.
But it is one of prime importance in the whole
of our problem; and in conclusion, I will furnish
you with a Table which I find to be of great use.
The engineer can choose his facts for him-
self absolutely, can choose what he considers
to be the right value of the electrical horse-
power every year for the number of hours he
proposes to run. He can also choose the cost
of copper which he thinks it will suit him to lay.
Having done that, he proceeds in this manner :
I will take as an example copper costing £100
a ton; take 7 as the rate of interest; I look
along the column of Table IIb. (p. 13) until I
find £100, look down until I come to 7, and find
the figure 316. I then look to the top of the
Table IIa. (p. 13), and I have £8 a year, say,
for my electrical horse-power. I look along
the column of £8 a year until I find the figure
8
nearest to 386, and I find that it comes to a
place beneath the number 2'7; in that case
2.7 would be the square inches which are re-
quired for the main on those conditions imposed
by the engineer himself. I have given another
Table (p. 12) for continual reference, showing
the resistance of 100 yards and various other
facts, also the current which will heat the wire.
Before leaving the subject of the cost, allow
me once more to impress upon you that I con-
sider this matter of primary importance, and
no consideration must ever lead the engineer
to deviate from the strict rules which regulate
the cost. It may be in some special cases not
always practicable to regulate our wires to
carry the current exactly at this rate. It may
be because it is easy to get a stock of con-
ductors at slightly different size, or it may be
inconvenient to be always varying the estimate
in the size. But these principles must be gone
into for every part of the scheme, and in our
practical application we must stick as closely
to our results arrived at there as we possibly
can. It is no use for the engineer to say that
financial people will not bring forward the
money for these costly mains. The engineer,
in my way of looking at it, has no right to
look at what the financiers want to do. He
must tell them honestly what is the most
economical thing to do. If the financier wants
to lay out capital in a particular direction,
knowing that he will be causing a waste of
energy, the engineer ought to have nothing to
do with such matters. He ought honestly to
give the value of the current which is most
economical.
I have dealt now fully enough with the
first cause that prevents us from diminishing
the thickness of our conductors. The second
cause why we should not reduce too much, is
the heating of the conductors. There are, in
this, three injurious facts; in the first place,
it spoils the insulation; the insulating power
of the material diminishes by being heated,
and the material itself becomes injured; more-
over, when it is hot, it usually becomes
soft, and the conductors can sink into it,
and thus become decentralised. And in
the second place, the conductors themselves
are injured, because their resistance is in-
creased by the increase of temperature, and
these increases of temperature, mark you, are
very considerable. And in the third place,
the increase of temperature may be very
serious, and may actually be objectionable
along the streets. I have here a small piece
of cable which shows the decentralising action
along the streets.
2345
of bituminous compound. This has been
lying for six or eight months in a cool part of a
cool room, always lying in the same position.
I believe when I got it it was perfect, but in a
cool place it gradually sunk, and now it is very
decidedly out of centre. An old experiment
which I used to show when I held my chair at
Glasgow, illustrates the viscosity of objects.
It was first suggested to me, and I first saw it
done, by Sir William Thomson in his labora.
tory. A block of hard brittle pitch-or
shoe-makers' wax would serve the same
purpose is set with a bullet on the top and
corks underneath; in six months the bullet
will have sunk into the pitch, and the corks
will have risen several inches up through it.
This simply shows you how such bituminous
compounds must be carefully watched, and
how very objectionable is any viscous material
in the way of decentralising the conductor.
Now, as to the question of heating con
ductors, I will not take up much of your time
this evening, because I have already, in'a
paper which I read at the Society of Tele-
graph Engineers last year, gone into the ques-
tion very fully. It used to be supposed by
some that if the currents in different wires
were proportional to the section of the wire,
the heating would be the same in all. This is
not so, and when we look into the matter we
could not expect it to be so. Heat is gene-
rated in a wire at a steady rate, and, if the
temperature of the wire has reached a stationary
condition, the same quantity of heat is carried
off from the surface of the wire.
I showed by experiment, in 1882,* that to
give the same heating in different wires (when
these wires are small) the diameters of the
wires should be nearly proportioned to the
currents they have to carry.
I will show you by a simple experiment that
if the currents should be proportional to the
section, the thicker wire would get hottest.
Here I have two wires of the same length;
one is ten times the thickness of the other.
I unite their ends in parallel and send a
current through. The current splits up into
two parts proportioned to the section of the
wires. Both wires get hot, but the thick one
hottest, as you see by its white incandescence,
whilst the other is not luminous.
I only draw your attention to the question
now, because there is an important point
which, I am glad to say, needs correction.
A discovery has been made of an error near
the end of the paper which might be mislead-
British Association Report.
9
ing, and which probably has misled some. I
will give you a corrected edition of it.
Here is the Table to which I have referred.
It gives you underground conductors. I have
recommended sheets of copper for under-
ground conductors, because the temperature
is far less raised when you have a thin con-
ductor.
Width in inches, of
copper conductor,
x cmr. thick.
Cross-section
in square inches.
Current to raise
surface temperature
10° C.
ampères.
3.2
O'25
250
12.7
0.98
1,000
·38.1
2.95
3,000
63.5
4'92
5,000.
127.0
9.84
10,000
889.1
68.88
70,000
This is a most important point. We have
absolute control over the temperature; by
widening out our sheet we have diminished
temperature, and can make the heat of con-
ductors subservient to economy.
It is not essential that copper sheet should be
used. The same mass of copper put into rods,
or wires side by side, would produce the same
effect if the average thickness of copper con-
tinues to be one centimetre, and these rods
might be insulated in any way, or put in pipes.
The depth at which these are laid does not
affect the heat of the surface of the pavement
so long as the depth does not exceed two feet,
but the temperature of the conductor itself is
greater at the greater depth.
It is satisfactory to find that the considera-
tions of heating the insulation and heating the
surface of the pavement, lead to the same result
as that of economy, viz., that we should have
1 square inches per 1,000 ampères of current.
I pointed out that if you do not bury your
conductors more than about two feet, the sur-
face temperature is not affected; only the
temperature of the conductor. If you go two
feet deeper, you will affect the surface tempe-
rature also. I have thought that up to 10° C.
is the limit endurable by foot-passengers. In
the summer the rising temperature of the pave-
ment is most objectionable; fortunately, this
is the time when the current is the least used.
Moreover, the temperature does not imme-
diately pass through the ground. The daily
variations of surface temperature differ as the
diurnal change of position of the sun; it does
2346
not penetrate very deep down -is very slightly
perceptible at two feet depth. If we have 500
ampères flowing for 24 hours, the effect would
be almost exactly the same as if 1,000 ampères
were flowing for six hours. Another point-
instead of laying a sheet one centimetre thick,
you might lay cables with the same result,
provided the average thickness was one
centimetre.
In speaking of the economical size of con-
ductors, I arrived at the conclusion that I
might use 2.7 inches, or say three inches for
1,000 ampères; but mark you, though 1,000
ampères is the average current, it is not the
maximum current to pass through that con-
ductor. The maximum is a very different
thing indeed to that. When we have an aver-
age of 1,000 ampères, it does not in the
least mean that that is the average quantity
of current which is flowing through it, because
the wasted energy depends upon the square
of the current. This leads to a very different
law, and a very important one, about which I
have a word or two to say. Suppose n, is the
number of hours during which a quarter of
the lamps are burning, n₂ one-half, n, three-
quarters, and 4 the number of hours during
which all the lamps are burning; then the ratio
of average current to maximnm current is-
√
2
(4)² n, + (})² n₂ + (†)° n¸ + n,
n₁ + n₂ + n¸ + n₂
3
= a.
The following Table gives a for different
values of n₁, n₂, n¸ and n¸.
3
RATIO OF
AVERAGE
MAXIMUM
CURRENT.
"1
112
123
24
a
O
10
a, and hence 1'5 square inches to the maxi-
mum current of 1;000 ampères. It seems to
me, for a working hypothesis-which no one
need adopt-a good enough value.
The third reason why we cannot reduce the
size of the conductors too much is, that the
potential falls, and the thinner the conductor,
the greater the fall of potential between the
dynamo and the lamps. With a large current
there is a great fall of potential (experiment
shown), thus showing that in a central light-
ing station the fall of pressure, and, therefore,
the brightening of the lamps in the district,
depends upon the number of the lamps in use
at the time. This is a serious thing, and the
most difficult engineering problem with which
we have to deal. We have arrived at the con-
sideration that a square inch and a-half for
1,000 ampères is the size we must use, which
means a fall of potential of 16 volts for each
conductor in every 100 yards, that is to say, a
fall of nearly 3 volts, with the double con-
ductor, for a distance of 100 yards; and
whether you like it or not you must have it.
It may be met by making distant consumers
use lamps requiring a different pressure to
those nearer. This is the thing which has
given the most trouble, and the point will be
considered in the next lectures.
I had hoped to have gone a little into a
description of systems of laying mains which
have been already adopted, but time is press-
ing too much. I will just say a few words
abcut some of the systems I saw at the Phila-
delphia Exhibition last year. People seemed
to have missed altogether the point that is to
be aimed at in underground conductors. There
was an invention shown, simply consisting
of tiles with holes through them, the cables
to go through the holes.
EDISON'S CONDUCTORS.
O
O
I
I'000
O
I
O
I
0*790
I
2
2
I
0.744
I
I
I
I
0.685
2
2
I
I
0.604
Outside in inches.
Area of
one conductor in
circular mils.
Maximum current
in ampères.
2
I
0.500
Thus the average quantity can be got from
the maximum quantity by multiplying by the
correct value of a. If half the lamps are
burning two-thirds of the time, and the rest
of the time all the lamps are burning, we get
ů == 5. Therefore, instead of having 2'7, we
only have 1 35 as the actual area of for 1,000
ampères. As a matter of fact, I shall select
for the rest of the lectures 5 as the value for
3.5
1,639,890
1,400
3:0
862,976
760
2.25
262,951
370
1°31
107,289
220
1.05
33,000
100
These are laid in bituminous compounds in
iron pipes, and seem to work pretty well for
low potential work, but every electrical
·
2347
engineer thinks we shall be able to introduce
high potentials some time or other, and reduce
the cost of these mains.
What is it that makes it so difficult to
insulate these mains properly? It is very
difficult to say.. It may be that there is a faint
leak, and a spark passes to the iron pipe in
which the conductors are encased, and that
gives rise to an increasing leak. It may be
that where there is the faintest leakage there is
a partial decomposition of the water that
comes into contact with it, and that brings
electrolytic action into contact with the insu-
lating material, which we know it generally
destroys, and so the leak becomes worse, and
very bad indeed. Through the kindness of
the Brush Company, I have here a specimen
of a fault in one of their underground City
conductors showing where it is eaten into. In
Philadelphia, there were some systems shown
in which there was a very wide trough and
glass plates introduced here and there, in
which was a large number of holes. Glass
is a very bad substance to use: it gets
moisture upon it, and, besides, there is a
tremendous wasting of space for small wire.
In another, copper rods were carried through
pipes made as water-tight as possible, sup-
ported on rings of glazed porcelain, so that
there is a very small surface of leakage
possible. With the rings here and there, of
•
II
course, dampness was a serious obstacle.;
and in this system it was proposed to
blow dry air through the pipes so as to
keep the moisture continually out of them.
I can only say of this that it is only a pro-
position; the thing has never been done."
I had hoped to speak to you of what has
been done in underground conductors, but
really there is very little to tell you, and that
can be said in very few words. In Philadelphia,
there was a system of underground conductors.
put down by the Excelsior Company, and they
worked pretty well. They used large troughs,
and where there are large troughs, there is no
difficulty about it. But these large troughs
had very serious inconveniences that one
hardly expected from electricity. Three times
during the time I was at Philadelphia the
troughs in Chestnut-street blew up, a most un-
expected result from an electric conductor, but
it was a positive fact, and the secret was
they were too near the gas mains, which
leaked and positively filled the troughs,
and, consequently, they blew up when a
light came near them. However, these were
accidents that might have been prevented with
care.
I have an illustration here of the installation
at Colchester, which illustrates the way in
which very large troughs are laid with con-
ductors cut along them.
CURBING
S
PAVEMENT
HOUSE
WOOD
TROUGHING
SERVICE
MAINS
SECTION OF
CHANNELLING
SERVICE
POLES
CHANNELLING SHOWING CHARGING AND SUPPLY CABLES.
The Jablochkoff Company on the Thames-
embankment has had a lengthened experience,
extending since 1878, and with a small 7-16
strand wire, covered with gutta-percha and
tape, and put in troughs underground, where
it has given very little trouble. Then, again,
in the City, the Brush Company has had these
conductors underground since April, 1889, and
they have had a great deal of trouble. They
'tell me that they were put in first very loosely,
and covered with sand for some reason or
other, and in drawing the cables through the
pipes, the sand wore them away, and the con-
sequence was the insulation went.
Among the most successful underground
cables which I have seen are those used by
2348
B.W.G.
the Indiarubber Company at Silvertown.
The
cables are numerous, and all made of copper
coated with indiarubber, with a protecting
cover of cold-drawn lead. These are laid in
troughs underground, with frequent man-holes
12
to assist in the insertion of new cables. Parts
of these troughs are always full of water;
other parts are always dry; elsewhere there
are variations of wetness and dryness. An
electromotive force up to 550 volts has been
Diameter in Inches.
Section
in square inches.
lbs. Copper per
roo yards.
TABLE I.
Resistance per
100 yards at 15°5º C.,
or 60° Fah.
Wire heated to 9º | Wire heated to 25°
above tempera-
ture of air.
above tomperature
of air.
B. A. Legal
Units. Ohms.
Current.
Loss in
Volts.
Current.
Loss in
Volts.
Diameter in Inches.
B.W.G.
per
per
100 yds.
100 yds.
2'26
4'0
4608.
*000634
*00062.7 1514'
*998
2490°
1'730
2'26
2'11
3'5
4032'
'000724
*000716 1384'
1'042
2246'
1'783
2'II
I'95
3'0
3456.
*000845
*000835 1228°
1'079
1995'
1'47
1'95
1.78 2'5
2880'
'00101
*000999 1072'
1*125
1739°
I'931
1*78
1'60
2'0
2304°
'00127
*00126
913'
1'205
1482*
2'059
1'60
1'38
1'5
1728*
00163
'00161
732'
I'288
1188.
2*187
I 38
I'13
1'0000
1152'
'00253
'00250
542°1
1*426
880'0
2°446
I'13
1'00
*7854
904'78
*00326
'00324
451'5
1'513
732'7
2*586
ΤΟ
*75
*44178
508'93 *00584
*00578
293'0
1'746
475'5
2'991
*75
*707
*39250
452'16 *00653
*00651. 268'0
I 800
435'2
3°081
*707
*500
*19635
226'18 *01307
*01292
159'4
2'139
258.6
3*659
'500
oooo
'454
*1618
000
*425
*1419
00
*380 *1134
130'64
*354 *09842
о
*340 *09079
186 39
*01567
163'47 *01786 *01766
*02236 '02211 105'7
113°37
*02605 *02576
104'60 *02824 '02793
'01550 138'1
2'248
224°1
3'854
*45+
0000
125'1
2'323
203'0
3'977
'425
000
2'456
171'4
4°201
*380
00
95'I
2°546
154'3
4'357
*354
89'4
2'594
145°1
4'442
*340
I
*300 •*07068
2
*284
*06334
3
*259
*05268
81'42 '03637 *03597
73'00 *04048 *04003
68.68 *04867 *04823
74'0
2*755
120'I
4'722
*300
I
6863
2.850
III 4
4'880
*284
59 60
2'981
96'7
5'102
*259
3
4
*238 *04448
51.61 05764
5
*220 *03801
43.78 *06740
'05700
*06665
52°37
3'102
85°0
5°315
*238
4
46'5
3°213
75'5
5'521
*220
5
6
*203 *03236
7
•180 '02544
8
*165
9
*148
*02138
*01720
· 10
*134 '014102
37°27 *07937 *07849
29°3 *1006
*08943
34°31
24'62 '1199 *11857 30°25
19.81 *1492
*14643 25°28 3.878
16'25 *1812 *17919
41'27 3'360
63.97
5*762
•203
6
3'553
55'69
6'084
•180
7
3°728
49'09 6°384
*165
8
41'03
6.630
*148
9
22.12
4°133
35'90
7'075
'134
10
11
*120 '011309
13'00 *2267
*22418
18.74 4°366
30'41
7'473
'120
II
12
*109 *009331
10*74 *2748 *27175
16:25 4'589
26'38
7.857
*109
12
13
*095 *007088
8:16 *3617 *35769
13'09 4'866
21.25
8°332
*095
13
14
*083 *005410
623
*4739 *47064
10'84 5*280
17:58
9'031
*083
14
IS
*072
'004071
4'68
•6 98
'62281
8.723 5'646
14'14
9'652
'072
15
16
065
*003318
17
*058 *002642
3.82
'7727
3'04 *9711
*76412
7'481 5'931
12'14 10*169
*065
15
*96032
6.371 6'354
10*24
10'771
*058
17
18
*049 *001885
19
20
*035
2'07 I'3598 I'3447
*042 *0013854 1'60 1'8502 1'8297
'0009621 1108 2.6650 2'6354
4'876
6·813
7'95
11.691
*049
18
3°883 7',85
6'31
12 658
*042
19
2'953
8.087
4.80
13'866
*035
20
Legal volts. 96 per caut. conductivity copper. Heating of bare copper wire, emissivity00025 C.G.S. units,
2349
Anaval Cost OF ELLCIRICAL HORSE-LOWER.
TABLE IIa.
Section per Thousand AMPERES IN Inches.
221 206* 192180 170 160 150
*255237 22:
*305284,265247230 216 203* 192* 180° 170
356331*309 288 269 252 237° 224*210* 199* 188
*458426397*370* 346324 305288 270 256 242 229217
*509473441411*384*360* 339*320*300* 284 269 254 241 229
473° 442
I
I'I
1'2
1'3 1'4 1'5 1.6 1'7 1-8 1'9
2
2'I
2'2 2'3 2'4
2'5
2'6
2°7 28 29 30 31 32 33 34 35 36 37 38 39
44°55'05°56'0
£
5 1628 1*356| 1*147
61954 1627 | 1*377
*980❘ *857
1*176 1*028
72°279 1898 1606 1°372 1*199 1'044
8 | 2'605, 2'169 | 1·836 1.568 | 1°370 | 1°194 | 1°053
92°930 2'441 | 2°065 | 1*764 | 1°542 | 1°343 | 1*185 | 1°053 *942
·848
*746 658 585 *523 471 *426 386
*386 355 *324 *298
*895 *790
*702 *628 *565
*463 426
'511
*389 *358 *331
*921 *819 *733 •660 *596 *540 *498 *454 *417
*936 | 838
*754 ⚫682 *618 569 518 *477 *442
695
*695 640 583
*583 536
276 255 |* 237,*
*386
*407 *378, *353*329307288*271 256 240 227 215 203
767
*497
⚫852
'772 *711 *648 *596
*552
AI
12
13
14
15
*849
*782
*712 656
607
*715
*662
*718
*773
*828
17
38
19
20
•883
*938
*994
·
·
1450
6
7
8
9
ΤΟ
II
12
ཱ སྠ 8 9 s
14
10 3'256 2712 2'295 1960 1713 1°492 1*316 1*170 1'047 *942
| |
|
2°983 2°524 2'156 | 1*885 | 1'641 1°448 1°287 1*152 1037 937
560*520 485 452 422396*373° 352330312 296° 279° 265 * 252° 240
| |
| | |
2*754 2°352 2°056 | 1°790 | 1°580 1°404 1256 1131 1'022 *926 853
*853 *778
*611*568*529* 493 461 432 407* 384 * 360*341*323* 305*289* 275 262 206
2'548 2227 1'940 | 1°711 1'521 1*361 1°225 1°108 1'004 *924 *842 *775
662615 573534 499468*440*416 390 369 350 330313298 283° 224181
| |
2°398 20891-843 | 1°638 | 1°466 | 1°319 | 1*193 1'081 *995 *907 ⚫834
713 ·662 617 575 538 504 475 448 420 398 379 356 337 321 305 241195*162
2'238 1975 1755 | 1°570 | 1°414| 1°278 | 1°158 1*066 *972 *894
*764710*662617576540*509 480 450 426 404381 362 344 327 258 209174 147 15
2*106 1.872 1675 1°508 1*363 1°235 1*137 1037 *954
814757 706 658 614576542*512*480*454 430 406 386 366 349,* 275 223 186 156 16
1*990 1780 1'602 1'448 1*312 1208 1*102 1013
750-699-653-612-576 432-410
•865804 750 699 653 612 576 544 510 483 457 432 410 389371 292237 199 166 17
1.884 1696 1534 1*390 1°279 1*166 1073
*916 •851*794740, 691 648 610576 540511484457° 434412 392 310 251209 176|18
1*790 1.619 1°467 1°351 1°231 1'132 1'049
*
*967 *899*838781, 730684644 608570540511 483 458435414° 327265 220*18619
| | | | · ·
678|·640¦•
1°704 | 1°544 | 1°413 | 1°296 1192 | 1*104 | 1018946 882 822 768720678 · 640 600 · 568|·538)· 508 · 482|· 458*436·344·279•232196/20
|
•
Per-centage
allowed for interest
and depreciation
per annum.
TABLE IIb.
Cost of Laying one additional Ton of Copper.
£60 £65 £70 £75
£80
£85
£90
£95
£100 £110 £120 £130
£140
£150
£200
£250 £300
£350 £400
£450
£500
5
'231
*154 *167 •180
*251
*193
*206
*219
*23x
*244
*257
*283
*309
*334
*360
*385
'514 *643
*772
10
270 *289
*308 *334 *360 *386 *411
*328
*309
*347
*366 *386
'424 *463
*501
*540
*579
*771
*964
1*157
1*029
*900
I'350 1*543
1*157
1'286
5
1*736
I'929
7
*462
*437
*488
'514
*565
⚫617
*668
*720
*770
I'029
1'286
I'543
1.800
2*315
2'057
2'571
10
221
*385 *418 *450 *482 *515 *546 *$78 •610 ⚫643
*707
•772
*835
*900
*964
1*285
1*607
I'929
2*250 2'572
2.893
3*205
12
15
*720
25
*463 *501 *540 *578 •617 *656 *694 *733
'6x6 *668
*771 ⚫824 *875
*976
*925
*771 •835 '900 *964
1*156
1'093
"771
⚫849
*926
1'003
1'080
1*155
1*543
1'928
2°314
2*700
3'086
3°471
3*857·
15
1'028
1'221
1*285
I'029 1*131
1'415 I*543
1*235 1*336 I'440
1'540
2'056
2'571
3*089
3'600
4'115
4*629
5*144
20
1*671
1.800
1*925
2'572 3*125
3*857
4'500 5°143
5'786
6'430
25
Per-centage
allowed for interest
and depreciation
per annum.
13
2350
constantly used on most of these cables for
several years, and although the insulation
has varied with the weather, it has not in a
single case been permanently injured, and I
am informed that no repairs to the underground
cables have been in any case necessary, nor
have the man-holes been opened, except to
lay down new cables.
With respect to the printed Tables included
In this paper, the following rules apply to the
second one.
RULES FOR FINDING FROM ANY GIVEN DATA
THE SIZE OF THE MAINS REQUIRED.
Data required :-Annual cost of electrical horse-
power and per-centage for interest and depreciation
14
per annum, and cost of laying one additional
ton of copper, the approximate size having been
assumed.
Rule 1.-In Table IIb. look down the column of
cost for additional ton until you reach the given
per-centage allowed. Take out the number there
indicated.
Rule 2.-In Table IIa. look along the line with
the given cost of horse-power until this number is
found. The number at the head of that column is
the section per 1,000 ampères in inches.
Rule 3.—If this section be largely at variance with
the approximate one selected, use now this value for
a second calculation.
2351
13
LECTURE II-DELIVERED FEBRUARY 9, 1885.
În my last lecture, I introduced to your
attention the elementary principles which must
guide the engineer in the selection of the right
size of mains to use. These principles main-
tain whether it be a private installation of the
electric light or a large supply from a central
station. But, in the future, I shall confine
my remarks chiefly to the latter class. In
whatever manner the mains be laid down, the
mass of copper contained in them is very large,
and their establishment constitutes a large
portion of the prime cost of laying down a
system of central station lighting. For 100,000
Edison lamps we require over a ton of copper
per yard run, and everyone knows how rapidly
the number of miles of mains mounts up, even
in a small district, owing to the large number
of side streets.
Now, when a bridge like the Forth or the Tay
bridge, or the Brooklyn bridge at New York,
is designed, the engineer spares neither time,
labour, nor expense, in his preliminary calcu-
lations of the weight of metal required in
the several parts to combine strength with
economy. In such bridges the mass of metal
is enormous, and the reduction of cost in this
item is very important, independently of the
fact that, within a certain limit, the less metal
there is in it the more efficient is the bridge.
Consequently, the proportions of the different
parts must be most carefully calculated by the
ablest mathematicians.
Now, I maintain that exactly the same care
should be taken in the estimation of the pro-
portions of different parts of our electric mains.
It is a point which has been sadly overlooked
in the past, even by some of the most advanced
and far-seeing of electricians. But when we
consider the enormous amount of capital which
must be sunk in mains, I hope that engineers
will see how intensely important it is to spare
neither trouble nor expense in preliminary cal-
culation in order to ensure the best result.
Now, in the present state of electric lighting,
economy is of primary importance. Judging
by the experience of the New York central
station for electric lighting, we should be pre-
pared to deny the possibility of economically
furnishing the electric light to the British
public. I, however, do not hold this view. I
see several defects in that example of electrical
distribution. The dynamos are of an expen-
sive kind, and the outlay in this matter has
been excessive. Moreover, the mains are laid
on unsound principles, and are both expensive
and, I believe, unsatisfactory. The general
scheme for an installation is not to be written
down casually on a few sheets of paper; it
requires weeks, or even months, to prepare the
estimates, and to calculate the requirement of
any such central station. I have no doubt the
defects that I have alluded to are due largely
to the early period at which that station was
designed. But even in later estimates, and in
our own country, I have seen the want of that
detailed calculation which can alone lead to
economy.
In any system, at the present time, economy.
is the main thing to be considered in design-
ing a system of distribution. Other difficulties,
such as equalisation of potential, must be
looked upon as difficulties to be faced and
conquered by the engineer.
•
In my previous lecture I have given you
three reasons why we must not try to econo-
mise too much by laying very thin conductors.
Ist. It is not economy, on account of the
wasted energy in heating the conductors.
2nd. The conductors may become so hot as
to injure insulation, increase the resistance
excessively, and even be uncomfortable to the
foot passenger.
3rd. The fall of potential over a district,
and the variation of the potential at each
point of a district, are both increased by thin-
ning the wires.
2352
1 showed that, by due selection of the method
of laying mains, the second can be reconciled
with the first, which thus becomes paramount,
leaving the third to be overcome by the en-
gineer as best he can.
I showed you the general principles which
must guide us in the economical selection of
the size of mains, and I gave you some tables
which, I trust, will be found of great value to
the engineer. Nothing is there chosen for
him. He may put his own price on the cost
of an electrical horse-power and on the cost
of laying mains. In any special case, and in
all parts of the scheme he is designing, these
tables give him, almost at a glance, the
economical size of main he must employ. He
can then, by the aid of my formulæ, determine
approximately the rise of temperature under
different systems of laying, and he will see
whether these mains may be laid in a single
conductor of circular section, a flat sheet of
definite thickness, or a series of cables side by
side.
Then comes the question of equalisation of
potentials, which we shall have to deal with
very fully in this and the following lecture.
I shall now, by way of introduction to what
follows, lay before you the principal diverse
systems which have been proposed, and shall
afterwards examine each in detail. These are
five in number, varying either in the way the
lamps are connected with the main, or in the
introduction of some special appliance. They
are as follows :-
1. Multiple arc.
2. Series.
3. Multiple series.
4. Accumulators.
5. Secondary generators.
Some of these have a large number of sub-
heads. I shall confine myself to-day to the
first class, as being at present the most im-
portant. It will be convenient to subdivide
this system into several classes, which I venture
to name as follows:-1. Parallel line. 2.
Reversed parallel line. 3. Network mains.
4. Tree mains. 5. Multiple tree mains.
Independent wire mains.
LAMPS IN SERIES.
6.
The oldest propositions for electric lighting
had no reference to multiple arc. It was pro-
posed to put all the lamps in series. This
method economises largely in the cost of mains,
but the number of lamps which can be supplied
is very limited. The pressure required for
16
lamps in series is greater than for lamps in
quantity or multiple arc, in proportion to their
number. The hydraulic analogy to electricity
is always instructive. Now a lamp is repre-
sented by a water-engine or turbine giving off
a certain amount of energy; a certain differ-
ence of pressure between the inlet and outlet
of the water-engines is required to give off
this energy. If, now, the outflow goes into a
second water main, which again feeds a second
water-engine, these engines are in series, and
the pressure which must be supplied is exactly
proportional to the number of engines placed
in series. If the water-engines were all put
upon the same main, the pressure required
would be the same as for one, but the volume
of water required would be greater than for
one, exactly in proportion to the number of
water-engines. Moreover, the size of pipe
must be increased to allow this larger volume to
pass without too much resistance from friction
of the pipes.
These hydraulic facts, so simple and self-
evident, are the exact analogues to facts in
electric lighting. If lamps are in series, the
electric pressure must be increased in propor-
tion to their number. The electric mains
supplying many lamps in multiple arc require
the same pressure as for one lamp, but the size
of the mains must be increased to prevent
waste of energy by their resistance to the
electric current.
Thus, if we have ten lamps in series, the
current is one-tenth of what is required for ten
lamps in multiple arc, and hence, on the
economical considerations, the copper mains
be about one-tenth of the sectional area.
may
But the number of lamps which can so be
put in series is limited. The highest potential
which has been used hitherto, so far as I am
aware, is 5,000 volts, and some people will say
that even this is dangerous. I do not hold
this view at all. If, as in America, a line be
properly insulated, and if it be tested once or
twice a day at the dynamo-house, there is no real
danger to consumers; and if, as in America,
the workmen at the dynamos wear india-rubber
gloves or the homely golosh, there is no
danger for them. I have no hesitation in
asserting that the dangers from high potential
electricity are far less than those from gas.
Hardly a week passes but we read of dreadful
explosions of gas. Suffocation is not un
common, and in the first days of gas, when
ignorant people often blew out their light, it
was a dreadfully common occurrence.
If, now, we have 5,000 'volts, and consume
2353
100 volts in each lamp, we can only put 50
lamps in series. But, on the other hand, if
such a system were to be adopted, it would be
desirable to use lamps of much lower potential.
When talking of the multiple arc system, I
said it was desirable to use lamps of as high a
potential as possible to economise the mains;
so here I say, in a series system, we must use
lamps of as low a potential as possible, so as
to economise pressure. If we could have 20-
candle lamps of 2 voits, we could work 2,500
lamps off a single wire with 5,000 volts (neg-
lecting the resistance of leads). Assuming
3 watts per candle-power, this would mean a
current of 30 ampères. In many cases this
would be a highly economical system of
distribution. There are, however, two ob-
jections to this plan which I look upon as
fatal.
If one lamp is put out of circuit, it puts out
all the other lamps. Consequently, the switch
for a lamp must be one which will short circuit
it, just as the plugs of a resistance box cut out
resistances by short circuiting them. Then
the engine-driver must regulate his dynamos
so that the current is constant.. Automatic
adjustments have been made for this purpose
with arc lamps, and their action is excellent.
These are to be found in all American arc
systems, and are a great point in their favour.
If, however, the filament of a lamp breaks, all
the other lamps in the series go out also. It
would be necessary to have an automatic
arrangement to short-circuit a lamp when its
filament broke. This is no easy matter, and
could hardly be done without a local battery,
or a second wire from the dynamo. In any
case, the introduction of any such apparatus
into each lamp would add to its cost and
liability to get out of order.
It may be said, however, that with the thick
low-resistance lamps of 2 volts (1's ohm), they
would not break, but would be changed long
before they got thin enough to break. In
this case, however, the second objection is
fatal.
The second objection is that with such thick
filaments for lamps, it would be impossible to
get anything like a candle for three watts.
I think it was in 1874, when the Russian
Logodine showed his incandesent lamps of
thick carbon, that I tried some experiments at
Anderson's College, Glasgow, where I was then
Professor of Natural Philosophy. These experi-
ments convinced me that incandescent lamps
of that kind could never be economical. The
heat carried away by the terminals was so great
17
as to waste a large part of the energy put into
the lamp. This is the objection which I have
to the Bernstein lamp. I shall never forget
the astonishment with which I first saw one of
Mr. Swan's lamps with a thin filament. My
astonishment was at seeing the filament glow-
ing white up to the terminal. This can only
be done to perfection by a lamp of very high
resistance.
I remeniber seeing an able man of science
showing some of the small fairy lamps to a
scientific audience, and he asserted that its
efficiency was doubtless the same
as the
20-candle lamps, "because it is made of the
same material." This was à serious mis-
statement.
I think enough has been said to convince
you that, although in some cases, this system
may be worthy of consideration, it is not
generally applicable. If the lamps are of low
resistance they are not cconomical. If of high
resistance we have few in series, and require
a special device to short circuit a lamp when
the filament breaks.
It would not be well, however, to leave this
system without pointing out to inventors that
it has one more advantage as compared with
the multiple arc system. Our present lamps.
(designed for multiple arc) have a serious
drawback compared with gas. You cannot
lower them to give less light. Even if there
were a means of reducing the current through
them you would not get economy because of
the lowered temperature. Now with the series
arrangement it is conceivable that the filament
might by some means be lengthened and
shortened, and since the current is constant,
the brightness would depend on the length,
and all lengths would be equally economical
except for the absorption of heat at the
terminals. I do not wish to invent, so I will
say no more.
In America, arc lights are seen in series,
sometimes to the number of 100. One cannot
help feeling pleasure either in secing the
dozens of dynamos at work in the central
station, or in admiring the graceful curves of
overhead wires, well insulated, and supported
on well-shaped steel poles, as in Philadelphia,
and in seeing the bright light which they are
spreading over seventy miles of street, and
with which they are gladdening the hearts of
thousands. In some systems, with ten ampères
flowing, an arc lamp is replaced by ten in-
candescent lamps in parallel, each using an
ampère, and with switches to substitute resist-
ançes for lamps,
B
2354
MAINS WITH LAMPS IN MULTIPLE ARC.
I think it may be fairly assumed that a 16
or 20 candle-power lamp is what is most likely
to be generally adopted. It is found that we
can get one candle-power for an expenditure
of three watts of work. Now this three watts
is the product of the current and the pressure,
and may be made up in a variety of ways.
We may increase the ampères of current, and
diminish the volts of pressure, or vice-versa.
So far, however, as economy of mains is con-
cerned, there is no doubt what is the best
course to follow. The smaller the current, the
smaller are the mains. Hence it is clearly
desirable to use lamps of a high potential-
100 volts is at present about the limit that is
used-but I am informed by Mr. Swan that
equally good lamps could be made of 400 volts
if there were a demand for them. There is at
present an absurd regulation of the Board of
Trade limiting the pressure in houses to 200
volts; but, I think, we may take it for granted
that more enlightened views will ultimately
prevail. If such lamps were used, the cost of
mains would be reduced to about one quarter,
which is, of course, a very great step.
•
Here, then, is a step which, according to
the information before us, can be taken at
once. Why it is not taken I am at a loss to
understand. If lamps of 20 candle-power can
be made with a long life, using 400 volts and
'15 ampère, the question of central station-
lighting on economical principles is advanced
enormously. The inventors and manufacturers
are alone to blame if, by delaying to take this
step, they hinder the adoption of this system
of lighting.
These remarks apply, more or less, to nearly
all the systems of distribution, but especially
to the multiple arc system, where the mass of
copper in the mains is so great.
Now let us look at the simplest distribution,
where we lead mains along a single street, and
take off the current at various points, using
each such point as a source of supply to a
house, or it may be to a whole district.
The diagrams below show different systems of
laying the mains. In the single parallel line
it will be noticed that the potential falls off as
we go farther from the station. If the size of
conductor is proportioned to the current with
1 square inches per 1,000 ampères of maxi-
mum current, the fall of potential is regular,
and amounts to 322 volts per 100 yards of
double conductor when the maximum number
of lamps are in use,
$
This is a good opportunity to draw attention
to a point which meets us in studying nearly
every system of distribution. Since the size of
conductors is proportioned to the current, they
are abruptly diminished in section at each
point of consumption. It follows that, so far
as weight of copper is concerned, this system
is equivalent to one in which separate wires
all of the same size go from the central station
to each point of consumption.
The difference between these two plans-
(1) the massive main system and (2) the inde-.
pendent wire system-consists in this, that
SERIES
+
PARALLEL IRE
REVERSED PARALLEL LINE
C+C
Ꭺ
+
오오​오오오
​Α'
T
B' C+C
MULTIPLE SERIES
2
3
द द
၄ } } }
5
while their action is identical in reducing the
pressure when all the lamps are lighted, their
action is different when some lamps are ex-
tinguished. With the independent wire system,
the conductors leading to points of consump-
tion not in use lie idle. In the massive mair
system the equivalent mass of metal is used,
under the same conditions, to diminish the
resistance of conductors to the points of con-
sumption which are in use. This would seem
at first sight to be all in favour of the massive
main system; this, however, is by no means
sure. If only the nearest and most distant
points of consumption were in use, and R be the
resistance of mains between these points, V the
pressure at the'near point, and the resistance
2355
The current is
of lamps at the far end, the energy used up by
the distant lamps and the mains to them is
V³
V
R is greater for
R+r
R+ r
the independent wire system than for the
massive system. Hence the Current and
energy used are less with the former than the
latter system. Moreover, since the current is
less, is greater. Hence, à fortiori, the
energy used with an independent wire system
is less. In fact, with the massive mains, the
distant lamps will be far too bright. If, how-
ever, the fall of potential with the maximum
current is only a few volts, this would not be
important. The system of independent wires
takes away from the inconvenience of varying
pressure at definite points of consumption.'
It seems at first sight to be ridiculous to
think of having a separate wire to each lamp
from the central station. But it is by no
manner of means ridiculous. In fact, it is well
worthy of serious consideration.
In a previous part of the lecture I have shown
what loss of energy we must allow in the leads
and other conductors. Now this loss of energy
shows itself by a fall of potential. If V be the
difference of potential between two points of a
main, R the resistance between these points,
and C the current, then & V = CR.
Now, I have resolved to assume in these
lectures a section of 1 square inches per
1,000 ampères. The resistance of 100 yards
of a copper conductor of this section is
00161 ohm, and 8V = 1,000 X 00161 = 1.61
volt. That is, we have, with such a conductor,
a fall of 1'61 volts in every 100 yards of single
conductor, and a fall of 3'22 volts per 100
yards of double conductor. This takes place
when the maximum current is being used.
With a smaller current the loss is less. With
500 ampères to the 1-inch conductor, it is
only 1.61 volt, and with 100 ampères or less it
is nearly inappreciable.
Now, while it is very satisfactory to the
engineer to find that with small currents there
is so little waste of energy, still there is a
counterbalancing disadvantage of serious im-
portance, I may say the most serious import-
ance, in considering the question of laying
mains. [In the following remarks I will assume
that the engine is perfectly governed.]
Suppose there is a distance of 500 yards
between the engine-house and the farthest
lamps, and that lamps are being supplied all
the way along, and that the conductor is
properly proportioned to the current, on
19
economical considerations, at every point.
Then while the maximum number of lamps are
in use, those nearest to the engine-house have
an electrical pressure 161 volts higher than ·
those farthest from the engine. Well, this
might be counteracted by causing the con-
sumers at a distance to use lamps of 16.1 volts
lower potential. That is all very well while
the maximum current is flowing. But when
the number of lamps is reduced one-tenth, the
difference of pressure to the two consumers is
only 1.6 volts. Thus, if the nearest consumer
has a constant pressure, the distant one has
his pressure varying by 14:49 volts. It is true
that in this case we might vary the pressure at
the engine-house, so that the near consumer
was 7.25 volts below, and the distant one 7·25
volts above his normal pressure; but even
these variations are very serious. A variation
of 7.25 volts in the potential of lamps is a most
serious matter, even if we look at this variation
as being only 3.62 volts above and below the
pressure for which the lamp is constructed.
To illustrate this, I will give vou three curves
on a diagram. The first shows how the candle-
power is affected by the pressure; the second.
how the life is affected by the candle-power;
and the third, how the life is affected by the
pressure. The first is Mr. Edison's table of
1883; the second is from the experiments of
Mr. J. Zacharias; and the third I have de-
duced from the tests of Woodhouse and
Rawson lamps at the Vienna Exhibition.
Generally, in 100 volt 16-candle lamps, a volt
makes a difference of a candle.
I will now show you, experimentally, the
fall of potential along a main. I have three
lamps of equal brightness; when I connect
the two at opposite ends of my main, the
distant one is much feebler than the near one.
If I insert a third half way, the distant one
falls still more, because the main has to take
more current. [Experiment.] This is one of the
most serious problems which have to be
considered in engineering the mains of a
central station, and a large portion of this
course of lectures will be devoted to the devices
which have been proposed for getting over the
difficulty.
I have next to describe to you the different
systems of connecting the lamps of consumers
with the engine-house. In the remarks which
have gone before, I have confined my illustra-
tions mainly to a multiple arc system; but
there are several others, each of which has
certain advantages.
With the massive main system it has some-
2356
times been proposed to equalise the pressure
for lamps over a district by putting in pro-
portionate resistances at the points of con-
sumption. It has also been proposed to
prevent variation of pressure when the con-
sumption varies, by making these resistances
adjustable automatically. This, however, must
not for a moment be thought of. I pass over
the fact that automatic adjustable resistances
have generally been a failure, because the
designers are alone to blame for this; but I
do insist that an economical system of work-
ing is incompatible with the free use of resist-
ances in the working circuit, which use up a
large quantity of energy. It is better to use
lamps of different qualities in different parts
of a district than to introduce such resistances,
and the engineer must find some other means
of dealing with the variations of pressure with
varying consumption.
The remarks I have made about the inde-
pendent wire system must be looked upon as
parenthetical. We shall recur to the subject.
We have now examined the single parallel
line, and have seen that, so far as weight of
copper is concerned, it is equivalent to a
separate wire to each lamp. We have also
seen how the pressure falls off as we go from
the station.
The reversed parallel line (Fig. p. 18) was
devised to prevent this fall of pressure. Two
wires run side by side; one end of one wire is
attached to the + pole, and the other end of
the other wire is attached to the pole.
Thus the current supplying each lamp goes
around the whole circuit, and so there is a ten-
dency to equalise the pressure for all lamps.
In the diagram the wires are shown of taper
form, but they have been generally taken to be
of uniform thickness. It has been shown by
Professor Ayrton that, in this case, the pres-
sures are not equalised if a larger current is
taken off at one point than another.
Suppose at point A a large number of lamps
is supplied, and at B a small number, so that
a current C passes through the lamps at A, and
a current c through those at B. Let R be the
resistance of A B or A' B'. The fall of potential
from A to B is cR, and from A' to B' it is CR.
Hence the pressure at B is greater than at A
by the quantity (C − c) R ; e.g., with 500 lamps
· at A and 10 lamps at B, and 0.75 ampères per
lamp, and with A B 200 yards, and resistance
= .0032, the fall of pressure is 1.17 volts.
Mr. Kapp (Electrician, May, 1883) has gone
further, and shown that with lamps equally
distributed over the whole line the middle
20
ones have less pressure than those at the two
ends.
But it must be noticed that if at each point
the section of conductors is made proportional
to the current, then the quantity CR' = cR,
and the fall of potential to both terminals of a
lamp is the same, where R R' are the re-
sistances of A B and A' B' respectively. If the
size of conductors be properly proportioned,
the pressure is constant at all points of the
line. Now what does it mean to make the
section of conductor proportional to the current?
It means that, so far as weight of copper is
concerned, it is equivalent to having a sepa
rate wire for each lamp going round the whole
circuit. Here is the weak point of the whole
system. Equalisation of pressure is attained
by putting in useless resistance. The wire
might go up to the lamp, and then back to the
dynamo, without making the whole circuit, and
equalisation of pressure attained by putting in
a resistance at the lamp equivalent to the
copper wire which has been cut out. Such a
resistance could be made of much cheaper
material than copper. Thus the reversed
parallel system, beautiful at the first glance,
is the same in efficiency as, and inferior in
economy to, the direct parallel system, with
resistances in the lamps to equalise pressure.
It seems to me that this consideration is
absolutely condemnatory of the reversed
parallel system for application to mains. It
is worse than the direct parallel system with
resistances introduced, and we have already
condemned the latter. It becomes then hardly
necessary to speak of it further but a some.
what similar arrangement may be used with
multiple series systems. I cannot refrain from
pointing out to you a device by means of which
the equalisation of pressures might be main-
tained, even when the maximum number of
lamps is not in action. In this case the pro-
portion of the + and conductors should be
altered in some parts. Suppose the conductors
to be made up of a number of insulated
wires in sections, and that at each end of a
section each wire is attached to the + bundle,
or the
bundle of wires. It would be easy
to design an arrangement by which these
terminals could be changed from the + to the
bundle, or vice versa. It would also be
easy to design an automatic switch by which,
when the size of the + and mains was not
proportioned to the currents in them, the two
terminals of one or more wires should be so
transferred from the bundle which is too great
to the one which is too small,
2357
We have now reached the most important
and difficult part of the problem. Leaving
behind the case of a single street, we come to
a district. In the choice of districts to light,
care should be taken in the selection of those
which will give the best return for outlay of
inoney and cost of maintenance. It is need-
less to say that a district with many theatres
and restaurants is favourable, and that many
storeyed houses have a larger consumption for
a given area than a district of low houses.
The first thing to be done is to estimate as
well as possible (and it is not possible to be
exact) the number of lights to be supplied in
each part of the district. The only alterna-
tive to this method would be to lay mains
large enough to supplant gas entirely. This
would involve a great outlay in mains which
for years would generally be lying useless, or
at most diminishing in a feeble degree the
cost of wasted energy. It is quite right that
the engineer should calculate the cost of
mains on these lines, but in general it could
not be recommended to spend so much money
on laying them. It is generally better to
trust to laying additional mains as required.
Tree Main.-First let us suppose that we
have all the mains connected in parallel with
all the dynamos. This is a case which I find
has been well discussed by Mr. Kapp in The
Electrician, August 4, 1883, but it is a
system which we shall soon find reason to
condemn. The reason why I object to this
system is that the size of mains is not made
dependent on considerations of economy, but
on that of variations of pressure allowed by the
Board of Trade. This must be the case with
the above mode of working, if the district is
large. The difference of potential between
the near and distant lamps is insensible when
there are few lamps burning. The difference
when the maximum number of lamps are burn-
ing is considerable. Hence, if the near lamps
are kept at constant pressure, the far lamps
will
vary at different times by the amount of
the difference between the near and far lamps,
when all are on. Now, the Board of Trade
forbid a greater variation than 10 per cent.
(5 per cent. up and down). Hence the maxi-
mum difference of pressure between near and
far lamps must not exceed 10 per cent. Here
I may say that 10 per cent. is a far greater
variation than is permissible. Two or three
per cent. up and down is quite as much as can
be allowed. Now, Mr. Kapp assumes the size
of conductors to be limited by these considera-
tions. He assumes the maximum difference
2 t
of pressure between the nearest and the
farthest lamp to be the maximum which can.
be allowed. On this view notice the following
facts:
1. If we have two similar areas, with equal
number of lamps to light, one larger than the
other, the mains in the former must be so
increased as to make the fall of pressure to
the most distant lamps the same in both.
Hence the section of mains is proportional to
R, this maximum distance, other things being
equal, and their length varies as R, so the
cost varies as R².
•
2. The section of mains varies as 7, the
number of lamps.
3. The section of mains depends in two
ways on the pressure required for a lamp; (a)
the current and section of mains are less in
proportion to the pressure; (8) the variation
in pressure allowable (being a per-centage) is
proportional to the pressure. Hence, on the
whole, the section is inversed, as the square of
E, the electric pressure of a lamp.
4. The section of mains varies inversely as
p, the per-centage variation of pressure allowed.
On the whole, the section of mains, and the
cost of mains (assumed proportional) vary as
follows--
Section varies as
n R
PE2
7 R2
Cost varies as ——
ÞE²
Cost in pounds = 0.9 X
72 R2
Mr. Kapp has deduced a coefficient from
actual estimates and finds-
n R2
or 1.2 X
PE2
PE2
where R is given in 100 yards, and E in 100
volts, according as the most favourable or the
lcast favourable of likely distributions is
adopted. [The co-efficient 12 is used for
equal distribution of lamps, and o'g when the
number of lamps at distance varies as .]
To take an example where = 60,000 lamps,
R = 7 (hundred yards), E= (hundred
4
10 5
1'00
1'40
and
I
r
volts), p= (2 per cent. up and dow..).
£661,500 £882,000.
... Cost is between
£135,000 £180,000.
If we used lamps of 420 volts, the cost would
lie between £15,000 and £20,000, instead
of the lower pair of figures. But these
figures are of no value; first, because 10 per
cent. is too great a variation of pressure ;
and, secondly, because the economical size of
mains is the primary consideration, ard
2358
22
we must find a way out of the difficulty of engineer in designing mains must fix on these
variations of pressure.
We must now consider to what distance we
may use the method of connecting all the
mains, and charging them all with the same
dynamos. I think we may say that 2 per cent.
variation of pressure up and down is per-
missible. This gives à variation of four candles
in an Edison 16-candle lamp. Now, by atten-
tion to the dynamos, this allows a range of
4 per cent., all lamps in the district requiring
the same pressure. If telegraph wires came
from the most distant and nearest lamps to
the engine-house to indicate on voltmeters the
pressure at those points, the engineer would
have his instructions to keep the near lamps
as much above the normal pressure as the
distant ones are below. Suppose that 100
volts is the normal pressure. When very few
lamps are on, both near and distant mains.
would indicate 100 volts. This is the case
where metal is laid for a large number of
lamps, even at the distant points, and in any
actual installation it may be taken to be
approximately accurate. When the maximum
number of lamps are on, there will be 4 per
cent. difference. The engineer keeps the near
lamps at 102 volts, and the distant ones at 93.
volts, and we have only a 2 per cent. varia-
tion. If, however, the near lamps be supplied
with 102 volt lamps, and the far ones with
98 volt lamps, it will be seen that we can double
the distance, with of course double the fall of
pressure, giving 8 per cent. variation, with only
2 per cent. variation up or down in any lamp.
For when few lamps are on, the near and far
lamps have the same pressure. The engineer
makes this 100 volts, which is 2 per cent.
for near lamps, and + 2 per cent. for far
lamps. When all the lamps are on, the
engineer makes the near lamps 104 volts, or
+ 2 per cent., and the far lamps 96 volts or
-2 per cent., giving a difference of 8 per cent.,
and doubling the distance which can be sup-
plied. This method has the advantage of not
always using the near lamps above, and the
far lamps below, their normal pressure; but
I must confess I do not like the idea of supply-
ing different consumers with lamps of different
pressure, if it can be avoided without loss of
economy.
We have now to consider at what distance
from the central station we may supply lamps,
so that the fall of potential does not exceed
4 per cent. or 8 per cent. This depends on the
pressure required for lamps, and on the size of
conductors chosen per 1,000 ampères. Every
points for himself, but in order to fix our ideas,
I will take the case of 100-volt lamps, and
1 sq. in. per 1,000 ampères.
With that size of conductor the loss of pres-
sure with the maximum number of lamps is
3.22 volts per 100 yards of double conductor;
4 per cent. is lost in a distance of 124 yards,
and 8 per cent. in a distance of 248 yards; so.
that this is the greatest distance of a lamp
from the central station (according as we
supply lamps of the same or different normal
pressure's to different districts) which is con-
sistent at the same time with economical size
of conductors, and with a maximum variation
of 2 per cent., up and down, in the pressure
supplied to any lamp.
•
From what has been said, it will be seen
that in this way of working, the pressure at
the station must be constantly regulated, either
by the speed of the engines, or by introducing
resistance into the field magnet coils. I prefer
the latter method, unless the newly invented.,
electrical governors (such as Willans') prove
a success.
The above considerations apply to what' I
call the tree system of laying mains. The
trunk of the tree starts from the engine-house,
and throws off branches, from which twigs
spring, and leaf stalks from these, and the
lamps are represented by leaves. The above
considerations do not apply to cases where
feeder mains go from different dynamos, or
generally where the pressure in different mains
at the station is different.
It appears, then, that the tree system is of
limited application under the conditions which
I assumed, the maximum distance being
248 yards. If, however, we had lamps of
400 volts, the maximum distance (measured,
of course, along the line of leads) would be
992 yards.
In the tree system we must lead our con-
ductors along the shortest route from each
lamp to the central station, and then count the
number of lamps supplied, and so determine
the section of copper required by each point
of the mains. If we connect the ends of the
positive twigs and the ends of the negative
twigs, we do not alter the flow of current
when the maximum number of lamps are on,
if the size of mains is chosen for this maximum
distribution; but when the consumption is
limited, we consume a little more energy in
proportion, and the distant lamps are a little
brighter. But, considering the uncertainty
of estimating the relative consumption in
•
2359
different parts of a district, the distant
lamps will probably be better served if the
+ twigs are joined together, and so with the
twigs.
I wish to repeat the statement that, in the
tree system, the amount of copper in all parts
of the mains is the same as if a separate wire
came from every lamp to the station. As a
consequence, the engineer must notice that if
a plant has been laid down for a certain
number of lamps, and it be afterwards desired
to extend the boundary of the district, the
conductors already laid down are of no use in
leading current to the beginning of the ex-
tended district. The conductors must be en-
larged, or else new mains must be led to
supply the newly-added district. The engineer
must also use his influence strongly to prevent
the natural tendency to take a larger number
of lamps in a district of supply than that for
which the conductors have been calculated.
It must be acknowledged that the simple
tree system, where all the dynamos are con-
nected in parallel with the mains, presents a
very serious obstacle in the rapid fall of
potential, the maximum distance of a lamp
from the station along the line of conductors,
I consistent with the economical considerations,
being 124 yards, if the pressure required for all
lamps is the same. In the year 1880, Mr.
Edison took out a patent in England (No.
3,880), besides other countries, in which he
gets over the difficulty by using what he calls
feeder mains. It is a result which would
certainly have been arrived at by any one who
thoroughly and intelligently worked out the
problem. But, so far as I can discover, he
was the first, by a long time, to hit upon this
cure for the evil; and I must say that it is
interesting to find how thoroughly he had gone
into the problem at that early stage of electric
lighting, although, in a patent of slightly
earlier date, he describes the tree system as
being all that is required for electric lighting,
and does not notice the fact of fall of potentials
as affecting the problem.
In the patent cited above, Mr. Edison gives,
among other irrelevant matter, two solutions
of the theory which I may call the multiple
tree system and the network system of laying
conductors. I will not follow him in his method
of using these systems in practice, because he
does not use them to the best advantage. In
this case, as heretofore, I will advance with
you, by common-sense arguments, to the more
perfect types.
Multiple Tree System.-I will assume that
23
all lamps are of the same pressure. In this
case, the size of conductor per 1,000 ampères
being fixed, 124 yards is the limiting length of
conductor. Now notice that this is not neces-
sarily the limiting length of conductor from
the station, because it does not much matter
what the fall of potential from the station to a
lamp is; but it is the limiting length of con-
ductor between the farthest and the nearest
lamp, or the difference in length of conductor
to the station from the farthest and nearest
lamps; for here the injurious variation of
potential comes into play. If the nearest
lamp were 124 yards from the central station,
there would be a loss of potential of 4 volts in
that distance, in order to comply with economi-
cal considerations, but that loss of potential
would not affect the potential between different
lamps, if the engine driver regulates the près-
sure by telegraphic indications of the potential
at the nearest and farthest lamps. Compen-
sated galvanometers may be, introduced in
the engine-house to indicate the potential of
distributing boxes, when variable currents are
flowing.
Our first tree system extends to a distance
of 124 yards; beyond that we must have a
sccond tree system with feeder mains to a dis-
tributing box, from which branches go out to
supply a district, no part of which is more than
124 yards from the distributing box, or less
than 124 yards from the station. From these
distributing boxes a pair of thin wires might
go to a voltmeter in the engine-house, an end
of each wire being attached to the mains in
the distributing box. With a similar tell-tale
coming from the most distant lamp of the
system, the engineer knows exactly what pres-
sure is required. This second district, with
feeder mains losing 4 volts, is generally larger
than the first, and will generally require a
number of feeder mairs, or roots, feeding
separate trees. It will be noticed that each
root is connected to a separate dynamo.
If we extend the distance still further, we
must put on a new set of roots or feeder mains,
each losing 8 volts; and so on up to any dis-
tance. The further we go, the greater is the
cost of mains, but this cost is more nearly in
proportion to the distance than to the fourth
power of the distance, as in Mr. Kapp's paper
(which is not founded on the economical con-
siderations).
I must here put in a warning, necessary from
what I have seen of the practice of this system
here and abroad. The distributing box of a
feeder must not be in the centre of the district
2360
supplied by that feeder, or you waste all the
extra copper going to the lamps nearer to the
station than the distributing box. The point
of distribution must be the point of the district
rearest to the central station, in order that we
may have a maximum economy of copper.
Suppose we are lighting a town like Phila-
delphia or Chicago, which is built in square
24
blocks, and suppose two sides of each square
are 124 yards long, we should have a fed centre
for each block on the diagram below where I is
the central station.
Within the square indicated by the figure
I no feeder mains are required. The dis-
tance of all the points 2 from the station is
the same if measured along the streets. There
ما
4
4
IIS.
4
NE
……
3 3
PINK
BLUE
PINK
LIGHT DARK LIGHT DARK
BLUE BLUE BROWN BROWN
BROWN
4
no
L.
are four squares and eight half squares thus
supplied, equivalent to eight squares. The
first feeder main supplies the district between
the squares marked 2 and 3 respectively,
equivalent to twenty-four squares; the second
set of feeders supply forty squares, the third
fifty-six, and so on. The copper in the service
of a block is one-half of the copper in 124
yards of the feeder main for a block, since
some supply conductors are short, and others
124 yards long. Thus, to supply twenty-four
squares with the first feeder, the latter must
have the copper of supply conductors for forty-
eight squares. In this way we find the cost of
supplying the districts up to 1,
2 3, &c.
Let I. be the cost of copper for one square :<
2361
Cost for district i is
between 1 and 2 (supply)..
Cost of district 2 ....
"
25
8L for 8 squares.
(feeders)
24L
481.
80L for 32 squares.
between 2 and 3 (supply)....
40L
19
""
(feeders up to 2)
(from 2 to 3)
80L
80L.
·
Cost of district 3
280L for 72 squares.
between 3 and 4 (supply)
56L
18
"
(feeders up to 2)..
II2L
(2 to 3)
II2L
(3 to 4)
112L
99
Cost of district 4
The cost of lighting a square up to distance.
""
""
672L for 128 squares.
124 yards is
L per square.
2 X 124
19
2.5L
•
3 X 124
4 X 124
""
3.8L
5:25L
It will be seen, then, that the cost does not,
in this system, vary in a proportion even ap-
proaching the fourth power of the distance,
but is much more nearly proportioned to the
distance, especially when we go to great dis-
tances. The following Table compares the
cost of lighting districts of various sizes with
and without feeders and distributing centres:-
No. of
lamps.
No. of Cost with
squares.
feeders.
Cost with-
out feeders.
z district ..... 8
2 districts.... 32
3 districts...... 72
4 districts...... 128
8,000
90,000
280,000
672,000
8,000
128,000
648,000
2,048,000
1,600
6,400
14,400
25,600
The system which I have now described is
nearly the same as that which was proposed
(in an imperfect form) by Mr. Edison in 1880.
In 1883, Mr. R. E. Crompton proposed a
somewhat similar arrangement for the Victoria
provisional orders (also imperfect). As shown
before, telegraph wires from distributing boxes
(proposed by Mr. Edison) are unnecessary; a
compound-wound galvanometer attached to
the mains in the engine-house serves the same
purpose.
I would draw attention to the fact that the
ends of the twigs, or the branch conductors,
in parts of a district fed by different roots or
feeders, may be connected when they are close
together, thus making a network of the whole
district, the proportions of conductors remain-
ing the same as when not connected. This is
a distinction from the network proposed by
Mr. Edison, and a distinction necessary for
economy. In this case there is more difficulty
in managing the potentials, but it has this
advantage, that if an accident happens to one
feeder main, its fed district will, in some cases,
be not quite in the dark. Considering the
comparatively small chance of accident to
feeders, as shown by our experience of gas, I
would waive this, and in some cases I might
even prefer that each block should be supplied
from its distributing box by independent wires
to each lamp. The potentials of all lamps are
then absolutely constant, and, as shown before,
there is less waste of energy in the distant
lamps.
At Paddington, Mr. Gordon uses a modifi-
cation of the independent wire system by lead-
ing a group of wires for a main, and cutting
out more or less of them automatically, or by
signals from the engine-house, according to
the proportionate consumption in different
parts. This is one example of many devices
which the engineer may resort to in special
cases, but which are not satisfactory as a
general system.
The different potentials may be given to the
mains in a variety of ways. Edison puts re-
sistances in the feeders. Gordon does the
same by cutting out some conductors of the
main feeders. I prefer, after getting 100 volts,
to add to the pressure by a number of dy-
namos of large quantity and only two volts
pressure. Terminals come to studs, along which
feeder contacts slide till the right pressure is
attained.
I have not time in three lectures to go into
2362
all these details. I must stick to the main
questions.
NETWORK MAINS.
I now come to the network system, and
after the care we have bestowed upon the
multiple arc system generally, there is not
much to say. In the form proposed and
carried out by Mr. Edison, it is not econo-
mical, and I shall show you why. He leads
his conductors along the face of each block of
buildings, and wherever the conductors in-
tersect, the and conductors are connected
together respectively. Distributing centres
are provided with feeders supplying them, and
with wires to the engine-house to indicate the
potential. Resistances are introduced into
the feeder circuits to equalise the potentials.
This is a beautiful idea carried out without
calculation, and consequently not economical.
It is verbally identical with what I have
called the tree system, with the branches of
separately fed districts. connected. The chief
practical difference is that Mr. Edison lays
his conductors of the same size for a long
way. In the tree system the economical size
of conductor is chosen in every part. Secondly,
Mr. Edison equalises potential by resistances
in the mains which is hostile to economy. The
importance of having a large number of feed-
ing boxes and feeders is very great, for two
reasons:-(1.) Repairs are more easily exe-
cuted with less interference to many people.
(2.) The equalisation of potentials may be
made practically perfect.
The advantages of independent wires from
lamps to distributing boxes are enormously
increased by the fact that repairs do not affect
26
other lamps. The only consideration to weigh
against its advantages is the extra cost of thin
insulated wires. This is a matter which it is
impossible to touch in a general statement of the
problem, but which the engineer must calculate
for every special case before finally deciding.
The only advantage of connecting separately-
fed districts is the prevention of darkness in
case of accident to a feeder. I prefer to guard.
against this by splitting each feeder into two.
It would rarely happen that both were damaged
together, if laid separately.
Notice, in all systems of laying mains, the
size of conductors in different parts is propor-
tionate to what it would be if a wire came
from each lamp by the shortest 1ɔute.
On the wall is a diagram to show you the
arrangement proposed by Mr. Edison, where you
see separate dynamos connected with separate
feeders, going to separate distributing boxes,
which are connected to the whole network
system.
My object in these lectures is to lay methods
before you, not to give opinions, but it may be
right that I should state to you my belief that
the most satisfactory multiple arc system pro-
posed is as follows:-1. A large number of
distributing boxes as follows (the number
depending on the type of dynamo, or vice
versa). 2. Each box fed by a different feeder.
3. Each distributing box must be nearer to
the central station than any lamp fed from it.
4. Small groups of lamps to be fed from the
distributing box by separate wires.
5. The
relative section of conductor at every point
of a street to be the same as if every lamp
had a separate wire going by the shortest -
street route to the central station.
2363
27
LECTURE III.-Delivered FEBRUARY 16711, 1885.
In the last lecture, I was engaged in describ-
ing the different methods which have been used
to apply what is called the multiple arc system
of electric lighting. The multiple arc system
is a system in which there are one positive and
one negative lead between which the lamps are
placed. I think that we succeeded in arriving
at several very general conclusions which
simplify the consideration of the manner of
laying mains a great deal. I think I am right
in saying that in the past the practice of
designing mains has been to a certain extent
haphazard; the mains have been selected a
little at random, and then perhaps afterwards
adjusted to a slight extent; but there has not
been that thorough estimating of the effects
which could be arrived at by calcula-
tion, and in consequence of that there have
been some grievous failures in electric lighting
on the multiple arc system. I think we arrived
at one or two important generalisations which
must be accepted as necessary for economy,
and in such a system-the multiple arc system
-the amount of copper used in our mains is
so enormous that everyone must admit that
economy is the first consideration, and that all
such engineering difficulties as there may be
must be met by the engineer as difficulties which
can be conquered. The most important results
which we arrived at were, I think, pretty clearly
shown by illustration by the diagram of the city of
Chicago, as we chose to call it (Fig. p. 24),
in which it was shown that, in order to have good
distribution, there must be no great variation of
pressure in the mains, electric pressure in the
mains corresponding, as you will remember,
exactly with hydraulic pressure if it were a
service of water; and in order to prevent our
having too great a variation of pressure in
different parts of the district, or in the same
district at different periods of the night, when
the consumption over the district varies, it is
necessary, as I showed by means of the dia.
gram, to have a large number of distributing
boxes with mains, trunk lines of conductors
coming to these distributing boxes and feeding
them, and each one of these distributing boxes
then serving to light up a certain space, which
in the diagram is essentially a triangular
space. And I also gave you the rules
for determining what is the size of the
district which may be lighted up by such a
distributing box, and I think everyone here
will agree with me that the limit was very
confined indeed, compared with the general
ideas which have prevailed as to the number
of distributing boxes which are required; that
is to say, that upon the assumption upon
which we have been working of the size of con-
ductor required to carry a certain current, we
concluded it would be necessary to have the
distributing boxes so close that no lamp should
be at a greater distance than 124 yards from
the distributing box. Another important point
which has been, I think I may safely say,
altogether neglected in all schemes which
have been hitherto issued for distribution of
electricity from central stations is this, that
the distributing box, the point from which the
distribution takes place, must be closer to the
central station than any of the lamps which
are fed by that distributing box. As a general
rule, the distributing box has been put in the
centre of the district which it feeds, and that is
a mistake; it ought to be nearer the central
station than any of the lamps which it feeds.
I gave you also in the last lecture some
account of the relative cost of different systems
of lighting in the multiple arc way, and it was
found that by introducing a large number of
distributing boxes in this way the cost was
very materially reduced; but, at the same
time, the cost was very great, even with these
distributing boxes. And the cost may be
divided into two parts; first, the cost of the
supply wires, the conductors which are sup•
2364
28.
plying the electricity from each distributing
box to the houses, which are represented by
the square lines round each block of buildings
(Fig. p. 24); and secondly, there is the
expense of the feeders, the conductors going
up to the distributing boxes. Now when we
increase the size of our district to any con-
siderable extent, the cost of these feeders,
these trunks which carry the electricity to the
distributing boxes, is far greater than the cost
of the supply system of conductors. If there
be a means of reducing the cost in this way,
that is to say, any way of cutting out these
feeding conductors, that will be a very great
economy indeed.
This evening I will leave altogether apart
the system of multiple arc lighting, which is
the system which has been almost universally
adopted in the past, and I shall speak this
evening about the different systems which
have been proposed and carried into effect for.
using higher pressure in the mains. The work
which is done by a certain number of lamps is
a perfectly definite amount of work, and it is
measured by the product of the pressure of the
electricity into the quantity of the electricity
which flows. If we increase the pressure, we
diminish the quantity of electricity that flows;
that is to say, we diminish the current, and if
we diminish the current, we can diminish the
size of our conductors.
Now a great deal has been talked about the
danger of introducing high pressures in electric
distribution. I think that I shall find general
agreement, among competent people when I
say that a great deal of what has been talked
in this way is pure nonsense, and that high
pressures are not in the least more dangerous
than our present systems of illumination; that
if we have to bring high pressures of electricity
through a district, those pressures are confined
to the wires, and it is only in the case where there
is disgraceful negligence of duty, and a dis-
graceful leakage towards the earth in some
part of the system, that it is possible for any-
body to receive a dangerous shock from the
wires of such a system. The wires which
conduct the electricity into a house of any of
these high potential schemes can never have a
greater difference of pressure between them
than what is required for the lamp; that is,
in the present state of affairs, something like
100 volts. We will say that is the highest
pressure there can exist between the two
wires, and it seems almost incredible that there
should ever be allowed to be a leak in the
system so great that when a person touches
one of the wires he should have a high current
flowing through his person which would be
dangerous. If we are to abolish the idea of
using high potentials simply because of this
vague notion that some time a shock might be
experienced, we might as well abolish the
whole system of gas lighting because it is
possible that people can go into rooms where
there is a leakage of gas with a lighted candle.
The danger from gas is infinitely greater than
that which can ever come from high potential
electricity, and the difficulty of detecting a
leakage of gas is likewise .infinitely greater
than the difficulty of detecting a leakage of
electricity. A properly organised system of
distribution of electricity at high potential
would render a severe shock to any person
absolutely impossible, and that is the point
which needs to be dealt on very strongly at
present, because so much has been talked-
and so much nonsense has been talked-about
the dangers of high potentials.
·
I have often found a great convenience in
describing the effects of electricity and the
systems of distribution by reverting to the
analogy of water pressure, and, I think, those
of you here who are not deeply conversant with
the subject of electrical engineering will
perhaps be assisted by a few words of refer-
ence to the analogy of water pressures. At
present we see through different parts of
London pipes being laid for supplying power
by means of water at high pressure. This
water is utilised in motors or turbines, through
which the water passes. The water pressure
is remarkably analogous to the pressure of the
electricity in our mains; the turbines or other
motors which are used to develop the power
have remarkable analogy to the incandescent
lamps or the arc lamps, or the electric motors
which may be used with a system of distribu-
tion. Now, in the manner of laying pipes for
water-power which we have all observed in the
streets in London, all these turbines or water
engines are connected directly on to the same
set of pipes; in other words, they are all con-
nected in multiple arc, as we would say in
electric language. But it would be quite possible
to conceive of two turbines connected together in
series; that is to say, with a very high pressure.
in the mains first driving through one of these
turbines, and then the outflow of water from
that turbine still admitting of considerable
high pressure to a second turbine, which it
would work with the superabundant pressure
which would exist. This is exactly analogous
also to the electric system of distribution in
2365
series; and this will be clear by examination
of the diagram (Fig. 1), where this circle
represents the dynamo machine with the two
leads coming from it, and here are a number
of circuits, each circuit having two lamps in
series. This is exactly equivalent to a main
to come along here, split into a number of
--
FIG. 1.-MULTIPLE SERIES.
water pipes, with two turbines put in series.
It follows that the pressure of water required
to drive these two turbines is double the pres-
sure required to drive the one. So it is exactly
the same in electric distribution. We simply
have to increase the pressure when we put a
large number of lamps in series.
Now, there are several different ways in
which high potentials can be used effectively
and with economy. I will begin with mention-
ing the probable future which there may be in
the application of secondary batteries. We
often hear it remarked that the present systems
of electric distribution are weak in some points,
and that if only a system of secondary batteries
were introduced, everything would be clear;
and there is no doubt that by introducing
secondary batteries a great deal of facility is
given to the scheme. In the first place you
can have a much smaller engine power, much
smaller dynamo power, because your dynamos
can be working the whole day charging these
accumulators, and only used for supply when
it is required. In the second place, you can
put your secondary batteries all in series over
a large district, and charge them all up in
series, and then discharge them each to its
local district, a small number at a time, and a
small number at one place. In this way, by
using high potentials, of course we should use
small currents. In the hydraulic analogy, by
using high pressures we require a smaller
volume to flow, and therefore we should require
smaller conductors, and, consequently, there
would be a saving in laying down our
copper. This is perfectly true, and there
is not the slightest doubt a secondary bat-
tery system is of the utmost value, and
. would help us enormously. But at the present
29
moment there are several difficulties in the
way of introducing secondary batteries like
this, and the first is perhaps the most fatal
one, and that is that we have no secondary
battery. I do not mean to say that much
has not been done in the last four years
in improving secondary batteries; but at
the present time we have not suficient con-
fidence in the length of life and economy
of secondary batteries to justify any en-
gineer in depending upon them in design-
ing a scheme of distribution. But I must
say that there is a great probability of some-
thing being done in this direction, because
there is such a vast amount of intellect in the
whole world being devoted to this particular,
line, trying to perfect it, and already I have.
seen such enormous improvements in secondary
batteries of late, that I cannot help thinking
that very likely soon we shall arrive at some-
thing much more near perfection; and for this
very reason I consider it is of the utmost im-
portance that engineers should consider all
such schemes which enable them to use high
potentials, because, even though at the
present time such a scheme as that intro-
duced is imperfect to a certain extent, those
schemes which lay down small wires for using
with high potentials are the very schemes
which will become applicable when the
secondary battery is really a commercial
thing in our possession; and, therefore, any
person who has at the present moment to lay
down a large system of lighting with the
multiple arc system, would perhaps find, in the
course of a year or two, that the whole of this
enormous cost of copper he had laid down
would be utterly wasted, because some dis-
covery which had been made would enable
him to use smaller conductors. For this reason.
I consider in designing a scheme of electrical
distribution an engineer.should consider the
great importance of a probable discovery in
the way of secondary batteries.
·
There has been one large experiment in the
way of secondary batteries made at Colchester,
and I have got diagrams here showing schemes
of electrical distribution: With respect to the
diagram at the other end of the room, which
was referred to in the first lecture (Fig. p.
11), I would simply say, if you have troughs,
or good-sized channels in which your con-
ductors are laid, there is very little difficulty
about your insulation; with a good trench
and plenty of room, the engineering difficulties
are comparatively trivial, so long as you will
remember the facts which I pointed out in my
2366
first lecture, that you are not to trust to your
insulating material as the support for the con-
ductor. Your conductor must be supported
by a substance capable of supporting it, not
by a bituminous compound through which the
conductor will sink in the course of years. But
there are no engineering difficulties if you are
able to have a dry trough for conducting your
wires, and I am perfectly of opinion that if you
have the mains laid down in that way you can
use your 5,000 volts with perfect facility, and
there will be no danger; and with proper tests
regularly made, such a system would not only
be possible, but perfectly safe. The diagram
(Fig. 2) shows the arrangements which are
30
made at Colchester by the South Eastern Brush
Company for distributing their electricity. The
dynamos with the charging mains act through
what is called a rocking switch into the
secondary batteries. Now in this supply
system, first we have charging mains coming
to the secondary batteries situated in different
districts through the town, and then from the
secondary batteries we have service mains
going away to different houses which are to be
supplied, and this rocking switch is controlled
by what is called a master cell, which is
simply a cell with a diaphragm, so that
when the ebullition of gas becomes too great,
the diaphragm is raised and the contact is
CHARGING
MAINS
ROCKING SWITCH
A
Bla
ле
FIG. 2.
ma
TC
SUCCESSIVE
SETS
SERVICE MAINS
MASTER CELL
STORACE
BATTERIES
TO END
OF SET
måde, which switches over this rocking switch,
and the cells then being considered to be
thoroughly charged, are transferred from the
charging system of mains to the service system
of mains. That is the arrangement which was
adopted there. One of these cells which aré
used there is shown here, one of the Consoli-
dated Company's cells, which I have lately had
the opportunity of testing very carefully, and
which seem to give fair results; and I have
upon the tables below two plates, a positive
and a negative plate, and you can examine
them and see how they are constructed. Let
me put in a word here in parenthesis. I do
hope that those who are electricians will not
allow the term negative to be applied to what
ought to be positive, and the term positive to
what ought to be negative. I cannot under-
stand why, since secondary batteries have been
introduced, the whole language which elec-
tricians have been accustomed and got ha-
bituated to should be utterly reversed, and if
certain companies who make these batteries
persist in calling the plates in that way, I don't
see why electricians should adopt them, and
why they should not stick to the terms they
2367
31
have been accustomed to use. I only hope a
word said in season here and there will lead to
electricians insisting on proper terms being
given to these plates. Here also I have some
plates well worthy of examination kindly lent
me by the Electrical Power Storage Company.
I may say that I had the good fortune to look
through the work they have been doing of late,
and I have been very much struck by the
enormous progress they seem to have made in
the practice of the construction of cells, and
the maintenance of them in good order, and the
prevention of the sulphating of these plates,
which has been a source of very great trouble;
and one of the chief things I was shown was
the way in which these negative plates are kept
in good condition, and how it is apparently
impossible to injure them by overcharging. I
believe I am right in pointing to this one [in-
dicating a cell on the table] as one which has
been persistently overcharged with the idea.
of trying to damage it, trying to make it worse,
and if you look at it you will see as good a
plate as you ever saw in your life in any
secondary battery, the material perfectly
sound and excellent. It really seems to
show that one of the chief difficulties that
has been met with is charging with too weak
a current, and allowing the battery to de-
generate, and not keeping it thoroughly
charged up.
Next, I wish to draw your attention to a
system of supply with high potentials which
has been introduced by means of secondary
induction currents. It is a very old idea to
use induction currents in order to use a high
potential current in the mains, and a low
potential current in the supply service. I
believe that the first patent which I have
come across taken out in connection with
this, was by Mr. Harrison, in the year 1857,
and since then it has been patented over and
over again, and here, is a general idea of it
shown in this diagram (Fig. 3), where there
are supposed to be rods of iron sur-
rounded by coils of the main wire; here is the
main wire coiling around one end of these iron
bars. The lamps, then, have their terminals
connected by a wire which coils around the
iron bar also, an alternate current is used to
pass through these main coils, and it sets up
alternate magnetisation in opposite directions
by these iron bars, and the magnetisation in-
duces electric currents in this wire which is
connected with the lamp, and, consequently,
we are able to magnetise this bar by the main
wires with any potential that we please, and
we are able to draw off, by these induced cur-
rents, a current of any potential that we please.
In this way different lamps in different parts
of the circuit can be fed with a current of what-
ever pressure you please, although the main
exciting current is of very high pressure
indeed; but, mark this, there is absolutely no
danger in this system, because the charging
current is in a closed circuit which never goes
near the rooms where the lamps are actually
at work; a lamp thus never has over the
potential which is required for that lamp, and
the high pressures which are used in the mains
are confined simply to a closed circuit of wire;
therefore there is absolutely no danger in such
a system so far as the conduction of electricity
to any person is concerned. I may say that,
owing to the construction of such apparatus, it
acts as a condenser, and so might give a severe
shock. But this danger can be reduced to
iff
FIG. 3.
limits of safety, and tested for safety by ordinary
electrical methods. I have said that this is a
very old system. The idea is very old; but it
is only in the last few years that it has been
worked out practically and with confidence,
with a confidence that docs honour to M.
Gaulard, I may say, for the way in which he
has attacked this problem; he was confident
from the very first. I think it was three or
four years ago when we first saw his ap-
paratus in the Westminster Aquarium; since
then he has been improving it, and has
brought it to a practical issue. Since then
I have not myself had the opportunity of
experimenting upon the apparatus, but
I simply draw my conclusions from the
reports, in the first place, made by Dr. Hopkin-
son and others; and I have not the slightest
doubt that from these secondary generators it
is possible to get a return of 90 per cent. in
This is a result which is
the lamp circuits.
very remarkable, and is worthy of far more
2368
serious consideration than it has received up
to the present time from most people, though
of course many advanced electricians have
been looking with eager interest at the result
of these experiments. During the course of the
last summer experiments were being made, as
most of you are aware, at the Electrical Exhi-
bition at Turin, and I have on the wall a plan
of the scheme which was used there, and of the
way in which the wires were used. Altogether
the circuit had a length of about fifty miles;
and we have evidence of the large number of
different kinds of lamps used upon that
circuit--a large number of Bernstein, Swan,
Siemens, and Edison lamps, arc lamps and
glow lamps--a large number of different lamps
of different pressures, all worked from that
central station over that great distance, so
that the matter of distance is apparently over-
come; these distances were of course much
greater than they need be in any town distri-
bution. I don't think I will say anything
more about the system just now, except this,
that if there is no difficulty about the expense,
it is well worthy of far more attention than has
been given to it up to the present. I had the
pleasure of looking at the installation which is
being commenced at the Grosvenor Gallery
the other day, and I see there is no doubt we
shall have an opportunity very soon of seeing
a very large installation there, and at the
Inventions Exhibition there is going to be a
considerable amount of work done by the same
system. After those two experiments we shall
be in a position to judge whether economically
it is good. In every other point, except per-
haps the induced currents which the alternate
current machines may create in telegraph
wires and other circuits, there really seems to
be no objection to the system. It is true there
is a great objection to alternate current
machines, but when we come to examine it,
there is very little ground for these objections;
if the leading and return wires are brought
very close together, induction in neighbouring
telegraph wires is small, and I really think
that we ought to look - all electrical engineers
ought to look-very closely into these experi-
ments which are being made just now, for they
really promise well.
Now let us go on to the other systems, and
which are more analogous to those which we
have been describing previously; and first,
let us speak of the multiple series system.
Here is a system, which I have alluded to, of
multiple series on which there are two lamps on
every series (Fig. 1, p. 29). Now the trouble
- 32
After
of that was, when it was first introduced, that if
one of those lamps went out, the other in the
series went out. In order to prevent that, it
was suggested to bring a wire connecting the
intermediate position to all the lamps in the
circuit. Then if one goes out, the other does
not, because it is fed by the current coming
from the other lamps. The sketch shows that
very well by the dotted line. Another example
shows it in a different manner. There we go
through successive pairs of lamps, the pressure
gradually falling as we go along, and pass
through the nine different series connected up.
I do not know when this system was first prc-
posed; it is very old, I believe. The first
time that it was practically seen in action was, '
I believe, at the Paris Exhibition of 1881,
when Mr. Edmunds lighted the Congress
Salon by Swan lamps, the lamps all being
fitted in multiple series in this manner.
that the most important experiments madė
were those by Mr. Preece, at Wimbledon, last
year, when, in some experiments he made for
the Commissioners of Sewers, he lighted up a
large part of Wimbledon with incandescent
lamps, all on the multiple series system; and
quite lately we have had brought before our
notice by Mr. Kierzkowski-Steuart an ad-
mirable account of the lighting of Temesvar,
in Hungary, by means of a multiple series.
system like this, in a very remarkable article
which appeared in a recent number of
Engineering, giving a detailed description
of the arrangements there, which had up-
doubtedly been worked out with very great care
before laying down the installation. Now, the
multiple series system is one which is admirably
adapted to Temesvar, in Hungary, because it
is only used there for street lighting, and the
lights are always all required at the same
time. But it is not suitable for house-to-
house distribution, simply for the reason
that if some of the lamps are put out,
then the other lamps on the circuit have
too much current. [Experiment to show
this effect.] Now it would be intolerable,
in a general supply of electricity, that
when one house in a block of buildings was
using rather less current than usual, othei
persons in that block should get far too
much current; and that the next block
of houses should receive so little current
as was shown by these lamps (in the experi-
ment) would also be intolerable. Various
devices have been proposed for getting over
these difficulties. I will deal with one or two
The first system which I shall speak of is one
•
2369
which has already been put into practice, and
it is undoubtedly a most ingenious principle.
That is what is called the three-wire system,
which Dr. Hopkinson originated. There we
have two dynamos at the central station work-
ing in series, working through each other;
that is to say, in the hydraulic analogy two
pumps working in series, so as to send the
water from the pumps at a very high pressure,
if such a thing could be introduced into
hydraulic engineering. The supply mains
come from the extremities of two wires, but
there is a third supply main which comes from
the intermediate point and connected between
the two dynamos, and the lamps are attached
to branches which may come from the first
main to the intermediate, or, as it has been
called, the compensating main, and some of
the lamps are attached to branches which are
connected with the last main and the com-
pensating main in the middle. We are able
to use twice the pressure by using the dynamos
in this way. Of course a great difficulty, as I
have mentioned, would occur were it not for
this central connection of the compensating
wire; if there are more lamps in use in the
first series than in the second series, then it
would be necessary to drive the first dynamo
so as to give a greater current than the second
dynamo is giving, and then by adjusting the
pressure of the two dynamos we are able to
give a constant supply to both seis of lamps,
and at the same time to work them in series.
This line on the diagram is supposed to re-
present a point of very large consumption,
such as a theatre, when the wires come, some
from the first main and the compensating con-
ductor, and some from the second main and
the compensating conductor, but in about an
equal number, so that if the lights of the
theatre be put out of a sudden, the disturbance
in one series of mains will be the same as in
the other, and there will not be that change
in the light shown you just now.
Now, as to the economy of this system. In
the first place you will notice that, as I have
arranged it here, which is the manner in which
Edison has used it, the fall of potential is at
the same rate as it is with the ordinary multiple
arc distribution, therefore, according to this
way, in which lamps are led off from two pairs
of mains at every part, the distance to which
these mains can extend is still limited, as it
was in the multiple arc system, to 124 yards.
But it would be equally possible to use only
the first main and the compensating main, up
to a distance of 124 yards, and then to use the
33
compensating main and the second, the lower
potential main for another 124 yards. Now
as to the economy. A great deal of exaggera-
tion has been introduced in America into the
accounts of economy in this system. It has
been said that since you are using only half
the current when you double the number of
dynamos, therefore you half the size of mains ;
but then you have three mains instead of
four, therefore, they say, you have a gain
of 25 per cent. for that reason; but then,
they also say, you have got twice the pres-
sure you had before, and, again, you may
halve your mains, and, altogether, they tell you,
you can make a saving of copper of 62 per
cent. Now this may suit American financiers,
but it is not electrical engineering. As a matter
of fact, in the two cases, with an equal number
of lamps, in place of having one dynamo and
one pair of mains, I introduce two dynamos
and three mains. I have half the current
passing through that wire, and, therefore, I
may have half the section of it, but there is no
further reduction possible. I assume that I
may take it for granted that the axiom which
we worked out in the first lecture must be
accepted as an axiom in all future time, that
is, that to get economy in our mains we must
use the most economical size of conductor
possible. In that case the size of conductor is.
approximately proportionate to the current it
has to carry; therefore, the total amount of
copper you have to lay down is simply three-
fourths of the mass of copper which would be
laid down in an ordinary multiple arc system.
At a meeting of gentlemen interested in.
electricity lately, this subject was broached,.
and I ventured to mention this point then,
simply because the originator was present, and.
I may say that Dr. Hopkinson thoroughly
coincided with me in the views I have given.
you, so that the erroneous notion is evidently-
purely an American idea.
If we increase the number of wires from.
three to a larger number, then we increase the
economy, but if all the wires are of the same
size, then the limit of economy, the maximum
economy would be to reduce the copper by
one-half; but it is possible to reduce the com-
pensating wire, and I should think it might
be reduced to one-half, and in that case the
limit will be one-fourth; that is to say, when
you put a large number of series you will have
about one-fourth of the copper which you have
otherwise in a multiple arc system. However,
if we wanted to be absolutely certain that our
lamps would be in perfect working order, and
C
2370
that our conductors would be of suitable size,
perhaps it would be right that all these three
conductors should be of the same size, because
such a consumption might arise. I am not of
this opinion; but suppose we say that then
would come the question whether it is not
possible to devise some other means of re-
ducing the thickness of these intermediate
wires-these compensating wires. And this is
what Mr. Edison has accomplished, on paper
at least. In a very interesting patent which
he took out in 1883, he has described a means
of switching over the lamps from one pair of
mains to the other. Now I believe there is a
great deal in this, and I believe it is possible
in this way to make the householders them-
selves regulate their supply to a great extent.
Just think what you do with your own gas.
When you first light your gas, if your burners
are as bad as burners usually are, your light
flares, and you have to turn it down; after a
time, when everybody else is using the gas,
you have to turn it up again; then, late át
night, when everybody has gone to bed and
you are hard at work, you require again to
lower it. If every householder had a switch,
so that he could switch his own lamps on to
one pair of mains or the other when he found
his light dull, he would fiddle away with his
switch, and in that case he would not only
make his own light better but everybody's else,
and every person in the district would be
helping, the others to acquire the right poten-
tial. No knowledge of electricity is required;
no householder has to know what he is doing;
he has simply to follow the natural instinct
which a householder has of fiddling with his
gas-jet until he gets it to work the best way
possible and thus it is just possible that to
some extent that may be of use. Mr. Edison
proposed to use this system of switches
with the three-wire system in combination
with it, so that he will not get a perfect
compensation by either the one or the other;
by the combination of the two, he will get a
perfect system and a perfect compensation.
He has also proposed, in the same patent, to
introduce automatic switches, switches which
may be influenced by the pressure of these mains
locally, or switches which may be influenced
by the person in charge at the engine-house,
so that wherever there is a deficiency of
potential, lamps may be switched over. It is
very probable that some development on this
line may lead to important results. I have
myself tried to extend the system a little,
not in connection with the three-wire system,
34
but in onnection with the simple two-wire
system.
I feel pretty certain that the lighting
of a town from a central station must be
done on some multiple series system until
secondary batteries are so economical as to
permit the general introduction of such a
system as that in use at Colchester, The
chief difficulty lies in the fact that each section
receives the same current whatever be the
number of lamps in use.
To obviate the excess of current, we might
introduce conductors in those sections where
it is required to carry off the excess of current.
Thus we should save the lamps at the expense
of energy. These conductors might be in the
form of adjustible resistances acting automa-
tically. This system is wasteful, but there are
many cases where, at the present time, it is
the most economical.
Another plan is to introduce in each section
a secondary battery of low resistance, which
shall act as a regulator. But secondary
batteries are still rather expensive.
I have shown a diagram of multiple series.
arrangement, in which two wires go round the
circuit with breaks occurring alternately in the
two wires: If we alter the position of these
breaks we can always have the same number
of lamps on each section, and so avoid all
excess of current, and all waste of energy.
[Experiment shown.]
Now the time has come when we must con-
clude this course of lectures, and, in conclu-
sion, I have only to say that I think you will
all agree with me that when we attack the
problem of electrical distribution in a serious
vein, we find that it is rather simpler than it
seems at the first blush. It has been well said
by one of our most distinguished electricians
that in the past the distribution of electricity
has been the crux of electric lighting; it has
been there that the difficulty has been. Un“.
doubtedly the Electric Lighting Act has done
an enormous deal to hinder electric lighting,
but every electrician must admit that there has
been a difficulty in the question of distribution ;
and I think you will all agree that the further
we go into it, the simpler are the rules which
guide us, and it is only that when schemes
have generally been commenced in a slightly
haphazard fashion, that difficulties of a serious
character have seemed to present themselves.
In every special district the engineer must use
his discretion as to the kind of distribution
which he is going to employ. But even in
large districts, I think you will all agree that
2371
the consideration we have given to it shows
that it is a possibility to lay mains on eco-
nomical principles which shall suffice for
lighting large districts, if no undue hindrance
is put in the way of enterprising undertakers
by the authorities that are in power. The
past History of electric lighting has chiefly
dealt with the system which I first spoke of in
my last lecture, the multiple arc system, but
I do not hesitate to say that the future of
electric lighting, on a large scale, will deal al-
most entirely with the systems which have been
touched upon to-day. And especially I would
draw attention to these different schemes and
their value for the reason which I have already
mentioned, that in the future we may have
inventions in secondary batteries, or we may
have other inventions, but whatever invention
there is favouring electric lighting, it will be
of a nature suitable for using the thinner
conductors which we should naturally lay down
with any high potential system which I have
spoken of this evening. Therefore, the engi-
neer, in designing a system of mains, would
have a natural bias towards such thin con-
ductors, such high potential mains: for that
reason he would advise it, as well as for other
reasons. When we are able to use, as I con-
fidently believe we shall, a pressure of 5,000
volts, we can diminish the thickness of our
conductors to one-fiftieth part, and for a
district of 50,000 lights we should only require
a conductor of about an inch section of copper..
When we are leaving the idea of masses of
copper of the size of a man's body, and coming
down to masses of copper an inch or even two
35
inches in diameter, I think we are really
coming to the question of practical electric
lighting.. And all this has been done—is not
merely theoretical; it has been done to a con-
siderable extent already, and that is the
direction in which progress is being made at
the present time.
I can only say that I hope the Parliamentary
difficulties which have partly stood in the way
of electric lighting in the past will soon be
entirely removed, and that others will prose-
cute the question of electric distribution, so
that we may be all thoroughly ready for it
when we have greater facilities for electric
lighting in the future, because there is not the
slightest doubt that the question of distribu-
tion had not been sufficiently developed when
the Electric Lighting Act was passed; and if
we are ready in the future, when those great
concessions which must be granted by this or
a succeeding Government-because it is
simple justice—when those concessions have
been granted, let us trust that engineers will
be ready, and be able to supply a scheme
which is perfectly satisfactory.
The CHAIRMAN (Mr. W. H. Preece, F.R.S.),
in proposing a vote of thanks to Professor
Forbes, expressed his agreement with what the
lecturer had said with reference to the danger
of high potentials. He was
quite sure that
electricians were far more able to protect the public
from even 50,000 volts, than gas engineers were to
protect the public from explosions, or ordinary steam
engineers from bursting boilers.
•
LONDON: PRINTED BY W. TKOunce, 10, gough-square, flpFET-STREET, E.C
2372
Complainant's Exhibit, Sprague's Electrician Article.
THE ELECTRICIAN, SEPTEMBER 9, 1882.
403
there is only a disengagement of hydrogen at the negative THE EDISON SYSTEM OF ELECTRIC DISTRIBUTION.
electrode without a deposit of iron.]
Chlorite of potassium (negative electrode - hydrogen
and base. Positive electrode little or no dis-
engagement of oxygen)....
92*
[The liquid of the positive, branch of the voltameter is
yellow in colour, reddens at first, and afterwards discolours
litmus blue.].
■
80*
54*
Bromide of potassium (negative electrode - hydrogen
and base. Positive electrode bromium)
[The yellow colouration of the positive branch of the
voltameter is due either to oxides of bromium or to per-
bromide, as has been observed by M. Berthelot.]
Iodide of potassium (negative electrode - hydrogen.
and base. Positive electrode - iodine)
[A zinc-carbon element decomposes quickly the iodide
of potassium with deposit of iodine at the positive electrode,
and disengagement of hydrogen at the negative electrode.
A zinc platinum element with dilute sulphuric acid also
decomposes, although more feebly, the iodide of potassium.
After M. Berthelot a zinc platinum couple will not decom-
pose iodide of potassium. It is probable that M. Berthelot
operated on a solution of iodide of potassium too extended,
and in this case his electrolysis ought to produce itself less
easily. In fact, the iodide of potassium absorbs, in order
to be decomposed, fewer calories than water, and, conse-
quently, the more concentrated the solution the easier to.
decompose it.]
BY F. J. SPRAGUE, U.S. NAVY.
I do not propose to enter into any discussion as to the priority
of the claims of this inventor as compared with any other, but
to speak of Mr. Edison's system as it has appeared to me after a
thorough investigation and study of the same, extending over
several months, and with great facilities at my command'; and my
conclusions are based, not on Mr. Edison's claims, or the claims of
his friends, but are the result of a candid examination. Mr. Edi-
son's ambition has been far reaching, and he designs to establish a
system of distribution, not alone for lighting, but for almost
every purpose to which the electric current can be put, and he
recognises the all-important principles, that all parts of such a
system are mutually dependent; that thorough mathematical
and engineering talent must be used; that no detail is so unim-
portant, no real objection so trivial, but that it requires patient
districts laid out, capital invested, and energy wasted, must all
consideration; that dynamos, meters, lamps, motors, conductors,
be calculated with reference to each other-in short, that
economy and reliability are the great ends to be attained. The
result is, that he comes now before the world, after three years
of hard work and patient experimenting, feeling fully equipped
and able to establish thoroughly reliable and extensive installa-
tions. I have stated some of the requirements of a system of
general distribution, and will consider that with Mr. Edison in
detail and as a whole. I shall not give a full description of all
the parts, but intend rather to consider it from a practical and
economic view.
In the first place, let me speak of the
Dynamos.
•
These generators, which have armatures wound or connected
on a modification of the Hefner-Alteneck system, may be divided
into three classes :-
¿
In offering some criticism on M. Tommasi's results, M.
Berthelot, the distinguished chemist, expressed the opinion
that a zinc-carbon couple cannot be regarded as the equiva-
lent of a zinc-platinum couple in the calculation of the
quantities of heat developed by reactions which give birth to
the voltaic couple. In fact, the heat disengaged by the
attact of the zinc and acid is not the total with carbon, which
exercises reactions proper and peculiar to itself. It absorbs
hydrogen, oxygen, and these bodies interfere with the pure
action of the carbon, as has been demonstrated by the
researches of M. Ed. Becquerel (Ann. de Chimie et de
Physique, 3rd series, Vol. 48, p. 256) on the electromotive
force of such couples. He also points out that the thermic
values which express the electrolytic reaction are only estab-case with the same weight of metal and a shorter length. On
lished for dilute liquids, and that the effects due to the
separation of a trace of acid from the base in saturated
saline solutions cannot be rigorously calculated because of
the changes of concentration and secondary reactions. The
principles of the calculation are the same, but the data fail.
In reply to M. Berthelot, M. Tommasi points out that he
has shown that with two zinc carbon couples and dilute sul.
phuric acid, it is possible to decompose a solution of sul-
phate of potassium when that decomposition cannot be
effected by two zinc platinum couples and water accidulated
by SO H². This experiment has been repeated by him with
solutions of sulphate of potassium of strengt varying from
1 per cent. to saturation, but no appreciable difference was
observed in the electrolysis of these solutions. He also
points out that even if there were metallic impurities in the
carbon they would only serve to increase the difference of
potential between the two extremities of the circuit. As to
the substitution of pure carbon for platinum in a zinc-pla-
tinum couple with water accidulated by SO* H2, M. Ed.
Becquerel has already observed, in 1856 (Ann. de Chimie
et de Physique, 3rd series, Vol. 48), that the electromo-
tive force of this couple diminishes instead of increasing. M.
Tommasi further thinks that the increase in E.M.F or carbon
couples is not due to the absorption of hydrogen or oxygen
by the carbon, for, as he has already observed, to obtain
good results with these couples it is necessary that the car-
bons should enclose in their pores a gas, carbonic acid, for
example, which, by its presence, forbids, or, at least, retards,
the polarisation of the positive electrode of the battery. At
the same time, he does not deny that the absorption of cer-
tain gases by the carbon is not the cause of the increase of
energy of carbon couples, but he does not consider such a
supposition justified by experiment.
* Calories or Electrolysis after M. Berthelot.
1st. Those having wire-wound armatures, the coils being
wound on a wooden cylinder wrapped with a soft iron wire.
These armatures are driven by belting, and rotate between the
faces of long, vertical magnets at a speed of from 800 to 1,200
revolutions per minute, according to the size of machine and the
number of lamps. By using a large mass of metal a powerful
magnet may be created, rendering necessary a less number of
convolutions of wire, and, consequently, less heat and waste in
the armature for a given electromotive force. By using long
magnets the mean resultant of the convolutions of wire is
brought much nearer the centre of the core than would be the
account of this a more active magnetic field is produced; one
with a greater projective power, and less current may be used in
the field coils. This can be exemplified in a striking manner
by reforging the cores with the same amount of iron, but
making them shorter, and rewinding with the same amount of
wire as is now used. With the same speed of armature and the
same number of convolutions, the E.M.F. of the machine will
fall very appreciably, and this lower E.M.F. can be obtained by
using the longer magnets with the faces at a much greater dis-
tance from the surface of the armature. The commutator is
long; its life, or time of running without repair, is thus
increased, and should a movable commutator be fitted the trouble
of taking care of a machine may be reduced to a minimum.
There are four varieties, or classes, with capacities of 70, 150,
250, and 500 lamps, and the number of magnets depends upon
the size of the machine. Each pair of cores is in series; if two
or more pairs are used the pairs are thrown in parallel circuit.
Roughly speaking, the resistance of the field coils may be
expressed by the fraction 3,000, where L is the full number of
lamps. In the 70 lighter this resistance is 404 ohms cold, and
415 warm, and the field is in parallel circuit with the external
circuit. The machine generates an E.M.F. of about 110 volts,
and runs very quietly. Ordinarily 60 lamps would be the proper
load if running for a long time, but do can be readily carried for
a shorter period. The only limit to the power of a machine,
ordinarily speaking, is the heating of the armature, which
depends upon the total volume of current flowing. The arma-
ture has a resistance of 16 ohm, cold, and 20 warm.
With a
difference of potential of 100 volts at the terminals, the field
coils would require 10,650 foot-pounds of electrical energy
expended per minute, or 32 horse-power, represented by about
a pound of coal per hour. The energy lost in the armature
would be C2 8848, C being the total current in amperes. With
a circuit of 70 140-ohm lamps, the external resistance, includ-
ing the field coils, but not the conductors, which are very low,
would be 2 ohms, over 9.5 times the internal. Reference to the
curve shows it to be very flat at this point, and the change in
E.M.F. of the machine for a large reduction of lamps would be
•
L
2373
404
THE ELECTRICIAN, SEPTEMBER 9, 1882.
small. If the number be cut down to half, the drop in the E.M.F.
would be but about 4 per cent. My experience with the larger
capacity machines of this type does not warrant me in comment-
ing on their performance, but from the knowledge of their con-
struction I should judge their efficiency to be about the same. I
should have said that about 9 or 10 horse-power should be
delivered to the pulley of the 70-light machine.
magnets,
2nd. The second class comprises machines with long magnets,
as in the first, which may be coupled in series, or in parallel
circuit making their resistance about one-fourth, and enabling
a given E.M.F. to be obtained with a lower speed. The armature is
built up of iron discs, and has a sheathing of copper bars con-
nected across the ends by copper discs. One pair of bars and
one pair of discs form a complete coil. This armature is of very
low resistance; in the ordinary size it is one-tenth that of the
armature of the 70-lighter. It is run at about the same speed,
develops a lower locomotive force, and is suitable for lamps of
lower resistance. One of these machines was very carefully
tested by Mr. J. A. Howell, at Stephen's Institute, and no better
idea can be formed of its efficiency than by reference to the fol-
lowing table, which is compiled from Van Nostrand's January
magazine. Three tests were made, and all sources of error were
eliminated as far as possible. The first was by means of the
voltameter, the second by calorimeter, and the third by the
E.M.F. and resistance method. By "efficiency" is meant the
ratio of the total electrical energy developed to the power
required to turn the armature in the magnetic field. By
commercial efficiency "is meant the ratio of energy appearing
in the external circuit to the power required to drive the machine,
including friction.
"
Data.
Time of duration
Speed of dynamometer
Resistance of armature...
Total resistance of circuit
E.M.F....
C.
Efficiency
Commercial efficiency
1st ex. 2nd ex. 3rd ex. Average.
15... 16...
400.5... 394... 355...
•016... ·016... ⚫016...
773... ⚫696... .658...
64.74... 55·10... 53.00...
83 75... 79-17... 80-55...
·955... •967... .935...
.861... •901...
·87...
Foot-pounds of electrical energy
Appearing in armature... 4965... 5604... 5026...
Field coils..
4646... 4216... 3347...
External circuit .230268...233940...198301...
Per centage of same appearing :
In armature.
Field coils..
Both
External circuit
⚫951
887
2.07... 2:30... 2:43... 2.27
1.94... 1.73... 1·62... 1·73
4.01... 4.03... 4.05... 4·03·
95.99... 95 97... 95 95... 95.97
Little comment need be made on these results. With a simi-
lar machine, the field magnets in parallel circuit, 240 8-candle
lamps of about 65 ohms resistance have been run. These arma-
These arma-
tures are somewhat difficult of construction, but it seems to me
that their efficiency is so remarkable that the extra expense is
warrantable, and I should like to see more machines constructed
on this rather than on the wire principle.
·
experiments, we find that one lamp of 140.5 ohms resistance
required, for an illuminating power of 16 candles, a potential of
99 volts, and used 3,107 41 foot-pounds of energy per minute.
The potential and resistance give a current of 7046 ampere.
This is about the average of five lamps, and we may base some
calculations on this. 1320 lamps would require 930 072 amperes,
and the external resistance, that of the lamps, would be 1064
obm, or 28 times the internal. Call the resistance of
obm,
leading wires 01 ohm, i.e., one-tenth of the lamp resist-
ance, which will give a lamp circuit resistance of 1164
The resistance of the field coils, cold, is 6.73
ohm.
ohms, which, in parallel circuit with the lamps, gives an
external resistance of 11425 ohm, and a total circuit resis-
tance of 11839 ohm, allowing an increase of 5 per cent. for
the resistance of the field coils, and 10 per cent. for the
armatures. For convenience, I regard the leading wire resis-
tance as entirely entering between the commutator brushes and
the lamps. This will give a difference of potential at the brushes
or terminals to the field coils of 108 05 ohms, and a field current
of 15 29 amperes; whence we have a total current in the arma-
ture of 945 36 amperes, and an E.M.F. of 111.67 volts. This
gives an equivalent of 73,090 foot-pounds in the field coils,
387,200 in the leading wires, 163,690 in the armature, and
4,064,050 in the lamps, making a total of 4,688,030 foot-pounds of
electrical energy per minute. In the absence of exact data, let
us suppose the efficiency of this machine to be the same as, or
rather let us say that it is 2 per cent. less than that of the small
machine we were before considering, i.e., 93 per cent. There
would then have been applied 5,040,892 foot-pounds per minute to
the axis of the armature, or 152 75 horse-power, of which there
was expended 123 15 in the lamp circuit, 11 73 in the external
conductors, 2.22 in the field circuit, 4.96 in the armature, and
10-69 otherwise wasted; or, expressing it in per centages, 80'6,
7.6, 1.5, 3.3, and 7.0 per cent. respectively. Although 496 horse-
power may seem in itself a large amount to be lost, in the
armature, it is, we see, a very small per centage of the
whole, yet a diminution of 0001 ohm would diminishi
the loss by 3,916 foot-pounds per minute. We thus see how
absolutely necessary it is to have the lowest possible resis-
tance in the armature when dealing with large currents, the
energy of which, expended in a circuit of given resistance,
increases with the square of the current. Suppose, for a
moment, an armature were built of the tenth of an ohm resist-
ance, and the same current 945 36 amperes were to flow through
it, there would be a loss of 118.6 h.-p., and with the resistance of
an ohm the power of 1,186 horses, or 19,569 foot-tons per minute,
would be lost; in fact, it would be practically impossible to build
an armature of that resistance to sustain the current.
•
Another rather instructive calculation may be made by
reducing an armature to a nominal equivalent foot conductor.
In this it is not necessary, in order that we may compare with
another machine, to consider the relative intensities of the field.
All machines have certain parts of the conductors which are in-
active, and the less this proportion the better for the machine
and the higher efficiency will it show. In this generator there
are 98 bars on the armature, the average length being 4ft. 9in.,
of which 4ft. 2in. are active. The circle of revolution is 27·5in.
3rd. This class comprises machines with armatures on the diameter. At each end are 49 circular plates, each of which I
same plan as the last, but very much larger, of lower resistance, consider the equivalent of a conductor 27 5in. long, and having
and of double the electromotive force. The field magnets are a velocity of a point at half distance from the centre. I think
horizontal, have 12 cores, and their resistance is about one-seventh that the speed of the engine was about 320 revolutions, because
that of the 60-lighter. The armature is connected directly to with a load of about 700 lamps its speed is 290 to 300 revolutions.
the engine, this being a well-powered, high speed, non-conden- I feel quite certain that it was not above that. With this data,
sing engine, known as the Porter-Allen. The governor controls I find the active part of the armature to be equivalent to a con-
the throw of the valve by shifting the position of the link. The ductor one foot in length, moving with a velocity of 15,682ft.
armature has a speed of from 280 to 340 revolutions per minute, per second, and the inactive part, comprising the ends of the
the ordinary speed being about 300 There are in Europe three bars and the discs, equal to a foot conductor with a second velocity
only of these machines, the first being in Paris, the second and of 6,507ft., or the whole equivalent to a foot conductor with a
third at the central station at Holborn-viaduct. These are not velocity of 22,189ft. per second. With an E.M.F. of 111 67 volts,
of the same size, No. 3 being the largest, and having capacity this gives a foot conductor a second velocity of 1987ft. per
normally of about 1,000 lights. I think six others have been volt developed, and with 5,040,892 foot-pounds per minute an
constructed, part of which have already been tested for the New absorption of 378 foot-pounds in a foot conductor per foot per
York lighting station. The resistance of the armature of No. 3 second, of which 93 per cent. is developed into electrical energy.
when cold is 0038 ohm, this low resistance being obtained by This is an admirable showing, and affords some data on which
the use of a few large conductors. The connections are plated to build a still larger machine. I am inclined to think that, were
with gold to prevent oxydisation. Although the normal capacity the armature built up of rings instead of discs, even less power
of No. 3 is about 1,000 lights, it can be readily run up to 1,200 would be wasted, and the machine be in every way probably as
or 1,300, and by coupling the field magnets so that their resist-efficient. But there is a limit to the size of machines to be built,
ance is about 4-9ths that of the Holborn-viaduct machine, Mr. which limit is reached when we determine how much waste can
Edison very recently ran 1,630 lamps at 20 candle-power. Of be afforded, and how much must, of necessity, be lost in the
course, on account of a certain amount of loss in conductors armature.
of a general system, a. generator must be able to develop an
E.M.E.. of from 10 to 20 volts more than difference of potentials
existing at the lamp terminals. I have been informed, on re-
liable authority, that the No. 3 machine was tested before leaving
New York with 1,320 lamps for fifteen consecutive hours.
suppose this was at 16 candles. Referring again to Howell's
oue
The current generated is taken off by four pairs of inde-
pendent brushes, the surface of the commutator being slightly
amalgamated. The sectional area of the brushes on
side is about four square inches. Unless adjusted carefully
there is a good deal of sparking, and consequent loss in wear.
but experience, in a little while, enables one to set these brushes
2374
THE ELECTRICIAN, SEPTEMBER 9, 1882.
sufficiently far ahead to make this almost entirely disappear.
The scoring of the commutator in a four mouths' run, which has
been, to a great extent, experimental, is about fin. The com-
mutator blocks should be movable, and I understand that all
large machines are now so constructed. I have seen the largest
machine here run one lamp at about 16 candles, and at other
times 800 to 1,000 at from 20 to 25 candles. Of course there is
no economy with a few lamps on a machine of this size. The
potential is such that the commutator brushes can be readily
grasped, but there is a peculiar sensation of heat experienced in
the wrists and forearm. The armature beats moderately, the
radiation being hindered by a thorough insulation, but a blower
forces air around it to prevent undue rise of temperature. As
interesting experiments, the two machines at Holborn-viaduct
have been joined in parallel circuit, although of unequal capa-
cities, and a sixty light machine could be just as readily coupled
to the same circuit. One machine has been stopped, the circuit
broken, and the load taken by the other generator, all in about
twenty seconus, One machine has been stopped, and the load
thrown on the other without extinction of the lamps; and once
the engineer, by a mistake, kept throttling one machine down,
because he thought it was running too fast, to find that this
machine was being run as a motor by the other.
The engine scems to me to be an excellent one, and now that
opposition in some quarters to large dynamo machines has been
hushed, the engine becomes the moot point. The general ex-
perience has been that high speed engines, on variable work and
long runs, have given a great deal of trouble with lost action,
back lash, loosening nuts, and wear of piston, cylinder, valves,
and guide bars. In a large system of distribution, the variation
of load is not the same as in a tool shop or factory. It will be
generally much more gradual, and consequently the work is better
adapted for a high speed engine than many other kinds might be.
On behalf of large engines there may be urged less wear and tear,
fewer individual parts to look after, less liability to a break
down, a greater number of good engines to choose from, and
higher economy. On the other hand, there is, in favour of the
higher speed engine, less boiler space required, the size engine
for a given power being so much less, the individuality of each
engine, the less inertia, and in case of a break down the disabling
of a much smaller part of the plant. I confess to have had a
prejudice against high speed engines, but this has mostly
disappeared, and an inspection of one of the engines in
use at Holborn-viaduct shows it to be in th
be in thoroughly
good condition. I believe that Mr. Edison has another engine
under trial, and that he is not committed to the present one.
Why the change will be made, if such there is, I do not know,
unless because of greater regularity.
The boilers are the Babcock and Wilcox patent, adapted for
quick steam and high pressure. They need to be well taken care
of, but are widely and favourably enough known to engineers
to need no comment on my part.
Lamps.
On account of the need of having the external resistance high
compared with the internal--and this ratio necessarily increases
with the volume of current required; the resistance entering into
a part of the lamps, and not into others; the necessity for allow
ing but a small variation of illumination in different lamps; and
from the fact that a given illuminating power can be obtained
from a fine filament with a less loss of energy in cond"tors than
from a coarse one, Mr. Edison has aimed at carbons of a very
high resistance. There have been difficulties in the way by no
means easy to surmount, a fact with which all inventors of
incandescent lamps are probably conversant. One is that carbon
One is that carbon
diminishes its resistance when hot, another that strength, elas-
ticity, and life are wanted. A third is that lamps of like illumi.
nating power should have the same resistance, and the certainty
of a reasonable life. Remarkable advance has been made, and
16 candle-power lamps are now made of 240 ohms resistance
cold, dropping to 135 to 145 hot, and 10-candle lamps of about
475 ohms cold, and 275 hot, exceedingly strong and elastic, and
of long average life when used at the proper power. This life is
still quite variable, and it cannot be foretold. They may not last
300 hours, they may last 2,000. About 1,100 hours is their
average life at present. Made of the finest bamboo, they are
fibrous, of very even texture, and very fine; yet I have split, acci-
dentally, the carbon of a ten-candle lamp. There is another
variety, the eight-candle lamp, which is called the " B;" this is of
the same cross section, and one half the length of the "A" lamp,
but its use is limited, because in a general system, absolute
individuality of all lamps is a requisite. The carbons are joined
to the copper terminals of platinum wires in the glass, the
copper clamps and ends of the carbons being plated in a solution.
The platinum wires are sealed in a hot pressed joint, at the inner
end of a tube sealed in the neck of the globe, whence copper
wires lead to brass connections, which are brought into contact
405
with the similar connections in the socket. One contact is made
before the other can be, and this last is by firm pressure. The
carbons are so elastic that they will vibrate from one side of the
globe to the other, and keep up a rapid vibration for a long time.
When hot they are less elastic. To get lamps of higher illumi-
nating power, the width of the carbon is increased, while the
thickness remains about the same. Two or more carbous have
been used, but this is not a practical arrangement. This gives
about double the illuminating surface, half the resistance, and
requires double the energy. There is room for great improve-
ment in the matter of lamps of high power, for I have no
doubt in the near future that incandescent lamps of 200.
or 300
or 300 candle. power, and even higher, will be perfectly
practicable. It has been said that lamps should have
the highest possible resistance. This is not so. The
carbons have been reduced about as far as possible in width.
It is possible that they may be made thinner, and in this way a
step made to lighter weight, higher resistance, and greater eco-
nomy. But the real limit is the potential which can be used.
The resistance of a carbon of given illuminating power must
depend upon the foot-pounds of energy expended, and the poten-
tial at the terminals. I append the following table, which will
give the required lamp resistance at different potentials, and with
varying degrees of economy, in the case of a 16-candle lamp,
which candle-power we will suppose remains the same. I will
begin with the economy already obtained, about 3,000 foot-pounds
per minute per lamp.
Foot-pounds of
E.E. used in
lamp per
minute.
3,000
2,500
2,000
1,500
No. of
lamp
per
E.H.-P.
.....
......
......
11
13.2
16.5
22
......
Candles
per
E.H.-P
176
211.2
264
352.
Resistance of lamps in ohms
when the E.M.F. is (volts).
100 125 150 175 200
147 246 332 452 590
177 293 398 542 708
221 367 498 677 885
295 489 664 903 1,180
Already there has been produced about 12 lamps per E.H.-P.,
and, although I hope to see it reduced, I think that 2.000 foot-
pounds of energy is as low as can be hoped for, and I do not feel
we should go above 150 volts potential at the lamp terminals.
If this end can be obtained, the carbons must have a resistance
of 498 ohmas, hot, and there will be produced over 260 candles
per H.-P. of electrical energy. I am confining these computations
and statements to the case of lamps not giving over 16 candles
each-about the standard of which a long use of gas has led to
the adoption. Of course, with higher illumination per unit of
area, a greater given power per coal expenditure can be had, but
is attended with a shorter life.
The difference in work for a 140 ohm lamp at 15 and 16 candle-
power is about 84 foot-pounds. Referring to the lamp already
considered, and the equation of work, we find that at 15 candle-
power there can be an additional circuit resistance of two ohms
in one of two lamps, which is about one mile of No. 8, or 1,000
feet of No. 15 copper wire. With a higher resistance lamp this
circuit resistance can be increased. Neither a high resistance
nor a high potential is necessary to get a certain candle-power
with a certain expenditure of energy in a lamp of given mass,
but a greater current is necessary with the lamp of low resist-
ance. This means a greater loss in the conductors, a less effi-
ciency of generator, and a much more limited distribution. Let
me illustrate by a particular instance.
Suppose a system in which about 500 lamps is supplied from
the central station by a cable an inch in diameter. If this con-
ductor is not insulated, but is open to the air, the current is
sufficiently strong to raise the temperature very appreciably, say
15 deg. Centigrade. Now, what are the conditions under which
the main supply cables of a large system of distribution are laid
down? One condition is that they must be thoroughly insulated,
and, if so, then the free radiation of heat, although surrounded
by moist earth, is prevented; consequently, the rise of tem-
perature will be fully as great as in a cable open to the air.
Suppose with the same number of lamps double the current
is used. Now, if the resistance of the cable remains the same,
four times the work will be done, four times the number of heat
units will appear, and, since the heat radiated must be equal to
the heat generated, the temperature will rise until the difference
of temperature between the cable and the earth is four times that
which existed in the first instance. But what are the conditions
now? Copper increases its resistance with the rise in tempera-
ture, this increase being about 4 per cent. for each degree Centi-
grade, and if our rise in the first instance was 15 degrees, the re-
sistance now has increased some 30 or 40 per cent. Therefore,.
instead of four times the work being lost on the conductors,
there is something more than that, say five or six times, and
furthermore, the temperature of the cable is now dangerous y
high for the insulation.
2375
406
THE ELECTRICIAN, SEPTEMBER 9, 1882.
Meters.
After many trials of various kinds of meters or registers, Mr.
Edison has adopted that which depends on electrical deposition,
and has selected pure zinc for his plates, a strong solution of
sulphate of zinc for the liquid, and places the register in a shunt
circuit, allowing about 1-800th of the current to pass through it.
The weight of zinc deposited in one hour by one ampere of cur
rent is 1,198.8 milligrammes.. This, of course, gives a means of
determining the amount of current used, with little loss in the
registering apparatus. Polarisation is remarkably weak, and
there is very little variation when a large number of them are
tested together. Very careful weighing is necessary, and, pro-
bably, the popular desire to see for one's self what current one is
using, and thus have a check on the readings of the company,
could only be met with this meter by having a competent super-
visor of the weighing who was in no way connected with the
But in the meter economy and accuracy seem to have
been the objects. Error from a change of temperature is almost
entirely eliminated by a proper proportioning of plates and solu-
tion, the resistances of which change in opposite directions.
company.
Safety Arrangements.
Much has been said about the dangers of fire from the intro-
duction of electricity, but if the wires are properly laid, and
means be taken to cut out a circuit when for any reason a short
circuit takes place, causing, of course, an instant increase of
current, there is no reason for apprehension. All wires, besides
being insulated, should either be run through the brick or stone
of a structure, or run along the walls, and should be covered by
a moulding to prevent acidental joining of the two wires. Mr.
Edison has adopted this plan. The switches have large bearing
surfaces, and the contacts are broken sharply to prevent arcing.
But, aside from these arrangements, he has introduced a feature
which is an absolute necessity, which is now recognised essential
to any and all systems of distribution for domestic purposes.
This is a weak point in every main, derived, and sub-derived
circuit. This weak point is a bit of wire of lead and tin alloy,
which is mounted in a plug, and can be readily replaced when
destroyed. In the event of a short circuit, the sudden increase
of current fuses this wire before it can possibly heat the copper
conductors. The wide-spread application of these safety plugs and
their reliability, is, I think, one of the most admirable features in
this system.
•
The use
the lights could thus be regulated in intensity. The eye is a
very poor judge, and to indicate an abnormal potential a magnet
was bridged across the mains, just as the lamp is done, and the
tension of the armature spring regulated so that when the
potential increased, the increase of current caused the armature
to move and a bell to ring. Such an arrangement, however,
shows only the fact that the current is too strong, that is, the
potential too high, and in a large system a much more delicate
arrangement is used, the deflection of a spot of light on a
graduated arc of large radius. The manual labour now used
could be easily dispensed with, for the current in the galvanometer
circuit could control a delicately adjusted armature, which, being
moved one way or the other, would throw into action
mechanism to operate the lever, or could close or reverse
the current of a small motor to do the same.
of the regulator should be as limited as possible, because a
resistance which has no other function than diminishing a
current is not to be commended; therefore, but very few coils
should be in circuit for any length of time, and the regulator
should find its office principally in meeting any sudden changes
in the external resistance. With a resistance of one-fourth of
the field magnets 12 70-light machines would absorb for regula-
tion less than one third of a horse-power electrically-that is,
about the energy used in four lamps. This is so small an
amount that, considering the object that is attained, it cannot
be objected to. In a large system the change of E.M.F. will be
much smaller than would be necessary in a small one for the
same numerical change, and any marked changes will be met by
suitable changes in the number and speed of the generators;
and it is just when machines are added or taken away that the
regulator will be most in demand.
Were the lights at the Crystal Palace furnished by one machine
having an armature resistance equal to that of one of the arma-
tures of the small machines, there would be a loss of over ninety-
two horse-power, enough to drive nine machines. When the
machines are joined there is the same immunity from harm in
case of contact as in a single machine.
At Holborn-viaduct there are, as many of you know, about 1,100
to 1,150 lamps furnished from the central station, distributed over
a space extending from Holborn-circus to the Post Office. The
system of distribution here is that of mutiple arc and branch
circuits. Evidently, while simple circuits give perfectly satie-
factory results in buildings, and on the street for short distances,
they will not do for large districts. And it is this question of
distribution over large areas to which Mr. Edison has given a
great deal of thought, and has, I think, satisfactorily solved the
problem.
Whether the shunt system or the method of separate exciting
for the field magnets will be found preferable will, probably,
only be ascertained after a considerable experience. When there
are but few machines in action I think, unquestionably, the
shunt system, with comparatively high resistance of the field
coils, is by far the best. These questions will be settled by trial,
no doubt, when a large system is. in working order, and are mat-
ters of relative economy and practice, not at all of the successful
distribution of electricity, which is an assured fact. Just as
small machines may be coupled in parallel circuit, so may large
ones with satisfactory results. This coupling of machines of low
resistance in parallel circuit is absolutely necessary, and the
only way possible for a system of distribution to lamps direct
With the exception of the main conductors, which are en-from the machine. When so joined the loss of energy in the
closed in iron pipes and insulated by composition, I have con- armatures bears precisely the same ratio to the total energy ex;
sidered the principal points of Mr. Edison's system in detail. Let expended as exists in a single generator.
us look at it as a whole. I will first run hastily over the plant at
the late Crystal Palace Exhibition, a piece, of such thorougbly
satisfactory character that we may consider it with profit. There
were about 1,075 mixed lamps distributed in the entertainment
court, concert room, domestic exhibit, booths, and railway en-
trance, all supplied by the same main conductors, and arranged
in branch circuits with switches and safety plugs. These 1,075
lamps were the equivalent of about 840 standard lamps, and the
current was supplied by twelve dynamos. In designing the
plant, one object in view was to get an independence of power,
such that the failure of any part would not cause extinction of
the lumps. The motive power consisted of three Robey, non
Robey, non
condensing, double-cylinder engines, which are well enough
known to all of you. Each fly wheel gave motion to a loose
pulley, which, through the medium of a movable cone pulley,
drove a section of shafting to which were belted the dynamos,
In this way the breaking of an engine would stop four machines
only, two could be stopped by shifting the cone pulley, and one,
of course, by throwing off its belt. Aside from reliability, this
arrangement steadied the current, and minimised the effect due
any irregularity of an engine. With seventy standard lamps
as the full work of a dynamo, one machine should be added for
every seventy lamps added to the circuit, so that the relation of
internal and external resistances should remain the same. The
twelve machines being in parallel circuit, the internal resistance of
the system was about 017 ohm. The twelve pairs of field coils were
also in parallel circuit, making their resistance 3·46 ohms, and the
external resistance, not including the main conductors, was about
17 ohm, the ratios remaining the same as exists in a single
generator worked to its full capacity. The engines ran at 120
revolutions, driving the dynamos from 1,100 to 1,200. They did
their work steadily, developing about 40 to 45 indicated. horse-
power. The machines ran very quietly, and with very little
parking. In the field circuit was placed the regulator, which
consists of a series of open wire coils, joined to segments of a
circle, around which travels an arm, which, by successive contact
throws into circuit one or more coils, thus increasing the resistance
of the field circuit, and changing the ratio of the resistance of
this circuit to that of the lamp circuit without very materially
changing the total resistance. By the movement of the level
to
Imagine two great sheets of copper in juxtaposition main-
tained at a certain difference of potential. If in either of these
plates there exists a difference of potential at any two points,
there will be a general flow of electricity set up to restore the
plate to a state of equilibrium, just as occurs in the earth's sur
face, and this flow will continue as long as any inequality of con-
dition exists. If these plates be. joined by conductors, cur-
rents will flow proportional to the difference of potentials
and the resistance of the conductor, just as if these plates
were the terminals of a machine. Let such plates be the
terminals of a machine, or better still, of several machines,
and let the actual connections be made at several different points.
There would now be a system of distribution, as far as regards
the conductors, on the most perfect principles, and if the resist-
ance of the connecting paths is less, that is, the number of paths
greater at one point than at another, then there would be at that
point, on account of the greater demand for current, a greater
tendency to reduce its potential. and currents would flow to it
from the surrounding parts. Such plates are evidently impossible;
but perforate these plates, or in other words, replace them by
notworks or meshes of cables, and we have a perfectly prac
ticable method of providing a distribution, and I think the most
satisfactory one. The way of laying down a district on this system
is to lay the raain cables in each street, and wherever they cross
:
2376
THE ELECTRICIAN, SEPTEMBER 9, 1882.
join like to like. This is to be supplied by mains from the central
station at several different points, which points are determined
by the relation of the size of the conductors, and the resistance
of and allowed variation in intensity of the lamps. A pecu-
lir thing, at first sight, is that the direction of the current in
the street conductors will not always be the same, but will change
so that the maximum flow is towards the point where there is
the greatest demand. The relative sizes of conductors are calcu-
lated for the maximum currents they are to carry, and in order
that the percentage of loss may be the same a double current
would require a conductor of double cross section. The main
conductors diminish in size as the distance from the several
sources of supply increases, and the several districts in the
city, each being primarily fed by a single system of gene-
rators, are joined together. If one half of these conduc-
tors were broken, the remainder could still surply the
district. Small wires from every part of the city can be
taken to one central office, so that the actual state of the poten-
tial may be known at any instant at any point, and even an
automatic graphic record kept. In this way, one man can keep
constant supervision of the whole system, having thus a check on
the local engineers, and, by telephonic communication, give the
necessary directions to increase or lower the potential or supply.
In every dynamo room, a dial can be placed in a shunt from the
cable of each machine, which will indicate the number of lamps,
or the amount of current which the machine is supplying.
I have made no mention whatsoever of the application to
power, which I will consider at another date, nor have I spoken
of storage batteries in connection with this system, and I think
with Mr. Edison that they are not a necessary adjunct. The varia-
tion of light would be remarkably small, and the failure, as far
as the street mains is concerned, is practically impossible. There
then remains the question, what is the liability of breakdown at
a central station? If there is but one central station, the only
way in which it could be disabled would be the blowing up of
the major part of its boilers, and this is not very probable; in
fact, I do not see how it is possible for such thing to occur with
good boilers properly arranged. The breakdown of a single
engine, the failure of one or two armatures, is quite possible,
ana we may say, probable. But such breakage would not
seriously affect the supply, for aside from the fact that there
would probably be a reserve dynamo, the machines can be easily
run to over their normal power. In a city the entire destruc-
tion of a central station would not put out the lights in its own
district, for the mains would be supplied from those of the sur-
rounding districts. The calculation of the size and number of
the supply and distributing mains is a work of careful engineer-
ing. It involves the cost of iron and copper, of coal and property,
of labour, of capital invested and interest required-in short,
how much of the energy of the current, of the coal, can be
wasted, and in what part of the system. So each city must be
the subject of special calculation,at it is perfectly practicable.
Such is a brief résumé of Mr. Edison's system as it has appeared
to me after long and thorough study system in the fullest
sense of the word, one of supply, measurement, and consumption,
elaborate in detail, broad in conception. When we consider the
present uses of electricity, and the uses which will be developed
when it is at every householder's command, we will be more able
to appreciate the importance of Mr. Edison's work, and although
there is improvement to be looked for, I think he can feel satis-
fied that he has practically accomplished the work he set him-
self to do.
a
407
dially indeed, and the directors were in communication with persons for the
purpose of installing the light there, provided they could come to terms.
In the month of July there was a very extensive fancy fair hold in the city
took place having been most successfully lighted up, and the Company had
of Exeter, and the light was shown there, the hall in which the proceedings
received payment for the three days, and there was the payment for one
day to be received. There was a prospect of doing further business in
Plymouth, and there was a probability of their lighting the dockyard. One
or two shareholders had expressed the opinion that the directors might
have done more business. Business could be done to any extent, but the
directors wished to make a profitable return, and wero cautious
not to go into matters which might not result profitably. They were
carrying on negotiations for the introduction of their electric light at
Penzance, the hoad-quarters of the mining interest of Cornwall. There was
there a very large field for the introduction of the light into Cornish mines.
yet the electric light would be of immense advantage to them. An exhibi-
Although the Cornish mines were not in any danger from gas explosions,
tion of the light would be made at Penzance on the footing that Penzance
should cover all the expenses, and he thought that that would be a very
good advertisement to the Company. This being the statutory meeting,
he had no resolution to propose.
Mr. J. S. TYLER said the Company issued a prospectus stating that the
Company had the exclusive right to the Lane-Fox incandescent lamp, but
he found on search that a general license had been granted to the British
Electric Light Company for the use and sale of the lamp to Great Britain
and Ireland. It seemed from the register that that license was granted in
consequence of an agreement which Mr. Lane-Fox had previously entered
into with the British Electric, and in consequence of proceedings which
they took against him in the Court of Chancery. He searched the register
carefully, and did not find that there had been any revocation of that license,
and, even if the license were revoked, the non-registration of the revoca-
tion was a serious matter for this Company, seeing that if the British
Electric Company liquidated, and Mr. Lane-Fox become bankrupt, the
trustee of his bankruptcy or the official liquidator of the British Electric
Light Company might have very important rights, to the detriment of this
Company, in consequence of the non-registration of the revocation. He
also asked whether any fresh contracts had been entered into since his
interview with the directors yesterday.
The CHAIRMAN said the questions put by the last speaker resolved
themselves into one, because it was the head and front of the thing. The
question was, "Is it or is it not a fact that such and such a transfer was
made? whether, in fact, they had the exclusive and legal use of that
which had been guaranteed to them. Unless the directors had supposed
that they had such a right, they certainly would not have issued such a
statement in their prospectus. If the facts were not as stated, certainly
Western Company, and the Great Western had its remedy against the
this Company had a remedy against the parent company, the Great
Anglo-American Brush. If the vendors had sold what they had no right
to sell, it was pretty clear there was a remedy.
Mr. TYLER did not consider the explanation satisfactory, and moved for
a committee of shareholders to investigate the question.
The motion was not seconded, and, after some furtl.er discussion, a vote
of thanks to the chairman terminated the proceedings.
COMPANIES' SHARE LIST.
COMPANIES.
Anglo-American
Do. Preferred
Do. Deferred
Brazil Submarine
Cuba
Direct Spanish
Do. Preference
Do: Preference
Direct United States Cable
Eastern Telegraph
TELEGRAPHS.
Do. 6 per Cent. Preference..
CLOSING PRICKS
1111-16..
101
131-16
114
10 3-16
-
BUSINESS DONE WEEK
ENDING SEPT. 6.
SEPT. 6.
50%, 51
Highest.
Lowest
511
501
81, 82
814
80
20,
21
21
20
114, 12
12
91,
101
103-16
16,
17
―
6,
6
6 7-16
6 7-16
15,
16
11,
12
10%,
101
11 11-16
10
.....
123,
13
123
105
111,
113
German Union
91,
101
118
10
11 3-16
10
Globe Telegraph and Trust Company.
Do. Preference
G2,
63
611-16.....
124,
13
13
12
12 124
124
12
29,
30
2, 2
21
21
81}, 9
9
9
121, 13)
121
12
255,
265
260
258
11,
21
81 91
2 1-16
D
1 15-16
91
82
7,
7
7
7
128
103
Do. 5 per Cent. Debentures, 1899... 100,
Eastern Extension
THE DEVON AND CORNWALL ELECTRIC LIGHT Great Northern
AND POWER COMPANY.
Indo-European
Mediterranean Extension
Do. Preference
The first ordinary general meeting of this Company was held on Wednes. Renter's
day, at the Caunon-street Hotel, Mr. W. H. Owen in the chair.
Mr. F. B. LIDSTONE (the secretary) having read the notice convening
the meeting,
Submarine
West India and Panama
Do. 1st Preference..
Western Brazilian………….
West. Union 7 per Cent. 1st Mortgage 123,
Do. 6 per Cent. Sterling Bonds...... 100,
TELEPHONES.
11, .
10 10
Cousol. Telephone and Maintenance
Griental...
United Telephone..
Maxim-Weston
Eastern Electric
The CHAIRMAN said that this was what might be termed their statutory
meeting. It was the meeting which was usually held according to the
statute regulating joint stock companies' proceedings, which provided that
the first general meeting should be held within four months of the time of
registration of a company. Usually there was nothing to say at such
meetings further than to give such information as the shareholders might
desire to have, and that he would proceed to give as shortly as possible.
The first thing he might say was that he rather regretted to see so few of
the shareholders present, but no doubt the directors might take it as a com-
pliment, because if they had wanted to find fault they would have attended. Anglo-American Brush
The Company only having seen formed a short time, not much business
had been done. The nature of the goods they had to offer to the public
was not such as to admit of their simply being shown and a purchase
made. The introduction of the electric light was a process which must be
gone through cautiously, carefully, and quietly, as there was a very strong
interest in the gas companies opposing it. People expected to have the
electric light on the same terms as gas, but he argued that they ought not
to expect to have a superior article at the same price as an inferior. Still,
there was a prospect of doing something, particularly at Plymouth, a very
enterprising place. Plymouth had received offers of the light very cor-
11
1}
15-16
11-16
111
91
ELECTRIC Light.
..
101. 11
21 (£4 paid)
9-16
12
10%
27 (£4 pd) ...
2
མྦྷས
TRAFFIC RECEIPTS FOR AUGUST, 1882.
June, 1882. June, 1881. Incrse. Decres
COMPANIES.
Cuba Submarine Company.
Direct Spanish Telegraph Company
Eastern Extension Telegraph Company
Eastern Telegraph Company
Great Northern Telegraph Company .........
2,550
1,780
32,025 30,349
61,600
2,401
1,507
49
283
1,676
38,171
13,429
23,300
I
2377
Complainant's Exhibit, Gatehouse Nature Article.
Nov. 14, 1878]
NATURE
larly on the whole than the maxima and minima of sun-
spots.
But why do we beat about the bush when all that is
needed is half-a-dozen of Pouillet's pyrheliometers with
skilled observers, who will seize every clear day to deter-
mine directly the heating power of the sun? Why do
we not go direct to the Great Luminary himself, and ask
him plainly whether he varies or not? If he answers
No! then some of us must reconsider our theories, and
perhaps endure a little ridicule. But if, as is much more
probable, he should answer Yes! then the time will come
when the most important news in the Times will be the
usual cablegram of the solar power. Solar observatories
ought to be established on the table-lands of Quito or
Cuzco, in Cashmere, in Piazzi Smyth's observatory on the
Peak of Teneriffe, in Central Australia, or wherever else
the sun can be observed most free from atmospheric
opacity. An empire on which the sun never sets. and
whose commerce pervades every port and creek of the
sunny south, cannot wisely neglect to keep a watch on the
great fountain of energy. From that sun, which is truly
"of this great world both eye and soul," we derive our
strength and our weakness, our success and our failure,
our elation in commercial mania, and our despondency
and ruin in commercial collapse.
W. STANLEY JEVONS
THE WERDERMANŃ ELECTRIC LIGHT
WE are able this week to give some further details
concerning Mr. Werdermann's method of dividing
the electric light.
The real difficulty was found in devising a form of
light which could be divided into several, and still give
enough illuminating power for practical use; and it is in
this particular that Mr. Werdermann has apparently
succeeded. It may be interesting here to state Mr.
Werdermann's reasons for adopting this particular form
of lighting.
זן
37
negative electrode. The section of this deposit is about
that of the positive carbon itself, and it is about } of an
inch high.
When in an electric lamp, electrodes having the same
sectional area are used, the changes at the points between
which the voltaic arc passes, take place in a manner which
is well known, viz., a crater or hollow is formed in the
positive electrode which emits the light, the crater itself
being heated by the current to white heat, and the sur-
rounding part to redness. The negative electrode which
assumes the form of a cone, is only heated to redness,
and emits scarcely any light.
It was found that an increase in the sectional area of
Mr. Werdermann was led to make these experiments
by the idea that perhaps by altering the sectional area of
the carbons a similar effect might be produced to that
which is obtained in electrolysis when a plate
used as
one electrode and a small wire at the other, and from the
the positive electrode diminishes the light emitted by that
electrode, and if the increase is continued gradually, the
light on that electrode finally disappears entirely, where-
as the heating effect upon the negative electrode in con-
nection therewith increases, until finally light is emitted
by the same. Again, by increasing the sectional area of
the negative electrode, the heating effect upon the same
decreases proportionally to the increase of its area, until
the area having been sufficiently increased the heat
al ost entirely disappears, and consequently the con-
sumption or wearing away of that electrode is scarcely
´appreciable.
The light given out by the positive electrode in connec-
tion therewith, on the contrary, increases in proportion to
the difference existing between the sectional area of the
two electrodes, and instead of a crater being formed in
the positive carbon, the latter assumes the form of a cone
as formerly was the case with the negative carbon. The
greater the difference between the areas of the two
carbons the shorter is the length of the voltaic arc which
can be obtained between them, and when the area of the
positive is gradually diminished and that of the negative
increased, the light is produced by the carbons apparently
in contact, and a small deposit of graphite is seen on the
a
FIG. 1.
results obtained he devised his present system of electric
lighting.
His lamp is constructed in the following manner :-
He places the negative carbon which is in the form of
a disc 2 inches in diameter, and about 1 inch thick,
uppermost. This carbon is clasped all round by a copper
band which is prolonged to the terminal to which one of
the leading cables is attached. The lower or positive
electrode is a small pencil of carbon 3 millimetres in
୪୪୪
FIG. 2.
ug
1990
diameter, and can be made of any suitable length. This
slides up vertically in a tube placed directly underneath
the disc. This tube guides the pencil and also forms a
contact for it, the top of the tube being solid copper in
two pieces, one being rigid and the other pressing against
the carbon by means of a regulating spring. The carbon
pencil protrudes above the tube about of an inch, and
touches the negative disc, and this length when the
current passes is made incandescent.
2378
38
NATURE
The small carbon is pointed at its upper extremity and
retains this point while burning. A small electric arc is
formed round the points of junction, and to this is due
the greater part of the light and not to incandescence alone.
The carbons are kept in contact by chains attached to
the lower end of the pencil passing over pulleys and
down again to a weight of about 1 lbs., which is
sufficient to keep the pencil pressing gently against the
disc.
The sketch, Fig. 1, shows the arrangement of the
lamp; a is the negative carbon, connected by the
semicircular piece of metal f to the conductor e on the
right-hand side which forms part of the lamp-post. The
metal fis hinged so that the top carbon may be moved
back when a globe is put on. bis the pencil or
positive carbon sliding in the tube c, this tube being con-
nected to the conductor e on left-hand side. The pressure
of the contact upon the small carbon is regulated by the
spring d. The tube is shown in perspective for greater
clearness. The arrangement and details of the lamp
being thus shown, we will now describe the experiments
which have recently been exhibited at the works of the
British Telegraph Manufactory in the Euston Road.
The display was mostly of an experimental character,
the lamps being somewhat different in construction to
those which will be made use of in actual pračce, but the
principle remains the same. The chief object of the
inventor was to demonstrate that a number of lights can
be steadily maintained in one circuit. The first experi-
ment tried was that of putting two large lamps such as
will be used for street-lighting in circuit with a Gramme
clectro-plating machine. It may be here remarked that
this is probably the first time that such a machine was
ever used for the purpose of producing an electric light.
The two lamps were said to give a light equal to 360
candles each, but they gave to all appearance a conside-
rably higher illuminating power.
A pure white light was given out, perfectly steady, and
showing none of the blue or purple rays observed so fre-
quently in the ordinary form of electric arc. The wonder-
ful steadiness of the light is one of its chief features. After
burning for some considerable time the current was
switched on to a row of ten smaller lamps arranged on a
shelf. The light from each lamp was apparently of the
same strength and the effect was very brilliant, but the
total illuminating power was not nearly so great as in the
case of the two larger ones. But it seemed to show that
a form of light had been devised that could be split up
into a considerable number of smaller ones, each of
which could be made use of in a practical way. The ten
lamps were estimated to have a lighting power of forty
candles each, but this is probably somewhat above the
mark. But the results obtained, both as regards the
wonderful regularity of the lamps and the practical de-
monstration of dividing the light, seem to have been
satisfactory; and the more remarkable from the fact of
the weak electro-motive force of the machine, which is
only equal to that of four Daniell's cells. More lamps
could have been lighted even from this machine had they
been at Mr. Werdermann's command, but of course with
a diminution of light. When suitable machines have
been constructed Mr. Werderman is confident of being
able to put 50 or 100 lights in circuit, but he does not
believe in the indefinite division of the current for
lighting purposes.
-
The lights were all connected parallel, as shown in
diagram, Fig. 2. The thick wires + and connect the
lamps with the machine, the nrst lamp on the + cable
being last on the wire. The spirals a are extra resist-
ances put in the circuit of each lamp, the object being to
render the divided current less sensitive to any slight
variation in the resistance of the lamps themselves, due
to unequal pressure of contact, &c. The resistance of
each lamp, including the wire a, is about 0 39 ohms. The
[Nc. 14, 1878
resistance of the ten in parallel circuit about 0'037 ohms;
The carbon pencil consumes: at the rate of from 1 to
2 inches per hour in the small lamps; the large ones taking
4 millimetre carbons, consume about 2 or 3 inches in
23
the same time. The pencils are made in Paris, costing
about I franc per yard, which length will last for twelve
hours. The discs are of ordinary carbon.
However many lights may be in use, one, two, three,
or any number can be put out without affecting the
others, the regulation of the current being provided for
by a switch attached to each lamp. But if necessary, the
current which originally went through those that are ex-
tinguished can be added to those kept alight, of course
increasing their illuminating power. The lamps are set
in action simultaneously, can be as easily put out, and
again re-lighted.
Returning again to the intensity of the light, it was
stated that the large lamps were equal to 360 candles.
Now the effect of this light upon the eyes is apparently
not injurious, and it is Mr. Werdermann's intention to
use only globes of ordinary glass, as in the present form
of gas-lamps; by this means the loss of light will be very
slight indeed as compared with other systems, where the
loss is from 20 to 30 per cent., incurred by using opal or
ground glass globes.
Owing to the very small electromotive force of the
machine the insulation of the cables can easily be pro-
vided for, and Mr. Werdermann hopes, with sufficiently
powerful machines, to be able to carry the current to a
considerable distance without any appreciable loss.
In conclusion, it may be worth while giving a few
details in regard to the Gramme machine used. It is an
electro-plating machine of the old pattern, having four
upright electro-magnets and two bobbins, one for feeding
the electro-magnets, the other for taking off the light-
producing current. The bobbins are wound with thick
copper bands. The electromotive force, as before stated,
is only equal to four Daniell's cells, and the resistance of
the taking-off bobbin is about o'008 ohms. The quantity
of current produced is of course large.
It may be mentioned that the large lamps were con-
nected parallel, but having no extra resistances, as in the
case of the 10; their resistance is also a trifle less.
The resistances given are when the lamps are not alight;
when burning it would be somewhat less. The power
required to drive the machine described is about two
horse-power.
A curious fact about the light is that the top carbon is
not consumed, or at any rate so slowly, that it is not
noticeable; therefore, to all intent and purpose, the lower
carbon only is wasted.
T. E. GATEHOUSE
DUPLEXING THE ATLANTIC CABLE
THE simultaneous transmission of two telegraphic
messages in opposite directions upon one wire, now
known by the name of duplex telegraphy, dates bark
from the year 1853. In that year Dr. Gintl, the director
of state telegraphs in Austria, described a method by
which this feat could be accomplished, and in July of
the same year the method suggested by Gintl was tried
between Prague and Vienna. An improvement on this
method was suggested by a German electrician, Frischen,
by Messrs. Siemens and Halske, of Berlin, and other
workers at this subject. Nevertheless, owing to practical
difficulties, the experiments were little more than interest-
ing additions to our knowledge. So little hope, indeed,
was there of the practical realisation of this important
matter that, in a standard work on telegraphy, published
in 1867, after describing the early methods of duplex
telegraphy, the author remarks :-"Systems of telegraph-
ing in opposite directions and of telegraphing in the same
•
FRIDAY
10
p.m.k.
HIGHER
10
Weat
Kir
1
a.m
12
5 6 7
8
G
2379
Complainant's Exhibit, Brevoort's Gas Pressure Diagram.
SATURDAY
.p.m.
10.
12
2
3 4
5 6
:
NUT
6
"2
SUNDAY
a.m
10
12
5 6 7 8
10
X-
12
pm
2
3
4 5
20
NASSAU CAS CO
JAN 9 70 71 7891
01-
10
9
2380
for each lamp in unit distance
Resistance of wire
:
30 Lamps
100
0 ohms each-resistance 10 to 1.
(2068×2=24136
10536×2=21072
8939,×2= 17878
7279×2=14558
5555×2–1/110
3767×2=7534
1916×2=3832
13537,×2=27074
30/91× 2–60382
30127×2–60254
30000×2–60000
29808×2=59616
29553+2=59106
29233×2=58466
28350×2–56700
27903 ×2=55806
27393×2=54786
26818×2-53636
26179×2=52358
25477×2-50954
24711×2-49422
23881×2=47762
22987×2=45974
22029×2=44058
21007×2=42014
(9922×2=39844
(8772×2=37544
17559×2=35118
16282×2-32564
14941 × 2=29882
10192|93|19|10|10|12|19|18|190 191 192 193 194 195
wires in space between each lamps
Resistance of the aggreate
465
completely multiple-arad
beyond each lamp when
Resistance of circuit
lamp alone to be in use.
for each lamp supposing that
Resistance of entire virant
1
10/10.10
77 98 19 20 21 22 23
10
-
10
I 1200;
10100 1800
29
o fect.
89. 439
10
16.8115+765
=16.8721
89.
118
20.1375+140=20.2089
10
100.7574
100.8288
簽
​88 803
10
25.1275+14=25.2152
100,9165
88.
494
88 191
87. 894
33.4455+17=33.5604
101.0314
87
10
50.0832+1=50.2527
101.2009
10
100.
+30-100.3333
101.5342
30
87. 601
100.
98. 235
97. 693
97. 167
100:.
99.40115
98.79397
Resistance of entire line
multiple arc.
in
3.5687+465– 3.5902
3.6792+
- 3.7008
3.7981 + = 3.8197
3.9262+
4.0647+465-4.0867
100.0215
10
100.0431
10
100.0647 462
3.9480
10
4.50
4.2147+ = 4.2369
100.0865
100.1085
100.1307
10
459
10
455
10
450
10
96.
658
4.3777+ = 4.4002
444
100.1532
96. 164
95. 683
95. 215
94. 761
94.
318
93
467
93.
057
92 657
92. 268
91. 886
91 513
91. 148
791
90.
90.442
90
101
89. 767
· 93. 886
4.5552+437=4.5781
10
4.7493+129-4.7726
10
=
4.9623+420 4.9861
5.1970+4100 = 5.2214
10
5,9568+399 5.4819
10
5.7460 +387 5.7718
6.0696+374 = 6.0963
6.4340 + 360
6.4618
6.8475+35 6.8764
7.3205+329 7.3509
7.8666+ 312 7.8987
8.5043+29094 8.5383
9.8584+1275 = 9.2948
10.1638+2235=10.2030
10
234
10
100.1761
100.1994
100.2232
100.2476 410
100.2727
100.2985
100.3252
10
437
10
429
10
420
10
10
399
10
387
387
3974
10
100. 3530
360
10
100.3820
100.4124
100.4445
100.4785
312155
329
312
10
294
-
100.5149
115
100.5541
255
11.2710+ =11.3137
100.5968
缳
​TO
12.6556+212 -12.7027
100.6439
2/2
14.4364+ 189 -14.4893
100.6968 189
12. 399
10 634
Edison Complainants Exhibits
V.
Clarke's calculations
Westinghouse) N. 1.
Rebry
18.1891
J.J. RA
Sat
до
Weight of copper 440 th.
14.76. per lamp..
Number of circular, mils of copper wir
L
100.
Clarkes Calculations 96:2.
9340115
2381
60382
60z54
60000
59616
59106
58466)
56700
38.79597
198.255
197.699
97.167
February 18* 1891.
96.658
96/64
195.683
95.215
194764
Entrel
194.818
95.86
&
93467
93.05 92.65792.268
91.518
91.142
199.791
00.14200-101
89.767
189.-
1.400 89.116, 88.803
8.5687
3.6792
8.7981
3.0262.
4.0647
4.2147
4.3777
4.55523
4.7405,
4.9623
5.1970
5.4568
87601 Volks above Danum line of Curves 6" ¦ Vertical scale dvolks to 1 linch
3.6902 3.7008 3.8/97 3.9480 40867 4.2569,
Datum Line of Curve DT Vertical | scale 40 ohms, to
0.2030 11.6
11.8187 12.7027 14.480
457814:7726 49861 5.2214 5.48/9 µ5.7 7/8 06.0965 646/806.8764 7.5609 7-8987 85
163.42738/84 87894
1
A
inch
180
1
5.7460
6.06960
4.4840
6.8475
7.8205
9998%
9.2584
15.0721
Curve
20.208
D'
10.1638
11,2710
12.6556
14.4364
16.8115
20.1375
26.2152]
33.5609
25.1275
33.4455
50.0882
100
System of Thirky Lamps in Multiple Arc
Resistance of Lamp when incandescent, 100 Ohms.
Resistance of conductor for each lanji,
Resistance of copper
mil foot. 10.642 Ohms:
conductor
реч
10 Ohms.
Curve a represents the resistance of the conductor for the lamp at that point for the unit distance of one hundred.
and twenty feet, (60'x2) the resistance of entire conductor for each lange being so ohms.
Curve B. represents the resistance of aggregate conductor for the corresponding space, (60'x2);
Curve C: represents the resistance of entire circuit for each loung, when the resistance of lamp is included.
Curve D represents the resistance of entire line beyond that point, all the lamps being in closed circuit.
the values written virtical to the curve represent the resistance including the banny. at that joint.
and the horizontal values give the resistance back to the next lamp without including
Curve & represents the fall ing the conductor in circular mils. The aggregate com 240. 4. th.
Curve Fo`represents the size of the conductor in circular mils. The
circular mits. To
this feet long, the weight 220.35tt's or
for both
Weight of circular mil. foot
Edison Laboratory
.00000 302705325 lbs
it
amount will be 1213250
1100.100 400.100/100.1002/0
1
Menlo Park
June 1880.
N.J.
1 Dakum line of Curve B.
Vertical scale 100 chips to 1 inch
100 ohmus above datum line of curve C
Vertical scale #ohnus to 1 inch
"
L
2 2 49
1
149
18
ohms 1
Datum line of curve "A" | Vertical 'scals 14 chins to ↑ such
55806
54786
53636|
39e79
50954
49442
60'
Upplif
60d/48000
47762
45974
44058
42014
39844
37544
1
10
100.4174
100.5820
284
100.8530
100.82
100.2965
100.3727
10
.2222 490 | 189
10 1 594520 245 529 |
312! 204
245
1
387
1
et
12
.499
351:8
32564
29862
27074
24130
21072
Edison
17878
14558
01111
7532
2686
Curve
100.4541
100.6149.
"C.
100.6065
100.6459
Complainants exhibit
Westinghouse) Cloche Calculations the 2.
Jebry.18. 1890. J. J. R.
2.J. Spe
Spe. Par
100 8280 10
100.7674
100.6968
70
212!
Curve™
30 Romps.
100,9165
101.0814
67 101-2009
1101.09.42
385
87.601 VK:
2382
30 Lamps,
100 Ohms each.
Resistance of conductor for each lamp, 3 ohms in distributing line.
and 7 ohms in feeder, Total 10.
!
Resistance of aggregate wires
in unit distance on feeder
14
31×30-930
Resistance of wire for unit space
per lamp on feeder
31
Resistance of wire for
each lamp in unit distance.
Resistance of the aggregate wires
in space between each lamp.
Resistance of entire circuit
for each landp, supposing that
lamp alone to be in use. The
total resistance of feeder is 350 r .2335
Resistance of circuit beyond
each lamp when completely
multiple - arced.
Juni1550
1880
C. L. Clarke
29
6
6
66
9
21
6
9
6
اه
20160000010000
29 56 81 104 125 144 161 176 189 200 209 216 221 224 225 237
Now if the left hand
distributing branch be thrown
into circuit the resistance of
entire distributing system
in multiple-arc will be
diminished one half.
therefore the resistance
will be 6.8205 -3.41025
2
1. !
62 42 7 2 2 % 4 % % % $ 5
3 x
616
6
୧
의
​224 221 276 209 200 189 176161 194125104|81|562
8205
100.2467
100.2737
100.3006
7.3044
9.2/0.3+
9.2390
= 8.4854
100.3284
100.3571
100.3871
100.4188
100.4529
100. 4904
=16.8035
194.
100.5314
=20.1371
100.5799
100.6376
-33.4786
=50.1603
100.7117
100.8188
100+ 2 =100.2069
100.9257
7.8217+7.8488
6.8072+130
7.2776+224
8.4576+
10.1146 +200=10.1446
11.2211+189 −/1.2528
12.6053+7=12.6394
14.3861 +18=14.4234
16.7618+
!
521+1680*07
25.0816+10=25.1393
33.4045+
50.0532+
3.41025 + .2333=3.64355 will be the resistance of entire circuit
in multiple
arc.
Edison
Complainants Exhibits
Clarke calculations
Westinghouse) N.3.
Febuary 18. 1891
J. GR., Ap bar
106.84L.
100 volts.
001
47 888
47 675
47 036
45 972
44482
42 567
40.225
37 459
34 266
869 02
26 604
22 135
17 239
616 11
99.805
99.439
960'66
98.771
98.464
98.173
97.896
97.632
97.380
97.140
96.909
989'96
96.472
96.266
6172
96.068
2383
100.206D
1009257
/00.8/S8
106.841
Curve "E" for feeding Conductor
Clarkes Calculations 9:4
February 18th 189).
96.068 VOLTS
94.266
100.
30.0632
Euroz
98.77/ C
984
98./79
07652
97.380
97.896
96.909
97.149
Curvz &
| 99.605 109.459 of
Curve &
09.096
98.77/
1
༽r.as
7.40%
7.550 07.140 96.808 96.686 9LATE, 06.266
volts to 1 much
96.968 Volts above datum line of curse & Vertical scale of 4 retical scale to ohms to the inch
for feeding Conductor 3.44354
/ Curve Di
324045
25.0816
20.0891
20.1371
$16.8038-14.
16,7618
/4.386/
12.6053
12.
/1.22/1
10.1146
10.1946
9.21
8.4676
-7.8488 7.8044
7.8217
7.2776
6.8072
6.8072
Datum time of Curve D. Vertical 40
7.3044 7.8486 8.4654
7.2776
7.8217
8.4576
390_10.1446 11.2628/8,6894
9.2/05
10.1146
11.2211
12.6063.
148861
40
16.8030
76.Bass Currie
20.1371
25.7303
15.7786
16.7618
20.089/
26.08/6
50/603
38.4045
50.0632
100
•
2007/17 100LSTE
Curve "@"
|100.5791
100.53/$
704
1804902
1
100 4520 100.41801008871 10
17421100
Curve B for feeding Conductor!
B.
Datum line of curve,
Vertical scale 100 ohms to linịch
100.2737
haa887/
100.25715
Curve
276 115 100.2467/0024674 21 270 209 200 189 176
I
1
·100 ohms above Dalinn line of curve "C
Vertical scale % ohmiko 1 inch
| #to
Voa 83/3
1904902
144
100.5771
125
1
姦
​Curos a
I 2
2
for feeding
conductor / 60°
60'
1 Saturn line of dive o
60
scale 4 oblus xp 1 such
84830
M
402251
37459
34266
30648
26604
22185
17239
1/0 19
e.a/68
100 2068
100.92.57
60'
30 Lampix
6172
System of thirty Lamps in Multiple Orc.
Resistance of Lamp when incandescent 100 ohms
Resistance of Distelbuting Conductor for each lamfi 3 Ohmse
Resistance of Feeding Conductor for each lampe 7 Ohmus.
Resistance of copper
Juar
mil. foot 10.644 Ohms.
Conductor
Curve & represents the resistance of conductor for the lamp at that point for the corresponding double distance.
Curve B. represents the resistence of aggregate conductor for the corresponding space
Curve C: represents the resistence of entire circuit for each lamp, when the resistance of lamp is included
Curve D. represents the resistance of entire line bey and that point, all the langs being in closed circuit.
The values written vertical to the quire represent the resistance micluding the lamps at that front.
coup
and the horizontal values give the resistance back to the next comp
-back to the next lomp without including it
represents the fall in &.NE. force at each lamp
represents the size of conductor in circular mills. The aggregate amount will be, 956686 urcular mills
in distributing enductor: 60 feet long, and weighing 1.73.76 tbs, and in figeding conductor 1314865 mils
weighing 238.81 tts. a total of 412.57 tbs for each line, or 825.14 for both.
Total resistance of feeding conductor
Resistance of each distributing branch. 6924 ohmus.
Curve "&"
Curve F
Edison Laboratory
730 Ohm.
Menlo Park
June 1880.
N.J.
Edison
·Vs.-
}
Complainants Exhibit
Westinghouse) Clarke Calculations N°4
February 18.1891
J.J. R. Sp. Exc
•
#6.068 VoLTS,
2384
نسل
li
Jun 15801
་
y
30 Lamps, 100 Ohms.
Resistance of conductor for each lamp, 3 ohms in distributing line,
and 7 ohms in feeder, Total 10.
Resistance of Wire for
each lamp in unit distance
Entire pesistance of fading conductor 0.35
}
Entire resistance of feeding.
၃ ၀ ၀ ၀ ၀
conductor
Resistance of aggregate
Wire in unit space.
Resistance of circuit
beyond each lamp
multiple arc .
in
Weight of feeding, conductor
1st System.
Weight of feeding conductor
2nd System...
Total weight of distributing
conductors,
Total weight
278.50
146.
154.24
578.74
106.804
6
In this system the resistance
of each branch in multiple.
multiple arc is 10.2886 and
the resistance of both will be 10.2886 - 3.143
add to this the resistance of feeder (.35) we
have total 3.4943
901'96
95.826
95.318
94.853
99.426
94.031
93.664
93.320
93.000
92.691
92.399
LOL'E
100
99.708
99.180
Total
14.405
6/3
6/2
6
웠음
​15 17
18
응
​6/3
6/2
છ
616 6 16
100.99.96 91 184
66
6
|8|75| $4,51 136
1
10.2586+7.00
= 10.2886
11.3707+9=11.4313
12.7670+96
14.5696+
16.9830 +
84
12.8295
= 14, 6355
17.0544
20.3773+ 75–20.4572
25.4985+ 64
34.1078 +59
50.0788 +
25.5923
— 34. 2254
=50. 2455
➡100. 3158
6
Add to the resistance of distributing
conductor (10. 2886) that of feeder (.7)
we
have total 10.9886 ·
98.697
98.252
97.841
97.459
97.102
96.768
96.447
96.143
3.857
Total
10.661
6/2
Edison Complainants Exhibit.
V
Clarke Calculations
Westinghouse No5.
Jebmory 18.18917. FR Splat

LAWRENCE Miles
TOW
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Complainants Exhibit
Trentore Mase
January 6, 1571
GUIDE MAP
OF
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TRENTON
NG AND SUBURBS
Published expressly for
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T
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Globe Rubber Co
Prospect
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D & B.B. R. R.
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China
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Delaware
FRAZIER
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RESERVOIR
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RUTHERFORD
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DANIEL
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CHRISTOPH AVE
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Hillofest
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Moon Island
Entered according to act of Congress in the year 1881 by & Robinson in the Office of Librarian of Congress
Edison French Patent--1879.
2387
Complainant's Exhibit Edison's French
Patent No. 130,910, and the English
Translation thereof.
Copie du
Mémoire Descriptif
Annexé au
Brevet d'Invention de 15 ans
Pris le 28 Mai 1879,
par
MR. THOMAS ALVA EDISON,
pour
"Perfectionnements apportés dans la production de
l'Electricité, dans la lumière électrique ainsi que
dans les machines et appareils employés à ces
"effets."
Dans mon brevet d'invention du 8 Novembre 1878,
j'ai décrit et indiqué des moyens pour développer les
courants électriques et pour éclairer au moyen de
l'électricité.
Mes présents perfectionnements se rattachent à la
dite invention et ils se rapportent à la construction du
brûleur à l'ajustement automatique du brûleur, au
système de circuits dans lesquels les lumières sont
employés, aux moyens pour développer les courants
électriques, au mesurage de la quantité d'électricité
employé et à d'autres dispositions se rattachant à mon
système d'éclairage électrique.
J'ai reconnue que, lorsque des fils ou des feuilles de
platine, iridium ou autres conducteurs d'électricité qui
2388
Edison French Patent--1879.
fondent à une haute température sont exposés à une
haute température, se rapprochant de leur point de
fusion dans l'air, pendant plusieur heures, en y passant
un courant d'électricité, et ensuite en les laissant
refroidir, le métal est rompu, et sous le microscope on
voit une myriade de fentes suivant différentes direc-
tions, dont plusieurs atteignent presque le centre du fil.
J'ai également réconnu que, contrairement à l'opinion
émise, la platine, ou un alliage du platine et iridium
perdent de leur poids quand ils sont exposés à la
chaleur d'une chandelle, que même l'air chauffé leur fait
subir une diminution de poids, que cette perte est si
grande qu'elle donne une teinte verte à une flamme
hydrogène et sous influence d'un courant électrique à
une chaleur blanc-jaunâtre la perte est considérable.
Après un certain temps le métal se désagrège d'où il
résult que le platine ou alliage de platine et d'iridium,
tels qu'ils existent actuellement dans le commerce, sont
inutiles pour émettre une lumière par incandescence.
Premièrement, parce que la perte du poids les rend
dispendieux, détruit rapidement le brûleur et ne
présente aucune garantie.
Deuxièment, parce que leur résistance électrique
change par suite de leur perte de poids et que leur
émission de lumière, en égard à la surface totale, est
considérablement diminuée, par suite de fentes et cre-
vasses; le point de fusion étant déterminé par le point
les plus faible où la plus grande différence de potentiel
du courant électrique est présente, ce qui a pour effet
d'appeler plus des chaleur en cet endroit que sur le
restant du fil, encore pour l'obtention d'une lumière
stable, il est essentiel de protéger le brûleur en platine
contre le contact de l'air et lorsqu'il est ainsi protégé
en étant placé dans un vase ou verre, les verre est rapi-
dement revêtu d'une couche de noir provenant du pla-
tine. Une spirale en platine amenée à l'incandescence
dans ces circonstances peut être appelée à émettre une
lumière égale à trois chandelles étalon, lorsqu'elle est
près des son point de fusion et lorsque la surface rayon-
Edison French Patent.--1879.
2389
nante est d'un peu plus d'un millimètre et demi, mais
cette somme de lumière sera graduellement réduite
comme il a été ci-dessus décrit.
Grâce à mon invention ou découverte je puis empê-
cher la détérioration du platine ou de ses alliages en
détruisant ou interceptant l'action atmosphérique. Un
fil de platine ou spirale ou toute autre forme placée
dans un tube en verre avec le fil près de ses extrémités
passé scellé dans le verre, l'air est épuisé du tube ou
verre avec une pompe "Sprangel" jusqu'à ce que la
décharge d'une bobine d'induction de soixante-quinze
millimètres ne passera pas entre les extrémités de fils
placés dans le tube à un écartement de 4 millimètres.
Les fils de platine de la spirale sont alors reliés à une
machine magnéto-électrique ou à une batterie dont le
courant peut être contrôlé par l'addition d'une résis-
tance. Un courant suffisant est passé dans les fils pour
l'amener à une température d'environ 65 degrés centi-
grades, on le laisse sous l'influence de cette température
pendant 10 ou 15 minutes; pendant ce chauffage l'air et
les gaz renfermés dans le métal en sont expulsés par la
chaleur ou aspirés par l'effet du vacuum. Pendant que
cet air ou ces gaz sortent du métal, laupompe à mercure
doit fonctionner constamment. Après environ 15 minu-
tes le courant dans le métal est augmenté de sorte que
la température sera d'environ 150 degrés centigrades,
et il reste exposé à cette température encore pendant 10
à 15 minutes. La pompe à mercure doit fonctionner
et la température de la spirale doit être élevée par in-
tervalles de 10 à 15 minutes jusqu'à ce qu'elle arrive à
une incandescence vivide et le verre est contracté où il
est passé à la pompe et fondu de sorte que le fil est
dans un vide parfait et dans un état inconnu jusqu'à ce
jour, car la température peut être élevée jusqu'à l'incan-
descence la plus éblouissante, émettant une lumière de
25 chandelles étalon tandis que, avant ce traitement le
point de fusion moyen d'une série de spirales ayant la
même longueur et dimensions de fil ainsi que la même
surface rayonnante n'était que d'environ 3 chandelles..
2390
Edison French Patent--1879.
Les fils soumis à ce procédé d'élimination de l'air et
de gaz ont un poli depassant celui de l'argent et qui ne
peut être obtenu par aucun autre moyen; on ne peut
apercevoir aucune fente, même après que la spirale a
été élevée soudainement à l'incandescence plusieurs fois
par le courant, et aucune volatilisation n'a lieu attendu
qu'il ne se forme aucun dépôt sur le tube en verre; de
plus, en se servant d'une balance délicate, on ne dé-
couvre aucune diminution de poids dans le fil après
qu'il a brûlé plusieurs heures consécutivement.
J'ai de plus, découvert que si un alliage de platine et
d'iridium ou un fil de platine seul est recouvert d'une
couche d'oxyde de magnésium de la manière ci-après
décrite et soumise au procédé du vide décrit, qu'une
combinaison a lieu entre le métal et l'oxyde donnant à
ce dernier des qualités remarquables. Avec une spirale
ayant une surface d'un peu plus d'un millimétre et
demi, une lumière égale à celle émise par 40 chandelles
étalon peut être obtenue tandis que la même spirale
non revêtue par mon procédé fondrait avant d'émettre
une lumière de 4 chandelles. L'oxyde de magnésium
durcit le fil d'un manière étonnante et le rend plus
réfractaire. Une spirale faite avec ce fil est élastique
et fait ressort, même quand elle est chauffée à une
incandescence éblouissante.
J'ai trouvé que le fer chimiquement pur et le nickel
étirés en fils et soumis au procédé du vide émet une
lumière égale à celle du platine dans l'air libre.
Des crayons des carbone peuvent également être
purgés d'air de cette manière et être amenés à une
température telle que le carbone devient pâteux et si
on le laisse alors refroidir, il est très homogène et dur.
Des tiges et des plaques faites avec des mélanges de
matières conductrices finement divisées peuvent ainsi
être purgées d'air et des gaz.
Je décrirai actuellement la forme de brûleur ou lampe
que j'emploie. Afin de faire fonctionner pratiquement
plusieurs centaines de lumières électriques, égales
chacune à une bec de gaz ordinaire, sur un circuit, il est
Edison French Patent--1879.
2391
essentiel pour plusieurs raisons, en ce qui regarde la
facilité, l'économie et la sûreté des résultats, de les
placer toutes en arc multiple, et enfin d'empêcher que la
résistance de plusieurs centaines de lampes ne tombe
si bas qu'il faille avoir recours à des conducteurs
principaux de dimensions immenses avec une faible
resistance et des machines à produire l'électricité de
caractère correspondant, il est essentiel de renverser le
système actuel des lampes qui n'ont une résitance que
un ou deux ohms et de construire des lampes qui
auront, quand elles émettent leur quantité de lumière
voulue une résistance de plusieurs centaines d'ohms.
Je me suis rendu compte par des expériences que la
perte de l'énergie électrique est en proportion avec
l'étendue de la surface qui émet la lumière et indépen-
dante de la résistance des conducteurs, donc avec mille
lampes ayant chacune une surface éclairante de 6 mill-
mètres et chacune une résistance d'un ohm, la perte d'é-
nergie électrique est égale à 1000 lampes ayant la même
surface rayonnante, chacune ayant une résistance de
1000 ohms; la perte d'énergie pour chaque lampe dans
chaque cas, lorsqu'elle émet une lumière de 15 chan-
delles, sera la même, mais avec 1000 lampes chacune
d'un ohm, la résistance combinée sera un millième d'ohm,
d'où il résulte qu'il faudrait un conducteur principal
énorme, tandis que les 1000 lampes de 1000 ohms cha-
cune, lorsqu'elles sont combinées, n'auront une resis-
tance que d'un ohm, et un conducteur de dimensions
très modérées suffira. En pratique une résistance de
deux à trois cents ohms sera suffisante dans le brûleur.
Avec des lampes d'une faible résistance les connections
et les fils principaux doivent être grands, afin d'empê-
cher une grande perte d'énergie par la résistance, les
fils conducteurs des conduites principales sont grands,
dispendieux et volumineux à manoeuvrer. La faible
résistance du brûleur ou conducteur incandescent exige
de larges terminales pour conduire le courant, et ces
dernières présentent par leur conduction, un véhicule
pour la dissipation rapide de l'énergie sans produire
2392
Edison French Patent--1879.
aucun effet, tandis qu'avec une lampe à haute résistance
toutes ces objections disparaissent.
Le fil pour le brûleur ou lampe, préparé comme il a
été ci-dessus décrit, est enroulé sur une bobine indiquée
en L, Fig. 1, composée d'un oxyde infusible, tel que
l'oxyde de calcium, cerum, zirconium ou magnésium
purgé de silica, formé au tour à l'aide de baguettes
moulées par la pression hydraulique. Le brûleur com-
plet est indiqué en a, Fig. 1, comme étant installé dans
le tube à vacuum b, sur une tige b' composé du même
matériel que la bobine. Le tube vacuum t est supporté
par la caisse k et une caisse en verre i entoure ce
tube; cette caisse i est scellée de manière à intercepter
tout passage d'air dans un but ci-aprés décrit.
La Fig. 2, représente un brûleur ou lampe a, fait
comme il vient d'être dit, mais le fil pyro-insulé est
enroulé sur une pièce de matière infusible de forme
sphérique au lieu de sur une bobine. Je ferai remar-
quer que j'appelle le fil pyro-insulé, quand il est revêtu
de l'oxyde métallique ci-dessus mentionné; à la Fig. 3,
la bobine de fil pyro-insulé est enroulé sur un mandrin
dont elle est séparée et, des spires étant attachées par
des fils métalliques, la bobine est alors attachée sur un
disque de la matière infusible.
Dans certaines formes de lampes, il est préférable de
supporter le brûleur a dans le tube b par des fils de
platine 1, 2, comme ils conduisent moins de chaleur du
brûleur que s'il était supporté par une tige en chaux
ou autre matiére infusible b', Fig. 1.
A la Fig. 4, le brûleur a est représenté comme étant
suspendu par les fils de platine 1, 2, dans le globe b.
Dans les Figs. 5 et 6, la bobine de fil pyro-insulé a
est enroulé sur un cylindre aplati.
Dans la Fig. 7, la bobine de fil est faite en deux
parties séparées par une bague centrale de matière
infusible.
Fig. 8, représente le brûleur a comme étant confec-
tionné d'une bande plate de métal platina-iridium
enroulée en spirale et soutenue par une tige de
matière infusible b'; cette bande doit être pyro-insulée.
Edison French Patent-1879.
2393
Fig. 9, illustre une manière de pyro-insulé un fil. Le
fil est appelé d'une bobine et passé dans les flammes
d'une ou plusieurs lampes ainsi que dans des éponges
d contenant une dissolution de chaux ou de magnésie.
Le fil à son passage dans les éponges est revêtu d'une
couche de cette solution laquelle et décomposée et
l'oxyde déposé sur le fil lors du passage du fil dans la
flamme.
A la Fig. 10, le fil après avoir reçu la dissolution
pyro-insulante passe dans un tube qui est chauffé par
des lampes et qui effectue la décomposition.
Les Figs. 11, 12 et 13, illustrent une autre forme de
brûleur pyro-insulé. Ce brûleur est confectionné avec
un fil aplati de platine-iridium enroulé spiralement, et
entre chaque tour de la spirale il est placé une couche
de zircon-magnésium, calcium ou autres oxydes dont
les point de fusion sont très élevés.
Dans la Fig. 14, la lumière est produite par l'étincelle
électrique qui rend incandescente de la chaux qui a été
préparée en brûlant un acetate de chaux. La chaux
préparée est placée dans un tube entre deux disques
métalliques; comme la chaux préparée est très légère
et poreuse, les plus petites étincelles l'amènent à l'état
d'incandescence vivide.
La Fig. 15, indique comment la chaux obtenue en
brûlant un acétate de chaux peut être rendue incandes-
cente par une flamme oxhydrogène. c est un vase à dé-
composition contenant l'eau acidulée et deux électrodes
séparés l'un de l'autre par un diaphragme poreux de
manière à former deux cellules. Le vase est pourvu
d'un couvercle et un tube conduit de chaque cellule.
Lors du passage d'un courant électrique dans les cel-
lules, de l'oxygène et de l'hydrogène sont émis et con-
duits par des tubes à une chambre ou tuyau de mélange
7, et à l'extrémité de ce tube, le gaz est allumé et la
flamme projetée sur la chaux préparée en a l'amène à
l'incandescence, produisant une lumière brillante à
l'aide d'une si petite quantité de gaz qu'on ne
produirait difficilement aucun effet si on en fait usage
avec de la chaux ordinaire.
•
2394
Edison French Patent-1879.
La disposition indiquée à la fig. 16, est semblable à
celle qui vient d'être décrite, sauf que le brûleur est
entouré de deux demi-cylindres en verre dans lesquels
pénètrent les gaz des cellules à décomposition avant
qu'ils ne passent dans le tube de mélange et au brûleur.
Dans les figures 17, 18 et 19 le brûleur est confec-
tionné avec du platine finement divisé, de l'iridium, du
ruthinum ou autre métal de fusion difficile, incorporé
avec une matière non conductrice. Le brûleur ou
chandelle peut être de toute grandeur ou forme voulue,
et les particules en deviennent incandescentes par le
passage du courant et les matières non metalliques sont
lumineuses et augmentent l'éclat. Je mélange avec ces
conducteurs finement divisés des matières infusibles,
telles que le magnésium ou zirconium, suivant différen-
tes proportions afin d'obtenir le degré de conductibilité
voulue; les matières sont mélangées ensemble et mou-
lées à la forme voulue pour la bougie. Il est préférable
de fair usage d'une bougie fendue comme celle repré-
sentée dans les figs. 18 et 19, parce que le courant
remonte par un côté et descend par l'autre.
Les figs. 20, 22, 23 et 23ª représentent différentes
formes de brûleurs faites avec cette matière finement
divisée mentionnée en dernier lieu.
Fig. 21 représente la matière du brûleur indiqué
dans les figs. 22 et 23 couchée à plat.
A la fig. 24, le brûleur a est fait avec une tube en
verre cintré suivant la forme indiquée, est percé d'un
très petit trou; l'air est épuisé de ce tube et la lumière
est produite par le passage dans le tube d'une étincelle
provenant d'une bobine d'induction.
Les figs. 25 et 26 représentent le brûleur a comme
étant composé de six spirales montées sur des baguet-
tes en chaux, les spirales étant réunies ensemble de la
manière indiquée à la fig. 26, et pyro-insulées.
Je décrirai actuellement les moyens pour régler le
courant aux brûleurs.
Dans mon susdit brevet la réglementation du courant
était effectuée par la chaleur du brûleur ou par l'inten-
Edison French Patent-1879.
2395
sité des organes opérant le courant qui contrôlait le
courant et maintient la ou les lumières à une éclat
uniforme; j'ai encore recours à ces méthodes, mais j'ai
modifié et perfectionné les organes employés.
Dans la fig. 1, le brûleur a est situé à l'intérieur du
tube scellé b comme il a été susdécrit et le tube best
entouré d'un globe en verre i porté sur une socle k.
Une chambre anéroïde flexible est moulée dans la
partie supérieure de ce socle ou caisse; elle débouche
dans la chambre formée par le globe i, de sorte que
l'air, quand il est dilaté par la chaleur, peut passer dans
ladite chambre anéroïde et transmettre un mouvement
au diaphragme flexible et pièces y réunies. Quand le
courant a l'intensité voulue, il entre dans le fil 3, passe
dans le brûleur et par le fil 4, au ressort insulé 5, au
massif 6 et au fil 7. Si le courant devient trop intense
faisant émettre une trop grande chaleur au brûleur,
l'eau dans le globe i est dilatée et déprime le diaph-
ragme l, alors une broche montée sur le diaphragme
déprime le ressort 5 et l'en sépare du massif 6, ce qui
rompt le circuit au brûleur par 5 et 6.
Cette ouverture et fermeture du circuit ne sont que
momentanées, d'où l'éclat uniforme de la lumière n'en
est pas atteint, et il n'y a pas de danger que le brûleur
ne s'échauffe trop.
Dans la fig. 25, l'air chauffé et dilaté à l'intérieur du
globe i agit dans les chambres de l'anéroïde pour
fermer un circuit d'embranchement entre 5 et 15
permettant à une partie du courant de passer par la
résistance r, et si la chaleur se maintient, le mouvement
du levier et de l'arrêt 15 sur 5 rompt le circuit à la
lumière électrique en séparant 5 de 6; la résistance de
r est égale à celle du brûleur.
Dans la fig. 27, une spirale de fils platina-iridium est
représentée à l'intérieur des chambres flexibles d'ané-
roïdes, et cette spirale s'échauffe par le passage du
courant et chauffe et dilate l'air à l'intérieur des
chambres / pour actionner les leviers 15 et 5 comme il
a été ci-dessus expliqué.
2396
Edison French Patent-1879.
Dans la fig. 28, la spirale actionnée par la chaleur est
représentée comme étant placée dans un petit globe a²
en verre opaque, à l'intérieur du globe en verre i; ledit
globe a² et la spirale pourraient être logés à l'intérieur
de la caisse k, figure 25, de manière à ne pas être vus.
Dans la fig. 29, l'air chauffé et dilaté provenant de la
caisse transparente i passe dans une chambre conte-
nant un diaphragme qui est mû par cet air pour ouvrir
ou fermer le circuit en 5 et 6 et effectuer la réglementa-
tion thermale du courant.
Dans la fig. 30, l'air chauffé de la caisse i agit sur du
mercure contenu dans un tube a³ pour le dilater et le
contracter et à l'aide d'un flotteur sur le levier 5 ouvrir
le circuit en 6, 15 au brûleur et le fermer par 15 et 5 et
la résistance r.
Dans la fig. 31, le courant lui-même passe dans le
mercure pour le chauffer et le dilater suivant l'intensité
du courant et effectue ainsi la réglementation du
courant au brûleur par la dilatation du mercure qui
actionne le flotteur et le levier 5.
Fig. 32 représente un électro-aimant axial m établi
dans la casse k et le noyau de cet électro-aimant est
attaché à un ressort n. Le courant au brûleur a passe
dans la bobine n et si l'intensité de ce courant në
dépasse pas le point voulu par la lumière, le noyau
n'est pas attiré avec une force suffisante pour être
abaissé apparamment; si le courant excède le point
maximum nécessaire pour la lumière, alors le noyau est
attiré davantage et abaissé de sorte qu'une tige dont il
est armé ouvre le circuit en 5 ou 6, et le courant dirigé
sur le brûleur est momentanément interrompu comme
il a été ci-dessus expliqué. Le ressort n servant à
maintenir le noyou m élevé, pourrait consister en une
spirale à l'intérieur d'un tube dans la bobine de m
comme cela est indiqué à la fig. 34. L'aimant-axial
pourrait être remplacé par l'électro-aimant m, fig. 33,
avec ses noyaux adjacents au ressort n pour attirer ledit
ressort 5 et rompre le courant lorsque le courant
devient trop intense.
Edison French Patent—1879.
2397
1
Dans les figs. 12 et 13, la réglementation du courant
et par conséquent de la chaleur du brûleur, est effectuée
par la dilatation et la contraction du brûleur lui-même
qui fait mouvoir le levier 5. Lorsque le courant est de
l'intensité voulue, il passe au brûleur par le fil 3, fig. 13,
et par la tige et le levier 5 au fil 7; si le courant devient
trop intense, le brûleur a se dilate en haut, mobilisant
le levier 5 qui fait contact avec 6 et présente un trajet
raccourci pour le courant par le fil 10. Le levier g est
un organe de sûreté pour faire contact avec la vis stet
offrir un autre parcours pour le courant dans les cas où
5 et 6 ne feraient pas un contact électrique.
La disposition indiquée à la fig. 12 est matérielle-
ment la même que celle dans la fig. 13, sauf qu'une ré-
sistance rest placée dans le circuit d'embranchement.
Les organes sont représentés dans la position qu'ils
occupent lorsque le brûleur est dilaté et lorsque le cou-
rant passe dans le circuit restreint et la résistance.
A la fig. 17, le courant pass par la tige t et s'il est
trop intense, cette tige se dilate et amène 5 en contact
avec 6 et établit un circuit restreint entre 5 et 6 pour
le courant.
A la fig. 35, la dilatation du corps a qui émet la lu-
mière ferme le circuit entre 5 et 6 et le courant passe
par l'électro-aimant m qui attire le levier armature et
amène plus ou moins de pression sur deux boutons de
carbone en 12 par lesquels le courant passe au circuit
restreint 10, interceptant ainsi le brûleur; ce circnit
restreint offre plus ou moins de résistance suivant la
pression du levier d'armature sur les boutons en
carbone.
Dans la fig. 36, la dilatation du corps a émettant la
lumière, agit pour immerger plus ou moins d'un côté
une bobine de fil dans un bain de mercure et ainsi
augmenter ou diminuer la résistance dans un circuit
restreint ou circuit d'embranchement passant dans le
mercure pour diriger le courant si la chaleur devient
excessive. La dilatation continue du corps a émettant
la lumière, fig. 37, diminue graduellement la résistance
2398
Edison French Patent-1879.
dans le circuit restreint entre 3 et 7 en amenant les
ressorts 5 successivement en contact avec le massif 6
et en fournissant un circuit restreint à la résistance r.
Dans la fig. 38, la dilatation et la contraction conti-
nue du corps a émettant la lumière, mobilise le levier 5
et amène les résistance r successivement en circuit et
la seconde résistance est plus grande que la première
et ainsi de suite.
A la fig. 39, 3 brûleurs a as a sont indiqués; le
courant arrivant de 3 ne passera pas par a5 a® parce-
que le parcours de la moindre résistance est pour 15,
14, 18, 17, 16 et 19 à 7.
Lorsque a se dilate, son levier 5 sépare 14 de 15 et
le circuit doit passer de a par a et par a¹ à 18; de là,
par 17, 16 et 19 à 7. Si la lumière se dilate encore
davantage, la broche insulée sur 14 pousse 16 le
séparant d'avec 17 et le courant est contraint de passer
de a5 par aº en 7.
Fig. 40 illustre une disposition semblable à celle de
la fig. 39, mais l'arrangement des circuits est légère-
ment varié.
Dans ladite fig. 40, le courant passe de 3 par le levier
5 et le ressort 14 à 7. Si a se dilate par l'effet de
l'augmentation du courant, alors le levier 5 mobilise
le ressort 14 et sa broche métallique 22 touche le
ressort 16 et ouvre deux parcours pour le courant, l'un
par a, 5, 14 à 17 et l'autre par a5 19, 16, 22, 14 à 7. La
continuation du mouvement du levier 5 ferme 23 sur le
ressort 18 ét un troisième parcours est ouvert au
courant par le trajet a 24, 18, 23, 22 et 14 à 7.
Dans la fig. 41, le courant venant de la ligne 3 passe
par 16, 17, 14 et 15 au brûleur a, aimant axial m et la
ligne 7; si le courant augmente, le levier 5 de m est
attiré en bas en séparant 14 d'avec 15 et le courant
passe actuellement par 3, 16, 17 et le fil 18 au brûleur
að et a ce qui affaiblit le courant. Si l'intensité du
courant augmente, alors l'aimant m attire le levier 5
encore plus bas en séparant 16 d'avec 17 et le courant
passe par a a5 et a, ce qui augmente la résistance et
empêche la fusion de la spirale.
Edison French Patent-1879.
2399
•
A la fig. 40ª la dilatation de la tige t par l'effet de la
chaleur émise par un brûleur a mobilise le levier 5 et
intercepte le circuit par le brûleur plat a et ferme le
circuit par l'autre brûleur a5.
A la fig. 42 la dilatation de la tige t par l'effet de la
chaleur émise par le brûleur a actionne un levier qui
amène la résistance r proportionnellement à l'intensité
du courant.
Dans les figs. 43 à 52 inclusivement, la somme du
courant dirigé sur le brûleur du corps a qui émet la lu-
mière et par contre la chaleur du dit brûleur, est réglée
ou contrôlée par le courant passant par un électro-
aimant, ou des électro-aimants m', les dits aimants dans
chaque cas attirant son levier d'armature 5 et rompent
le contact avec b, lorsque le courant excède l'intensité
nécessaire pour maintenir la lumière au point voulu,
interceptant ainsi momentanément le circuit au brûleur,
contractant le courant et empêchant toute avarie au
brûleur. Ces dispositions seront clairement comprises
en se reportant aux diagrammes. Je ferai cependant
remarquer que deux électro-aimants sont représentés
dans la fig. 44, afinqu'il y ait deux endroits où le
circuit est ouvert ou fermé simultanément pour réduire
l'éticelle électrique.
Dans les figs. 45 et 46, le circuit n'est ouvert ni
fermé par l'action directe du levier d'armature 5 mais
par un levier actionné par cet organe 5.
Dans la fig. 47, l'électro-aimant m est posé dans un
circuit d'embranchement.
Dans la fig. 48, l'aimant m' est fait avec de fils en-
roulés à travers lesquels le courant passé en sens op-
posé et quand il est égal, il n'a pas d'effet sur le levier
armature; la bobine m'est faite avec du gros fil et se
trouve dans le circuit principal avec le brûleur, tandis
que la bobine m² présente une grande résistance et se
trouve dans le circuit d'embranchement qui ne passe ni
par le brûleur ni par m'. L'inégalité de la résistance du
brûleur produite par l'élévation de la température sert
à varier le courant passant par les parcours d'embran-
2400
Edison French Patent-1879.
chement et le noyau de m' m2 devient aimenté et attire
le levier armature 5 et ouvre le circuit de 3 au brûleur.
Fig. 49 représente l'électro-aimant m' comme étant
ajustable. En variant la distance entre son noyau et le
levier 5, l'intensité du courant nécessaire pour actionner
5 est déterminée.
Fig. 50 représente une disposition pour obtenir le
même résultat, en ajustant le ressort m² qui porte
contre le levier 5 et qui empêche que ce levier ne soit
attiré jusqu'à que ce que le courant passant par le
brûleur et l'aimant ait acquis l'intensité voulue.
Dans la fig. 52, le mouvement du levier 5 rompt le
circuit par la lampe a et le ferme par la résistance r et
le point 6.
Dans la fig. 53, le levier m' comprime ensemble les
enroulements de la spirale ou brûleur a lorsque
l'aimant est actionné, amenant ainsi certaines des
spires en contact et diminuant la résistance en établis-
sant un circuit restreint pour une partie de la spirale.
Dans la fig. 54, j'ai représenté une machine électro-
magnétique miniature comme étant placée dans le
circuit au brûleur a; cette machine est mise en rotation
lorsque le courant excède le point voulu, elle place
ainsi la résistance dans le circuit et rompt en même
temps le circuit au brûleur.
Dans la fig. 55, la machine est représentée comme
étant pourvue d'un régulateur. Lorsque les boules du
régulateur s'élèvent par suite de l'augmentation du
courant au brûleur et à la machine, le levier 5 est
soulevé et intercepte le circuit à 6.
La fig. 56 représente une batterie thermo-électrique
t2 en proximité intime avec le brûleur a; et dans le
circuit à la pile t2, m' est l'aimant qui devient actif,
quand la chaleur du brûleur excède le point voulu et à
l'aide du levier 5 ouvre le circuit en 6.
La fig. 57 représente un barre t faite avec deux
métaux ou autres matières qui se dilatent inégalement,
de sorte que la barre t sera cintrée vers le brûleur a
quand la chaleur émise par cette dernière atteint le
point voulu et interceptera le courant en 6.
Edison French Patent-1879.
2401
La disposition indiquée à la fig. 58 est semblable à
celle indiquée à la fig. 57, mais quand le contact entre
t et 6 est rompu, le circuit n'est pas interrompu à la
ligne, mais un nouveau parcours est ouvert par la
résistance r' qui affaiblit le circuit au brûleur.
La fig. 59 représente la barre à dilatation t comme
étant reliée au levier 6, lequel à son tour est relié avec
un levier composé t'. Lorsque la chaleur du brûleur
devient excessive, la dilatation de la tige t fait balancer
le levier ten proximité intime avec le brûleur a et il
absorbera une partie de la chaleur et protégera le
brûleur contre toute avarie.
La fig. 60 représente une barre à ressort t confec-
tionné avec des métaux ou matières qui se dilatent
inégalement; elle est dirigée vers le brûleur a et en
absorbe la chaleur, lorsque la chaleur de a excède un
point prédéterminé.
La fig. 61 représente la matière qui émet la lumière
sous forme de deux carbones a à placés à une faible
écartement l'un de l'autre à leurs extrémités. La tige à
dilatation t se trouve dans le circuit par ces carbones
e elle est reliée à l'un deux. Le ressort fin tend à
séparer un carbone de l'autre, jusqu'à telle limite que
la dilatation de la tige t le permet.
La fig. 62 est semblable à celle 61, mais il s'y trouve
deux tiges à la dilatation t et les deux pointes en
carbone sont mobiles.
Dans la fig. 63 est indiqué une tige ou cylindre en
oxyde noir de fer qui est un non conducteur d'électricité
lorsqu'il est froid, mais qui est bon conducteur lorsqu'il
est chauffé au rouge. Les fils du circuit sont disposés
de manière que quand le brûleur a accuse une
certaine température, cette barre ne sera pas chauffée
suffisamment pour que le courant puisse y passer
comme circuit restreint, mais si la température est
élevée, la barre w devient chauffée et le brûleur est
inclus dans un circuit restreint par une portion du
courant passant par w.
La fig. 64 représente un brûleur dans lequel les deux
2402
Edison French Patent-1879. -
poles sont dissemblables, l'un étant en carbone a affec-
tant la forme d'une tige et l'autre fil mince a composé
d'un alliage de platine iridium. Le carbone produit la
lumière. L'infériorité de contact entre le métal et le
carbone crée une résistance considérable et cette infé-
riorité de contact est augmentée au fur et à mesure que
ces pièces s'échauffent, d'où le carbone devient exces-
sivement incandescent.
J'ai représenté le carbone comme étant tenu vers la
tige a en platine-iridium à l'aide de cordes, de poulies
et d'un poids. La tige ou carbone a pouvant être ali-
mentée en bas vers la tige a5 en platine-iridium à l'aide
d'un poids attaché à la partie snpérieure du carbone,
des guides 23, 23, étant établis pour passer dans des
ouvertures pratiquées dans les poids comme cela est
illustré à la fig. 65.
Fig. 66 représente des moyens pour alimenter auto-
matiquement les carbones a. Une caisse e5 d'uue lar-
geur suffisante pour recevoir librement les tiges en car-
bone, est soutenue au-dessus du globe i et le fond en
est incliné avec une ouverture à sa partie la plus basse,
d'une grandeur appropriée pour laisser passer une bou-
gie en carbone se projettant partiellement dans le
globe i. La poulie e à l'aide d'une corde et d'un poids
maintient une légère friction sur le carbone et tend à
l'alimenter en bas et à le maintenir en contact avec la
tige at en platine-iridium. Lorsque la partie supé-
rieure du carbone suivant avance pour occuper sa
place, sa partie inférieure s'engage dans le tube et
porte sur le dessus de celui-ci qui est en combustion.
Une autre partie de cette invention a rapport à une
disposition de fils conducteurs principaux, afin d'obte-
nir un circuit métallique complet et en même temps,
tirer partie de la conductibilité de la terre, de sorte que
le masse de métal dans l'un des conducteurs puisse être
réduite, la terre et le conducteur métallique servant en
même temps comme une protection pour les conduc-
teurs insulés.
Fig. 67 est un diagramme illustrant les connexions.
Edison French Patent-1879.
2403
fer;
Les machines magnéto-électriques sont représentées en
M. Elles peuvent être disposées entre les deux conduc-
teurs principaux A B en rangées ou en arcs multiples de
trois, quatre ou plus chacun, et les connexions doivent
être faites pour l'intensité; on a représenté quatre
machines magnéto-électriques M dans chaque rangée.
A, est un tube couché dans le sol préférablement en
il constitue avec la terre une moitié du circuit.
Dans le tube est placé un conducteur insulé B, formé
préférablement d'une série de torons en cuivre tordus
ensemble sous forme de câble, un des torons du câble
étant supprimé, soit à chaque trentaine de mètres, de
sorte qu'à l'extrémité du circuit, il ne s'en présentera
qu'un seul. Un tube d'embranchement A² contenant un
seul toron détaché du câble doit pénétrer dans chaque
maison ou bâtiment, et du rez-de-chaussée de plus
petits fils sont dirigés vers les différentes parties de la
maison où l'on désire établir de lumières.
Chaque lampe a doit être pourvue d'un levier de
contact 32, de manière à l'intercepter des fils conduc-
teurs. Les générateurs d'électricité à la station centrale
sont pourvus d'un champ constant d'aimants dont les
bobines sont dans le circuit électrique; donc, si toutes
les lampes alimentées par les conducteurs principaux
en sont détachées ou séparées par leurs leviers de con-
tact, le circuit sera rompu et il ne passe pas de courant
par ces conducteurs de la station aux lumières, et la
machine à vapeur fonctionne avec un effort amoindri et
avec une moindre dépense de force. Si dans ces condi-
tions le levier de contact d'une seule lampe est tourné,
la lampe sera réunie aux fils d'embranchement par les
conducteurs principaux, le circuit est fermé et il ne
passe pas de la station centrale qu'un courant suffisant
pour alimenter la lampe parceque la résistance externe
détermine la quantité du courant. De cette manière
le courant sera proportionné au nombre des lampes
dans le circuit. Je préfère que chaque lampe contienne
une résistance lorsqu'elle est incandescente d'environ
100 ohms.
2404
Edison French Patent-1879.
Après que le levier a établi le contact de manière à
relier la lumière aux conducteurs, le courant passera
par une résistance r (voir fig. 68), égale à la lampe,
mais si la vis régulatrice thermale 6 est tournée en bas,
la lampe sera mise dans la circuit et le courant divisé
suivant le quantité dont la vis régulatrice a été
tournée comme cela a été ci-dessus expliqué.
Comme cela a été ci-dessus mentionné, la connexion
d'une ou plusieurs lampes fait développer une quantité
de courant suffisante à la station centrale pour mainte-
nir cette lampe incandescente; il s'ensuit que si des
machines magnétiques M sont disposées expressément
en tension et en quantité, plusieurs centaines de lampes
peuvent être placées en avant entre les conducteurs
principaux, la réduction de la résistance lors du place-
ment de chaque lampe dans le circuit appelle la
quantité voulue de courant des stations; donc, la plus
grande économie possible est obtenue en faisant que
toutes les résistances en dehors des conducteurs prin-
cipaux soient des substances qui émettent la lumière.
Fig. 69 représente une disposition de sûreté pour
faire fonctionner des machines magnéto-électriques en
arc multiple. Si une quelconque d'une série de machi-
nes magnéto-électriques fonctionnent en arc multiple
vénait à s'arrêter pour une cause quelconque et ainsi ne
produire aucun effet utile, son fil agirait comme une
seule résistance; donc, la puissance des autres machi-
nes passerait par ce fil et tendrait à le détruire et en
même temps à produire une réduction momentanée
dans la quantité de lumière émise par les lampes; il
est donc très important que de tels accidents ne
puissent se produire.
M M M sont des machines électro-magnétiques dis-
posées en arc multiple et réunies aux conducteurs
principaux. Entre un conducteur principal et chaque
machine est placé un électro-aimant enroulé de très
gros fil métallique, de manière à ne présenter qu'une
faible résistance et empêcher une perte d'énergie par
la chaleur. Chaque aimant est armé d'un levier et d'un
ressort retratile.
Edison French Patent-1879.
2405
Fig. 71 est un petit diagramme représentant plusieurs
machines électro-magnétiques disposées en arc multi-
ple et alimentant les conducteurs principaux avec le
courant. A l'extrémité des conducteurs principaux,
deux fils plus petits retournent à la station et une lampe
est placée en travers ou comprise dans le circuit; par
ce moyen l'état de toute le circuit est représenté à la
station centrale.
Fig. 72 illustre la méthode d'arrangement pour les
lampes établies dans les rues en arc multiple entre
deux conducteurs principaux.
2
Fig. 73 illustre une méthode pour mesurer la quan-
tité d'électricité employée. BA est une boite dans la-
quelle passent le fils 50, 51 provenant des conducteurs
principaux. K² est une bobine de très gros fil métalli-
que dont la résistance est proportionnée au nombre de
brûleurs employés dans la maison. Cette résistance
n'est qu'une portion de la résistance d'une seule lampe.
Une cellule électrolytique P est employée pour le
compteur. Cette cellule qui contient une dissolution
neutre de sulfate de cuivre, a deux électrodes en cuivre
dont l'un est très épais, tandis que l'autre est très mince.
La petite portion du courant qui passe dans la cellule 、
transporte du cuivre et le dépose sur la plaque mince;
une résistance considérable est ajoutée en R2 afin que
celle de la cellule ne soit qu'un faible facteur. Si une
lampe est placée en connection, elle appelle du courant
du conducteur principal et la quantité proportionnée
passant par la cellule effectue un dépôt sur la plaque
mince, si une autre lampe est ajoutée, une quantité
double est déposée et ainsi de suite; à la fin d'une
période quelconque, soit un mois, la plaque est portée
par l'inspecteur au bureau central où elle est pesée
avec soin. Comme le dépôt de cuivre sur la plaque
mince sera proportionné à la quantité totale d'énergie
passant dans la maison, il présente nne mesure correcte
pour établir le prix de l'électricité employée.
Je suppose un électro-aimant à l'intérieur de la
boîte B¹ pourvu d'un levier d'appel 5, de sorte que, si
2406
Edison French Patent-1879.
par suite d'une cause quelconque, le couraut passant
aux lampes dans la maison présentait un grand excé-
dent, le levier sera appelé.
A la fig. 73, j'ai représenté une lampe a ayant soit
une résistance de 1000 ohms placée dans un embran-
chement et dans un autre embranchement, j'ai repré-
senté 4 brûleurs électriques a′ a² a³ a¹ formant une
lampe; comme ces brûleurs sont placés en proximité et
disposés dans deux circuits d'embranchements, la résis-
tance de chaque branche étant de 2000 ohms, les deux
branches présenteront conjointement une résistance de
1000 ohms la même que la résistance d'une lampe.
A l'aide de cette disposition, diverses séries de lam-
pes peuvent être placées dans des circuits d'embran-
chement entre les mêmes conducteurs principaux et la
résistance sera égale dans chaque embranchement, la
surface rayonnante des brûleurs étant réduite.
Fig. 74 démontre comment des batteries secondaires
peuvent être employées pour emmagasiner l'électricité
devant être employée pour faire brûler les lampes a.
La ligne principale as est reliée avec une machine.
électro-magnétique ou aux sources d'énergie électrique.
8
•
b³ est le fil métallique de retour ou la connexion
terrestre. La ligne principale a³ est reliée par les fils
métalliques c8 aux batteries secondaires A3 B3 et les
fils de retour d³ es passent par le levier de contact fo
et le fil is b³. Les lampes électriques a sont représen-
tées en circuit d'embranchement entre le fils 8 et k³.
Le fil ho s'attache à une extrémité des batteries secon-
daires A³ B³ et le fil 8 au levier de fs. Ce levier
représenté isolé à la fig. 75 est cylindrique avec deux
demi-cylindres isolés 34 et 35 contre lesquels portent
les ressorts es et ds et cet organe peut être tourné
périodiquement à la main, par un mouvement d'hor-
logerie ou tous autres moyens mécaniques appropriés.
Lorsque le levier f8 accuse une position, le circuit
principal est fermé par as cs A³ d8 34 36 et is à b³ et
le circuit secondaire est fermé de B³ par h³, des
lampes a, le fil ks, le levier 35, 37 et le fil es à B³.
Edison French Patent--1879.
2407
8
3
Lorsque le levier f occupe l'autre position, le circuit
principal de a³ passe par c³ à B³ et par e³ 34, 36 et is
à b³ tandis que le circuit secondaire venant de A³ est
par h³, les lampes a, le fil k³, 37, 35 et le fil № 8 à A³
de sorte que quand le batterie secondaire B³ fournit
l'électricité accumulée avec lampes a le courant prin-
cipal charge la batterie secondaire A3 et vice-versa.
8
Quand une batterie secondaire est complètement
chargée, la décomposition du liquide commence et des
gaz sont développés. Je tire partie de ces effets pour
actionner un régulateur de circuit et pour séparer le
circuit principal. Les deux caisses fermées dans les-
quelles les batteries secondaires sont placées, sont pour-
vues de tuyaux g³ (voir fig. 76) passant à une chambre
78 en dessous d'un diaphragme flexible t8, et dans le
circuit métallique cº il y a un levier u³ qui est actionné
pour rompre le courant électrique aux batteries secon-
daires entre u8 et une vis u quand les gaz se sont
accumulés suffisamment pour mobiliser le diaphragme.
Les gaz accumulés à l'intérieur de A3 et B3 combinent
et se faisant maintiennent l'action électrique des bat-
teries secondaires. Au fur et à mesure que la pression
décroit, le circuit est de nouveau fermé par la levier u³.
Une autre partie de cette invention a rapport à la
construction des machines électro-magnétiques; dans
cette machine, je fais usage d'un cylindre dont la
surface est recouverte d'un fil enroulé dans le sens de
sa longueur et parallèle à l'axe de rotation. Le courant
électrique passant par le fil enroulé convertit le cylin-
dre en un aimant; un côté du cylindre est de polarité
nord et le côté opposé de polarité sud. Une coquille en
fer est employée, à l'intérieur de laquelle ce cylindre
magnétique est tourné et par induction la coquille de-
vient aimantée, d'où les forces magnétiques dans la
coquille tournent autour de cette dernière en harmonie
avec le cylindre magnétique tournant. Il existe un es-
pace entre le cylindre magnétique tournant et l'intérieur
de la coquille, et dans cet espace il se trouve des fils
`longitudinaux reliés d'une manière toute particulière à
2408
Edison French Patent--1879.
un commutateur, et dans les fils il s'établit un courant
d'induction par suite des forces magnétiques en rota-
tion qui traversent et coupent ces fils pendant la rota-
tion du cylindre magnétique à l'intérieur de la coquille
et du commutateur le courant est dirigé sur les fils de
la ligne.
Dans le dessin, fig. 77, est un plan de la machine
magnéto-électrique complète; fig. 76ª en est une coupe
transversale suivant la ligne x x. Fig. 78 est un plan
de l'aimant rotatif. Fig. 79 en est une vue en bout.
Fig. 80, un plan de la coquille entourant cet aimant
rotatif et la bobine d'induction. Fig. 81 en est une
vue en bout. Fig. 81ª est une diagramme indiquant le
mode d'enroulement de la bobine d'induction, et la
fig. 81B un diagramme de connexions de circuit.
L'arbre a est pourvu d'une cylindre en fer; il peut
être ou massif ou creux et en fonte ou en fils métalli-
ques enroulés; le fil passant en rayonnant de l'arbre,
monte le long d'un côté du cylindre, en travers de
l'autre extrémité de retour de nouveau sur l'autre côté
et en travers l'extrémité et ainsi de suite jusqu'à ce que
toute la surface du cylindre soit couverte de fils qui
sont parallèles ou presque parallèles avec l'axe du
cylindre. Une extrémité de ce fil insulé passe le long
de l'arbre dans une entaille à la bague insulée a et
l'autre extrémité est reliée au ressort du commutateur
ou brossen qui est insulé sur un disque g fixe a' et
tournant avec l'arbre a; l'autre commutateur et sont
ressort x est relié à la bague d sur l'arbre a.
Le ressort ď porte contre la bague d et le fil de la
ligne 3 y est attaché et le ressort g' porte contre la
barre a et le fil de retour 4, ou la terre, y est attachée
ou vice-versa. Il doit être entendu que la machine
magnéto-électrique peut être employée dans un circuit
contenant des lumières électriques ou tout autre
instrument ou disposition actionné par l'électricité
auquel le courant engendré peut être adapté. Cet
arbre a est monté dans des parties ou bâtis h et mis en
rotation par une force motrice appropriée. L'enveloppe
b est établie au moyen de fil de fer enroulé ou de
Edison French Patent-1879.
2409
bagues en fer et attachées ensemble par des boulons 5;
et entre les bagues il y a des feuilles de papier ou autre
matière isolante afin de les séparer et d'empêcher que
les courants magnétiques ne circulent dans la direction
de l'axe de rotation; mais les bagues sont l'une et
l'autre aimantées par induction du cylindre magnétique
b et les lignes de force magnétique rayonnent du
cylindre aux bagues et aux fur et à mesure de la
rotation du cylindre à l'intérieur de la coquille, ces
lignes de force magnétique se meuvent autour rapide-
ment avec le cylindre magnétique.
Dans les machines électro-magnétiques, les courants
les plus potentiels ont lieu dans les fils qui sont passés
en travers des lignes de la force magnétique. C'est
pourquoi je place des fils longitudinaux dans l'espace
existant entre le cylindre magnétique rotatif et sa
coquille afin que ce fils soient traversés par les lignes
de la force magnétique pendant sa rotation. La bobine
d'induction est composée des fils parallèles s sur la
surface du cylindre mince t; ces fils croisent l'extrémité
du cylindre ; à l'extrémité opposée où se trouvent les
leviers commutateurs u à l'endroit du commutateur des
fils sont réunis à une rangée circulaire de barres qui
sont isolées et sur lesquelles portent les ressorts.
Le fil de la bobine à induction parallèle est de fait
sans fin et il est enroulé en vue d'obtenir un courant
continu. Le diagramme, fig. 81, représente le mode
d'enroulement des fils; le nombre d'enroulement paral-
lèles peut varier en plus ou moins, mais je trouve que
le but désiré peut être obtenue de la meilleure manière,
en faisant usage d'un nombre pair d'enroulements
parallèles longitudinalement à la caisse et d'un nombre
impair de plaques commutateurs.
Le courant engendré dans les fils à l'intérieur du
champ magnétique du pôle nord surtout suivent une
direction et les courants engendrés dans les fils, dans
le champ du pôle sud, seront tous dans l'autre direc-
tion.
J'enroule les fils de telle manière que tandis que le
fil est continu et que le courant passe dans tout ce fil
2410
Edison French Patent-1879.
le courant passera par 2 fils de la bobine d'induction
à une plaque commutateur, ensuite en s'en écartant,
passera par un plaque opposé de commutateur et
passera par dans la bobine dans laquelle il enroulera à
l'autre plaque commutateur. Supposons que les ressorts
portent sur les plaques commutateurs a et e, le courant
se dirigera vers a des fils 1 et 6 s'éloignant de e par les
fils 12 et 7. En suivant les flèches, on verra que tout
l'enroulement est un circuit complet dans lequel les
portions parallèles des fils dans le champ sud de
l'influence magnétique ont un courant développé
suivant une direction et dans le champ nord dans une
autre direction obtenant ainsi l'effet dynamique, et il
ne produit aucune interruption ou pulsation du courant,
les ressorts touchent au commutateur avant d'en
abandonner un autre.
Bien entendu que le courant est renversé dans les
portions parallèles des fils succesivement, par exemple,
le courant dans 7 et 14 est renversé pendant que les
aimants et les brosses tournent autour d'eux ensemble,
lorsque le ressort passe de d par 14 à 7 dans la direc-
tion opposée et à 12 comme avant. Quand le ressort
passe de n à g le courant dans 8 et 7 est renversé; il
passe de 6 comme aupravant et en traversant, il est
renversé en i et retournant en 8 suivant des directions
opposées, il est enlevé par g. Les flèches ponctuées
indiquent ces changements successifs de direction,
d'où il résulte que les courants sont dirigés par deux
fils à chaque commutateur successivement de tout le
champ magnétique.
Le courant passera du ressort g' par a'; de là, par
les fils parallèles enroulés sur le cylindre b au commu-
tateur n; de là, par la barre sur laquelle il porte le long
de la bobine d'induction parallèle sur un côté du cylin-
dre t retournont le long de l'autre côté, à la barre com-
mutateur par le ressort z à la bague et au ressort d'
à la ligne. On doit tenir compte que la bobine d'in-
duction parralèle t et les barres commutateurs u restent
stationnaires et que les ressorts n x tournant autour
des barres u par l'intensité de l'arbre a et le ressorts
Edison French Patent--1879.
2411
de commutateurs doivent être placés par rapport au
cylindre magnéto-rotatif de manière à enlever le courant
à l'endroit ou il présente sa plus grande énergie.
Le courant sera continu ou presque continu et suivra
une direction; il y aura cependant quelquefois une étin-
celle entre les barres commutateurs quand le circuit de
l'enroulement parallèle à induction est interrompu,
mais ceci sera diminué en cintrant les ressorts de com-
mutateur de manière à ce qu'ils portent sur plus d'une
barre commutateur. Il sera évidemment que la caisse et
l'enroulement parallèle à induction peuvent être mis en
rotation, si le cylindre magnétique reste stationnaire,
ou s'il tourne dans la direction opposée, et je fais
observer que le cylindre supportant l'enroulement
parallèle à induction s peut être construit avec des
matériaux appropriés quelconques, mais je préfère et
je fais usage des fibres vulcanisés.
Les organes de cette machine ne sont pas sujets à
s'échauffer dans des conditions de fonctionnement
ordinaire parceque les fils ne sont pas enroulés les uns
avec les autres et l'atmosphère peut circuler dans la
masse. Cependant, dans certain cas, je fais usage d'un
ventilateur sur l'arbre a monté dans une caisse com-
muniquant avec le portions internes de la machine de
manière à induire un courant d'air.
Fig. 82 représente une nouvelle forme de machine
dynamo-électrique dans laquelle le champ magnétique
est concentré et les fils de la bobine coupent le champ
avec une grande rapidité et la quantité de fil parcouru
par le champ peut être augmentée jusqu'à toute limite
voulue sans augmenter la vitesse de rotation de l'arbre.
a10 est une bague composée de fil de fer; autour de
cette bague est enroulé du fil métallique isolé par sec-
tions dont il y a plusieurs centaines; les fils métalliques
entre les sections sont réunis comme dans la machine
Gramme au commutateur. 10 est l'aimant du champ
p10
qui peut être actionné d'énergie par la bague a¹º ou
par une source externe ; il sera pourvu de pôles p¹º p¹0
q¹º q¹º qui sont représentés en coupe; dans la machine
actuelle ces pôles recouvrent entièrement la bague, sauf
10 10
1
10
2412
Edison French Patent--1879.
une petite fente où les raies de la bague viennent s'y
adapter. c10 est un ressort du commutateur lequel
suivant toutes les positions de la bague établit la
communication à la bobine entre l'aimant du champ;
d10 et e10 sont aussi des ressorts réunis ensembles et
réunis aussi par la roue du commutateur avec les
bobines sur chaque côté des aimant du champ. Cette
portion seulement du fil sur la bague en proximité de
l'aimant du champ est employée ou ajoute une résis-
tance au circuit, de sorte que la résistance du fil, la
longueur de l'aimant et la concentration du champ sont
indépendantes du diamètre de la bague qui peut avoir
un diamètre de quelques métres. Il n'en est pas ainsi
de la bague Gramme, car si l'on veut augmenter la
vitesse avec laquelle le fil passe dans le champ, la
bague doit être plus grande, mais ceci augmentera la
résistance, et, comme la totalité du champ devrait être
couverte par l'aimant du champ, il doit être réparti de
telle sorte qu'il en résulte un affaiblissement du champ,
empêche qu'on obtienne de grandes vitesses, sauf pour
une rotation accélérée de l'arbre ce qui augmente le
frottement.
Quand la bague dans ma machine est mise en rota-
tion dans le champ magnétique, un courant passe du fil
enroulé sur chaque côté de l'aimant, l'un provenant de
c10 et l'autre de d¹º, tous les deux dans la même direc-
tion, et il se dirige de la machine à une lampe ou autre
disposition électrique.
Fig. 83 représente la même machine disposée avec le
fil enroulé de l'aimant du champ dans le même circuit
que le fils de la bague.
Fig. 84 représente un aimant de champ double 10
avec une bague passant à travers les pièces du pôle à
son centre; les 2 pôles nord de la machine sont réunis
à une pièce et les 2 poles sud à une autre.
Fig. 85 représente ce système disposé avec un méca-
nisme à action réciproque, c10 est un arbre, 10 un ex-
centrique, a¹º est un aimant recouvert de fil métallique
qui reçoit une action alternative par l'excentrique et la
tige /¹º. 71º est l'aimant du champ; S S sont les pôles
1
•
Edison French Patent-1879.
2413'
m10
α
u
sud et N N les pôles nord. Un fil métallique 10 est
attaché au
centre du fil sur a10; les deux autres
extrémités de
de a10 sont réunis ensemble et forment
l'autre pôle. Des courants alternatifs sont engendrés
dans la bobine a¹0 par son action alternative entre les
α 10
pôles magnétiques et ceux-ci peuvent par l'emploi d'un
commutateur être dirigés dans des courants continus.
Fig. 86 représente ce principe appliqué à un télé-
phone; m¹º en est le diaphragme; a10 l'enveloppe en
fer et fil actionné dans le champ magnétique par le
mouvement du diaphragme a¹º. SS sont les pôles sud
et N N les pôles nord des aimants 10; les fils sont
réunis comme dans la fig. 85. Bien entendu des aimants
permanents peuvent remplacer les électro-aimants 10.
J'ai représenté une batterie locale L B pour polariser
d'une manière permanente les aimants, mais ces
aimants peuvent être placés dans le circuit principal
a1º et la batterie peut être installée sur la ligne.
10
Fig. 87 indique comment l'aimant additionnel du
champ d'une machine Gramme peut être supprimé et
la bague elle même faite au moyen d'un aimant de
champ et d'un aimant le traversant en même temps.
En admettant que T B soit une batterie thermale ou
autre source d'énergie électrique, le courant passerait
à la bague par les ressorts de commutateurs t¹º passant
du dessus et du dessous de la bague en fer a10 N et S
respectivement. 10 est une masse de fer seulement.
v10 v10 sont les commutateurs usuels. Si ce derniers
sont fermés et la bague mise en rotation, le courant
engendré tend à faire un pôle nord à droite et un pôle
sud à gauche, d'où la polarité de la bague est angulaire
par rapport à la pièce en fer ¿10; de là l'attraction
qui tend à retarder la rotation en ceci engendre des
courants.
Fig. 88 représente un disposition d'après laquelle
des courants continus et alternatifs peuvent être obte-
nus d'une machine Gramme ordinaire quelconque; les
commutateurs v10 sont ou fermés ou disposés avec le
fil sur l'aimant du chanıp, de sorte que le courant
engendré dans la machine actionnera l'aimant du
2414
Edison French Patent-1879.
champ à un point à angle droit avec les ressorts de
commutateur, aussi bien sur le dessus que sur le
dessous de la bague, ainsi la continuité est rompue et
les deux extrémités des fils sont menées à des disques
sur l'arbre sur lequel des ressorts frottent; à ces
ressorts sont attachés des fils et si ces fils sont fermés,
des courants continus seront enlevés par v10 et ils
actionneront les aimants du champ, tandis que des
courants alternatifs passeront par ces circuits 46, 47,
48 et 49 sont des circuits réunis à des pointes en carbone
pour former une lampe à étincelle ou arc voltaïque.
Fig. 89 représente seulement le dessus de la bobine
annulaire a¹º coupée avec ses deux extrémités réunies
à des disques ou bagues sur lesquels portent les
ressorts n" m".
Fig. 90 représente une machine dynamo-électrique à
quantité. $10 est son arbre; m12 un aimant avec fils,
les deux extrémités des fils sont reliées à des disques
50 et 51. s³ et s sont des coquilles en cuivre qui
entourent l'aimant m¹2 au centre; les coquilles font
une communication électrique avec le fer doux de
l'aimant m12; sur les extrémités des coquilles se
trouvent des poulies métalliques. Des câbles métalli-
ques, flexibles servent à imprimer la rotation à ces
coquilles et à diriger le courant; ce coquilles tournent
en sens opposé. Les courants y dirigés passent par le
noyau en fer de m12 et l'arbre devient une extrémité
du circuit tandis que les poulies et les câbles métalli-
ques en forment l'autre extrémité; une coquille
alimente le courant à l'aimant du champ 10.
Je mentionnerai que pour régler la force des courants
dans une machine Gramme, les deux ressorts ou brosses
de commutateur peuvent être reliés à un disque rotatif
et si ce disque est placé à angle droit avec leur position
appropriée, aucun courant n'est engendré ou sa puis-
sance absorbée par la machine; mais si elle est tournée
d'une très faible quantité vers la position voulue pour
obtenir un courant maxinium, alors un courant est en-
gendré proportionnellement à ce mouvement, d'où en
tournant les commutateurs, on peut obtenir un courant
Edison French Patent-1879.
2415
de toute force voulue sans arrêter la machine ou
donner lieu à une plus grande absorption de puissance
que celle nécessaire pour engendrer le courant.
Fig. 91 représente un tuyau dans lequel il passe de
l'eau chaude et toute sa circonférence doit être recou-
verte de couples thermo-électriques sous forme de pla-
ques rayonnantes. Il est reconnu qu'une grande portion
de l'énergie théorique de la combustion du charbon
dans une chaudière à vapeur est perdue par le fait de
la condensation de l'eau chaude dans un bon conduc-
teur. Comme une rivière coule avec une chute d'eau
d'environ 2 millimètres par kilomètres, jė propose de
disposer plusieurs mètres de tuyaux passant dans une
chambre dans un sens et dans l'autre plusieurs fois et
de faire passer de l'eau chaude du condenseur dans
toute cette longueur de tuyaux à la citerne et je me pro-
pose d'en extraire la chaleur en recouvrant la surface
entière de ce tuyau de batteries thermo-électriques; les
jonctions chaudes de la batterie thermale portent sur
la surface du tuyau point non conductrice de l'électri-
cité et si cela est nécessaire, afin d'obtenir une aug-
mentation d'effet, les autres jonctions sont placées en
contact avec une autre série de tuyaux dans laquelle il
circule de l'eau froide. Ces couples thermales sont ré-
unis ensemble de la manière appropriée pour que leur
courant puisse être utilisé pour maintenir un aimant
constant de champ pour machines magnéto-électriques
que j'emploie dans mon système d'éclairage. Une cer-
taine portion de tuyaux est réservée pour la batterie
thermale de chaque aimant. 10, fig. 92, représente de
ces aimants dans des machines magnéto-électriques.
Les batteries thermales sont admirablement adaptées
pour ce service particulier parce que le résistance des
aimant du champ peut être très faible.
Fig. 93 représente un dynamomètre pour mesurer la
force motrice absorbée par les machines dynamométri-
ques pendant qu'elles fournissent un courant. Ce sont
des poulies moulées sur un arbre s; ces poulies sont
commandées par une courroie 54, 55 et 56 sont les
disques isolés montés sur l'arbre s¹6; des ressorts
..
2416
Edison French Patent-1879.
portent sur ces disques d' est un disque réuni d'une
manière permanente à l'arbre s; me est une électro-
aimant également réuni d'une manière permanente au
disque d'; il comporte une armature sur l'extrémité
d'un bras qui est attaché à une poulie folle p* ou à un
manchon attaché à ladite poulie également passée sur
un arbre sº; de la poulie p' il part une curroie à la
machine dynamique. Les ressorts de 55 et de 56
forment une liaison avec une batterie B¹º, une résis-
tance R10 et un galvanomètre G10. 55 et 56 sont
réunis à l'aimant me est 55 est réuni avec le disque dr
et 54 avec la pointe arrière 68 qui établit un circuit
quand le bras de p' porte contre le bras b8 dans lequel
circuit sont montés un timbre et une batterie 58.
La machine dynamique sera commandée par une
courroie provenant de p' et quand on désire savoir la
somme de force absorbée par la machine dynamique
la batterie B10 est mise en circuit et m attire le bras
de p' d'avec b8 au fer doux de l'aimant me et la force
de l'aimant doit être suffisante pour maintenir le bras
pendant que le rotation continue. L'opérateur surveille
actuellement le galvanomètre et commence à insérer de
la résistance dans le circuit jusqu'à ce que la puissance
de l'aimant est tellement affaiblie que l'armature sur le
bras p' cesse d'être tenue par les fer doux et le levier
d'armature retombe en arrière sur ¿³; ceci forme le
circuit du timbre et juste au moment où le timbre se
fait entendre l'opérateur remarque la déflexion du
galvanomètre que donne la force du courant provenant
de B10 et ayant préalablement déterminé la quantité
des poids qui appellerait le bras d'avec me avec des
forces différentes de courants; il peut, en prenant la
vitesse de rotation, calculer avec précision la force
absorbée en kilogrammes-mètres.
m
Fig. 94 représente une disposition pour mesurer la
somme du courant consommé dans un temps donné.
m13 est un électro-aimant, 14 un levier relié à un pis-
ton fonctionnant avec précision dans une cylindre m15.
m¹º est de la glycérine ou de l'huile. Ce cylindre est
relié avec un réservoir m17 par un tube ayant un très
Edison French Patent-1879.
2417
petit trou à une extrémité. Ce mesurage est obtenu par
la pression produite par l'aimant sur le piston qui re-
foule l'huile très lentement dans le réservoir mais en
proportion avec l'attraction de l'aimant qui est comme
le carré de la force motrice électrique du courant.
Je revendique comme de mon invention:
Premièrement.
Conjointement avec une chambre à
vide scellée, faite en verre, un conducteur métallique
incandescent continue comme cela a été ci-dessus
décrit.
·
Deuxièmement. La méthode ci-avant décrite pour
préparer les conducteurs électriques pour les lampes ou
brûleurs électriques consistant à libérer les conducteurs
métalliques des gaz dans le vide et après à sceller
hermétiquement la caisse transparente étanche que
l'on entoure comme cela a été ci-dessus spécifié.
Troisièmement. - Dans une lampe électrique la com-
binaison avec une caisse à vide transparente et scellée
d'une bobine de fil pyro-insulé enroulé sur une sub-
stance infusible comme cela a été ci-dessus spécifié.
Quatrièmement.- La combinaison avec une caisse
transparente à vacuum, d'un conducteur continu
formant un brûleur ou une chandelle électrique et
d'une seconde caisse transparente formant une cham-
bre close dans les buts ci-dessus exposés.
Cinquièmement. La combinaison du conducteur
formant la lampe ou chandelle électrique avec la caisse
transparente scellée i renfermant la caisse b et le régu-
lateur thermostatique 1, 5, 6, comme cela a été ci-
dessus spécifié.
Sixièmement. Là méthod pyro-isolatrice du fil ou
bande de métal pour le conducteur consistant à passer
ce fil ou bande dans une dissolution de chaux ou de
magnésie et ensuite dans une flamme ou un foyer, pour
1
2418
Edison French Patent-1879.
effectuer la décomposition de la dissolution comme cela
a été ci-dessus spécifié.
Septièmement. La combinaison dans une lumière
électrique de couches de métal incandescent avec des
pyro-isolateurs intermédiaires comme cela a été ci-
dessus décrit.
Huitièmement. Une spirale ou hélice de métal
avec des pyro-isolateurs intermédiaires, solidement
comprimés, conjointement avec le régulateur thermal
de circuit comme cela est représenté aux figs. 12 et 13.
Neuvièmement. Le combinaison avec un conduc-
teur incandescent continu formant brûleur ou lampe,
d'un rhéostat ou résistance et de connexion de circuit,
comme cela est indiqué à la fig. 12, pour maintenir une
résistance presque uniforme dans le circuit électrique
comme cela a été ci-dessus spécifié.
Dixièmement. La combinaison avec la lumière
électrique a et la disposition à dilatation thermale,
figs. 12 et 13, des leviers 5 et 9 et des pointes de
contact 6 et 8 et des connexions du circuit comme cela
a été ci-dessus spécifié.
Onzièmement. La méthode de production d'une lu-
mière électrique qui consiste à passer une étincelle d'in-
duction dans la chaux contenue dans un tube à vacuum
comme cela a été décrit par rapport à la fig. 14.
Douzièmement. Le matériel produit en brûlant un
acétate de chaux pour être utilisée dans l'éclairage
électrique comme cela a été ci-dessus décrit.
Treizièmement. Les dispositions indiquées dans
les figs. 15 et 16 pour produire une lumière oxyhydro-
gène comme cela a été ci-dessus spécifié.
Quatorzièmement. Dans l'éclairage électrique, un
conducteur d'électricité formé de métal divisé finement
Edison French Patent-1879.
2419
incorporé avec un non-conducteur d'électricité comme
cela a été ci-dessus décrit par rapport aux figs. 17, 18,
19, 20, 21, 22, 23 et 244.
Quinzièmement.
Un corps rigide a émettant la lu-
mière électrique, figs. 17, 18 et 19 ayant une incision
ou séparation longitudinale depuis la base jusqu'à près
de son extrémité pour assurer la circulation du courant
électrique dans tout le corps comme cela a été ci-
dessus spécifié.
Seizièmement.
Conjointement avec un corps rigide
a et servant à émettre la lumière et ayant une incision
longitudinale, un régulateur thermal à dilatation pour
le circuit afin de contrôler la force du courant par
l'effet de la chaleur développée dans le brûleur comme
cela a été ci-dessus spécifié.
Dix-septièmement. — Une spirale régulatrice thermale
dans le même circuit que le brûleur, mais dans une
caisse étanche séparé du dit brûleur et actionnant des
organes réglant le circuit comme cela été décrit par
rapport aux figs. 27 et 28.
Dix-huitièmement. L'aimant axial m dans le circuit
du corps a qui émet la lumière conjointement avec le
ressort n auquel le noyau de l'aimant est attaché, le
ressort 5, la pièce b et les connexions du circuit comme
cela a été spécifié par rapport aux figs. 32, 34.
Dix-neuvièmement. Les organes et circuits repré-
sentés dans les figs. 35, 36, 37, 38 et 42 pour varier la
résistance dans le circuit au brûleur suivant l'intensité
du courant passant au dit brûleur.
Vingtièmement.
Les dispositions et circuits repré-
sentés dans les figs. 39, 40, 40A et 41, à l'aide desquels
un ou plusieurs corps émettant la lumière sont placés
dans le circuit avec le brûleur principal, si le courant
devient trop intense, ce qui a pour effet de réduire le
2420
Edison French Patent-1879.
courant dans le dit brûleur principal comme cela a été
ci-dessus spécifié.
Vingt-et-unièmement. La combinaison avec un
corps métallique émettant la lumière d'un ou plusieurs
aimants dans lesquels passe le courant au brûleur et
les circuits électriques représentés, d'où la quantité de
courant dirigé sur le brûleur est réglée par l'intensité
du courant passant dans ledit aimant ou les dits aimants
comme cela a été ci-dessus décrit et représenté dans
les figs. 43 à 8.
Vingt-deuxièmement. - La combinaison avec le corps
a émettant la lumière d'une petite machine électro-
magnétique dans le circuit au brûleur, comme cela a
été ci-dessus décrit par rapport aux fig. 54 et 55.
Vingt-troisièmement. - La combinaison avec le brû-
leur a de l'électro-aimant m de la batterie thermale p²
et des circuits disposés comme cela est indiqué à la
fig. 56.
Vingt-quatrièmement. - La combinaison avec le brû-
leur a de la barre à dilatation t' et des circuits électri-
ques disposés comme cela est indiqué dans les fig. 57
et 58.
Vingt-cinquièmement. -- La combinaison avec le brû-
leur a de la barre t out absorbant la chaleur, figs. 59
et 60.
Vingt-sixièmement. - Le carbone a qui émet la lu-
mière pivote à une de ses extrémités et à son autre ex-
trémité contiguë à l'autre carbone conjointement avec
la tige de dilatation t et le ressort comme cela a été
ci-dessus spécifié et représenté dans les figs. 61 ou 62.
Vingt-septièmement. -- La combinaison avec le corps.
a qui émet la lumière d'un levier u, fig. 63, qui est un
non-conducteur d'électricité à froid et un conducteur à
Edison French Patent-1879.
2421
chaud pour régler le courant ou brûleur comme il a été
ci-dessus specifié.
Vingt-huitièmement. La combinaison dans une
lampe électrique d'un crayon en carbone et d'une tige
métallique de fusion difficile et d'un poids pour main-
tenir la pression nécessaire à la pointe de contact
comme cela a été ci-dessus représenté.
Vingt-neuvièmement. La caisse e5 à fond incliné
adapté pour recevoir plusieurs crayons en carbone
conjointement avec la tige métallique a5, fig. 66, et des
moyens pour guider ces crayons et en maintenir la
pression au point de contact comme cela a été ci-
dessus décrit.
Trentièmement. - Les conducteurs métalliques isolés
B, fig. 67, à l'intérieur d'une caisse métallique qui
constitute avec la terre le circuit de retour, comme
cela a été ci-dessus décrit.
Trente-et-unièmement. -- La disposition automatique
de sûreté, figs. 69 ou 70, pour intercepter le courant
à la machine électro-magnétique dans les cas dérange-
ment de la dite machine.
Trente-deuxièmement.
La méthode spécifiée par
rapport à la fig. 73 pour déterminer le courant électri-
que, employé dans les lampes électriques qui consiste
à faire déposer du métal par le courant qui passe,
à peser ce métal déposé, et à estimer de cette manière
la valeur du courant comme cela a été ci-dessus décrit.
Trente-troisièmement. La disposition de 4 lampes
électriques, fig. 78, dans un circuit d'embranchement
divisé entre deux conducteurs principaux comme il a
été ci-dessus décrit.
Trente-quatrièmement. Un électro-aimant m', fig.
78, dans le circuit au brûleur dans un bâtiment qui
fonctionne quand le courant excède un point prédéter-
2422
Edison French Patent-1879.
miné pour attirer un levier d'armature et l'arrêter et
interrompre le circuit aux tels brûleurs comme cela a
été ci-dessus décrit.
Trente-cinquièmement.
La combinaison avec les
lampes électriques a, fig. 74, et avec un circuit princi-
pal de 2 batteries secondaires et connexions de circuit,
pour changer alternativemet les circuits principal et
secondaire, comme décrit.
Trente-sixièmement.
Le circuit secondaire conte-
nant des lampes électriques, la batterie secondaire et
la caisse conjointement avec le circuit principal par la
batterie secondaire, un diaphragme actionné par
l'accumulation des gaz dans la batterie secondaire avec
un levier de contact dans le circuit principal comme
cela a éte ci-dessus décrit.
Trente-septièmement.
Un cylindre magnétique b,
figs. 76ª, 77, 78 et 79, composé d'un cylindre en fer
dont la surface est recouverte d'un fil isolé disposé
parallèlement à l'axe de rotation et en traverse les
extrémités comme cela a été ci-dessus spécifié.
Trente-huitièmement. La combinaison dans une
machine dynamo-electrique et d'un cylindre magnéti-
que rotatif b, d'une caisse ou coquille en fer l entourant
ce cylindre et de fils enroulés et réunis au massif
du commutateur, comme cela a été ci-dessous décrit
formant un organe d'induction parallèle s qui occupe
l'espace entre le cylindre magnétique et l'enveloppe
comme spécifié.
Trente-neuvièmement. -- La combinaison dans une
machine magnéto-électrique d'un cylindre magnétique
rotatif b portant des fils métalliques le long de sa
surface, parralèles ou presque parallèles à l'axe, une
coquille en métal 7, un bobine d'induction parallèle s,
de barres commutateurs u, des ressorts n x, des bagues
de et les connexions de circuit décrit.
Edison French Patent-1879.
2423
Quarantièmement. -- Dans une machine électro-mag-
nétique, une bobine d'induction parallèle dont le fils
métalliques sont enroulés de la manière indiquée dans
la fig. 814 et le connexions à commutateur à ces fils,
d'où le courant est enlevé de la bobine d'induction
parallèle sur deux points ou directions opposées,
comme décrit.
Quarante-et-unièmement. Les bobines d'induction
rotatives, aimants stationnaires, commutateurs et cir-
cuits représentés et décrits par rapport aux figs. 82, 83,
84, 87, 88 et 89.
Quarante-deuxièmement.
- -
La bobine d'induction
animé d'un mouvement dans la direction de sa longueur,
les électro-aimants et les circuits décrits et représentés
par rapport aux figs. 85 et 86.
Quarante-troisièmement. - La disposition indiquée
dans la fig. 93, pour déterminer la force consommée
pour la commande des machines magnéto-électriques,
comme cela a été ci-dessus décrit.
Quarante-quatrièmement.
La batterie thermale et
les tuyaux de chauffe représentés dans les figs. 91 et 92
conjointement avec la machine électro-magnétique
comme cela a été ci-dessus décrit.
2425
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Translation of Edison French Patent-1879. 2439
COPY OF THE SPECIFICATION.
Annexed to the Patent for Fifteen Years.
Taken the 28th of May, 1879,
BY MR. THOMAS A. EDISON,
"
FOR
Improvements introduced in the production of
electricity, in electric lighting, as well as in the
"machines and apparatus employed for
for those
"purposes."
In my patent of November 8, 1878, I have described
and shown means for developing electric currents and
for lighting by means of electririty.
My present improvements are connected with the
said invention and they relate to the construction of
the burner to the automatic adjustment of the burner,
to the system of circuits in which the lights are used,
to means for developing electric currents, to the meas-
uring of the quantity of electricity employed, and to
other matters relating to my system of electric lighting.
I have found that when wires or leaves of platinum,
iridium or other conductors of electricity which melt
at a high temperature, are exposed to a high temper-
rature, approaching their point of fusion, in the air for
several hours by passing through them a current of
electricity, and then allowed to cool, the metal is
ruptured, and under the microscope there appear a
miriad of cracks in different directions of which some
reach nearly to the centre of the wire.
I have also found that, contrary to the opinion which
has been expressed, platinum or an alloy of platinum
and iridium lose weight when they are exposed to the
heat of a candle, that even heated air causes them to
undergo a diminution of weight, that this loss is so
great that it gives a green tint to a hydrogen flame,
2440 Translation of Edison French Patent-1879.
and under an influence of an electric current to a
yellowish white heat the loss is considerable. After a
certain time the metal is disaggregated, from which it
results that platinum or an alloy of platinum and
iridium, such as are actually found in commerce, are
useless for giving a light by incandescence.
First, because the loss of weight renders them
expensive, destroys the burner rapidly and gives no
reliability.
Secondly, because their electrical resistance changes
on account of their loss of weight and because their
emission of light, relatively to the total surface, is
considerably diminished on account of the cracks and
crevices; the point of fusion being determined by the
feeblest point where the greatest difference of poten-
tial of the electric current occurs, the effect of which is
to create more heat at this point than upon the
remainder of the wire; and furthermore for obtaining
a stable light it is essential to protect the platinum
burner from the contact of air, and when it is thus
protected by being placed in a glass chamber, the glass
is rapidly covered with a coating of black from the
platinum. A platinum spiral brought to incandescence
under these circumstances may be made to give a light
equal to three standard candles when it is near its
point of fusion and when the radiating surface is a
little more than a millimetre and a half, but this
amount of light will be gradually reduced as has been
above described.
By reason of my invention or discovery I am able to
prevent the deterioration of the platinum or its alloys
by destroying or intercepting the atmospheric action.
A platinum wire in the form of a spiral or any other
form being placed in a glass tube with the wire near its
extremities passed through and sealed into the glass,
the air is exhausted from the glass tube with a "Spran-
gel" pump to such a point that the discharge of an in-
duction coil of seventy-five millimetres will not pass
between the extremities of wires placed in the tube at
a separation of 4 millimetres. The platinum wires
Translation of Edison French Patent--1879. 2441
of the spiral are then connected to a magneto-electric
machine or a battery of which the current may be
controlled by the addition of a resistance. A sufficient
current is passed through the wire to bring it to a tem-
perature of about 65 degrees centigrade, it is left
under the influence of this temperature for ten or fifteen
minutes; during this heating the air and the gases
contained in the metal are expelled from it by the heat
or drawn out by the effects of the vacuum. While this
air or these gases are going out of the metal the mer-
cury pump should be worked constantly. After about
fifteen minutes the current in the metal is increased so
that the temperature will be about 150 degrees centi-
grade, and it is exposed to this temperature again for
ten or fifteen minutes. The mercury pump should be
worked constantly and the temperature of the spiral
should be raised by intervals of ten to fifteen minutes
until it reaches a vivid incandescence, and the glass is
contracted where it is joined to the pump and melted
in such a way that the wire is in a perfect vacuum and
in a state hitherto unknown, for the temperature can
be raised even to the most dazzling incandescence,
giving a light of twenty-five standard candles, while
before this treatment the average point of fusion of a
series of spirals having the same length and dimensions
of wire as well as the same radiating surface was only
about three candles.
The wires submitted to this process of elimination
of the air and of gas have a polish surpassing that of
silver, and one which cannot be obtained by any other
means. No cracks can be perceived even after the
spiral has been suddenly raised to incandescence
several times by the current, and no volatilization
takes place since no deposit is formed upon the glass
tube; moreover, no diminution of weight is found in
the wire by the use of delicate scales after it has
burned several hours consecutively.
I have further discovered that if an alloy of platinum
and iridium or a wire of simple platinum is covered
with a coating of oxide of magnesium in the manner
2442 Translation of Edison French Patent--1879.
described below and submitted to the vacuum process
described, a combination takes place between the metal
and the oxide giving to this latter remarkable quali-
ties. With a spiral having a surface of a little more
than a millimeter and half, a light equal to that given
by forty standard candles may be obtained, while the
same spiral not coated by my process would fuse
before giving a light of four candles. The oxide of
magnesium hardens the wire in a surprising manner
and renders it more refractory. A spiral made of this
wire is elastic and forms a spring even when it is
heated to a dazzling incandescence.
I have found that chemically pure iron and nickel
drawn into wires and submitted to the vacuum process
give a light equal to that of platinum in the open air.
Pencils of carbon can also be freed from air in this
manner and be brought to such a temperature that the
carbon becomes pasty, and if it is then allowed to cool
it is very homogeneous and hard. Rods and plates
made of mixtures of conducting materials finely divided
can also be freed from air and of gases in this way.
I will now describe the form of the burner or lamp
which I employ. In order to operate practically sev-
eral hundreds of electric lamps, each equal to an ordi-
nary gas burner, upon a circuit, it is essential for sev-
eral reasons, as regards convenience, economy and cer-
tainty of results, to put them all in multiple arc, and in
order to prevent the resistance of several hundreds of
lamps from falling so low that it is necessary to make
use of main conductors of immense dimensions, with a
low resistance, and of machines for generating electric-
ity of corresponding character, it is essential to reverse
the present system of lamps which have a resistance of
only one or two ohms, and to construct lamps which
shall have, when they emit their desired quantity of
light, a resistance of several hundreds of ohms.
I have ascertained by experiment that the loss of
electrical energy is in proportion to the extent of the
surface which emits light, and is independent of the
resistance of the conductors, therefore with a thousand
Translation of Edison French Patent--1879. 2443
lamps having each a radiating surface of six millime-
ters and each a resistance of one ohm, the loss of elec-
trical energy is equal to one thousand lamps having
the same radiating surface, each having a resistance of
one thousand ohms; the loss of energy in each lamp in
each case, when it emits a light of fifteen candles, will
be the same, but with one thousand lamps, each of one
ohm, the combined resistance will be a thousandth of
an ohm, from which it results that an enormous main
conductor would be required, while the one thousand
lamps of one thousand ohms each, when they are
combined, will have a resistance of but one ohm, and a
conductor of very moderate dimensions will suffice. In
practice, a resistance of two to three hundred ohms
will be sufficient in the burner. With lamps of a low
resistance the connections and the main wires should
be large in order to prevent a great loss of energy by
the resistance and the conducting wires of the main
conduits are heavy, costly and large to handle. The
low resistance of the burner or incandescent conductor
requires large terminals for conducting the current,
and these latter present by their conduction a vehicle
for the rapid dissipation of energy without producing
any effect, while with a lamp of high resistance all
these objections disappear.
The wire for the burner or lamp, prepared as has
been above described, is wound upon a bobbin shown
at L, Fig. 1, composed of an infusible oxide such as the
oxide of calcium, cerum, zirconium or magnesium freed
from silica, formed in a lathe from sticks moulded by
hydraulic pressure. The burner complete is shown at
a, Fig. 1, as being mounted in the vacuum tube b
upon a rod composed of the same material as the
bobbin. The vacuum tube t is supported by the
chamber k, and a glass chamber i surrounds this tube.
This chamber i is sealed in such a way as to intercept
all passage of air for a purpose above described.
Fig. 2 represents a burner or lamp a made as has
just been stated, but the pyro-insulated wire is wound
upon a piece of infusible material of spherical form
2444 Translation of Edison French Patent--1879.
instead of upon a bobbin. I will state that I call the
wire pyro-insulated when it is covered with the
metallic oxide above mentioned. In Fig. 3 the bobbin.
of pyro-insulated wire is wound upon a mandril from
which it is taken off, and the spires being connected by
metallic wires, the bobbin is then mounted upon a disc
of the infusible material.
In certain forms of lamps it is preferable to support
the burner a in the tube b by platinum wires 1, 2, as
they conduct less of the heat from the burner than if
it was supported by a rod of lime or other infusible
matter b', Fig. 1.
In Fig. 4, the burner a is represnted as being sus-
pended by the platinum wires 1, 2, in the globe b.
In Figs. 5 and 6, the bobbin of pyro-insulated wire
a is wound upon a flat cylinder.
In Fig. 7 the bobbin of wire is made of two parts
separated by a central ring of infusible material.
Fig. 8 represents the burner a as being made of a
flat band of metal, platina-iridium, wound into a spiral
and supported by a rod of infusible material b', this
band should be pyro-insulated.
Fig. 9 illustrates a method of pyro-insulating a wire.
The wire is drawn from a bobbin and passed into
the flame of one or several lamps as well as through
sponges containing a solution of lime or magnesium.
The wire in its passage through the sponges is covered
with a coating of this solution which is decomposed
and the oxide deposited upon the wire at the time of
the passage of the wire through the flame.
In Fig. 10 the wire after having received the pyro-
insulating solution passes through a tube which is
heated by lamps and which effects the decomposition.
Figs. 11, 12 and 13 illustrate another form of pyro-
insulated burner. This burner is made of a flat wire
of platinum-iridium wound spirally, and between each
turn of the spiral there is placed a coating of zirconium-
magnesium, lime or other oxides of which the fusing
points are very high.
In Fig. 14 the light is produced by the electric spark
Translation of Edison French Patent-1879. 2445
which renders incandescent lime which has been pre-
pared by burning an acetate of lime. The prepared
lime is placed in a tube between two metallic discs; as
the prepared lime is very light and porous, the smallest
sparks bring it to the state of vivid incandescence.
Fig. 15 indicates how the lime obtained by burning
an acetate of lime may be rendered incandescent by an
oxyhydrogen flame. c is a decomposing chamber con-
taining acidulated water and two electrodes separated
from each other by a porous diaphragm in such
manner as to form two small cells. The chamber is
provided with a cover, and a tube leads from each cell.
When an electric current is passed through the cells
oxygen and hydrogen are emitted and conducted by
tubes to a chamber or mixing retort h, and at the end
of this tube the gas is lighted and the flame projected
upon the prepared lime at a brings it to incandescence,
producing a brilliant light by so small a quantity of gas
that it would be difficult to produce any effect if it were
used with the ordinary lime.
The arrangement shown in Fig. 16, is similar to that
which has just been described, except that the burner
is surrounded by two half cylinders of glass into which
the gases of the decomposition cells enter before they
pass into the mixing tube and to the burner.
In Figs. 17, 18 and 19, the burner is made of finely
divided platinum, iridium, ruthinium or other difficultly
fusible metal, incorporated with a non-conducting
material. The burner or candle may be of any size or
form desired, and its particles become incandescent by
the passage of the current and the non-metallic mate-
rials are luminous and augment the brilliancy. I mix
with these finely divided conductors infusible materials
such as magnesium or zirconium in different propor-
tions, in order to obtain the degree of conductivity
desired; the materials are mixed together and molded
to the form desired for the candle. It is preferable to
make use of a split candle such as that shown in Figs.
18 and 19, since the current goes up on one side and
descends on the other.
2446 Translation of Edison French Patent-1879.
Figs. 20, 22, 23 and 23ª, represent different forms of
burners made from this finely divided material last
mentioned.
Fig. 21 represents the material of the burner, indi-
cated in Figs. 22 and 23, laid flat.
In Fig. 24 the burner a is made from a curved tube
of glass of the form indicated, and is pierced with a
very small hole; the air is exhausted from this tube
and light is produced by the passage in the tube of a
spark proceeding from an induction coil.
Figs. 25 and 26 represent the burner a as being
composed of six spirals mounted upon sticks of
lime, the spirals being joined together in the manner
indicated in Fig. 26 and pyro-insulated.
I will now describe the means for regulating the
current in the burners.
In my above-mentioned patent the regulation of the
current was effected by the heat of the burner or by
the intensity of devices working the current which
controlled the current and maintained the light or
lights at a uniform intensity. I have still recourse to
these methods, but I have modified and improved the
devices employed.
In Fig. 1 the burner a is situated in the interior of
the sealed tube b, as has been described above, and the
tube b is surrouded by a glass globe i, mounted upon
a holder k. A flexible aneroid chamber is cast upon
the upper part of this holder or chamber; it opens
into the chamber formed by the globe i in such man-
ner that the air when it is dilated by the heat may
pass into the said aneroid chamber and transmit a
movement to the flexible diaphragm and parts attached
to it. When the current has the desired intensity it
enters along the wire 3, passes to the burner, and by
the wire 4 to the insulated spring 5 to the contact 6
and to the wire 7. If the current becomes too strong,
causing too great heat to be emitted at the burner, the
air in the globe i is dilated and depresses the dia-
phragm 7, then a pin mounted on the diaphragm de-
Translation of Edison French Patent-1879. 2447
presses the spring 5, and separates it from the contact
6 which breaks the circuit of the burner at 5 and 6.
This opening and closing of the circuit is only
momentary, and therefore the uniform intensity of the
light is not interfered with, and there is no danger of
the burner becoming too highly heated.
In Fig. 25 the air heated and dilated inside the
globe i acts in the chambers of the aneroid to close
a branch circuit between 5 and 15, permitting a part
of the current to pass through the resistance », and if
the heat is maintained, the movement of the lever and
the detend 15 upon 5 breaks the circuit of the electric
light by separating 5 from 6. The resistance of is
equal to that of the burner.
In Fig. 27 a spiral of platinum-iridium wire is shown
in the interior of the flexible aneroid chambers, and
this spiral is heated by the passage of the current and
heats and dilates the air in the interior of the
chambers to set in operation the levers 15 and 5 as
has been above explained.
In Fig. 28 the spiral operated by the heat, is repre-
sented as being placed in a small globe a² of opaque
glass inside of the glass globe i. The said globe a²
and the spiral may be placed inside the case k, Fig. 25,
in such manner as not to be seen.
In Fig. 29 the heated and dilated air proceeding
from the transparent chamber i passes into a chamber
containing a diaphragm which is moved by this air to
open and close the circuit at 5 and 6 and effect the
thermal regulation of the current.
In Fig. 30 the heated air of the chamber i acts upon
mercury contained in a tube a³, to dilate and contract
it and by means of a float acting upon the lever 5 open
the circuit at 6, 15 to the burner and close it by 15 and
5 and the resistance 1.
In Fig. 31 the current itself passes through the
mercury to heat it and dilate it according to the
intensity of the current, and thus effect the regulation
of the current to the burner by the dilation of the
mercury which operates the float and lever 5.
2448 Translation of Edison French Patent-1879.
Fig. 32 represents an axial electro-magnet m, placed
in the chamber k, and the core of this electro-magnet
is attached to a spring n. The current of the burner a
passes through the bobbin 12 and, if the strength of
this current does not pass the point required by the
light, the core is not attracted with a force sufficient
to be lowered apparently. If the current exceeds the
maximum point necessary for the light, then the core
is attracted more and lowered in such manner that a
rod attached to it breaks the circuit at 5 and 6 and the
current sent to the burner is momentarily interrupted,
as has already been explained. The spring n serving
to keep the core m lifted might consist of a spiral
inside of a tube within the coil of m, as, is shown in
Fig. 34. The axial magnet might be replaced by the
electro-magnet m, Fig. 33, with its cores adjacent to
the spring n, to attract the said spring 5 and break the
circuit when the current becomes too strong.
In Figs. 12 and 13 the regulation of the current, and
consequently of the heat of the burner, is affected by
the dilation and contraction of the burner itself, which
moves the lever 5. When the current is of the desired
intensity it passes to the burner by the wire 3, Fig. 13,
and by the rod and the lever 5 to the wire 7; if the
current becomes too strong, the burner a expands
upward, moving the lever 5, which makes contact with
6, and forms a short circuit for the current through the
wire 10. The lever g is a safety device for making
contact with the screw 8, and offers another path for
the current in case that 5 and 6 do not make an
electric contact.
M
The arrangement indicated in Fig. 12 is substantially
the same as that in Fig. 13 except that a resistance, '',
is placed in the branch circuit. The parts are repre-
sented in the position which they occupy when the
burner is expanded and when the current passes
through the short circuit and the resistance.
In Fig. 17 the current passes through the rod t, and
if it is too strong, this rod expands and brings 5 into
Translation of Edison French Pateut-1879. 2449
:
contact with 6 and establishes a short circuit between
5 and 6 for the current.
In Fig. 35 the expansion of the body a, which emits
the light, closes the circuit between 5 and 6, and the
current passes through the electro-magnet m, which
attracts the armature lever, and brings more or less
pressure upon the two carbon buttons at 12, through
which the current passes to the short circuit 10, thus
cutting out the burner; this short circuit offers more
or less resistance according to the pressure of the
armature lever upon the carbon buttons.
In Fig. 36 the expansion of the body a emitting the
light, acts to immerse more or less a coil of wire at
one side in the bath of mercury, and thus augment or
diminish the resistance in the short circuit or branch
circuit passing through the mercury in order to divert the
current if the heat becomes excessive. The continued
expansion of the body a emitting the light, Fig. 37, di-
minishes gradually the resistance in the short circuit
between 3 and 7 by bringing the springs 5 successively
into contact with the contact point 6, and by providing
a short circuit to the resistance r.
In Fig. 38 the continued expansion and contraction
of the body a emitting the light, moves the lever 5 and
brings the resistance successively into circuit, and
the second resistance is greater than the first and so
on.
In Fig. 39, 3 burners a, ɑ5, a are shown; the cur-
rent entering at 3 will not pass through a aº, because
the path of the least resistance is by 15, 14, 18, 17, 16
and 19 to 7.
5
When a is expanded its lever 5 separates 14 from 15
and the circuit should pass from a through a and
through a to 18; from there by 17, 16 and 19 to 7.
If the light expands still further, the insulated pin
upon 14 presses 16, separating it from contact with 17
and the current is forced to pass from a through a
to 7.
Fig. 40 illustrates an arrangement like that of Fig.
39, but the arrangement of circuits is slightly varied.
B
2450 Translation of Edison French Paten-1879.
In the said Fig. 40 the current passes from 3 through
the lever 5, and the spring 14 to 7. If a expands from
the effect of the increase of current, then the lever 5
moves the spring 14, and its metal pin 22 touches the
spring 16, and opens two paths for the current, the one
through a, 5, 14 to 17, and the other through a5, 19,
16, 22, 14 to 7. The continuation of the movement of
the lever 5 closes 23 upon the spring 18, and a third
path is opened for the current by the path aº, 24, 18,
23, 22 and 14 to 7.
In Fig. 41 the current coming from the line 3, passes
through 16, 17, 14 and 15 to the burner a, axial mag-
net m, and the line 7; if the current increases, the
lever 5 of m is attracted downward, separating 14
from 15, and the current now passes through 3, 16, 17
and the wire 18 to the burner a5 and a, which weakens
the current. If the strength of the current increases,
then the magnet m attracts the lever 5 still farther
downward separating 16 from 17, and the current
passes through a, a5 and a, which increases the resis-
tance and prevents the fusion of the spiral.
In Fig. 40ª the expansion of the rod t from the effect
of the heat emitted by a burner a moves the lever 5
and intercepts the circuit through the flat burner ɑ and
closes the circuit through the other burner a5.
In Fig. 42 the expansion of the rod t by the effect
of the heat emitted by a burner a, operates a lever
which withdraws the resistance proportionally to the
strength of the current.
In Figs. 43 to 52 inclusive, the sum of the current
directed to the burner of the body a, which emits the
light, and consequently the heat of the said burner is
regulated or controlled by the current passing through
an electro-magnet or electro-magnets m', the said
magnets in each case attract their armature lever 5,
and break the contact with when the current exceeds
the strength necessary for maintaining the light at the
desired point, thus momentarily interrupting the circuit
to the burner, diminishing the current and preventing
Translation of Edison French Patent-1879. 2451
Ar 1
all injury to the burner.
This arrangement will be
clearly comprehended from an examination of the
diagrams. I will, nevertheless, remark that two
electro-magnets are represented in Fig. 44 in order
that there may be two places where the circuit is
opened and closed simultaneously so as to reduce the
electric spark.
In Figs. 45 and 46 the circuit is not opened or
closed by the direct action of the armature lever 5, but
by a lever operated by this part 5.
In Fig. 47 the electro-magnet m' is placed in a
branch circuit.
In Fig. 48 the magnet m' is constructed with coils of
wire through which the current passes in opposite
directions, and when it is equal there is no effect upon
the armature lever; the bobbin m' is made of coarse
wire and is placed in the main circuit with the burner,
while the bobbin m² offers a high resistance and is
placed in the branch circuit which does not pass either
through the burner or through m'. The inequality of
the resistance of the burner produced by elevation of
the temperature serves to vary the current passing
through the branch path, and the core of m', m²
becomes magnetized and attracts the armature lever 5
and opens the circuit to the burner at 3.
Fig. 49 represents the electro-magnet m as being
adjustable. By varying the distance between its core
and the lever 5 the strength of the current necessary
for operating 5 is determined.
Fig. 50 represents an arrangement for obtaining the
same result by adjusting the spring m2 which bears
against the lever 5 and which prevents this lever from
being attracted until the current passing through the
burner and the maguet has acquired the strength
desired.
In Fig. 52 the movement of the lever 5 breaks the
circuit through the lever a and closes it through the
resistance r at the point 6.
In Fig. 53 the lever m' compresses together the
2
2452 Translation of Edison French Patent-1879.
turns of the spiral or burner a when the magnet is
excited, bringing thus certain of the turns into contact
and diminishing the resistance and establishing a
short circuit for a part of the spiral.
In Fig. 54 I have represented a miniature electro-
magnet machine as being placed in the circuit to the
burner a; this machine is put in rotation when the
current exceeds the desired point, and it thus places
resistance in the circuit and at the same time breaks
the circuit to the burner.
In Fig. 55 the machine is represented as being pro-
vided with a governor. When the balls of the gover-
nor are raised on account of the increase of the
current to the burner and to the machine, the lever 5
is raised and interrupts the circuit at 6.
Fig. 56 represents a thermo-electric battery t2 in
close proximity to the burner a, and in the circuit of
the battery t², m' is the magnet which becomes active
when the heat of the burner exceeds the desired point,
and, by means of the lever 5, opens the circuit at 6.
Fig. 57 represents a bar t made of two metals, or
other materials which expand uneqally, in such
manner that the bar t will be bent toward the burner a
when the heat emitted by this latter attains the
desired point and will interrupt the circuit at 6.
The arrangement shown in Fig. 58 is like that
shown in Fig. 57, but when the contact between t and
6 is broken, the circuit to the line is not interrupted,
but a new path is opened through the resistance '
which weakens the circuit to the burner.
Fig. 59 represents the expansion bar t as connected
to the lever 6 which, in its turn, is connected to a com-
pound lever t'. When the heat of the burner becomes
ť.
excessive the expansion of the rod t makes the lever ť
move into close proximity with the burner a, and it
will absorb a part of the heat and protect the burner
against any injury.
Fig. 60 represents a spring bar t made of two metals
or materials which expand unequally; it is turned
Translation of Edison French Patent-1879. 2453
toward the burner a and will absorb the heat from it
when the heat of a exceeds a predetermined point.
Fig. 61 represents the material which emits the light
in the form of two carbons a a, placed with their ends
slightly separated from each other. The expansion
bar t is placed in circuit with these carbons and it is
connected to one of them. The fine spring tends to
separate the carbons from each other to such an extent
as the expansion of the bar t permits.
Fig. 62 is like Fig. 61, but there are two expansion
bars t and both carbon points are movable.
In Fig. 63 is shown a rod or cylinder of black oxide
of iron which is non-conductor of electricity when it
is cold but which is a good conductor when it is at a
red heat. The wires of the circuit are arranged in such
manner that when the burner a has a certain temper-
ature this bar will not be heated sufficiently to allow
the current to pass through it as a short circuit, but if
the temperature is raised, the bar w becomes heated
and the burner is included in a short circuit by a
portion of the current passing through w.
Fig. 64 represents a burner of which the two poles
are dissimilar, the one being of carbon a in the form
of rod and the other a fine wire a5 composed of an
alloy of platinum-iridium. The carbon produces the
light. The inferiority of contact between the metal
and the carbon creates a considerable resistance, and
this inferiority of contact is increased as these pieces.
are heated, from which the carbon becomes excessively
incandescent.
I have represented the carbon as being held against
the rod a of platinum-iridium by means of cords,
pulleys and a weight. The rod of carbon a may be fed
downward against the rod of platinum-iridium a5 by
means of a weight attached to the upper part of the
carbon, guides 23, 23 being arranged to pass through
the openings made in the weights, as is shown in
Fig. 65.
Fig. 66 represents means for automatically feeding
2454 Translation of Edison French Patent-1879.
!
the carbons a. A case e, of a length sufficient for
holding freely the rods of carbon is placed above the
globe i and the floor of it is inclined with an opening
in its lowest part of a size proper for allowing a rod
of carbon to pass and extend partially into the globe i.
The pulley cº, by means of a cord and weight, keeps a
slight friction upon the carbon and tends to feed it
downward and maintain it in contact with the
platinum-iridium rod a5. When the upper part of the
following carbon advances to take its place its lower
end engages with the tube and bears upon the upper
part of the one which is in combustion.
Another part of this invention relates to an arrange-
ment of the main conducting wires for the purpose of
obtaining a complete metallic circuit and at the same
time taking advantage of the conductivity of the earth
in such a manner that the mass of metal in one of the
conductors may be reduced, the earth and the metal
conductor serving at the same time as a protection for
the insulated conductors.
Fig. 67 is a diagram illustrating the connections.
The magneto-electric machines are shown at M. They
may be arranged between the two main conductors A
B, in groups or in multiple arc of 3, 4 or more each,
and the connections should be made for intensity. I
have shown four magneto-electric machines M in each
group.
A is a tube perfectly of iron, laid in the earth; it
constitutes with the earth one-half of the circuit.
In the tube is placed an insulated conductor B,
formed preferably of a series of strands of copper
twisted together in the form of a cable, one of the
strands of the cables being suppressed, say at each
thirty metres in such a manner that at the end of the
circuit there will remain but one. A branch tube A²
containing a single strand detached from the cable may
enter each house or building, and from the ground floor
smaller wires are carried to the different parts of the
house where it is desired to place lights.
2
Each lamp a should be provided with a contact lever
Translation of Edison French Patent-1879. 2455
32, in such a way as to disconnect it from the conduct-
ing wires. The generators of electricity at the central
station are provided with a constant magnetic field of
which the coils are included in the circuit; therefore,
if all the lamps fed by the principal conductors are dis-
connected or separated from them by their contact
levers, the circuit will be broken, and no current will
pass through these conductors from the station to the
lights, and the steam engine works with less power and
with a less expenditure of energy. If under these con-
ditions, the contact lever of a single lamp is turned,
the lamp will be connected to the branch wires from
the main conductors, the circuit is closed and there
passes from the central station only a current sufficient
for feeding the lamp because the external resistance
determines the strength of the current. In this
manner the current will be proportioned to the
number of lamps in the circuit. I prefer that each
lamp shall have a resistance, when it is incandescent,
of about 100 ohms.
After the lever has established contact in such
manner as to conncect the light to the conductors, the
current will pass through the resistance r (see Fig. 68),
equal to the lamp, but if the thermal regulating screw
6 is turned downward, the lamp will be placed in the
circuit and the current divided according to the
amount the regulating screw has been turned, as has
been explained above.
As has been mentioned above, the connection of one
or several lamps causes to be developed at the central
station a quantity of current sufficient for maintaining
this lamp incandescent; from which it follows that if
magneto-electric machines M are arranged for the
purpose in tension and in quantity, several hundreds
of lamps may be put on between the main conductors,
and the reduction of the resistance at the time of
putting each lamp in circuit, draws the required
quantity of current from the stations; therefore the
greatest economy is attained by arranging that all the
2456 Translation of Edison French Patent-1879.
resistances outside of the main conductors shall be
materials which emit light.
Fig. 69 represents a safety device for enabling mag-
neto-electric machines to be worked in multiple arc.
If any one of a series of magneto-electric machines
working in multiple arc should stop for any cause and
thus produce no useful effect, its wire would act as a
mere resistance, and, therefore, all the power of the
other machines would pass through this wire and tend
to destroy it and at the same time to produce a
momentary reduction in the quantity of light emitted
by the lamps; it is, therefore, very important that it
should not be possible for such accidents to occur.
M M M are electro-magnetic machines arranged in
multiple arc and connected to the main conductors.
Between one main conductor and each machine is
placed an electro-magnet wound with very coarse met-
allic wire in such a way as to offer but a feeble resist-
ance and prevent a loss of energy by heating. Each
magnet is provided with a lever and a retractile spring.
Fig. 71 is a small diagram representing several
magneto-electric machines arranged in multiple arc
and feeding the main conductors with the current.
From the extremity of the main conductors two
smaller wires return to the station, and a lamp is
placed across them or included in the circuit. By
this means the condition of the whole circuit is
represented at the central station.
Fig. 72 illustrates the method of arrangement for
the lamps placed in the streets in multiple arc between
two main conductors.
Fig. 73 illustrates a method for measuring the quan-
tity of electricity employed. BA is a box into which
pass the wires 50, 51 proceeding from the main con-
ductors, K2 is a coil of very coarse metallic wire, of
which the resistance is proportioned to the number
of burners employed in the house. This resistance
is but a part of the resistance of one single lamp.
An electrolytic cell P is employed for the meter.
This cell, which contains a neutral solution of sulphate.
Translation of Edison French Patent-1879. 2457
of copper, has two copper electrodes, of which one is,
very thick while the other is very thin. The small
portion of the current which passes into the cell car-
ries copper across and deposits it upon the thin plate;
a consideralbe resistance is interposed at R2, in order
that the resistance of the cell may be only a small
factor. If a lamp is placed in circuit it draws current
from the main conductor and the proportional quantity
passing through the cell causes a deposit upon the
thin plate, and if another lamp is added a double
quantity is deposited, and so on. At the end of any
period, say a month, the plate is taken by the inspector
to the central office where it is weighed with care.
the deposits of copper upon the thin plate will be
proportional to the total quantity of energy passing
into the house it will give a correct measure for
establishing the price of the electricity used.
As
I put an electro-magnet m' inside of the box BA
provided with a retractile lever 5 in such manner that
if, for any reason, the current passing to the lamps in
the house is greatly excessive, the lever will be re-
tracted.
4
In Fig. 73 I have shown a lamp a having a resist-
ance of say 1,000 ohms, placed in a branch circuit,
and in another branch I have shown 4 electric burners
a¹, a², a³ and a forming a lamp. As these burners
are placed in proximity and arranged in two branch
circuits, the resistance of each branch being 2,000
ohms, the two branches will have a joint resistance of
1,000 ohms, the same as the resistance of one lamp.
By means of this arrangement, several series of
lamps may be placed in branch circuits between the
same main conductors, and the resistance will be equal
in each branch, the radiating surface of the burners
being reduced.
Fig. 74 shows how secondary batteries may be em-
ployed for storing the electricity before it is used for
operating the lamps a. The main line as is connected
with an electro-magnetic machine or to sources of
electrical energy.
2458 Translation of Edison French Patent-1879.
8
68 is the return metallic wire or the ground connec-
tion. The main line as is connected by the metallic
wires co to secondary batteries A³, B³, and the return
wires d³, es pass through the contact lever fs and the
wire 18, b³. The electric lamps a are shown in branch
circuits between the wires h8 and 8. The wire h8 is
connected to one terminal of the secondary batteries
A³, B³, and the wire ks to the lever f. This lever,
shown as insulated in Fig. 75, is cylindrical, made of
two insulated half cylinders 34 and 35, against which
the springs e and do bear, and this instrument may be
turned periodically by hand, by clockwork or any other
proper mechanical means. When the lever fs takes
one position the main circuit is closed through a³, c³,
A³, d³, 34, 36 and is to bs, and the secondary circuit
is closed from B³ through h8, the lamps a, the wire k³,
the lever 35, 37, and the wire es to B³. When the
lever få occupies the other position the main circuit
from a passes by es to B3 and by es 34, 36 and is to
b³, while the secondary circuit proceeding from A³ is
through h³, the lamps a, the wire k8, 37, 35 and the
wire 8 to A³, in such a manner that when the second-
ary battery B³ supplies the accumulated electricity to
the lamps a, the main current charges the secondary
battery A³ and vice versa.
8
3
When the secondary battery is completely charged
the decomposition of the liquid commences and gases
are developed. I take advantage of these effects
to operate a circuit regulator and to disconnect the
main circuit. The two closed cases in which the
secondary batteries are placed are provided with tubes
gs (see Fig. 76), passing to a chamber 8 under a
flexible diaphragm 18 and in the metallic circuit c8,
there is a lever us, which is operated so as to interrupt.
the electric circuit to the secondary batteries between
us and a screw u, when the gases are accumulated
sufficiently to move the diaphragm. The gases accumu-
lated on the interior of A³ and B3 combine and in
forming maintain the electric action of the secondary
9
Translation of Edison French Patent--1879. 2459
batteries. In proportion as the pressure decreases the
circuit is closed anew the lever
8.
Another part of this invention relates to the con-
struction of electro-magnetic machines. In this ma-
chine I make use of a cylinder of which the surface is
covered with a wire wound in the direction of its
length and parallel to the axis of rotation. The elec-
tric current passing through the coiled wire converts
the cylinder into a magnet, one side of the cylinder is
of north polarity, and the opposite side of south
polarity. An iron shell is employed, inside of which
this magnetic cylinder is turned, and by induction the
shell becomes magnetized, from which it results that
the magnetic forces in the shell turn about this latter
in harmony with the rotating magnetic cylinder. There
is a space between the rotating magnetic cylinder and
the interior of the shell, and in this space are placed
longitudinal wires connected in a very peculiar man-
ner to a commutator, and in these wires there is estab-
lished a current of induction resulting from the mag-
netic forces in rotation which traverse and cut these
wires during the rotation of the magnetic cylinder on
the interior of the shell, and by the commutator the
current is directed upon the line wires.
In the drawing, Fig. 77, is a plan of the complete
magneto-electric machine. Fig. 76ª is a transverse
section on the line x x. Fig. 78 is a plan of the rotat-
ing magnet. Fig. 79 is an end view. Fig. 80 a plan of
the shell surrounding the rotating magnet and the
induction bobbin. Fig. 81 is an end view of it.
Fig. 81ª is a diagram showing the method of winding
the induction bobbin, and Fig. 81B is a diagram of the
connections of the circuit.
The shaft a is provided with a cylinder b of iron; it
may be solid or hollow, and of cast iron or of coiled
metallic wires; the wire passing radially from the
shaft goes up along one side of the cylinder across the
other end returns again on the other side, across the
end and so on until all the surface of the cylinder is
covered with wires which are parallel with the axis of
2460 Translation of Edison French Patent--1879.
the cylinder. One extremity of this insulated wire
passes along the shaft in a groove to the insulated
ring a', and the other extremity is connected to the
commutator spring or brush n which is insulated upon
a disc g attached to a', and turning with the shaft a,
the other commutator and its spring x is attached to
the ring d upon the shaft a.
The spring bears against the ring d, and the line
wire 3 is attached to it, and the spring g' bears against
the ring a, and the return wire 4, or the ground is
attached to it, or vice versa. It should be understood
that the magneto-electric machine may be employed in
a circuit containing electric lamps or any other instru-
ment or device operated by electricity to which the
current generated may be adapted. The shaft a is
mounted in parts or frames h and put in rotation by
a proper motive power. The envelope b is built up of
iron wire coiled, or of rings of iron held together by
bolts 5, and between the rings there are leaves of
paper or other insulating material in order to separate
them and prevent magnetic currents from circulating
in the direction of the axis of rotation, but the rings
are each magnetized by induction from the magnetic
cylinder b, and the lines of magnetic force radiate from
the cylinder to the rings, and in proportion to the
rotation of the cylinder inside of the shell these lines
of magnetic force are moved around rapidly with the
magnetic cylinder.
In electro-magnetic machines the strongest currents
are produced in the wires which are passed across the
lines of magnetic force. This is why I place the longi-
tudinal wires in the space between the rotating
magnetic cylinder and its shell in order that these
wires may be traversed by the lines of magnetic force
during its rotation. The induction bobbin is composed
of parallel wires s, upon the surface of the thin
cylinder t. These wires cross the end of the cylinder
t at the opposite end where the commutator bars u are
placed at the commutator end; these wires are united
Translation of Edison French Patent-1879. 2461
to a circular range of bars u, which are insulated and
upon which bear the springs.
The wire of the parallel induction bobbin is in effect
endless, and it is coiled with a view to obtain a contin-
uous current. The diagram, Fig. 81, represents the
mode of winding the wires. The number of parallel
windings may vary more or less, but I find that the
desired object may be obtained in the best manner by
making use of an even number of parallel windings
longitudinally to the case and of an uneven number of
commutator plates.
The current generated in the wires on the interior of
the magnetic field of the north pole will all follow one
direction, and the currents generated in the wires in the
field of the south pole will be all in the other direction.
I wind the wires in such a manner that while the
wire is continuous and the current passes in all the wire
the current will pass by two wires of the induction
bobbin to a commutator plate, then separating, will pass
through an opposite plate of the commutator, and will
pass through into the bobbin in which it will circulate
to the other commutator plate. Suppose that the
springs bear upon the commutator plates a and e, the
current will be directed toward a from the wires 1 and
6, leaving from e by the wires 12 and 7. By following
the arrows it will be seen that all the winding is a
complete circuit in which the parallel portions of the
wires in the south field of the magnetic influence have
a current developed in one direction, and in the north
field in another direction, obtaining thus the dynamic
effect, and there is produced no interruption or
pulsation of the current, the spring touching one
commutator plate before leaving another.
It should be understood that the current is reversed
in the parallel portions of the wires successively; for
example, the current in 7 and 14 is reversed while the
magnets and the brushes turn around them together,
when the spring passes from d by 14 to 7 in the oppo-
site direction and to 12 as before. When the spring
passes from n to g the current in 8 and 7 is reversed; it.
2462 Translation of Edison French Patent-1879.
passes from 6 as before, and in passing it is reversed in
¿, and returning in 8, following the opposite directions,
it is taken off by g. The broken lines indicate the suc-
cessive changes of direction, from which it results that
the currents are sent by two wires to each commutator
successively from the entire magnetic field.
The current will pass from the spring g' through a';
from there by the parallel wires wound upon the cylin-
der b to the commutator n; from there through the bar
upon which it rests along the parallel induction bobbin
upon one side of the cylinder t returning along the
other side to the commutator bar, through the spring
x to the ring d and to the spring d to the line. It
should be observed that the parallel induction bobbin t
and the commutator bars u remain stationary and that
the springs n, x turn about the bars u by the movement
of the shaft a and the commutator spring should be
placed relatively to the rotary magneto cylinder in
such a manner as to take off the current from the place
where it has the greatest strength.
The current will be continuous or nearly continuous
and will follow one direction. There will nevertheless
sometimes be a spark between the commutator bars
when the circuit of the parallel induction winding is
interrupted, but this will be diminished by curving the
commutator springs in such a manner that they bear
upon more than one commutator bar. It will be evi-
dent that the case and the parallel induction winding
may be put in rotation if the magnetic cylinder remains
stationary or if it turns in the opposite direction, and I
call attention to the fact that the cylinder supporting
the parallel winding of induction s may be constructed
of any proper material, but I prefer and I make use of
vulcanized fibres.
The parts of this machine are not subject to heating
under the conditions of ordinary use because the wires
are not wound one upon the other and the air can
circulate in the mass. Nevertheless in certain cases I
make use of a ventilator upon the shaft a mounted in
a case communicating with the internal portions of the
Translation of Edison French Patent-1879. 2463
machine in such a manner as to produce a current of
air in them.
10
10
10
10
10
Fig. 82 represents a new form of dynamo-electric
machine in which the magnetic field is concentrated
and the wires of the bobbin cut the field with great
rapidity and the quantity of wire passing through the
field may be increased almost to any amount desired
without increasing the speed of rotation of the shaft.
a10 is a ring composed of iron wire; about this ring is
wound insulated metallic wire in sections of which
there are several hundred. The metallic wires between
the sections are connected, as in the Gramme machine,
to the commutatar. 10 is the field magnet which may
be excited from the ring a¹0 or from an external source.
It is provided with poles p¹º, p¹º, q¹º, q¹º, which are
shown in section. In the actual machine these poles
cover the ring entirely except a small slot into which
the spokes of the ring are fitted. c10 is a commutator
spring which, following all the positions of the ring,
establishes communication to the bobbin through the
field magnet. 10 and elo are also springs connected
together and connected also by the commutator cylin-
der with the coils upon each side of the field-magnets.
That portion only of the wire upon the ring in
proximity to the field-maguet is employed, or adds a
resistance to the circuit, in such a manner that the
resistance of the wire, the length of the magnet and
the concentration of the field are independent of the
diameter of the ring, which may have a diameter of
some meters. This is not true of the Gramme ring,
for it is desired to increase the speed with which the
wire passes through the field the ring should be greater,
but this will increase the resistance, and, as the whole
of the field should be covered by the field-magnet, it
should be distributed in such manner that there would
result from it a weakening of the field, which prevents
high speed except with an accelerated rotation of the
shaft which increases friction.
When the ring in my machine is put in rotation in
the magnetic field, a current passes through the wire
2464 Translation of Edison French Patent-1879.
0
wound upon each side of the magnet, the one proceed-
ing from c¹º and the other from d¹º, both of them in
the same direction, and it is sent from the machine to
a lamp or other electrical device.
Fig. 83 represent the same machine arranged with
the wire wound on the field magnet in the same circuit
as the wires of the ring.
Fig. 84 represents a double field magnet 10 with a
ring passing across the pieces of the pole at its centre.
The 2 north poles of the machines are connected to
one piece and the 2 south poles to another.
Fig. 85 represents this system arranged with mech-
anism for reciprocating action.
c10 is a shaft, h10 an eccentric, a¹º is a magnet cov-
ered with wire which receives an alternate action from
the eccentric and the rod 710. 10 is the field magnet,
S S are the south poles and N N the north poles. A
metallic wire u10 is attached to the centre of the wire
upon a¹º. The two other extremities of a¹0 are united
ɑ10
together and form the other pole. Alternating cur-
rents are generated in the bobbin a10 by its reciprocat-
ing action between the magnetic poles, and these may,
by means of a commutator, be changed into continuous
1
currents.
0
Fig. 86 represents this principle applied to a tele-
phone; m¹º is its diaphragm; a10 the iron envelope
and wire excited in the magnetic field by the movement
of the diaphragm a¹º. SS are the south poles and N N
the north poles of the magnets 10; the wires are con-
nected as in Fig. 85. It is well understood that perma-
nent magnets may replace the electro-magnets
I have shown a local battery L B for polarizing the
magnets in a permanent manner, but these magnets
may be placed in the main circuit with a10 and the
battery may be connected in the line.
10.
Fig. 87 indicates how the additional field magnet of
a Gramme machine may be suppressed and the ring
itself made a field magnet, and a magnet traversing it
at the same time. Assuming T B to be a thermal bat-
tery or other source of electrical energy, the current
Translation of Edison French Patent-1879. 2465
would pass to the ring by the commutator springs t10,
passing from above and below the iron ring a¹º, N and
S respectively. 10 is a mass of iron merely. v10, v10
are the usual commutators. If these last are closed
and the ring set in rotation, the current generated
tends to make a north pole at the right and a south
pole at the left from which the polarity of the ring is
angular relatively to the iron piece i10, from which the
attraction which tends to retard the rotation in this
generates current.
Fig. 88 represents an arrangement by which continu-
ous currents and alternating currents may be obtained
from an ordinary Gramme machine. The commutators
v10 are either closed or arranged with the wire upon
the field magnet in such a manner that the current
generated in the machine will excite the field magnet
in a direction at right angles with the commutator
springs as well upon the upper side as upon the lower
side of the ring; also the continuity is broken and the
two extremities of the wire are carried to discs upon
the shaft upon which springs bear, and these springs
are attached to wires, and if these wires are closed,
continuous currents are taken off from v10, and they
will excite the field magnets while alternating currents.
will pass from these circuits. 46, 47, 48 and 49 are
circuits connected to carbon points forming a spark
lamp or voltaic arc.
Fig. 89 represents the upper side only of the
annular bobbin a10 in section, with its two extremities.
connected to discs or rings upon which bear the
springs n" and m”.
Fig. 90 represents a dynamo-electric machine for
quantity; s10 is its shaft; m12 a magnet with wires,
the two extremities of which are connected to discs 50
and 51; S³ and S4 are shells of copper which surround
the magnet 12 at the centre; the shells make an
electric connection with the soft iron of the magnet
m12. On the end of the shells are metallic pulleys.
Flexible metallic cable serve to communicate rotation
to the shells and to convey the current; these shells
2466 Translation of Edison French Patent-1879.
turn in opposite directions. The currents conveyed by
them pass through the iron core of m12, and the shaft
becomes one terminal of the circuit while the pulleys
and metallic cables form the other terminal of it. One
shell supplies current to the field magnet r¹0
I will mention that to regulate the force of the
currents in a Gramme machine, the two commutator
springs or brushes may be attached to a rotary disc,
and if this disc is placed at right angles with its
proper position no current is generated or power
absorbed for the machine, but if it is turned a very
small amount toward the position desired for obtain-
ing the maximum current, then a current is generated
proportionately to this movement, and hence, by
turning the commutator, a current of any force desired
may be obtained without stopping the machine or
causing a greater absorption of power than that
necessary for generating the current.
Fig. 91 represents a tube through which flows hot
water, and its entire circumference is to be covered
with thermo-electric couples in the form of radiating
plates. It is recognized that a large part of the
theoretical energy of the combustion of carbon in a
steam boiler is lost from the fact of the condensation
of the hot water in a good conductor. As a stream
flows with a fall of water of about two millimeters to
a kilometer, I propose to arrange several meters of
pipe passing into a chamber in one direction and the
other several times and to pass the hot water of the
condenser through this length of pipe to the cistern,
and I propose to extract the heat from it by covering
the entire surface of the pipe with thermo-electric
batteries. The hot junctions of the thermo-battery
bear upon the surface of the pipe, which is a non-
conductor of electricity, and if it is necessary, in order
to obtain an increase of effect, the other junctions are
placed in contact with another series of pipes in which
there circulates cold water. These thermal couples are
connected together in a proper manner so that their
currents may be utilized for maintaining a constant
Translation of Edison French Patent-1879. 2467
field magnet for magneto-electric machines which I
employ in my system of lighting. A certain portion of
pipe is reserved for the thermal battery of each magnet.
r¹º, Fig. 92, represents these magnets in magneto-
electric machines. The thermal batteries are admirably
adapted for this particular service because the resist-
ance of the field magnet may be very low.
Fig. 93 represents a dynamometer for measuring the
motive power absorbed by dynamometric machines
while they furnish a current. C are pulleys mounted
upon a shaft s". These pulleys are driven by a belt
54, 55 and 56 are insulated discs mounted upon the
shaft s¹º, springs bear upon these discs. d' is a disc
permanently attached to the shaft s; m is an electro-
magnet also permanently attached to the disc dr. It
carries an armature upon the extremity of an arm
which is attached to an idle pulley p" or to a sleeve
attached to the said pulley, which is also idle upon the
shaft sº. From the pulley p there extends a belt to
the dynamo machine. The springs 55 and 56 form a
connection with a battery B10, a resistance R¹º and a
galvanometer G10. 55 and 56 are connected to the
magnet mⓇ and 55 is connected with the disc d and
54 with the back oontact 68 which establishes a circuit
when the arm of p' bears against 68 in which circuit
are mounted a bell and a battery 58.
0
The dynamo machine will be driven by a belt pro-
ceeding from p", and, when it is desired to ascertain the
amount of power absorbed by the dynamo machine,
the battery B10 is put in circuit and m° attracts the
arm of p from b8 to the soft iron of the magnet mº
and the strength of the magnet should be sufficient to
hold the arm while the rotation continues.
The oper-
ator now watches the galvanometer and commences to
insert resistance in the circuit until the power of the
magnet is weakened to such an extent that the arma-
ture upon the arm p ceases to be held by the soft iron
and the armature lever falls back upon 68. This closes
the circuit of the bell and just at the moment when the
bell is heard the operator notices the deflection of the
2468 Translation of Edison French Patent-1879.
galvanometer which gives the strength of current pro-
ceeding from B10; having previously determined the
amount of weight which would withdraw the arm con-
tact with me with different strengths of current, he
can, by taking the speed of rotation, calculate with
precision the force absorbed in kilogramme-meters.
Fig. 94 represents an arrangement for measuring the
amount of current consumed in a given time. m¹³ is
m13
an electro-magnet; m14 a lever attached to a piston
working with precision in a cylinder m15. m¹0 is
glycerine or oil. This cylinder is connected with the
reservoir m¹7 by a tube having a very small hole at
one end. The measurement is obtained by the
pressure produced by the magnet upon the piston
which forces the oil very slowly into the reservoir but
in proportion to the attraction of the magnet which
is as the square of the electro-motive force of the
current.
I claim as of my invention :
First.-In combination with a sealed vacuum cham-
ber made of glass, a continuous metallic incandescent
conductor, as above described.
Second. The method above described of preparing
electric conductors for electric lamps or burners, con-
sisting in freeing the metallic conductors from gases in
a vacuum and afterwards in sealing hermetically the
air-tight transparent chamber in which they are
enclosed, as herein before specified.
Third. In an electric lamp, the combination with a
transparent sealed vacuum chamber of a bobbin of
pyro-insulated wire wound upon an infusible material,
as herein before specified.
Fourth.--The combination with a transparent vacuum
chamber of a continuous conductor forming an electric
burner or candle and a second transparent case form-
Translation of Edison French Patent-1879. 2469
ing a closed chamber for the purpose hereinbefore set
forth.
Fifth.--The combination of the conductor forming
the electric lamp or candle, with the sealed transparent
case i containing the case b and the thermostatic regu-
lator / 5, 6, as herein before specified.
Sixth.--The method of pyro-insulating the wire or
strip of metal for the conductor consisting in passing
the wire or strip through a solution of lime or
magnesia and then through a flame or a fire for
effecting the decomposition of the solution, as herein-
before specified.
Seventh--The combination in an electric light of
layers of incandescent metal with intervening pyro-
insulators, as hereinbefore described.
Eighth.--A spiral or helix of metal with intervening
pyro-insulators, solidly compressed, in combination
with the thermal circuit regulator, as shown in Figs.
12 and 13.
Ninth.--The combination with a continuous incan-
descent conductor forming a burner or lamp, of a
rheostat or resistance and circuit connections, as shown
in Fig. 12, for maintaining a nearly uniform resistance
in the electric circuit, as herein before specified.
Tenth.--The combination with the electric light a
and the thermal expansion device, Figs. 12 and 13, of
the levers 5 and 9, and the contact points 6 and 8 and
circuit connections, as herein before specified.
Eleventh.---The method of producing an electric
light which consists in passing an induction spark
through lime contained in a vacuum tube, as described
by reference to Fig. 14.
Twelfth.--The material produced by burning an
2470 Translation of Edison French Patent-1879.
acetate of lime for utilization in electric lighting, as
herein before described.
Thirteenth.--The apparatus shown in Figs. 15 and 16
for producing an oxyhydrogen light, as herein before
specified.
Fourteenth.--In electric lighting, a conductor of
electricity formed of finely divided metal incorporated
with a non-conductor of electricity, as herein before
described by reference to Figs. 17, 18, 19, 20, 21, 22,
23 and 244.
Fifteenth.--A rigid body for emitting electric light,
Figs. 17, 18 and 19, having a cut or longitudinal
separation from the base to nearly the extremity for
securing the circulation of the electric current in the
entire body, as herein before specified.
Sixteenth.--In combination with a rigid body a
emitting the electric light and having a longitudinal
incision, a thermal expansion regulator for the circuit
for controlling the strength of the current by the
effect of the heat developed in the burner, as herein-
before specified.
Seventeenth.-A thermal regulating spiral in the
same circuit as the burner, but in an air-tight case
separated from the said burner, and operating appara-
tus regulating the circuit, as described by reference to
Figs. 27 and 28.
Eighteenth. The axial magnet m in the circuit of
the body a, which emits the light in combination with
the spring n, to which the core of the magnet is
attached, the spring 5, the piece b and the circuit
connections, as hereinbefore specified by reference to
Figs. 32 and 34.
Nineteenth. The apparatus and circuits represented
in Figs. 35, 36, 37, 38 and 42, for varying the resist-
Translation of Edison French Patent-1879. 2471
ance in the circuit to the burner according to the
intensity of the current passing to said burner.
Twentieth. The apparatus and circuits represented
in Figs. 39, 40, 40ª and 41 by means of which one or
several bodies emitting light are placed in the circuit
with the principal burner, if the burner becomes too
intense, which has the effect of reducing the current in
the said principal burner, as herein before specified.
Twenty-first. The combination with a metallic body
emitting light of one or several magnets through which
the current passes to the burner, and the electric
circuit shown, by which the quantity of current sent to
the burner is regulated by the current passing through
the said magnet or the said magnets, as herein before
described and shown in 43 to 48.
Twenty-second.—The combination with the body a
emitting the light of a small electro-magnetic machine
in the circuit of the burner, as hereinbefore described
by reference to Figs. 54 and 55.
Twenty-third.—The combination with the burner a,
the electro-magnet m, the thermal battery r² and
circuits arranged as shown in Fig. 56.
Twenty-fourth.-The combination with the burner a
of the expansion rod t and electric circuits arranged as
shown in Figs. 57 and 58.
Twenty-fifth. --- The combination with the burner a,
of the bar t or ť absorbing the heat, Figs. 59 and 60.
Twenty-sixth.—The carbon a which emits the light,
pivoted at one of its ends and with its other end
contiguous to the other carbon in combination with
the expansion rod t and the spring r, as herein before
specified and shown in Figs. 61 or 62.
Twenty-seventh.--The combination with the body a
·
2472 Translation of Edison French Patent-1879.
which emits the light, of a bar u, Fig. 63, which is a
non-conductor of electricity when cold and a conductor
when hot for regulating the current in the burner, as
herein before specified.
Twenty-eighth.—The combination with an electric
lamp, of a pencil of carbon and a refractory metallic
rod, and a weight for maintaining the necessary pres-
sure at the point of contact, as herein before shown.
Twenty-ninth.-The case e with an inclined floor
adapted for receiving several carbon pencils, in com-
bination with the metallic rod a", Fig. 66, and means
for guiding these pencils and maintaining their pres-
sure at the point of contact, as herein before described.
Thirtieth.--The insulated metallic conductors B,
Fig. 67, within a metallic case which constitutes, with
the earth, the return circuit, as herein before described.
Thirty-first.—The automatic safety device, Fig. 69
or 70, for interrupting the current to the electro-
magnetic machine in case of derangement of the said
machine.
Thirty-second.—The method specified by reference
to Fig. 73 for determining the electric current employed
in the electric lamps, which consists in causing metal
to be deposited by the current which passes, in weigh-
ing this deposited metal and in estimating in this
manner the value of the current employed, as herein-
before described.
Thirty-third. The arrangement of 4 electric lamps,
Fig. 78, in a divided branch circuit between two main
conductors, as herein before described.
Thirty-fourth.
An electro-magnet, m', Fig. 78,
placed in the circuit of the burner in a building, which
operates when the current exceeds a predetermined
point to attract an armature lever and hold it and
Translation of Edison French Patent-1879. 2473
interrupt the circuit to such burners, as herein before
described.
Thirty-fifth. The combination with the electric
lamps a, Fig. 74, and with a main circuit of 2
secondary batteries and circuit connections for
changing alternately the main and secondary circuits,
as described.
Thirty-sixth. -The secondary circuit containing
electric lamps, the secondary battery and the case in
combination with the main circuit through the second-
ary battery, a diaphragm operated by the accumula-
tion of gas in the secondary battery and a contact
lever in the main circuit, as herein before described.
Thirty-seventh.--A magnetic cylinder b, Fig. 76ª,
77, 78 and 79, composed of a cylinder of iron of which
the surface is covered with an insulated wire arranged
parallel to the axis of radiation and across the ends, as
herein before specified.
Thirty-eighth. The combination in a dynamo-electric
machine a and with rotary magnetic cylinder b, of an
iron casing or shell / surrounding the cylinder, and in-
sulated wires wound and connected to the commutator,
as herein before described, forming a parallel induction
apparatus s which occupies the space between the
magnetic cylinder and the envelope, as specified.
Thirty-ninth.—The combination in a magneto-elec-
tric machine of a rotary magnetic cylinder b carrying
metallic wires along its surface parallel or nearly
parallel to the axis, a metal shell 7, a parallel induction
bobbin s, of commutator bars u, springs n x, rings de,
and the circuit connections described.
Fortieth. In an electro-magnetic machine a par-
allel-induction bobbin, of which the metallic wires
are wound in the manner shown in Fig. 814 and
!
2474 Translation of Edison French Patent-1879.
commutator connections to these wires by which the
current is taken of from the parallel-induction bobbin
at two opposite points or directions, as described.
Forty-first.-The rotary induction bobbins, station:
ary magnets, commutators and circuits shown and
described by references to Figs. 82, 83, 84, 87, 88
and 89.
Forty-second. The induction bobbin having a move-
ment in the direction of its length, the electro-mag-
nets and the circuits described and shown by reference
to Figs. 85 and 86.
Forty-third.—The apparatus shown in Fig. 93 for
determining the power consumed for the driving of
magneto-electric machines, as hereinbefore described.
Forty-fourth. The thermal battery and the heating
pipe, shown in Figs. 91 and 92, in combination with
the electro-magnetic machine, as herein before de-
scribed.
2475
♡ l l l l l l l l l l l l l l l l
X l l l l l l l O
O l l l l l l l l l O
[Fourth Edition.]
DEUTET.
SN
ON DROIT
Complainant's Exhibit Edison British Patent
Pro. 2402 of 1879.
A.D. 1879, 17th JUNE.
N° 2402.
SPECIFICATION
ΟΙ
THOMAS ALVA EDISON.
·
FOR
ELECTRIC LIGHTS AND APPARATUS
DEVELOPING ELECTRIC CURRENTS, &c.
LONDON:
PUBLISHED AND SOLD AT THE PATENT OFFICE SALE BRANCH,
38, CURSITOR STREET, CHANCERY LANE, E.C.
Price 18. Id.
1886.
Z O O O O O O O O O O O O O oooooooooooooooooooooooooooooooooOOOOOO
GO
0
2476
[Fourth Edition.]
A.D. 1879, 17th JUNE. N° 2402.
Electric Lights and Apparatus for Developing Electric
Currents, &c.
LETTERS PATENT to Thomas Alva Edison of Menlo Park in the State of
New Jersey United States of America, Electrician for an Invention of
"IMPROVEMENT IN ELECTRIC LIGHTS AND IN APPARATUS FOR DEVELOPING
ELECTRIC CURRENTS AND REGULATING THE ACTION OF THE SAME
PROVISIONAL SPECIFICATION left by the said Thomas Alva Edison at the
Office of the Commissioners of Patents on the 17th June 1879.
THOMAS ALVA EDISON of Menlo Park in the State of New Jersey United
States of America Electrician "IMPROVEMENT IN ELECTRIC LIGHTS AND IN
5 APPARATUS FOR DEVELOPING ELECTRIC CURRENTS AND REGULATING THE ACTION
OF THE SAME
"
I have ascertained that when wires or sheets of platina, iridium or other
metallic conductors of electricity, which fuse at a high temperature are exposed to
a high temperature, near their melting point in air for several hours by passing a
10 current of electricity through them and then are allowed to cool, the metal is found
to be ruptured, and under the microscope there is revealed myriads of cracks in
every direction, many of which are seen to reach nearly to the centre of the wire.
I have also discovered that contrary to the received notion, platinum, and iridium
alloy loses weight when exposed to the heat of a candle, that even heated air causes
15 it to lose weight, that the loss is so great that it tinges a hydrogen flame green,
and under the influence of an electric current and at a yellow white heat the loss
is very great. After a time the metal falls to pieces, hence wire or sheets of
platinum, or platinum or iridium alloy as now known in commerce are useless for
giving light by incandescence.
20
First: because its loss of weight makes it expensive and unreliable and causes
the burner to be rapidly destroyed.
Second: because its electrical resistance changes by loss in weight and its light
giving power by the cracks, or ruptures, the melting point being determined by
the weakest spot where the greatest difference of potential of the electric current
25 is present which causes this point to be brought to a higher heat than the rest of
the surface of the wire; again as it is essential to obtain a steady light the
[Price 18. 1d.] 22213-1.
A
2477
2
A.D. 1879.-N° 2402.
Provisionál
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
platinum burner must be screened from the air, and when thus screened, by being
placed in a glass vessel, the glass soon becomes coated with a black deposit of
platinum.
A platinum spiral brought to incandescence under these conditions may be made
to give a light of three standard candles, when near its melting point, and when the 5
radiating surface is 3/16 of an inch, but this amount of light will be rapidly reduced
as before described.
From my researches and experiments I am led to believe that the cause of the
rupturing of the metal when brought to incandescence, is due to the action of the
gases contained in the pores of the metal. These gases are probably compressed 10
within the pores during the rolling or drawing of the sheet or wire.
These gases, or air, when subjected to high heats are greatly expanded and
rupture the metal and it cannot be driven out by slowly heating the metal.
I have also discovered that the loss of weight and apparent volatalization of the
metal is due to the action of the air or gases against the highly heated surface. 15
Having thus ascertained the cause of fracture and loss of weight I have conducted
experiments to obviate these defects and have succeeded by the following
method. A spiral of platinum wire is placed in a glass bulb, with its ends passing
through and sealed in the glass, and the air exhausted from the bulb by a Sprengel
pump, until the discharge from a three inch induction coil, will not pass between 20
two subsiduary wires in the bulb, the ends of which are four millimetres apart;
the wires of the spiral are then connected to a magneto electric machine or battery
whose current can be controlled by the addition of resistance. Sufficient current is
allowed to pass through the wire, to bring it to about 150° Fahrenheit it is allowed
to remain at this temperature for 10 or 15 minutes while thus heated, the air or 25
gases in the pores of the metal is expelled by the action of the heat and the
expansion of the gases which tend to pass outward in consequence of the vacuum.
While this air or gases is passing out of the metal, the mercury pump is kept con-
tinuously working. After the expiration of about 15 minutes the current passing
through the metal is to be augmented so that its temperature will be about 300 30
degrees Fahrenheit and it is allowed to remain at this temperature for another 10
or 15 minutes. If the mercury pump be worked continuously and the temperature
of the spiral raised at intervals of 10 or 15 minutes, until it attains to vivid incan-
descence, and the bulb be then sealed, the metallic wire is then in a state heretofore
unknown for it may have its temperature raised, to the most dazzling incandescence 35
emitting a light of 25 standard candles.
Whereas before the treatment, the same spiral would only emit a light equal to
three candles, before attaining the melting point. The wires subjected to the
process of freeing them from air and gases, are found after the process, to have a
polish exceeding that of silver, and obtainable by no other means, no cracks can 40
be seen even after the spiral has been raised suddenly to incandescence many times
by the current, and no volatalization takes place as there is no deposit upon the
glass bulb, nor does a delicate balance show any loss of weight in the spiral after
burning for many hours continuously, because the spiral is in a vacuum,
that is so
nearly perfect that the action of the gaseous molecules is reduced to the minimum 45
and were it possible to obtain an absolute vacuum, there would be no loss what-
soever and the total loss after a years use, would scarcely be noticed. I have
further discovered that if an alloy of platinum and iridium or even platinum be
coated with the oxide of magnesium, in the manner hereafter stated, and subjected
to the vacuum process described that combination takes place between the, metal, 50
and the oxide, giving the former remarkable properties. With a spiral having a
radiating surface of 3/16 of an inch, light equal to that given by 40 standard candles
may be obtained, whereas the same spiral not passed through my process, would
melt before giving a light of 4 candles.
The effect of the oxide of magnesia is to harden the wire to a surprising extent 5:
and render it more refractory. A spiral spring made of the wire is as elastic and
springy when at dazzling incandescence as when cold.
2478
Provisional
Specification.
A.D. 1879.-N° 2402.
3
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
I have found that chemically pure iron and nickel, drawn in wires and subjected
to the vacuum process may be made to give a light equal to that of platinum in
the open air.
Carbon sticks may be also freed from air, in this manner and be brought to a
5 temperature, that the carbon becomes pasty and if then allowed to cool is very
homogeneous and hard rods or plates made of mixtures of finely divided con-
ducting and non-conducting materials may thus be freed from air. It is also
obvious that the metal might be heated by subjecting the containing bulb to a
considerable temperature, but this only partially frees the wire from its air or
10 gases.
I will now describe the form of burner or lamp which I employ.
To operate several hundred electric lights practically each equal to an ordinary
gas jet, upon one circuit, it is essential for many reasons both on the score of
economy, facility and reliability to place them all in multiple arc, and to prevent
15 the combined resistance of several hundred lamps from falling to such a low point,
as to require main conductors of immense dimensions, with low resistance, and
generating machines of corresponding character, it is essential to reverse the present
and almost universal practice of using lamps which have but one or two ohms
resistance and construct lamps which shall have when giving their proper light a
20 resistanee of several hundred ohms, because the more lamps there are in circuit, the
less will be the resistance. I have ascertained by experiment that the loss of
energy is in proportion to the extent of the radiating surface, independent of the
resistance of the conductor, bence we have 1000 lamps each of 1/4 of an inch
radiating surface and each of 1 ohm resistance, or 1000 lamps having the same
25 radiating surface and 1000 ohms resistance each, the loss of energy from each
lamp when giving each a light of 15 candles will be nearly the same, but the
combined resistance of the 1 ohm lamps will be Too of an ohm requiring an enor-
mous main conductor, whereas the combined resistance of the 1000 ohms lamp will
be 1 ohm requiring a conductor of very moderate dimensions. In practice a
30 resistance of 200 to 300 ohms in the burner will be sufficient.
Again with lamps of low resistance the lamp connections and leading wires
must be large to prevent great loss of energy by resistance, the leading wires from
the main conductors, are large, expensive, and bulky to handle, the low resistance of
the burner, or incandescent conductor requires large terminals to convey the current
35 and these offer by their conduction a medium for the rapid dissipation of energy
without producing any effect whereas with a lamp of high resistance all these
objections are obviated.
My burner consists of a bobbin composed of an infusible oxide, such as oxide of
calcium, cerium, zirconium magnesium freed from silica and turned in a lathe from
40 sticks moulded by hydraulic pressure, in a manner hereinafter set forth.
These wires serve to hold the bobbin in the centre of the sealed glass vacuum
bulb, and at the same time serve as conductors of the electric current to the wire
coiled upon the bobbin.
The two platinum wires are first passed through small tubes of glass which are
45 melted around the wires. The burner is introduced into the bulb and the wires are
passed out through the sides of the narrow neck leading from the bulb and the
glass is melted around them to prevent leakage, the glass of the neck being melted
to the small glass tube around the wires.
Before the burner is permanently sealed at the neck, the air pump is connected
50 therewith and the wire upon the bobbin is subjected to the vacuum process hereto-
fore described and the electric current is used to produce incandescence for about
one hour to heat the bobbin and thereby expel the air and gases, after which the
bulb is permanently sealed by melting the glass of the neck, and it is ready to be
used as a lamp.
55
The method which I adopt for regulating the light radiated from the burner,
consists in a small rotating magnet provided with a governor which serves to open
the lamp circuit when the strength of the current is greater than is necessary to
A 2
2479
4
A.D. 1879.-N° 2402.
Provisional
Specification,
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
produce the proper light in the bobbin. This apparatus is very reliable and
although the current supplied is not perfectly continuous, the total energy passing
to the lamp in one hour is nearly the same, no matter what the strength of the
current may be. The magnets are so arranged that the continuous metallic circuit
cannot be broken by the commutator of the revolving magnet and the extra current 5
produced by the reversal of the current in the revolving magnet is short circuited
by the fixed magnet, hence the sparks which would occur at the break points of
the governor are prevented.
-
The rotating magnet is upon a vertical shaft supported in suitable bearings, and
immediately over the rotating magnet is the fixed magnet, the cause of which are 10
in the path described by the rotating magnet. Upon the shaft is a reversing
commutator formed of an-insulated ring, the periphery of which is faced with
platina, and cut in two parts, one part being connected by a wire to one helix of
the revolving magnet, and the other part to the other helix of said magnet, the two
helices being connected. Rubbing on this ring are two contact springs which serve 15
to convey the currents to the revolving magnet
The current passes through the fixed magnet thence through the revolving
magnet, the rotation of the magnet being kept up by the reversal of the direction
of flow of the currents through the revolving magnet.
When the cores of the revolving magnet are nearest the cores of the fixed magnet 20
the direction of the flow of current is reversed by the action of the commutator
springs and commutator and the polarity changed, hence the attraction ceases, but
the momentum of the revolving magnet carries said magnet forward and mutual
attraction again takes place as the revolving cores approach the stationary cores
the current is reversed and the revolution continued.
Connected to the revolving shaft is a governor which consists of two collars
connected together by two springs: one collar is secured to the shaft while the
other is free to slide thereon.
25
Upon each spring a weight is secured and the rotation of the shaft causes these
to act centrifugally and bow outward the springs and raise the sliding collar 30
upward more or less in proportion to the speed of the shaft.
The sliding collar is made with a groove to receive the end of the circuit opening
lever which lever is moved by the rise and fall of the collar. The other end of the
lever has an insulated cross bar which is in contact with two circuit breaking
springs and serves to disconnect the springs simultaneously from their contact 35
points or blocks when the shaft has reached a certain velocity.
The object of using two springs is to open the circuit at two places simultaneously
and thus reduce the spark, which it does in the ratio of the number of simultaneous
breaks.
One of the two springs is connected by a wire to one of the commutator springs 40
and the other is connected to the wire leading from the main conductor, or a branch
therefrom. This method of breaking the circuit simultaneously in many places is
applicable to all kinds of electrical apparatus where large and powerful sparks
occur, as for instance if it is desired to transfer electric energy from one point to
another by Dynamo electric machines operating upon a magneto electric motor at a 45
distant station. If four springs are employed, and the circuit opened at the four
places simultaneously the spark will be reduced to '/16 of what it would be if it
was opened at but one place.
The block to which the two circuit breaking springs are secured is connected to
a screw so that said block and springs can be positioned or adjusted with reference 50
to the cross bar on the governor lever,
By turning this screw to the right the block and springs are moved until the
cross bar moves the springs away from their contact points or bars and disconnects
the lamp from the circuit: the reverse movement places the lamp in circuit, and
according to the proximity of the springs to the cross-bar of the governor lever so 55
the amount of current to the burner is regulated A stop is applied to the screw so
that it can be turned only to a determined point which limits the amount of current-
2480
Provisional
Specification.
A.D. 1879.-N° 2402.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
10
5
passing to the burner. I prefer that each burner shall give a light equal to 16
candles the burner being capable of giving 35 candle power without fusion
As there may be a point where the revolving magnet after being at rest will not
start when the current is put on. I use an automatic starter which consists of a light
5 lever and thin armature turned edgewise which is attracted by the fixed magnet
at the moment the current is put-on. The movement of this lever which carries
upon its end a click serves to give a sudden motion to the shaft of the revolving
magnet by the click engaging in a racket or toothed wheel secured to the shaft.
The click after making this movement pass beyond the ratchet and does not
10 come in contact again until the magnet is stopped and the current is broken
In the specification of my British Patent No 5306 of 1878. I have described the
manner of coating the wire with pyroinsulating material I employ that mode in
coating the wire after which a coil of said wire is wound upon one or more line
supports and placed in a sealed bulb that is connected to a spengel vacuum apparatus
15 and by gradually increasing the heat of the wire by the gradual rise in the strength
of the current as described in the first part of this specification the wire is not only
freed from air and rendered more refractory but the oxide is vitrified and shrinks
upon the wire from which it cannot be detached.
The coil after passing through this process may be wound upon the lime bobbin
20 of the lamp without breaking the pyroinsulation
After the bobbin is wound and placed in the final bulb it has any air which may
have passed into the oxides expelled by a gradual accession of current in the manner
heretofore described and the bulb is then sealed.
The oxides of the alkaline materials which are infusible attack the platina to a
25 slight extent and as here with greater tenacity to it than the oxides which do not
attack it such as cerium or zirconium but the compound thus formed renders the
wire more refractory.
It is not essential that the oxide should be in the form of a soluble salt as it may
be put on the wire directly by mechanically mixing the oxide with water, alcohol
30 or other liquids, but special devices are requisite to keep the mixture in constant
agitation to prevent settling.
35
It has been found very difficult to mould slender sticks of the oxides enumerated
on account of the bending and breaking of the plunger of the mould which owing
to the pulverulent nature of most of the oxides must be long and slender.
I have obviated this difficulty by devising a mould and plunger by which
pressures to the crushing point of steel may be concentrated upon one quarter of an
inch surface.
This apparatus is applicable to the moulding of any substance.
The block that receives the mould is of cast iron with a taper hole in the centre.
40 The mould is made of three pieces and has the same taper as the hole in the block.
The object of the taper and split mould is to allow the pressed piece to be taken
out without injury which it would receive were it forced out of the mould endwise.
The plunger is upon the end of a sliding stock and said plunger is only about
of an inch long and about 3/8 of an inch in diameter and it is adapted to pass
45 downwardly into the hole in the centre of the split mould.
After the mould has been filled to the top with the pulverulent oxide, a steel
washer or punch section is placed upon the oxide and forced into the mould by the
plunger Afterward another punch section is placed upon the first one and forced
into the mould in the same manner, thus sections may be added until the desired
50 pressure is obtained without any disarrangement of the apparatus. So powerful is
the pressure which may be obtained by this means that cylinders of the oxide of
magnesium are rendered semi-transparent.
55
The cylinder of oxide thus obtained is placed on a lathe and the bobbin turned
with a cutting tool without fear of breaking.
The electric generating machine which I propose to use consists of a powerful
field magnet between the poles of which rotate an induction bobbin.
The cores of the field magnet are each three feet in length and about six inches
2481
6.
A.D. 1879.-N° 2402.
Provisional
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
in diameter and wound with a helix of insulated copper wire having a resistance
of about one ohm.
The number of coils and the resistance of the wire may of course be varied to
meet various conditions. By the use of large masses of iron I am enabled to reduce
the resistance of the magnetic circuit to a very low point and at the same time by 5
reason of this large mass of iron of great magnetic conductivity, the use of a, single
layer of wire is possible thus obtaining the maximum economy.
The back or bar that connects the two cores of the magnet is of iron and is
greater in mass than in the same length of core The surface of both the back and
the end of each core are ground together and are permanently secured by bolts 10
and nuts By thus employing a large mass of iron for the back and grinding the
faces of contact to a point where air suction becomes powerful I reduce the resistance
of this point to a minimum and prevent the appearance of free magnetic poles,
There are iron poles bolted to the cores the surfaces being ground together.
Between the two poles there is a circular aperture in which the induction 15
cylinder rotates.
The cylinder may be of wood upon a shaft and at each end of the cylinder there
is a wrought iron head.
This cylinder or bobbin is wound with fine wire until the wire is flush with the
edge of the iron heads.
Over this cylinder is wound longitudinally the insulated induction wire the ends
of which are connected to the commutator. The wire of the parallel induction
helix is substantially endless and it is wound with reference to obtaining a con-
tinuous current.
20
The number of parallel coils may be more or less in number but I find the 25
desired object can be obtained by using an even number of parallel coils longi-
tudinally of the cylinder and an odd number of commutator plates
There are two insulated disks upon the shaft of the field magnet and a metallic
brush or spring is in contact with each disk, the line wires are connected to these
disks. One end of the wire of the field magnet is connected to one disk and the 30
other end of the wire is connected with one of the commutator brushes, the other
commutator brush is connected with the second insulated disk.
The path of the current is through one insulated disk to the field magnet through
it to one commutator block then through the induction coil to the opposite block
on the commutator and by brush and wire the second insulated disk and thence 35
to the line.
The current will be continuous or nearly so and ravėl in one direction there
will however sometimes be a spark between the commutator bars when the circuit
of the parallel induction coil is interrupted but this will be lessened by having the
commutator springs bent to rest on more than one commutator bar.
40
It will be apparent that the shell and parallel induction coil may be revolved if
the magnet cylinder remains stationary and I remark that the cylinder supporting
the parallel induction coil may be of any suitable material but I prefer vulcanized
fibre.
The parts of this machine, are not liable to become heated under ordinary circum- 45
stances of use, because the wires are not wound one on the other and the atmo-
sphere has an opportunity to circulate.
I however apply a fan in some instances upon the shaft of the field magnet
within a case communicating with the internal portions of the machine so as to
induce a current of air through the same.
As I have heretofore set forth the maximum economy of illuminating by elec-
tricity when using a great number of light giving points is only obtainable by
working the resistance in multiple arcs, hence it is also necessary that the gene-
rating machines should also be worked in multiple arc.
50
To work a great number of machines in multiple arc with economy and reli- 55
ability it is essential that all should have the same electro motive force and that
means must be devised to prevent the insulating covering of the induction bobbin
2482
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A.D. 1879.-Nº 2402.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
7
of any machine being burned should the same stop for any reason such as by the
breaking of a belt, because if the wire of the bobbin cease to be the seat of an
electro motive force the current from the other machines pass through it and tend
to produce sufficient heat to destroy the insulation and at the same time cause a
5 loss of available energy.
I prevent any such action by the use of a polarized magnet which prevents the
electric circuit being opened by the direction of the flow of the current from the
machine when in action tending to hold its tongue strongly against a contact point,
but if the machine should stop and cease to be the seat of an electro motive force, a
10 current from the other machines passes through the machine in a contrary direction
whereupon the tongue of the polarized magnet is attracted from its contact point
and the circuit opened.
15
20
Each machine being provided with this apparatus, it is freed from the danger
aforementioned
An ordinary magnet with its armature lever provided with a retractile spring
might replace the polarized magnet but the margin for adjustment would be very
small.
The resistance of the polarized magnet is made an exceedingly small fraction of
the resistance of the machine to prevent loss of energy.
The field magnets of the machine are energized by supplying their helices with
electricity from thermo-electric piles.
Compound condensing steam engines are employed at the large central stations to
drive the magneto electric machines and the heat given off from the surface con-
densers acts upon thermo electric piles to produce an electric current and the same
25 is passed through the field of force helices.
The field magnets may all be connected in multiple are and the thermo electric
piles arranged in the same manner with appliances whereby the strength of all the
field may be increased or decreased at pleasure, thus increasing or decreasing the
electro motive force of the induction bobbins thus making it easy and convenient
30 by the aid of electro meters at the central stations to counteract the rise and fall in
the electro motive force on the main conductors when the maximum and minimum
number of lamps may be working.
I will mention that the electro motive force of the machines is analogous to the
pressure in the system of gas lighting and at dusk when the lamps are being rapidly
35 connected to the circuit, the electro meter will show a slight drop on the electro
motive force or pressure and this may be increased by increasing the speed of the
prime mover or increasing the power of the field magnets, the later method is the
one I prefer.
The surface condensers which I employ consists of a great number of iron pipes
40 whose surfaces are painted with a thick coating of a non-conducting substance.
The pipes after painting are about five inches in diameter.
Over these pipes are slipped rings of the double sulphide of lead and copper.
These rings are cast in a mould and both the inner and outer edges are either
covered or plated with copper.
45 The inner copper ring of one disk connects with the outer copper ring of the
adjourning disk throughout the entire series of disks.
Owing to the exceedingly low resistance of these disks and the considerable
electro motive force which they give between low range of temperature, very
powerful currents are obtained and nearly as much energy is thus obtained in the
50 form of an electric current from the waste heat of the engine as can be obtained
from the engine itself through the medium of the Faradic machines
In British Letters Patent N° 4226 of 1878 granted to me, a method is described
and shown for measuring the total energy passing into the house of the consumer
during a given period of time, the same consisting of a depositing cell or cells in
55 which the weight of copper deposited by the current gives the indication.
Instead of the cell or cells shown two cells connected by a syphon may be used.
In one cell is a solution of cupric sulphite and a copper electrode and in thẹ
2483
A.D. 1879.-Nº 2402.
Provisiona!
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
other cell sulphuric acid and a copper electrode. No polaziation takes place; the
liquid of the syphon tube offers the requisite resistance.
The cells are sealed from the air to prevent loss by evaporation.
Any loss by this means may be made good by adding water, the results are
nearly independant of the strength of the solution.
5
The central stations are intended to light an area of 1 of a mile in every
direction. The method which I propose to adopt for conveying the current from
the central station to various points consists in laying double wrought pipes lined
with vulcanized rubber known as ebonite side by side under the flagging stones
near the edge of the sidewalk. The pipes are to be in 20 feet lengths, the four 10
ends passing into a cast iron box.
The pipes and box are water-tight.
The top of the box which is detachable has its upper surface even or flush with
the walk, from the same box small tubes serve to convey wires from the main
conductors to the houses of the consumers.
The wires forming the main conductors are small and may either be insulated
and laid loosely together or insulated with a thin layer of cotton In this case each
consumers wire will be independent, but the economy is greater when the wires
are all in contact, as then when few lamps are in use the resistance of the main
conductor is relatively small as compared to the lamps.
15
20
The practice of causing the total resistance of the circuit extraneous to the
generator to be equal to that of the generator and by which the maximum effects
is obtained from the machine, is very wasteful of energy, for by thus arranging
the resistance fifty per cent of the energy is lost in the machine itself, whereas if
the exterior resistance is four times greater than the machine, the capacity of the 25
machine to translate energy from one to the other is lessened, but of what is trans-
lated owing to the changed conditions 80 per cent may be utilized. -
For this reason I so arrange the resistance of the main conductors that they
should be but 1/10 of the total resistance of all the lamps, and the resistance due
to the the generating machines is kept down by keeping in multiple arc a greater 30
number of machines than is necessary to supply all, the lights which may happen
to be in circuit at the time.
2484
Specification.
A.D. 1879.-N° 2402.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
9
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Alva Edison in the Great Seal Patent Office on the 17th
December 1879.
THOMAS ALVA EDISON, of Menlo Park in the State of New Jersey, United
5 States of America, Electrician IMPROVEMENTS IN ELECTRIC LIGHTS AND IN
APPARATUS FOR DEVELOPING ELECTRIC CURRENTS AND REGULATING THE ACTION
OF THE SAME.
I have ascertained that when wires or sheets of platina, iridium or other
metallic conductors of electricity which fuse at a high temperature are exposed to a
10 high temperature near their melting point in air for several hours by passing a
current of electricity through them and then are allowed to cool, the metal is found
to be ruptured and under the microscope there is revealed myriads of cracks in
every direction many of which are seen to reach nearly to the center of the wire.
I have also discovered that contrary to the received notion, platinum, or platinum
15 and iridium alloy loses weight when exposed to the heat of a candle, that even
heated air causes it to lose weight, that the loss is so great that it tinges a hydrogen
flame green, and under the influence of an electric current and at a yellow white
heat, the loss is very great. After a time the metal falls to pieces, hence wire or
sheets of platinum or platinum and iridium alloy as now known in commerce are
20 useless for giving light by incandescence, 1st because its loss of weight makes it
expensive and unreliable and causes the burner to be rapidly destroyed. 2nd
because its electrical resistance changes by loss in weight and its light giving
power by the cracks or ruptures, the melting point being determined by the
weakest spot where the greatest difference of potential of the electric current is
25 present which causes this point to be brought to a higher heat than the rest of the
surface of the wire. Again as it is essential to obtain a steady light the platinum
burner must be screened from the air and when thus screened by being placed in a
glass vessel, the glass soon becomes coated with a black deposit of platinum. A
platinum spiral brought to incandescence under these conditions may be made to
30 give a light of three standard candles when near its melting point and when the
radiating surface is 3/16 of an inch, but this amount of light will be rapidly reduced
as before described.
From my researches and experiments I am led to believe that the cause of the
rupturing of the metal when brought to incandescence is due to the action of the
35 gases contained in the pores of the metal. These gases are probably compressed
within the pores during the rolling or drawing of the sheet or wire. These gases
or air when subjected to high heat are greatly expanded and rupture the metal
and it cannot be driven out by slowly heating the metal
I have also discovered that the loss of weight and apparent volatilization of the
40 metal is due to the action of the air or gases against the highly heated surface.--
Having thus ascertained the cause of fracture and loss of weight I have conducted
experiments to obviate these defects and have succeeded by the following method :-
A spiral of platinum wire is placed in a glass bulb with its ends passing through
and sealed in the glass and the air exhausted from the bulb by a Sprengel pump until
45 the discharge from a three inch induction coil will not pass between two subsiduary
wires in the bulb the ends of which are four millimetres apart: the wires of the
spiral are then connected to a magneto electric machine or battery whose current
can be controlled by the addition of resistance. Sufficient current is allowed to
pass through the wire to bring it to about 150° Fah: it is allowed to remain at this
50 temperature for 10 or 15 minutes. While thus heated the air or gases in the pores
of the metal are expelled by the action of the heat and the expansion of the gases
which tend to pass outward in consequence of the vacuum.
While the air or the gases are passing out of the metal the mercury pump is
2485
10
A.D. 1879.-N° 2402.
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
kept continuously working. After the expiration of about fifteen minutes the
current passing through the metal is to be augmented so that its temperature will
be about 300° Fahr. and it is allowed to remain at this temperature for another ten
or fifteen minutes. If the mercury pump be worked continuously and the
temperature of the spiral raised at intervals of ten or fifteen minutes until it attains 5
vivid incandescence and the bulb be then sealed the metallic wire is then in a
state heretofore unknown for it may have its temperature raised to the most
dazzling incandescence emitting a light of twenty five standard candles, whereas
before treatment the same spiral would only emit a light equal to three candles
before attaining the melting point. The wires subjected to the process of freeing 10
them from air and gases are found after the process to have a polish exceeding that
of silver and attainable by no other means, no cracks can be seen even after the
spiral has been raised suddenly to incandescence many times by the current and no
volatilization takes place as there is no deposit upon the glass bulb, nor does a
delicate balance shown any loss of weight in the spiral even after said spiral has 15
been burning for many hours continuously because the spiral is in a vacuum so
nearly perfect that the action of the gaseous molecules is reduced to the minimum
and were it possible to obtain an absolute vacuum there would be no loss
whatever.
I have further discovered that if an alloy of platinum and iridium or even 20
platinum be coated with the oxide of magnesium in the manner hereafter stated
and subjected to the vacuum process described, that combination takes place between
the metal and the oxide giving the former remarkable properties. With a spiral
having a radiating surface of 3/16 of an inch, light equal to that given by forty standard
candles may be obtained whereas the same spiral not passed through my process 25
would melt before giving a light of four candles. The effect of the oxide of
magnesia is to harden the wire to a surprising extent and render it more
refractory.
A spiral spring made of the wire is as elastic and springy when at dazzling
incandescence as when cold.
I have found that chemically pure iron and nickel drawn in wires and subjected
to the vacuum process may be made to give a light equal to that of platinum in the
open air.
30
Carbon sticks may be also freed from air in this manner and be brought to a
temperature that the carbon becomes pasty and if then allowed to cool is very 35
homogeneous and hard. Rods or plates made of mixtures of finely divided con-
ducting and non conducting materials may thus be freed from air. It is also
obvious that the metal might be heated by subjecting the containing bulb to a
considerable temperature but this only partially frees the wire from its air or
gases.
40
I will now describe the form of burner or lamp which I employ:-To operate
several hundred electric lamps practically, each equal to an ordinary gas jet, upon
one circuit, it is essential for many reasons both on the score of economy, facility
and reliability, to place them all in multiple arc, and to prevent the combined
resistance of several hundred lamps from falling to such a low point as to require 45
main conductors of immense dimensions with low resistance and generating
machines of corresponding character, it is essential to reverse the present and almost
universal practice of using lamps which shall have but one or two ohms resistance and
construct lamps which shall have when giving their proper light, a resistance of several
hundred ohms, because the more lamps there are in the circuit the less will be the 50
resistance. I have ascertained by experiment that the loss of energy is in propor-
tion to the extent of the radiating surface independent of the resistance of the
conductor, hence we have 1000 lamps each of 1/4 of an inch radiating surface, and
each of one ohm resistance, or 1000 lamps having the same radiating surface and
1000 ohms resistance each, the loss of energy from each lamp when giving each a 55
light of 15 candles will be nearly the same, but the combined resistance of the
one ohm lamps will be Too of an ohm, requiring an enormous main conductor,
2486
Specification.
A.D. 1879.-N° 2402.
11
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
whereas the combined resistance of the 1000 ohm lamps will be one ohm, requiring
a conductor of very moderate dimensions-In practice a resistance of 200 to 300
ohms in the burner will be sufficient-Again with lamps of low resistance the lamp
connections and leading wires must be large to prevent great loss of energy by
5 resistance, the leading wires from the main conductors are large expensive and
bulky to handle, the low resistance of the burner or incandescent conductor requires
large terminals to convey the current and these offer by their conduction a medium
for the rapid dissipation of energy without producing any effect, whereas with a
lamp of high resistance all these objections are obviated.
10
My burner b, consists of a bobbin composed of an infusible oxide such as oxide of
calcium, cerium, zirconium, magnesium, freed from silica and turned in a lathe from
sticks molded by hydraulic pressure in a manner hereinafter set forth, and upon this
bobbin fine wire of platinum or platinum-iridium alloy is coiled. This bobbin is
shown in fig. 1. It is secured to two platinum wires 1. 2. as in fig. 2. These wires
15 serve to hold the bobbin in the center of the sealed glass vacuum bulb and at the
same time serve as conductors of the electric current to the wire coiled upon the
bobbin.--Fig. 3. shows the manner of connecting the wire upon the bobbin to the
platina supports. The two platina wires 1. 2. are first passed through a small tube
a. of glass and the glass melted around the wires: the burner b is introduced into
20 the bulb c. and the wires 1. & 2. are passed out through the sides of the narrow neck
leading from the bulb and the glass is melted around them to prevent leakage; the
glass of the neck is melted to the small glass tube a. Before the burner is perma-
nently sealed at the neck, the air pump is connected therewith and the wire upon
the bobbin is subjected to the vacuum process heretofore described and the electric
25 current is used to produce incandescence for about one hour to heat the bobbin and
thereby expell the air and gases after which the bulb is permanently sealed by
melting the glass of the neck and it is ready to be used as a lamp as represented in
fig. 4.
The method which I adop for regulating the light radiated from the burner
30 consists in a small rotating inagnet provided with a governor which serves to open
the lamp circuit when the strength of the current is greater than is necessary to
produce the proper light in the bobbin. This apparatus is very reliable and
although the current supplied is not perfectly continuous the total energy passing
to the lamp in one hour is nearly the same, no matter what the current strength
35 may be, the magnets being so arranged that the continuous metallic circuit cannot
be broken by the commutator of the revolving magnet and the extra current
produced by the reversal of the current in the revolving magnet is short circuited
by the fixed magnet hence the sparks which would occur at the break-points of the
governor are prevented. Referring to fig. 4. b. is the bobbin with the platinum
40 iridium wire which forms the electric lamp. c is the sealed glass bulb. f. and g. are
supports to hold the bulb in position; these are insulated from each other.-The
platinum wires 1. and 2. from the bulb are connected to these supports.
q.
m. is a box for supporting the lamp and enclosing the governor. n. is the back of
the fixed magnet consisting of the spools o. o¹. p. pl. are the spools of the revolving
45 magnet: r. is the back of the same which is secured permanently to the shaft
upon which is a revolving commutator s. This commutator consists of a ring of
insulating material whose periphery is faced with platina and cut in two parts,
one part being connected by the wire 5. to the magnet pl. and the other part by
the wire 4. to the magnet p. The wire 65. connects the two spools p. and p',
50 together.
Rubbing on this ring are two contact springs s¹. t'. which serve to convey the
currents to the revolving magnet The current passes through the fixed magnet
o. o¹. see diagram fig. 5. thence by wires 4. 5. springs s¹. t'. through the revolving
magnet p.p¹. The rotation of the magnet is kept up by the reversal of the direction
55 of the flow of the currents through the revolving magnet.-When the cores of the
revolving magnet are nearest the cores of the fixed magnet, the direction of the
current through the former is reversed by the action of the springs s¹, t', upon the
2487
12
A.D. 1879.—Nº 2402.
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c,
commutator and the polarity changed hence the attraction ceases, but the
momentum of the magnet p. pl carries it forward and mutual attraction again takes
place as the revolving cores approach the stationary cores, the current is reversed
and the revolution continued.
Connected to the revolving shaft q. is the governor which consists of two collars 5
v. w. connected by springs 6 & 7: the collar v. is permanently secured to the shaft
while the collar w. is free to slide up and down upon it.-Each spring is provided
at its center with a weight and these weights act centrifugally to bow outwardly
the springs and raise the collar w. upwardly more or less in proportion to the speed
of revolution. Connected to w. by a sleeve is another collar 19. upon the surface of 10.
which rests the end of the circuit opening lever l. which rises and falls by the
action of the governor. A spiral spring . see fig. 5. on the axis of the lever l.
serves to keep l. in contact with 19. Upon the extreme end of the lever l. is a
block 18. in juxtaposition to circuit breaking springs 8 & 9. and serves to disconnect
the springs simultaneously from the metallic block 10. when the governor and 15
shaft has reached a certain velocity.-The block 10. is insulated from the frame 11.
and serves to keep the circuit closed between the springs.
The current passes by wire 84, to the spring 8. thence across the block 10. to the
spring 9. thence to the magnet and lamp by wire 85.
The object of employing two springs is to open the circuit in two places simul- 20
taneously and thus reduce the spark which it does in the ratio of the square of the
number of simultaneous breaks. This method of breaking the circuit simultaneously
in many places is applicable to all kinds of electrical apparatus where large and
powerful sparks occur as for instance if it is desired to transfer electric energy from
one point to another by dynamo electric machines. The distant machine which serves 25
to give out the power for driving machinery may be provided with a governor the
same as herein shown and the circuit may be opened in several places simultaneously
by the action of the governor shown in fig. 6. 7. is the lever operated by the
governor. 12 and 13. are contact springs which rest upon the bar 43. 14. and 15.
are also contact springs which rest on the bar 44. The current passes by wire 84. 30
to spring 12. across the bar 43. to spring 13. thence by wire 45. to spring 14. across
bar 44. to spring 15. to wire 85. When the governor reaches a certain velocity, the
insulated piece 18. of the lever l. comes in contact with all the springs simultaneously
and separates them from the bars 43. & 44. thus opeuing the circuit in four places
simultaneously the spark is reduced to 1/10 of what it would be if a single break 35
was used. Having shown the importance of breaking the circuit simultaneously
in many places, I will now describe how the illumination of the burner b. may be
increased or decreased or stopped entirely.
Referring to figs. 4. & 5. t. is the thumb nut for regulating the speed of the
revolving magnet and consequently the amount of energy which passes to the 40
burner. The nut 22. is provided with a slot or groove containing a stationary
pin p². aud into the nut 22. the screw 20. passes and by turning this screw the
block 10. may be drawn inwardly or forced outwardly, said block running on two
guide pins 23. 24. which prevent the block from turning, thus the block 10. may be
made to approach or recede from the lever l.
If it is desired to turn off the light and disconnect the lamp altogether from the
circuit, the screw is turned to the right until the block 18. separates the springs 8.
& 9. from the block 10. and opens the circuit. In this position the circuit is broken
and the lamp and magnets are entirely disconnected from the circuit.
45
If it is desired to have the lamp give light the screw is turned to the left when 50
the springs 8 & 9. come in contact with the block 10. and close the circuit, the
magnets immediately revolve and if the parts are left in such a position that the
piece 18. is in close proximity to the springs, the rotation of the magnet will operate
the governor and lessen the pressure of 8. and 9. on 10. and hence the speed will be
comparatively slow and the electricity passing to the light will be very small and 55
but little light will be given out, but by causing the block 18. to further recede
•
2488
Specification.
A.D. 1879.-N° 2402.
13
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
from 8 & 9. the speed of the magnet will increase and more energy will pass to the
lamp in a given time.
By continued turning of the screw 20. a point may be reached where the
governor lever l. will not separate the springs 8 & 9. from 18; in this case the entire
5 electric energy passes through the bobbin b. but in practice limiting stops are
applied so that when the screw has been turned a certain distance the further move-
ment will be prevented by the action of the stops, thereby determining the
maximum light which the consumer can obtain from the burner. In practice this
will be about sixteen candle power, the burner being capable of giving thirty five
10 candle power without fusion.
As there may be a point where the revolving magnet after being at rest will not
start when the current is put on, I use an automatic starter which consists of a light
lever and thin armature turned edgewise which is attracted by the fixed magnet at
the moment the current is put on. The movement of this lever which carries upon
15 its end a click serves to give a sudden motion to the shaft q. by the click engaging
in a ratchet or toothed wheel which is secured to it. The click after this move-
ment passes beyond the ratchet and does not come in contact again until the magnet
is stopped and the current is broken.
In the specification of my British Patent No. 5306 of 1878, I have described
20 the manner of coating the wire with pyroinsulating material: I employ that mode
in coating the wire after which a coil of said wire is wound upon one or more
bobbins and placed in a sealed bulb and connected to a vacuum apparatus and by
gradually increasing the heat of the wire by the gradual rise in the current strength
as described in the first part of this specification, the wire is not only freed from
25 air and rendered more refractory but the oxide is vitrified and shrinks upon the
wire from which it cannot be detached. The coil after passing through this process
may be wound upon the lime bobbin of the lamp without fear of breaking the
pyroinsulation. After the bobbin is wound and placed in the final bulb any air
which may have passed into the oxides is expelled by a gradual accession of current
30 in the manner heretofore described and the bulb is then sealed The oxides of the
alkaline materials which are infusible attack the platina to a slight extent and
adhere with greater tenacity to it than the oxides which do not attack it, such as
cerum or zirconium but the compound thus formed renders the wire more refractory.
It is not essential that the oxide should be in the form of a soluble salt as it
35 may be put on the wire directly by mechanically mixing the oxide with water,
alcohol or other liquids, but special devices are required to keep the mixture in
constant agitation to prevent settling:
It has been found very difficult to mold slender sticks of the oxides spoken of
on account of the bending and breaking of the plunger of the mold which owing
40 to the pulverulent nature of most of the oxides, must be long and slender.
•
I have obviated this difficulty by devising a mold and plunger by which pressures
to the crushing point of steel may be concentrated upon one quarter of an inch
surface. This apparatus is applicable to the molding of any substance and it is
shown by a vertical section in fig. 7. Fig. 8, is a plan of the divided mold. a². is
45 the plunger; upon the extreme end is the part d². which enters the die or mold.
This is only about one quarter of an inch long and about three eighths of an inch
in diameter and it is adapted to pass downwardly into the mold.
e². is a solid block of cast iron with a taper hole in its center and into this the
divided steel mold f². is forced: this mold is made of three pieces and has the same
50 taper as the hole in the block e². The object of the taper and divided mold is to
allow the pressed piece to be taken out without the injury it would receive were
it forced out of the mold endwise.-After the mold has been filled to the top with
the pulverulent oxide, a steel washer or plunger section h². is placed upon the oxide
and forced into the mold by the plunger; afterwards another plunger section is
55 placed upon the first one and forced into the mold in the same manner. Thus
sections may be added until the requisite pressure is obtained without any
2489
14
A.D. 1879.-N° 2402.
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
disarrangement of the apparatus. So powerful is the pressure which may be obtained
by this means that cylinders of the oxide of magnesium are rendered semi-
transparent.The cylinder of oxide thus obtained is placed in a lathe and the
bobbin turned with a cutting tool without fear of breaking.
The electric generating machine which I propose to use consists of a powerful 5
field magnet between the poles of which rotate an induction bobbin. This
apparatus is shown by a vertical section in fig. 9. and sectional plan fig. 10. F. is
the field magnet the cores of which are about three feet in length and the
diameter about six inches wound with a helix of insulated copper wire having
a resistance of about one ohm.-The number of coils and the resistance of 10
the wire may of course be varied to meet various conditions.-By the use of
large masses of iron I am enabled to reduce the resistance of the magnetic circuit
to a very low point and at the same time by reason of this large mass of iron
of great magnetic conductivity, the use of a single layer of wire is possible, thus
obtaining the maximum economy. a. is the back of the magnet and the mass of 15
iron is greater than in the same length of core. The surface of both the back and
the end of each core are ground together and are permanently secured by bolts and
nuts. By thus employing a large mass of iron for the back and grinding the faces
of contact to a point where air suction becomes powerful, I reduce the resistance
of this point to a maximum and prevent the appearance of free magnetic poles. 20
a¹. a. are iron poles bolted to the cores, the surfaces being ground together.
Between the two poles there is a circular aperture in which the induction cylinder
rotates The cylinder b³. is preferably of wood upon the shaft b, and has wrought
iron heads 65. This cylinder is wound with fine iron wire b. until the wire is
flush with the edge of the iron heads 65. Over this cylinder is wound longitudinally 25
the insulated induction wire in sections, the ends of which are connected to the
commutator i. as in fig. 11. There are heads e³. of hard rubber, vulcanite fiber or
equivalent material secured to the shaft b¹. see figs 16. and 17, outside the heads 65.
and are of larger diameter so that the induction wires e. that are wound longi-
tudinally may be kept from contact with the iron helix bº, or heads b'. so that the 30
current may not be short circuited even if the insulation of the induction wires e¹.
is imperfect.-e. is a pulley for driving the machine. e. is a loose pulley upon
which the belt from the driving shaft is thrown by a shifter when the machine is
to be stopped.
d. is a switch by means of which the circuit from the Faradic machine may be 35
opened-d¹ and d. are the commutator springs, h³. 3 a polarized magnet included
in the circuit which serves automatically to open the circuit should a reverse
current be sent through the machine. The connections are as follows:-From the
post 23. to the commutator i thence through the induction helix e. to the opposite
side of the commutator and by the brush d5, to the switch d3. thence to the tongue 40
of the magnet h³. if the switch lever is in contact with 25. thence through the
tongue of h³. to the point 25. and through the magnet h³. to the post h. The wire
upon the field magnet is connected to the clamping posts 13. and 74. I will now
describe the method of winding the induction cylinder and the direction of the
current relative to the commutator brushes.-The wire of the parallel induction 45
helix is substantially endess and it is wound with reference to obtaining a con-
tinuous current: the diagram fig. 11. illustrates the manner of vinding the
wires; the number of parallel coils may be more or less than that shown, but I
find the object desired can be attained the best by using an even number of
parallel coils longitudinally of the shaft and an odd number of commutator plates. 50
Starting say from the part b. of the commutator the wire passes to the space 4.
on one head e³. to the same space on the other head, then across the head to the
space 11. and to the same space on the other bead, theu across the head to the
space 4. and so on until the spaces 4 and 11 are filled with the wire and when
the last turn in 11. has been laid, the wire is led to the plate c. and then the spaces 55
2. and 9. are filled and the wire from 9. led to ; then 14, and 7. and a connection made.
2490
Specification.
A.D. 1879.—Nº 2402.
15
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
with e; then 12. and 5. connecting with f. then 10. aad 3. connecting with g. then
8. and 1. connecting with a. then 6 and 13. connecting with b. the place of beginning.
I wind the wires in such a manner that while the current is continuous and the
current flowing through the whole of it, the current will pass by two wires of the
5 induction coil to one commutator plate and then away and will enter by an
opposite commutator plate and pass by two wires out into the coil and circulate
through the same to the other commutator plate. Suppose the springs to rest upon
commutator plates a. and e. the current will flow towards a. from wires 1. and 6.
and away from e. by wires 12. and 7. By following the arrows it will be found that
10 the entire coil is a complete circuit in which the parallel portions of the wires in
the south field of magnetic influence have a current energized in one direction
and in the north field in the other direction, thus obtaining the dynamic effect,
and there is no break or pulsation of the current, the springs touch one com-
mutator before leaving another.
15 As I have heretofore set forth the maximum economy of illuminating by
electricity when using a great number of light giving points is only obtainable by
working the resistance in multiple arc, hence it is essential that the generating
machines should also be worked in multiple arc. To work a great number of
machines in multiple-arc with economy and reliability it is essential that all should
20 have the same electro motive force and that means must be devised to prevent
injury, by burning, to the insulating covering of the induction coil of any machine,
should said machine stop for any reason such as by the breaking of a belt, because
if the wire of the induction coil ceases to be the seat of an electro-motive force, the
current from the other machines pass through it and tend to produce sufficient beat
25 to destroy the insulation and at the same time cause a loss of available energy.
I prevent any such action by the use of the magnet h³. fig. 10. which being
polarized is prevented from opening the electric circuit by the direction of the flow of
current from the machine when in action tending to hold its tongue strongly
against the contact point i5. but if the machine should stop and cease to be the
30 seat of an electro-motive force, a current from the other machine tends to pass
through the machine in a contrary direction, whereupon the tongue of h³. is detached
from the point i. and the circuit opened.-Each machine being provided with this
apparatus is thus freed from the danger described. An ordinary magnet might
replace the polarized one and a retractile spring used but the margin for adjust-
35 ment would be very small.
40
The resistance of the magnet h³. is made an exceedingly small fraction of the
resistance of the machine to prevent loss of energy.
The field magnets of the machine are energized by supplying them with electricity
from thermo electric piles.
Compound condensing steam engines are employed at the large central stations
to drive the magneto electric machines and the heat given off by the surface con-
densers act upon the thermo electric piles to produce an electric current and the
same is passed through the field of force helices.
The field magnets may all be arranged in multiple arc and the thermo electric
45 piles arranged in the same manner with appliances whereby the strength of all
the field magnets may be increased or decreased at pleasure, thus increasing or
decreasing the electro motive force of the induction bobbins, thus making it easy
and convenient by the aid of electrometers at the central stations to counteract
the rise and fall in the electro motive force on the main conductors when the
50 maximum and minimum number of lamps may be working.
I will mention that the electro-motive force is analogous to the pressure in the
system of gas lighting and at dusk when the lainps are rapidly being connected to
the circuit, the electrometer will show a slight drop on the electro motive force or
pressure, and this may be increased either by increasing the speed of the prime
55 mover or an increase in the power of the field magnets; the latter method is the
one I prefer.
The surface condensers which I employ consist of a great number of iron pipes
2491
16
A.D. 1879.-N° 2402.
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
whose surfaces are painted with a thick coating of a non-conducting substance.
The pipes after painting are about five inches in diameter.-Over these are slipped
rings of the double sulphide of lead and copper. These rings are cast in a mold
and both the inner and outer edges are either covered or plated with copper. In
figs. 12. and 13. m³. is the ring or disk of double sulphide m¹. the copper ring 5
fitted in the hole of m³. m³. is a copper ring which fits over the circumference of
m³. to this ring a binding post and strip or wire me. is secured, the latter to connect
to the next disk, m. represents one of the condensing pipes.
m³. m³. m¹º & m¹¹ a series of disks arranged to give a current. The inner copper
of m³, connects to the outer copper of m⁹ and in this manner to many hundreds of 10
disks. Owing to the exceedingly low resistance of these disks and the considerable
electro motive force which they give between low ranges of temperature, very powerful
currents are obtained and nearly as much energy obtained in the form of an electrical
current from the waste heat of the engine as can be obtained from the engine
itself through the medium of the Faradic machines.
15
The central stations are intended to light an area of 1/4 of a mile in every direction.
The method which I have adopted for conveying the current from the central station
to various points, consists in laying double wrought pipes lined with vulcanized
rubber known as ebonite, side by side under the flagging stones near the edge of the
sidewalk. The pipes are to be in twenty feet lengths, the four ends passing into a 20
cast iron box. The pipes and box are water tight Fig. 14. is a vertical section of
one line of pipe and Fig. 15. is a perspective view representing the box and two
lines of conductors.
For electric lighting purposes I employ a main conductor M composed of many
wires uninsulated from each other but insulated as a whole from the earth by the 25
ebonite coating of the pipe P. but for telegraphic purposes each of the small wires
instead of acting as parts of one main conductor are to be insulated from each other
by being coated with cotton and afterwards passed through an insulating substance
such as resin, tar, paraffine or other non-conductor.
·
By first putting down pipes P. in sections of say twenty or twenty five 30
feet and boxes B. between the sections, wires may be introduced sufficient
for the purpose at the time, and in the future the number of wires may be
increased by drawing others through the pipes. The boxes B. allow for introducing
or guiding the wires by hand. In practice it will be preferable to employ small
pulleys in each box with a stout cord running backward and forward through 35
the line of pipe, for drawing the wire through each section. The box has a
cover c. which is bolted to it, and soft rubber, or oiled leather washers are placed
between the top and the box to prevent air or water leaking into the box. The
inside of the box and cover is to be lined with ebonite or other non-conducting and
water proof material. One end of the system of tubes passes into the central station 40
and if the other ends are closed a vacuum may be produced within the whole system
of pipes: this will promote the evaporation of any moisture which may have passed
into the pipes but the vacuum will only be required periodically. If the two ends
pass into central stations warm dry air may be passed through occasionally to
prevent dampness. In the system of electric lighting two lines of pipes are 45
employed on each side of the street but these may be separate and have independent
boxes; I prefer that both lines of pipes on each side of the street should be con-
nected to one range of boxes as illustrated in fig. 15. A small pipe s. insulated
with rubber is connected at right angles to the main pipes and passes from one of
the boxes into the house to be illuminated and carries the conductor which may be 50
made of one or more wires: from the other main conductor another small tube s.
serves to carry the second wire to the house. These wires entering the house
through the meter are carried into various rooms and the electric lamps connected
iu multiple arc between the two. The wires forming the main conductors are small
and as mentioned previously may be uninsulated and laid loosely together or 55
insulated with a thin layer of cotton. In the latter case each consumer's wire would
be independent but the economy is greater when the wires are all in contact as
2492
Specification
A.D. 1879.-N° 2402.
17
Edison's Improvements in Apparatus for Developing Electric Currents, &c.
then when few lamps are in use the resistance of the main conductor is relatively
small as compared to the lamps. The practice of causing the total resistance of the
circuit extraneous to the generator to be equal to that of the generator almost
universally prevails, and by which the maximum effect is obtained is very wasteful
5. of energy, for by thus arranging the resistances fifty per cent of the energy is lost
in the machine itself, whereas if the exterior resistance is four times greater than
the machine the capacity of the machine to translate energy from one to the other
is lessened, but of what is translated, owing to the changed conditions, eighty per
cent may be utilized.-For this reason I so arrange the resistance of the main
10 conductors that they should be but one tenth of the total resistance of all the lamps,
and the resistance due to the generating machines is kept down by keeping in
multiple arc a greater number of machines than is necessary to supply all the lights
which may happen to be in circuit at the time.
15
I claim as my Invention
First. The combination with a sealed vacuum chamber made of a glass vessel, of a
continuous incandescent conductor wound upon a bobbin of infusible material,
substantially as set forth.
Second. The method herein described of preparing metals and metallic conductors
for electric lamps or burners, consisting in freeing the metallic conductors of gases
20 in a vacuum and then hermetically sealing the surrounding air tight transparent
case, substantially as specified.
25
Third. In an electric lamp, the combination with a sealed transparent vacuum
case of a bobbin of pyroinsulated wire wound upon an infusible substance
substantially as specified.
Fourth. In combination with an electric light and the circuits thereof, two electro-
magnets one of which is caused to revolve, a governor operated by the speed, and a
circuit regulator controlled by the governor, whereby the uniformnity of the current
passing to the light is maintained, substantially as set forth.
Fifth. In combination with an electric light, an adjustable circuit regulator
30 composed of the insulated springs connected with the circuit wires, a contact block
upon which said springs rest, and a governor lever l. to regulate the pressure of the
contact springs upon the contact block, substantially as set forth.
Sixth. The process of molding sticks of pulverulent material consisting in filling
the mold with the material to be compressed and then compressing the inass by
35 successive operations by means of a plunger and plunger sections, substantially as
described.
Seventh. The divided mold f². and block e². in combination with the plunger a².
and plunger sections h2 substantially as and for the purposes set forth.
Eighth. The combination in a magneto electric machine of the helix of wire bº.
40 and the wires e. wound and connected to the commutator blocks i. as described and
forming a parallel induction coil that occupies the space and revolves between the
poles of the field magnet, substantially as set forth.
Ninth. The combination in a magneto electric machine of the magnetic cylinder
composed of the helix 6º. surrounded by the parallel induction coil e¹. and revolving
45 between the poles of the field magnet, the commutator i. springs d. and d³. and
circuit connections substantially as set forth.
Tenth. In a magneto electric machine, a parallel induction coil the wires of which
are wound substantially as shown in fig. 11. and commutator connections to the
wires whereby the current is taken off from the parallel induction coil at two points
50 in opposite directions, substantially as set forth.
55
Eleventh The cylinder b³. of wood or similar material with the iron heads
b. and intervening helix of wire b. in combination with the disks e³. of non-
conducting material and the induction helix e¹. wound lengthwise and into notches
in the edges of the insulating disks, substantially as set forth.
Twelfth. A. polarized electro-magnet in the multiple arc circuit of the magneto
electric machine for opening the circuit to the machine to which it is connected in
case of deragement of said machine.
B
2493
18
A.D. 1879.-Nº 2402.
Specification.
Edison's Improvements in Apparatus for Developing Electric Currents, &o.
Thirteenth. The thermo-electric piles connected as set forth upon the condensing
pipes of an engine in combination with the magneto electric machine substantially
as set forth.
Fourteenth. The combination with the electric conductors M. of metallic tubes
lined with hard rubber or similar non conducting substance, substantially as set 5
forth.
•
Fifteenth. The metallic tubes lined with non-conducting material such as hard
rubber, in combination with metallic boxes B lined with similar material, and
uniting the tubes and the conductors passed through such tubes substantially as set
forth.
Sixteenth. An induction bobbin nearly surrounded by the poles of the field
magnet and the combination therewith of an abnormally large field magnet which
shall be in proportion to the size of the pole-pieces as described, for obtaining a
powerful electro-motive force in the wires of the revolving bobbin without great
loss of energy as set forth.
In witness whereof I have hereunto set my hand and seal this Twenty fifth
day of November A.D. 1879.
Witnesses
SL GRIFFIN of Menlo Park N.J.
WM CARMAN of Menlo Park N.J.
10
15
THOMAS ALVA EDISON. (L.S.)
20
LONDON: Printed by EYRE AND SPOTTISWOODE,
Printers to the Queen's most Excellent Majesty.
For Her Majesty's Stationery Office.
[2867.-100.-5/86.]

2494
A.D. 1879. JUNE 17. N 2402.
EDISON'S SPECIFICATION.
(4th Edition)
FIG. FIG. 2. FIG. 3.
I
FIG. 6.
T
FIG. 5.
m
m
FIG. 7.
FIG. 4.
FIG. 9.
14
FIG. 8.
n.
FIG. 15.
Ol
Fill
M
FIG. 14.
LONDON. Printed by EYRE and SPOTISWOODE.
Printers to the Queen's most Excellent Majesty. 1886
M
FIG. 10.
C
FIG. 12.
FIG. 16. FIG. 17.
FIC.II.
FIG. 13.
my
(1 SHEET)
2495
100
l l l l l l l l
Complainant's Exhibit King's British Patent
No. 10,919 of 1845.
vo o l l l l l l l l l l l l l lllllooolllllllllllllllllllllllll l l l l l l
[Fourth Edition.]
000000000
2000000000
A.D. 1845.
N° 10,919.
SPECIFICATION
OF
EDWARD AUGUSTIN KING.
ELECTRIC LIGHTS.
LONDON:
•
PUBLISHED AND SOLD AT THE PATENT OFFICE SALE BRANCH,
4
38, CURSITOR STREET, CHANCERY LANE, E.C.
Price 8d.
1888
l l l l l l l l
E D D D D D D D D D D D D D D D D D D D D T JJ D C D D D ðððððð öðð oððð öðdðððððððððəddəðod Z
2496
[Fourth Edition.
A.D. 1845
N° 10,919.
Electric Lights.
KING'S SPECIFICATION.
TO ALL. TO WHOM THESE PRESENTS SHALL COME I EDWARD
Augustin King of Warwick Street in the County of Middlesex Gentle-
man Send Greeting.
WHEREAS Her present Most Fxcellent Majesty Queen Victoria by Her
5 Royal Letters Patent under the Great Seal of Great Britain bearing date at
Westminster the fourth day of November in the ninth year of Her Reign
did for Herself Her Heirs and Successors give and grant unto me the said
Edward Augustin King my exors admors and assigns Her especial licence
full power sole privilege and authority that I the said Edward Augustin
10 King my exors admors and assigns or such others as I the said Edward
19
Augustin King my exors admors or assigns should at any time agree with
and no others from time to time and at all times during the term of years
therein expressed should and lawfully might make use exercise and vend
within England. Wales and the Town of Berwick upon Tweed the Islands
15 of Jersey Guernsey Alderney Sark and Man and also within all Her said
Majesty's Colonies and Plantations abroad the "Invention of IMPROVEMENTS
IN OBTAINING LIGHT BY ELECTRICITY communicated to me by a certain
Foreigner residing abroad. In which said Letters Patent is contained a Pro-
viso that I the said Edward Augustin King shall cause a particular descrip-
20 tion of the nature of the said Invention and in what manner the same is to
be performed to be inrolled in Her said Majesty's High Court of Chancery
within six Calendar Months next and immediately after the date of the said in
part recited Letters Patent as in and by the same reference being thereunto
had will more fully and at large appear
25
NOW KNOW YE that in compliance with the said Proviso I the said
Edward Augustin King do hereby declare that the nature of the said Inven-
2497
2
A.D. 1845.-N° 10,919.
King's Improvements in Obtaining Light by Electricity.
tion and the manner in which the same is to be performed are fully described
and ascertained in and by the following description thereof reference being
had to the Drawings hereunto annexed and to the figures and letters marked
thereon (that is to say)-
The nature of the Invention consists in the application of continuous 5
metallic and carbon conductors intensely heated by the passage of a current
of electricity to the purposes of illumination. The metal found to be the
most advantageous to use for the purpose, is that which, while it requires a
very high temperature for its fusion, has but a feeble affinity for oxygen, and
offers a great resistance to the passage of an electrical current. Platinum 10
though not so infusible as iridium, has but little affinity for oxygen, and offers
a great resistance to the passage of the current, and as it is abundant and
easily worked into the requisite form, it appears to be preferable to any other
metal. The platinum should be worked into those exceedingly thin Sheets
known as leaf platinum. This may be accomplished by the ordinary process 15
of the gold beater, but a more accurate method is to place a piece of plati-
num foil between two thick plates of rolled Copper and reduce the whole to a
thin sheet by rolling, when on separating the the Copper pieces the platinum
leaf will be found of uniform thickness in every part. In this way it may be
obtained so thin that on holding it before a printed page the letters can be 20
distinguished through it. A strip is to be cut from one of these Sheets of a
width proportionate to the quantity of the current which with Grove's cells
having the platinum plates three inches long and two inches wide, is about.
one fourth of an inch and of a length proportionate to the intensity,which
of course varies with the number of cells. Great care must be taken to cut 25
the platinum strips of an equal width throughout, and with a clean edge, as
if this is not carefully attended to, the strip will be unequally heated and will
be fused in one part before the other parts have obtained a sufficiently high
temperature to produce a brilliant light. The platinum strip is now to be
suspended between two forceps in an Instrument made for the purpose 30
one form of which is shewn in section in the Drawing hereunto annexed
and marked No. 1, A is a square brass bar fixed into the wooden
stand C having a binding screw F attached to its lower end. The two
arms ED are attached to sockets which slide on this bar so as to admit
of their being placed at different distances from each other. They are both 35
bent at right angles as seen in the Figure and terminated by broad forceps
tipped with Platinum. These forceps are closed by the milled screws H. I
the arm E has a rod N with a screw cut on it passing through it and by
means of the two nuts B. B working on this rod, the arm may be adjusted to
•
J.
2498
A.D. 1845.-N° 10,919..
King's Improvements in Obtaining Light by Electricity.
any required height and the distance between the forceps thus regulated.
The rod passes through the stand and is attached to the binding screw G.
The socket K is lined with Ivory or some other non conducting substance, so as
to prevent any metallic communication between the arm E, and the bar; S is
5 the strip of platinum leaf which is first clamped in the upper forceps; the arm
E is now adjusted to any required height, and the lower forceps are closed so
as to clamp the lower end of the strip of platinum. It may now be included
in the battery circuit by attaching one of the wires to the binding screw at F
and the other to that at G. The current should be one of considerable intensity
10 and the distance between the forceps should be sufficient to prevent the platinum
being fused. The distance may bc lessened by raising the arm E, and shorten-
ing the strip of platinum until it attains the highest temperature it will bear
without fusing or the same object may be attained by increasing the intensity
of the current. The Glass Shade R which serves to screen the platinum from
15 currents of air, dust &c. may then be placed over the apparatus as seen in
the Drawing annexed. When Carbon is used it becomes necessary on
account of the affinity this substance has for oxygen at high temperature, to
exclude from it air and moisture. To accomplish this in the most perfect
manner it should be enclosed in a Tooricelieu vacuum. One form of the
20 apparatus for this purpose is shown in Section in the Drawing annexed and
marked No. 2, a is a Glass Tube similar to those used for Barometers,
except that it has its upper end enlarged into a cylindrical bulb, and a stout
platinum wire sealed in ac the top. A binding screw is fixed on the top of
the wire, whose lower end screws in the iron piece, d, to this piece the
25 forceps ƒ are attached, and it is connected with a similar piece at h by the
porcelain rod i. The forceps g are attached to h, and clamp the lower end of
the carbon piece c which has its upper end held by those at f. n is a copper
wire which is fixed into the piece at h and extends to the bottom of the tube,
the tube is filled with Mercury in the same manner as a Barometer, the usual
30 precautions being taken to expel the air; its length independent of the bulb,
should be about thirty inches, so that when it is inserted in a Cup of Mercury,
a vacuum will be formed in the bulb.-The Instrument is included in the
electrical circuit, by connecting one of the wires from the Magnetic or Voltaic
Battery with the binding screw fixed on the wire, e and the other with a wire
35 which passes into the Mercury in the Cup at the bottom of the tube The
circuit is thus completed by the Column of Mercury, and when it is depressed
in the tube by the formation of vapor of Mercury, the connection is preserved
by the copper wire n; that form of Carbon found on the interior of Coal Gas
Retorts which have long been used, is well suited for this purpose, and may be
•
2499
4
A.D. 1845.-N° 10,919.
King's Improvements in Obtaining Light by Electricity.
worked into the form of either small pencils or thin plates by the aid of the
Saw and File. As Carbon will bear a very high temperature without fusion
or volatization it may be employed when a very intense light is required.
When an intermitting light for the use of Light-Houses or for other purposes is
required it may be obtained by breaking the Circuit at intervals by Clock work;
to effect this, one of the wires from the magnetic or voltaic battery is con-
nected with a spring which is made to press on the circumference of a metallic
wheel fixed on one of the arbors of the Clock, having certain portions of its
surface cut away so as to break and close the Circuit at any required intervals.
When the apparatus is suitably sealed it may be applied to submarine lighting, 10
and also to the illumination of places where it is necessary to guard against
the inflammation of highly combustible or explosive Compounds, as in powder
magazines mines &. When a Current is of sufficient intensity two or more
lights may be made in the same Circuit, care being taken to regulate the
power by increasing or diminishing the number of armatures if a magneto- 15
electric machine is the source of electricity or the number of cells if a voltaic
battery be used, so that the united resistance of the strips of platinum or
carbon shall be sufficient to prevent the passage of such a quantity of elec-
tricity as would destroy them.
Claim- What is claimed as the Invention is the application of continous 20
metallic and carbon conductors intensely heated by the passage of a suitably
regulated current of electricity to the purposes of illumination as herein-
before mentioned
In witness whereof I the said Edward Augustus King have hereunto
set my hand and seal this second day of May in the year of our 25
Lord One thousand eight hundred and forty six
EDWARD A. (L.S.) KING.
AND BE IT REMEMBERED that on the second day of May in the year
of our Lord 1846 the aforesaid Edward Augustin King came before our said
Lady the Queen in Her Chancery and acknowledged the Specification afore- 30
said and all and every thing therein contained and specified in form above
written And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose
Enrolled the fourth day of May in the year of our Lord One thousand
eight hundred and forty six.
LONDON: Printed for Her Majesty's Stationery Office,
By DARLING AND SON. ·
[@ 169,-100-1/88.]
A
35
DOWDESWELL.
1
2500
?
A.D. 1845. Nov. 4. No 10,919.
KING'S SPECIFICATION.
(4th Editinır)
GARANTIINIMUM
WAJAN
QILINAD
E
1
Lamoy Printed by Darso and Sos
10. Her Majesty » Kistnery Office B17
D
进
​(2 SHEFTA)
DIKET I
GADACLATILUP
FIG I.
2501
A.D. 1845. Nov. 4. №º 10,919,
KING'S SPECIFICATION.
(4th Edition)
FIG. 2.
a
C
LONDON. Printed by DARLING and Son
for Her Majesty's Stationery Office 1087
(2 SHEETS )
SHEET 2
1
2502
Complainant's Exhibit French Patent to on. Gravier
Bertificates of Addition thereto.
and
RÉPUBLIQUE FRANÇAISE.
MINISTÈRE DU COMMERCE, DE L'INDUSTRIE ET DES COLONIES.
BREVETS D'INVENTION.
· Mémoire deSCRIPTIF annexé au
ето
Série G bis, nº¸1.-
M. C. I. et C. -
ཟ
brevet d'invention de Quinze
le
1880
Gravier (oh,
jiris
par le sieur.
ingenieur civil, rquésente par
Arixiengand
данд
b
a
lui
et qui
аше
Paris's 45 rue St Sebastian
it délivré par
a
été
arrêté du Ministre de
et du Commerce
août 1880, pour
Agriculture
endate du 24
un
nouveau proade
de distribution de l'électricite
app cable à la production de la
lumière électrique et à d'autres
usages
Brevet sinvention: N: 137.033.
گے
Description
'assimile la distribution.De.
2503
l'électricité à une Fistribution
Je Jamme dans l'industrie. Die
Comm
a
12. Uone usine – usine à élec-
gaz
il to
tricité qui,
teé
ра
par
une
qui, réduite
à
sa plus
simple expression, est représen -
pile hydro_ élec=
trique, thermo- électrique,
machine dynamo-électri_
мне
que.
2 = Une conduite d'émission.
ur li
que I appelle pour
cas
Je l'électricité. Conducteur d'émis-
sion.
3: Des conduites de distribution
que j'appelle conducteurs distric
buteurs
teurs.
on.
simplement : distribu
4r. Des récepteurs, appareils à
lumières, s'il s'agit d'éclai_
sole diverous parties coventiel.
les d'une distribution d'électr
remplir
cité dowent
i
plir les me
ди
дау,
gaz
une distri-
savoir
mes conditions
bution de
2504
L' vaine à électricité doit pro-
duire it émettre l'électricité
an fur et à mesure des besoins
de la consonimation
imation
La conduite d'émission doit
fonctionner comme réservoir,
c'est-à-dire avec
une résis-
tance aussi
мой
petite que possi -
ble.
Les conducteurs distributeurs
dowent être établis de façon
a ne laisser
passer que
la
quantité nécessaire d'électri-
cité
servent
appareils qu
ди
ils des
Les récepteurs doivent fons -
tionner indépendamment les
но
что
des autres
autres; c'est _ à _ dire
De façon qu'on puisse allumer,
un nombre quelconque
éteindre
des appareils de cet éclairage
sand troubler le service des
sutres appareils.
Cortés
ceo
conditions out:
été réalisées en
-D
partant des
loi's de Joule et d'Ohm.
: après Joule, la som _
d'énergie transformie.
2505
en
une
électricité
(1)
maine
que pent fournin
à électricité est
W = IE
I exprimant le nombre de-
ant le nombre de
exprimant
Webers.
E
Wolts.
produit
Evidemment
sur
n
pour Deviser je
récepteurs, it
suffit de faire que
(2) WIE
n
d'où l'on tire (3) Won IE
n
Les lois d'Ohm donnent,
pour
I. et Es la relation suivante :
(4)
погло
I - E
R,
Si dans l'équation. (1),
remplaçons I par
auror
w一​覧
​R
sa va
leur
Ę
пого
R
(5)
par suite, les
équations
морес
(2) et (3) deviennent
12
tivement
(6)
n
W E
n R
(7)
W
# 2
On R
des
le
courant
représenter Fla
résistances
d'énergie IE at
traverse
que
مهمه
نسرو
2506
:
12. La résistance du
du géné
22. La
rateur
que
nous désignons pants
La résistance du
ducteur d'émission
signons pas
con
que
nous dé
Re
J = La résistance des conduc_
distributeurs que
teuro
signons par
par. R
d
appareils à
nous dés
42 La résistance, dans les
himière des arcs
voltaïques que
рай да
D
apred
nous désigno.
cela, e
équation
L
(6) qui représente la to partic
'énergie totale devient:
de l
(8) W.
n
އ
E?
n (RD) + R / FR FR )
"'il faut multiplier
chacune des résistances
et indique qu
par
&
R & R R & R ², c'est _ à _ dire les
rendre in fois plus grande.
Il n'y
ditions à
pas
remplis.
d'autres con.
Si elles cont remplies four
chagire récepteur, la distribu_
tion
est
parfaite,
danro
pertes,
et, de plus, chaque récep=
teur fonctionne indépen
Damment des
autres.
•
2507
L
expérience m'a montre l'exe
actitude de la théorie pour 1
2, 3, 4 régulateurs Serrin alimen
tés suivant les
conditions de
la formule (8). par le couvant
émis
par
rine
chine Gramme type
A
'empêche évidem_
unique
Rien
ment, de remplir
tions
pour
ند
condi
des con
ملك
un nombre quel
conque de récepteurs.
Conditions matérielles d'exécution
Cclairage d'vn atelier.
ден
moyen d'une machine Gram-
me, par exemple, et de trois
régulateurs Serrin.
D'après la formule (8) les
ар
conditions
I'une distribution
à trois himières sont pour
chacune
W
W
3
E²
3 {R$ /+_R®/+R&F+•R
3 (R+ + 3 R + 3 R 2 + 3 R =
em
E &
a T
pour
your diviser
qui signifie que
trois
parties égales le pro-
2
duit W on IE on t il faudrait .
R
1 = que le circuit de
l'inducteur soit
are
lien de un
3
Simé de 3
fils de même
2508
E
unique
longuem que le fil unig
mais de section 3 fois plus
petite
de
طلع
2 = que le circuit d'émission,
reme
е
معسو
le circuit de
fils;
distribution voit composé de 3
Chacin étant 3
tant qu
I gue
fois plus
resis
le conducteur uni_
its représentent lorsque -
fonctionnent tous les trois
que qu
ils
à la fois
3. Dans les lampes, que
le charbon employé ait
section 3.
rene.
fois plus petite que
colle du charbon unique que
brüderait le courant total.
me
Mexis toutes
معنے
sont pas peated
réalisables
conditions
pas pratiquement
On ne
pent,
ހއ
effit torcher a la résistan_
Du générateur . On peut
сет
la faire plus
ove
moins ré
sistente, voilà tout.
est de même,
général, du condustan
d'émission
Four les rendre aux
is peu nuisibles,
mixibles que possible;
}
2509
il
it fout les fore aussi pur.
resistants que possible, shou
e I on peut toujours
que
Le
MIRMIRERAKR
n (Rot Rex Rd, Ra
xxxpression (8) W
devient, puisqu'on ; ne
Aorichar
a
R
д
() w
n
Fire.
peish
EL
ma Re
к Ro+ R ² + n Ron Re
rapprochera d'an -
tant plus de l'égalité que R2
Elle se
et R
Moris
seront
plus petito.
Application
avore
ހއއތއއ
Gramme qui
sidérant que
0, 10 ohm
Just;
et qui fournit
de
90.
Webers
et de 100 Wolte
ހ
machine
en ne
пе со
le circunt m
courant
Nous
avor
pour
EI
d'après Yout
l'expression de W=
Surb.
80 urb. x 100
wolts
3000
si le urcuit total a Ri
wilt
30
100
Web
b
ска
3,3.3 ohms
Dr Raw dort. être
R
1
لا
R++. Ret Rd + Ra
Nous aurons
dans le
cas
qui
نه
noris
occupe
2510
Ohms
Résistance de la machine generatrices. R ... 0,10
//
R...
du conducteur d'émission Re-___-0,15
du conducteur distributeur Rd
de l'arc
1,42
R = 3,334,66
Resistance totale. R = 3,33
Les conditions ci
dessus sont
les conditions de résistance d'une
distribution qui aurait une
alimentée par
courant. total d'une
lampe
chine Gramm
.4.
Dans le cas
ކއ
le
de dema
lampes utilisant toute la
source,
vertai
ame.
ам
en
de la formule (9) 14
lampe.
W
<.
lien
2.
1002
सन्न
0, 10 + 0,15 1,42) + (2 × 1,66
lien de
1500
24560
Dans le cas de trois
lampes utilisant ensemble
ватре
la
unt
همه
ам-
source
lampe
W <
W
lien
Dans
noris
али
accrono
100€
0, 10+ 0, 15 + 3 x ;,42) + (3×1,86
de 1000
le cas
7
41053
de quatre
lampes utilisant ensemble
toute la source nous
s aurons
7/
ine
lampe:
:
2511
.
1002.
W < 0, x 1,4e
0,40+0,3
; 10+ 0, 15+ (4 × 1, 42 (+ (4×1,56.
an lien de 750
سنه تالار
795
Diagramme indiquant
-les dispositions matérielles prises
pour une distribution à trois
lampes
BU COUMSAC -
MINISTERE
DIRE TIGN
Korean.
LA HIL
雅​昌
​B:
RY
75
CONGUE VEM LÖSEN.
Cond. Jesên lu¿4¼4%
:
4,46
D
sones. dy Pributeur
4.46
A B. bornes de la machine.
génératrice
où R &= Ohm 10.
A a B b Conducteurs d'émes-
Re
sion où R² = 0,15
ހ
me
D I distributeur formé d'
planche isolatrice our
-place
lagnelle.
10 des bornes de
prives
de courant
de istour-
E lis
lis
первома
un
އ
et les bornes
interi
interruptions
pour chaque
2512
circuit distributeur.
cd, cd, cd, conducteurs
distributeurs, fixes d'une part
drix
borne's du distributeur D et
airx lampes .
d'autre part aira
Chacun d'eux a,
les trois
lumières devant avoir la même
intensité
Ohm
pour résistance-
4.26 Phms.
3 Rd on 3×1, e
и
42
I, I, I". Lampes Serrin
autres.
La résistance de chacune,
c'est à dire celle des
est
tré
_
réglé à
L'expérience
е
que.
ага
arcs
3 x 1,66 = 4.98
4.98 Ohms
dano
того
ހ.އއދއ
a mom
lampe
utilisant tout le courant,
ре
de 16
on pent brisker du charlon
mm. de diamètre. (Ch.
de la fab : de Mi Carré).
En conséquence
les troio.
lampes qui font l'objet de
cette distribution
auront deo
fois
charbons de section
ہے
plus petite, c'est à _ dire
charbons de 9 mm envi-
des
n
އކބ
on
و
Fonctionnement
2513
Voyons
dans le
سفے
شبو
de
passe:
fonctionnement
La machine d'induction.
tourne à
goo
torers
par.
minute
je suppose
Cous les circuité sont ou.
vesta
La machine ne
produit pas d'électricité
Fermono
un
des trois
circuito distributeurd, chri
7
de la
Патре
To Cette
lampe
'allume
et
brücke
en
dormant unex
intensité lumineuse pro-
portionnelle à l'énergie
du courant
fourni
w
3
= 10.000
لف
qui
qui rest.
1008
lui est.
6, 10 + 0, 15+ (3 x. 1,42 / +(3 x 1, 66
1053
9,49 lien de
ай
Wi- 10.000
Fermons
9х9,95
=
1000
maintenant.
les
circunto de
१
Let Le'
ватрес
sal_
nsemble et brulent
Ces deux Campes
lument
ment en
en donnant l'intensités lu_
жена
proportionnelle
2514
à
و
'énergie que
levis est
fournie respectivement
qui
ui est
pour
Les déma
WY0000
0, 70 +0, 15+ (3 × 1,42)+(3 × 1, 66)
2053
sont fermés
pes I., 'I', I".
¥
=
au
lien de W
=
10.000 = 2000.
3x9,99
ढे
Lorsque les trois circuits
sur leurs lam
10.000
डै
0,70 +0, 15+ 942 + 1,66
3
g
cette ap-
= 9000
on a
On voit dans
plication; les conditions du
ne réalisées.
progest à dire Usine pro-
-programm
duisant et émettant l'élec-
tricité en
en proportion des be-
de l'éclairage.
Conducteur d'énrisaion
soins
fonctionnant à pes de chose
ре
comme réservoir
près
scaistance
dano
Conducteurs distributeurs.
donnant l'électricité
récepteurs que
ila
dera
desservent
evient les
чарский
les conditions pour
lesquelles its ont été établis
Recepteurs fonctionnant
2515
avec
pendance
parfaite indé -
En effet, dans le cas le
plus défavorable, sehn où
sente lampe
мне
Bumie
cette lampe
est al
an lien..
de donner le tiers de la lu_
ensemble, donne une _in_
mière produite
par les trois.
tensité qui
de 5' àì
eat
ungimentic
op % Cette varia
tion est bien inférieure à
celles
qui
produisent.
journellement dans l'éclair
падет
pas
arr
ал
sare
jaz, où il
n'est
de trouver des
variations de 90, 40
que
faite
et 50% off.
On peut donc
dise
la distribution ainai
est pratiquement
tisfaisante.
Ce sont ces
dispositions
extérieures, indépendantes des
machines
et avasi die
du sys
time de lampes que
revendiquons
invention et que..
nowro
notre
enten
Lons
breveter
Eller
n
'ont été
2516
avant
prises par personne ava
точно
que la division
puisque
de la lumiere faite dans
les
conditions
يسو
avon's indiqués
lisée nulle part.
Svic les
timis
n a été réa
courants
la société des ma-
chines Gramme
déclaré
ހ
toujours
imprimé dans
prospectus " que une machine
Gramme
fois "
ne
pent alimenter
qu'une seule lampe
La société
tation des
emploie
à la
l'exploi_
pour e
procédés Werderman
comm
مد محمد
مبله
circuito dérivés mais dans des
conditions arbitraires. Chaque
lampe est indépendante,
mais
c'est à la condition
d'employer
une seconde dési
d'égale résistance.
vation
condition qui
a
pour résul
tat de faire travailler ex
machine dynamo- électri__
que, toujours pour la tota
de l'éclairage qui
lité
'il y
2517
ait une
lumée
Aorites.
des
mais
ou
ди
le la
lampe
al-
'elles le soient
16. ^ Reynier emploie
dispositions différentes,
avec
les mêmes sin..
convénients, I est-à-dire
l'éclairage
que
soit ré
duit à
une
senle to
lamp
or
ди
'il soit.
ar.
complex
la machine consomme tou_
jours le même travail.
Avec les
courants alterna
tifs, la société générale met
-plusieurs bougies
même
ime
mais
ceo
circuit,
އ
en série
bougies
ont..
dans
мне
aboolie dépen_
Fance. Une seule extinction
entraîne toutes les
du même circuit.
Centres
Mr. M. Siemens et Hals
pratiquant aussi
ke
division
à la
la
mière de
la Société générale table
se soustrait à la dépen
dance des apparcits les cons
en employant.
des autres
2518
cine
dérivation analogue à
celle de Mi=
Reynier.
On
trouve dans
dispositifs
le même inconvenient
la machine travaille teri
venient
Jours
comm
де
était
si l'éclaira-
complet, quel-
ан
soit le nombré de
allumies
que
Campes
M = Loutin pratique
si la division;
il
it emploie
trouvent
plusieurs circuits, mais
les lampes
dépendre les
très
qui
me
de
mes des
معبد
Aucun de
Buen
معش کل
sere
ceo ayotimes
sont les plies
effectue la division com-
elle doit être entendue
comme
nie.
l'avons défi-
Résume.
En résumé
mon
vention conviste dans l
in
appli-
cation absolument nouvelle
des
circuits dérivés calculés
d'après les lors de Joule
d" Ohmi
et
et disposés (formules
2519
I et
دوند
de
en
en
pour
distrit
distribuer une sour
quelconque d'électivité
proportions déterminées
dans
une installation come
ant un
prenant
certain nom
bre d'appareils.
pour conserver, as cha-
que appareil, l'intensité
qui lui est propre,
ро
pour
assurer len in
dépendance les uns des an _
tres, de manière qu
puriase à tout instant, à
volonté, allumes, éteindre
un nombre quelconque :
مو
de Cremières sand troubles
le
que
2
régime
ates autres
et de manière.
la
manière encore
production et l'é-
mission de l'électricité
soient toujours
en
гар
rap-
avec les
besoins
de
port
l'éclairage.
Dano
nous
avon
noo
explications,
toujours conci-
déré l'éclairage
со
but de la distribution; mais.
2520
живо
Deux mots raye's me
il est bien entender que
nous.
noica
plication de ca
réservons l'ap-
procidé de
teurs
distribution à tous récep-
à
utilisant l'electricité.
Pari
le Juin 1880
aris le z
Tips A Gravier
ſigns : abamengard any.
Paris, to If ance
ош
1391
"Fear expedition certifiée conforme.
Leßef du dinireaude la Propriété Industricli's
Bur
A PROPRIETE
INDUSTELLE¡
2521
TRANSLATION.
of letter from the MINISTER OF COMMERCE to MM BRANDON &
FILS, Paris, dated April 29.91.
Gentlemen,
In answer to the letter which you wrote me
on the 20th of this month, in order to ascertain the date
on which was issued a certificate of addition annexed to
the patent of invention (N° 137033) taken out by Mr.
Gravier on June 3.1880, I have the honour to ir form
you that the official date of issue of the said certificate
is the 3.Jan.1881.
Receive, Gentlemen, the assurance of my perfect con-
sideration.
THE MINISTER OF COMMERCE, INDUSTRY & COLONIES,
The Chief of the Office for Industrial
Property.
signed: (illigible)
2522
¿Ministère,
du Cominerce
de l'Industrie··
et des Coloniea.
Direction
Diz
Commerce intérieur.
Bineau
the Ior Propriété Industrielle.
Brevets d'invention
Renseignencent.
reg
RÉPUBLIQUE FRANÇAISE.
Paris, le
avril 1891
29 avril
вы
Messieurs, en réponse à l'ax lettre
écrite, le 20 de ce mois, dans le but de connaître
la date à laquelle a été délivré un
se
que vous m'a
certificat & addition
re ratto chant au brevet d'invention ( 112 137.033) pris
pad the Gravier, le 3 Jinn 1890, j'ai l'honneur de
vocis
с
cat remionte
celle de la délivran
Einformer que la date
artificat
Reevey Messieurs, l'assuran
ce ducit curl
faite considération
ан
5 Janvier 1881.
l'assurance de ma
ce de ma par-
finistre du Commerce, de l'Industrie et des Coluies.
Se Ministre
م
antrisating
Le Chef du Bineau
de la Propriété Industrielle
Messieurs Brandon et files, rue de Provence N°59 Paris.
ぞ
​2523
´M. C. I. et C.
Série G bis, n' 1.
RÉPUBLIQUE FRANÇAISE.
MINISTÈRE DU COMMERCE, DE L'INDUSTRIE ET DES COLONIES.
BREVETS D'INVENTION.
MÉMOIRE DESCRIPTIF annéwé au
Corbilical d' addition prisle
9 novembro 1880, parle Sieir
Язнанство
Gravier, represents parle siir
Paris, we
Armenvand Ané, à
haut qu
3
. Sébastien N. 45, et he ratta -
breveted invention dee
15am prisle I Juin 1810, pour
un nouveau procédé de distribu-
tion de l'électricité, applicable
à la production de la lumière
électrique et à d'autres usages,
т
(eth for an Branch 1:
n: 137.033
Description
137.0
Dans la distribution électrique
que j'ai fait Crenter, j'ai défini
les Conditions que chaque orgone
doit remplir.
2524
Sa
pratique m².
m'ayout.
montre leur insuffisance free the,
amené à faire les
mifications.
Suivantes que je désire rattacher.
Crevet du &
à mon Crew
од
3 Juin 1880.
to Surle mode d'interruption
Le bunde l'interrupteur ost
Sumplement de former ou d'ouver
le Circuit qu'il. de West four
Donner pattage
он
au Courant
l'interrompre.
En pratiquo, Cela ne suffit pas.
Il faut absolument quela
of Son Circint tout enter
socent Supprimit, de la distre
bution.
lau
Campe
b
Voici pourquod, lorsqu'on
le Circuit d'une Campe
pour l'étendre, il Le produit
ouve
Dans ce Circuit in.
כ
in Courant
indint que recarjet, momentane
ment, Surte bite de lax,
вае
Distribution Sent Contraire
ен
du Courant de la Source slec
trique. I on
де
on résulte de Sex.
tictions Si la. Source n'est
pas plus puissante qu'il ne faut
}
2525
pour to Service de l' eclairage.
Pour obvier à et inconven wit
Supprime Completament dela
distribution la lampe et Son
Circuit tout enter.
Bistr
a
Figure 1 minte
ек
Je
9 face,
A montre in vue
I montres on
la
Coupe Suivant le liepos 1-2,
отвей
grandeur naturette le
Dispositif employé pour une
Campe. I to Compose d'ave
ア
​piece I prismatique in cylindri_
н
ébonite
on autre Substance
solante, mobile autour duc
que
Са
Centra
ев
о
H porte dame Contact
он сийче овные
staudie
suffisante pour que les deux
Systemes de ressorts in fore
nickelés a a, b.b. puissent)
в в у
trouver place et être
distances pour quel'étincelle
I'extra_ Courant ne puiste tra
Vorter of expace. In resorts
a db Sont
assez
in Communica
т
tion électrique avec
les
Corner A. x B où aboutikkent.
Les Condrecteurs d'émission; les
2526
Ces deux autres avl sont fars.
анх
Cornes Fit NE.
Les fugine's I et
2
mon.
trent larament que dans la
position indiquée du fritone P
le Courant port Toader,
дне
не
la
Si
aide Ja
atter, th
l'aide dela manette
à l
la
m, on fait 1/4 de tour dans
sent ou dans l'autre,
Canitse et Son Circuit Sont
mis bore de la distributiong
De Cette façon, be
ile.
Courant indliché sur lui-
dans to Circint, mit.
л
sueme
hors de la distribution,
Ансип
restants.
n'a
effet surles appareils
تمع
trent quim
ди
figures Set 2 no mon
топ
Seal. disjoncteur
disjons
Ии Собочек
Ue Certain nombre de Colorquined
organes.
reunis Sur une même table
Constitue,
Distributeur.
ai
maintenant,
топ
20. Jurles Conductours distribuctours.
Les Conducteurs distributeurs
ont pour but parlent. résistances
quey, a fixées, des mother une
qujia
"Campé dans une position Pokemine
盅
​2527
d'urtensité, de Constance et d'in_
dépendancy Complete.
La première de C Conditions
est actory difficile à realiter on
pratigue, Carlos fils du Commerce
ou moins Compoſenes,
diamètre plus
Sont-plus
I'ni
вид де
ed
ou moins
regulier. Si l'on Calcul la
Groueur nécessaire pour
мет
und resistance et que
Conqueur
Domees, dans le but d'bletamis
в вивелый
des lumières d'égale intimité
il arrive prexique toujours,
qu'on est obligé d'allonger
on de raccourcir le Circuit
он
час
pour arriver
à
୮
l'avalité deman
Pour evite (as remanse =
ments at (es tatoramento que
tout le monde no
peut faire,
uets dans chaique Ercuit
distributeur
ни
robinet.
quis
j'appelle niveleur et qui me
crmet de domverplus on
moins d'électricité, et de
очень
fixer le inveau dél intensite
lumineuse dans chaque
Compre. & dispositif te
е
2528
Compote essentiellement d'une -
Caisse de résistance, figures Set it,
à l'intérieur de laquelle est
fil de for stame
disposé un
millele on argenté", "Serpentant
de Cád
de cmà du
R
de dà C'
de dr à En el
aboutissant à la Corne L.
nutia
こ
​fol
est. mit wi
relation dres la sours par
la Corne A, le Commutateur
очие
А
C, mobile autour de Contre &
et qui prend Contact Sur de
on Cuivre C c', C "C"
се, ста
en
petites pies apres latte des-
во
в
же
ар
Cription, on voit le fonction-
nement : le courante du distribu-
kur, Corne N, arrive à la
Come A du nivaleur, passe
par to Commutateur C. par
la Corne Len Suivant le
Corine &
не
fil
ен
ане
а
to resistance, dans toutes
Ces. Circonvolutions, depuis le
Contact du Commutateur, a-
boutit
à la Campe et revient
ay dishibuteur par la Corne
L
of à la Source par le
par
Conducteur d'émission B.
2529
Dans ces nouvelles
Conditions, ainsi que jo l'ai
annonce; So Source électrique
fourint, intout par int
tant, l'électricité nécessaire
à chayque lampe et on proper
tion du nombre de lampes
a
allumées.
Le Kavail moteur est
ortionnel au nombre
proportionnel
dé lampes allumes of
leur intensité.
haque Cunnière ext
proportionnelle an foodint-
Webert × Wolls
qui traverse les électrodes,
L'independance de
Chaque appareil ett Complète.
In
де
yo
Résume:
u résumé je revendique :
To distributeur disposé
de façon à Supprimer de la
distribution haque Campe
хоршо
et Son Circuit tout enter.
20 Le nivaleur de lumière)
2530
Deux lettres ronyers
unllery.
C'est à dire l'appareil ofur
Sous la forme décrite ou toute
autre analoque permet de
uivaler l'intentité lumineuse
Get appareils à lumière.
Paris, le 9 ngrambe 1880
p. For Gravier
Signé : Armany and auré
:
Очей
Paris, le 15 mil 1891
Tour expédition certifico conflrme
Le Port du Bureau de la Proprieté Judjistrielle,
DIRECTIO
อน
TOKSENCE 191ERV
Brycat.
A PEBBRIC
→
Lampe
Q
2
B
®
Fig.1.
1
2
A
D
to
U
Frg 2
Lampe
Zampe
D
N
H
P
W.W
டாட்
P
п
2531
୪୪
Grandeur d'Erication
Distributeu
d d
Ө
2.
回
​2
Fig. 8.
Fig. 4
७
Mueleur de Lamiere-
Trevena an Contificat d'addition.
prosle Of merele 1880 pa
de Jr Grave
L
ul. 198
1371
ly
m
2532
M. C. I. ct G.
Série G bis, nº 1.
RÉPUBLIQUE FRANÇAISE.
MINISTÈRE DU COMMERCE, DE L'INDUSTRIE ET DES COLONIES.
BREVETS D'INVENTION.
Mémoire · DESCRIPTIF annexé au certificat d'additions pris le
دیتے
mars 1881, par le sieur Gravier
( c ) ingénieur evil représenté par
le Sinus denengand ainé, à Paris,
que St. Sébastions, no us et serraller
chant au bruit d'inventiones-pait
le 3 quise 1880. pour un nouveau
procédé de distribution de l'ébetricik
applicables à
for production De
la lumière électriques et à
d'autres usages.
1. le dit certificat
été délivré par arrête
d'addition.
са
In Ministe de l'agriculture et En
en date dusty quien 1881
Cormieree
Breet No.137.033
Dars notie brevet
principal du 3 juin 1880, no
1
2533
}
137.033, nous avons
considéré in
sexlement de la distrubating.
de l'électricité, celui qui corres
くま
​pond à l'état Réservoir du réseau.
De d'invision. Nous avons
err
އއއތއޔ
avons fait.
appuyant for des chriff-
que l'état réservoir est la coridation.
nécessaire et Luffisarites pour avoir
une distrubution d'électricité aussi
imple que celle die gaz
mais
plies
approchie de la perfection Luving
Fans i cas, produit et onnet
u. émet
l'électricité sous tension constante
2
من حمد
އމއ.
on
quantités variants
comme la consommiration.
En pratique,
севый фин
D' was se préſente; c'est celuig
to
ques
correspond à me Situationa
torité différente de celle qui nous
définie et caractériole
avoris
Tous le
Je réservw.c:
Celle situation com
alors que, par suite d
l'extension de la consomination
de l'électricité, les corodrecteurs
peuvent plus siiffire
besoins de la common
aur
Creation
2534
***
in certaines points de la dister
bution, Apres avow.
・fiam par
& état réservoir, ces conducteurs
&'étirt
مده
deviennent de véritables connus
އ
d'écoulement, dins lesquels, néces..
ſaiſenſent, l'énergie électrique
disponible ext plus faible
que
en.
amont...
ax avial
Si dans
ces
conditines,
l'risive continue à predicire ſous
ла дел
aval insuffisamment
Sersion co
istarite; on: aura
points in
Jesservis à certaines heures de lo
consommation et à déficits son
d'autant plus accentuées que la
consommation in accort Sera..
pilus grande.
Dis
gril
cetter sitten.
tion commence à se prodienne,
l'rosine doit changer les albiered,
modifier l'émission pour arriver
à combler le déficit qui tend à
se produire aux pairits les ples
éloignés, all doit faire varies
force électromotrice d'émissio
De façon à faire arriver nich
points les piles faible la somma
d'énergie qive of marque.
aix
la....
2535
Ce résultat part.
itie
atteint à la main où autora.
Liquenient.
ere
faisant varier
soit la vitesse des induits pour.
un charips maqnitique cont.
saist, ſoit behanep magréétique
inducteur pour une vitesse wies.
L'anté des induits :
Mais, dans tous les
cas, l'uvine, pour opérer sien
ment, in temps apportione, it
dans la mesure utile, doit être
informée de l'instant même
où la perturbation de produit:
Saur cela rien.
бали сева
Si, à la sortie, et à
la rentrée ou comant dans l'usine
024
pilace des
qulvanomètres
Désirez, à grees file et à fil fin.
Lore
дела
aura bien l'état exact de la
consommation à chaque instant-
mais nove l'indication des besoins.
Au contrairer, his an
point le plus faible pratigne
ment
reconnu, de la distribution
on fait
для
une prise do
prise de courant
I'on unine à l'usine an
moyen d'un fil spécial es
2536
дли
индив
que t'on fait passer Faces un gal.
vanometre Déprez à fil fine,
нама
accia.
04
chaque instant la véritatt
silention in a point. Dis lord,
le chef de l'assive porance agir
eis tout
commissar
Je
Naus appelous
ee.
courant spicial,
сошиалов Эс
de
etle
petaver, et le filé qui l'amine
à l'usine, fil de retour.
L'eipsic dice cxccrout
L'emple
sest le chose.. cxpritate de la distri
bution, lorsque les couchert
denissions ont cessé de fonctionner
ccéscrvoert, lares leu, pas
согемоде
се
V'imnission régulière possible.
elle serait le désordre le plus
conslet.
En se contentant
Des indications di gabranomike.
fournies par le conant daretour,
pour
nr faire ravier la force Mitro-
motrice de l'usine, on ama
installation fort simple
ие
އއކ
me apparcil, mais il faudia
ine iurveillance des plus atterr-
ހއއކ
lives pour faire les correctiont
Demandéco.
---
2537
Doux eviter cette atten-
tion sorterane qui est humaine
ment nupossible et sur bagrille
ut on peut compter,
consignement
noris employout le dispositif
trissant gue
et
.އއއއ
allous décrire
que nous appelons Régielatein
м
Dévision.
Il de car
expose: 1:
I've clutro. ainiant #B. Met la
bobine gunoie de fil five ext
Araversée par le couvant de-
retour; 20 dnu armatrine bas-
cutante: &ß montée consume me
fleau de balance series contion
26.1
އކއކ
for qui est le prolongemist
que pôle 4. Mi contre poids p
Sert
l'équilibrer lorsqu'un courant
Déterminé arsime l'électro-aimant
їдне
Elle porte; de chaque côté des contacts
c. l. i't' disposés, comme l'iri-
Dique da fig. 2 Du Tragramime;
lesquels out pour but de firmer
un incuit local ſur la bobine
relative bs, tantôt dans me
teris, tantôt dans l'authe: 8:
I une anature rotative b.s
ите
Carrie Siemens modifiée par
2538
+
M. Crouvé on
archie). Cette Cabine
actionnée d'ame part, par l'ébitro
aimant AB et d'autre part, par.
un coxcravet local, tourne tantôt.
à droite Fantôt à' gain the ſuivant:
فة
que l'amatua & ß bascule à
Droite ou à qo
•
à gauche. Cette bobine
est
parte sur son are prolonge,
Vitors, ince vis saus fine qui com.
manide mi voire devetée et qui
agit par cet inturnédiaire soit
sur la machine à vapeur pour
modifier sa vitesse, ſoit sur une.
Série de résistarice pour modities
l'intensité : Tu chianup magnétique.
éonitionnement
е
Tarvis
cas se présentent :
1º Le réseau forrétionne
e réservoir;
2: Le réseau ayant cessé
de fonctionner
frar suite de l
a
އއ
e réservoir
l'angmentation de
consommation, des points les
plus éloignés sont faiblinient.
disservis
Zr. Le réseau fonction,
consisse canal
want to your con
d'écoulement, les points les plies
2539
élvignies, par suite de la Immation
de la consommation génériel, esiting
un ixeis d'électricité:
чи
якой
ай
Dans le 14 cas, tout étant.
te
میاره
normal au ponit le plus éloigné,
l'inergic du courant de retocer ext
constante, l'armature & ßreater
C44.
équilibre et l'usine, produit
et insect l'électricité sous tension
constante, mais une quantité's qui
varient iune la consomma.
со
timelle nime.
ſommatione.
Dans le di cas, la co..
asey
mentant, il arrive.
en moment où les conducteurs
Janission deviennent insuffisants.
One voit alors l'energie du coivant.
de retour. ''abaisser; l'arqnative
: cessant d'être équilibrée, bascule
sous l'influence du poids to, berrice
à gauche
auche le circuit local sear la
bovine bs et la fait toumers
Esans le sens convenable four
faire tourner
plus vite les nuits
on bien pour diminuer la résis-
Hance
Marree Du ou des circuits inductees.
La force électromotrice d'éssersin,
J'éling
се ди
- voit bientôt for
qu'or
2540
l'action du courant de reboier. qui
rétablit l'équilibre de l'anniature
aß jusqu'à un nouvel abaissement
point le plus
de l'interision au point
élvigne
Dans le 34 car, la
consommatione Pinnimarit par
duite d'extinctions on so lu cessation
d'autres travaux, l'uroines travaillons.
brar
toujours sous la teusion qui lui
été Jermandée l'émargie de retour
Land à l'élever; alors l'action che.
α
геданный.
tamagnétique devient, pre
mirite à son tour, fait barcuter
l'armature, & 3 à toiles, fear
تم
މއ
le circuit towel. Je cc. côté et fait
ረ.
tourner la bobine
droite frour
Irmincer la vitesse des inducto
augmenter la vition résistance
des circuits inductuurt. La fore
électiontre d'émission barisse
et l'on voit bientôt l'active du
courant de retour rétablir l'équi
Libre de amature it I. Cela a
&
tieu
jusqu'au
les e
ſiement.
sint are
conducteurs d'érmission rède.
cement réservoirs.
C
Q'est alors que
lusina.
2541
I que
reprend son allure primitive face
trommard Yousterssion
велогон
coustunle→
a la cessation de loude
Jesqu'à la cessa
eruation qu'indiquent parfai-
tement les compteurs.
capteurs d'éésergie.
places, linn sur le cinquit d'émission.
α
sortie de lisesine, l'anche Lear
le circuit. De retorer. Laroque
a
ibry
plres de corivormisation en ville,
مین رحمة
އ
=
21
que
a pas de portet, leurs indi-
cations seront identiques.
އކމ
etors
venous de voir
в ченак
que lorsque le circuit ou le réseau.
d'errissime ne
me
fonctionne pas come.
me réservois, il est nécessaire Front
l'ușine modifie sa force électro-
motrice d'érmission dans le sirs
indiqué par le conviant de retour
pour faire arriver
arr
point le
де
plus éloigne la somme d'énergie
quity mangue
Mais cette correction.
nécessitée par le point le plus
éloigné n'apporte t. elle pas
certain trouble dans les autres
points de la Fiſtribution?
A videmment, il n'en
1
peut être autrement, car se
2542
tion relive la forces électromotrice
pour a point unique qui est te
filus faible tous les autres subisset
les conséquences de
и
fait.
Four y obvies; chagin
авойти анна.
so
avre à la dispositions pou
rigler sa corisommation.
u moyen.
analogue à celui que l'risine enchlos
pour régler sa force élicnornatrice.
suivant les besoins de la consomm
nination
prour
Nous emploieront
bust l'appareil qui nous
représenté fig, I et décrit-
plus haut comme
régulateur.
d'émission. Nous d'upheleron's
Régulateur d'énergie
matin.
le
не лё
анде сот
on de consom:
compose come.
Enteur d'émission, des
régulateur
mirnes asgarre
any
s.
Nr. électro aimant
A B garni de fil fire, d'énie armiative
- Casculante & Beb ime armisture,
rotative bis (bobine Siemens, mo
dificé par Trouve on anche).
Sei il n
pics
de.
courant de retour Le courses it car.
comanit
recteur est pris chez l'abormé
2543
чич
2
mence, Lorsque la tensions: tend.
s'eliver, l'éssergie électronna quétique.
de # B Tonsinera, fera Caseter i wi-
nature & B, et par suite fermer
circuit local you fera toumer
la Cabine bs dans le seus voulu
во
pour introduire dans le circuit.
distributeur la résistarice réécessaire.
au rétablissement de l'équilibre
de l'armature & B qui correspond
régime de l'a consommation
Au contraire, lorsque la turision
tendance à baisser le
contrepoids p deviendra piedoni.
nant; fera Casculer l'avonture
2/3 à gauche et aure pour effet
de faire toumir la bobine bs
au
олча
a
une
en ſers invert pour enlever
Du invenit distributeur la résistanc
an rétablissement Fre
siécessaire
rigine de la
li
consormation?
Coute la distribution est
En résumé:
Noni revendiquons.
notie invertion
1½ l'emploi du fil et –
Incoinant de retour
quee
Cond
2544
définis et distingues de retour give..
ral. Des courants à firome:
a
އ
Qe
courant de retour à pour buteniqu
d'apporter à l'roine, in partant
އ
d'un point convenablement choivi
les indications sans lequelles it
sams
in serait pas possible de donner
2.
à l'énciosion unse
a
drection rigu
верочно
lière inbordoniée aux besoins de
la consommation.
ля
sion que
20 Le régulateur d'éminis.
nous avons décrit et qui
pour but de régler automati-
quement la force électroniatria
De l'usine.
Одв
20
ف
сё
39. Lé régulateur d'énergie
natim.
он де
сол
course
22
Mais
ce que nous vison
tout particulièrement dans le présent
artificat d'addition, nous
le répétons,
c'est le courant de retour, pastaus
Dim
све
De plerocerend pornité-
extrêmes, et aboutissarit à l'usine
pour donner les indications néceſ_
daires
ал
réglage de l'einession
suivant : les besoins, ſoit à la
mami soit areto
soit automatiquement
au visagen
Du dispositif. Décrit
2545
Trois moto varjes mulo
et me renvoi d'un mot,
filus haut
Paris, le 19 Mars 1881
P. Gravier
этой
Signé : Annengard raine.
le
ا خبر میده
Paris, to ffamil
Pour axpedition certifice conferme
hef du Burcaude la Propriété Industrielie
Sycher
SIMERCE INTERIEUR.
Aureau
A PROPRIÉTÉ
INDSTR
2546
р
رقی است و به
Fig. 1
เมาก
fois le 22
Amune
Portifiento.
1881/v
P..
A
B
2.
Courant local
terceseenement
Fig.
¡dxe de l'arm at
um
2
courant local.
2547
M. C. I. ot G. —
Série G bis, nº 1.
RÉPUBLIQUE FRANÇAISE.
MINISTÈRE DU COMMERCE, DE L'INDUSTRIE ET DES COLONIES.
BREVETS D'INVENTION.
Mémoire deSCRIPTIF annexé au
تورد
Certificat d'additions
pris le 10 Joven 1871 par le
tiene Gravier (A.), ingésimur,
به
если
supr. surite pour le sieur
Armengand am
que At Sébastices
et.
te-catinchans
سه کننده
d'invention
Paris,
ریامی منن
އ
Gravels
be quings and
pris le & Juin
6. & Juin 1970, pour
Jera céde
distributions
applicable
"
Le
le
de l'ébotricité
la production
de la lumière électrique
61
D'autres utages.
Daddition
e-t
Cedis Certificat)
a été Vélimé pa
arrêtés du Ministre de
l'Agriculture et du Commer
in dobi der 28 acit 1987.
こ
​2548
be
f
Durch no 187.838.
Capose
La proxiente devonde
certificats d'addition a
bustion the ruttneter. a
mar: Crever.
впрек
ви
primitif ou
& Juris 1880 divers perpe
tionners inli
porter en
que j'ai ap-
گر
en nie d'ebtenir
mis homme, distribution et
un meilleurs répartition.
de l'électricity.
RA.
free sent
lution et placié..
centre inima-
ди
You residin
elles envoie autour d'elley
qu'elles
et dans toutes les Rications
des courants électrs gover
pain.
les applications
diverted auxquelles pent
denner here: l'emplar de
l'électricitie.
Mais ils pout
2549
en stre
autremerat
à
L'using peut avoir.
satisfaire d'autres
que
rettes
Les prin
bis prix
l'entrer
exigentend
de sa destination:
au perrains
An.
charbers
la sécurité publiqu
et d'autres considérations
ре
la
pourront influer sur
rétermination de sa plan
рвом
an las fixer hars de
villy
·la
bela étan,
pour recrpolir les conditions
nécessaires
Je distribution
at attirer
'un réseau.
ты
Тенностей.
la functions
Волостя
reservave, les défentes terart
érdemoment plus grandes,
I faudra des conducteurs
de sections doubles. paur
The dans les mêmes
Cors..
ditions quos précédemment
дляг
c'est à dire lorsque l'uding
ist centrale...
П. венскогу
все.
difficult in faisait a
1. B. Girand
a.
2550
appris à faire jour
Jaz
L
ز
Distribution,
Ce recipient de
vera mine."
batter scceridaire.
Plante
2.4.1..
Re M
taeste austra
словос
avour l'importance you
canvient:
in ploisi surtoret plus enco
пределен в
Ce reciprinol
On distributions an distributeur
con Fisheri
н
massi
métalliqu De la meilleur.
conduétibilité : possible.
حت
Jen l'en
ERIGE
lim ou l'autre
3. recipient de distribution
sina placé
plusieurs points
Suivant
eri
C-E-
ден
Eu reteau.
Qu
l'importauss: de
Je n'ai pas
ici l'éléiment-
a
décrire
de M. Flanter
Gille
sccondaires
est connue parlared_
Grant à la
2551
masti me
metalliques)
The
forme ratiurmelkes
calle
En t
phere
О. лицу Дели первечко
de toutes
quant
Igua
L
terest.
autres figures.
un point I
sous les points.
The
نے ہے۔
سے کہتے
surface extérieure, Eest
cette forme que
arce
'd-24-2
дей
& muncimur,
pourra exceplayer b
De métal
ellari dane
commandé par mati.
d'économiing
tex
Four finer les
::
vidées sur l'enefoler es
(Importance) de votre vier-
pient de distribution, j'au
ам еже
Ex
un dessin
a prident miseri
referédenlant
plusieurs dispositifs
Bescription.
Dans la figur
q. Que dessins suppose.
تے
any ville renference Laws
-périmètres A, B, C, D, E, F, G, H,
2552
1, J.K. L'usine
a
the places
exterieusement in X. La
masse métallique
récipient de distributions
Vens splacées in centrey
de la distribution, it com
réuning à l'usine par le
calle conduction
a
е
ei ac
cible d'émissions ett tant
fair indépendant de la
distributions
ent n'a d'autre
севый
service que celui
récipient &
pil de no tour
де
Bu
De V, ju
fais partir l'arigine
sur le plais
piiris
سنت
Ba
I manque
ހ
en prointitle
be ein même point
V partent dans tailes te
directions des conducteurs
а
agaut bi dimentions
nécessaires poux. Jonctionner
comme réservair
Ces conducteurs
tout retias
par des conducteurs trans
principaux
vertaux. b
l'électricité!
tes directions
ques partent
daus tautas
en Zant
U
2553
toutes les must
:
Je places are !
l'arging du courant
& retour
et
an vs.
Je mor
regulateur J'émer
simus, je finis la teutic is
a récipient.
Enes
la
valeur
t
valeir
quer
дис
l'expériences
J'a labh
l'éterminée
mixit l'été mincé et que
je veux
maintenir. constant.
dan's tait lig réseau
On comprend
sans peis. que Cas
électrique to nevtra
touts on VA
camd
l'usine lui
invoice) dant ('unité de
س
tempt; in voluming d'électri
cité précisément
à celui
que
égal
in sexti
Le recipient.
de distribations & remplace
non seulement Insive gear
нам
serait placé là
il met Dile point
mmais
point de départ unique
de las distributions
condition
dans la
2. my seurey
2554
infinitable Faut rébillonce
qui rezación de Cuding
inplant pare instant
la quantité d'érierques
par la contaminaties.
Decardie
Le rôle princisual.
appartient au récipient
de distribution Clecting
n'a plus qu
lame rate
eth dait obéin
بافندگی
penstuellement aux or
curvoyés du récipient
силазый выле
Passej
Eray
der tour.
Cats egiality
par b
pourra itre détruite
le fait même
mén
avilammation,
-inine gare.
équititer
suite
کے نے
کے
ކއލކ
the retire
a
lien fran
exagerator
ok. la dépointe) bernardin
a
un soul, convince tour
магу
unand
ޙ
Женские
distributeur t
ра
a
imrication & établies endre
laves per drous a' révélhi
l'équilibre, par les extrinski
in même
Clie
2555
дий
. temps qui.
d'émissions
que Cative
reque
aniti
are le
урам
de retour rétablis
la tiutions t
esl
celle de l'émissions
aug mesitut
drus
la proportions nécestave four.
агре
препе
aminer en V. le volume
Imande par là consommation.
évident.
canchicteur
Mest bien
dans chaque
eten
ен ск
chaque
point, par cela même
を
​y a moureinent le
пе
=
мину
tension différente égale
qu'il
ди
Sébit se fera
fera sant
دے سکتے
...
représentant
de la souve
dans l
la tension,
le récip
récipient V, ea
↑ la tention
avi se
el
au
ހ
ек
Project
fair le sikis bette
différences were très petites
fair, étant admis
conducteurs fenation-
Coming reterisic
que le
neut
te plies
!а аксинес
مصر
importante au point de
me du contourmateur, car,
cean I fant
>
fant à cetur cé
2556
c'est my tension
frute
•
au variant
une. this pretite limites
не
cons.
Dans une
distributions plus importante.
il serait
Amenéreux
difficile
pour arriver.
à bien desservir les
extrémités du réseau, ons
multiplierach, Ass
Марокко
terait les récipients v
des
a
دسنس
luraliter à cantonne aleir
important leaquels seraient
afors alimentei indipendiumrent
: is uns des autres, sino
par récipient central
V, sat- directement = par
l'using axinte que l'indiquent
les dispositys, figures. 2 x2
Ат
Esans chaque &
cas
qui
sera Determiné
а
J'écono
l'étude
snie
question
Decidera
Dans tous lai
chaque récipient t
mis n
Convina micalico)
les autres par
a
dor.
fil de
مروز
arze
tes extrauites,
restaur
2557
same regulateur d'émission
L'uting
'central.
Stat.....
in récipient.
pient
...>
ligen
Je n
ducteurt
L'emploi du réca
de distribution instal
fair permeta
employer de
Gwly
grat
grat con-
лич
عم
la
QM
faibles longueurs ende les
placer toujour la
sout le plus writes. Con
mot, il asture)
répartition
черн
Corne
в
de l'électricit
dans le réseau
minimans
aree
de defpeartedil
constitive, une rettenray
-impartante
en ce qu'il
met l'uting
en
quelque
че
sarti an. lice même de la
consommation
L'empler du
вы
récipient distributeur, per-
wat dand certains
ear
de be passer dus fil de
retena
висит
ears
Aucun avan
avantage économique
tantifurt
Jestions toulifurs à l
mentionsser Juni entiver
можу
2558
J'in der
la contrefaço
ди
ane point
V
il dait
avoir.
uke...
tention
constavili
mais
coviant
ق یہ ہے ت
la
dans. by
Frirsé
avoin.
l'usin doit
ettit
que soir
granber
-Joctobr
f.
tection
T'
Hautes- plat
Fautet
Jils
yen tarte qui I
sans laquelle
2
Jair le débit
HE
de l'using
est – variable. C'est à l'aide
fill de retour
et
برسات
régulation d'émissions qui
I has variations
à l'using
Gaur se
bin fil de retour
d'exposer
E
retean.
conserver..
се
سان سے جا کے سخت سے خوب
passin
incel & Hersie
Fandrac
y t
panti rateur.
El..
la plus
que n
perant Gas du tout ceous-
mique.
سے لگے 2ue
point de bain
de la production_
point-de
point de no
pia le
ai
des pertes
Files an défaut.
2559
Deux arts wels.
I statement.
Résume?
D'après la définitions
як в
et le sent
an re
cat
que j'ai donné
récipient I de distributions.
Je revendiquer l'emploi, pour.
Lutage spécial, voir di
l'ékment secondaire de M.
Plavile soir plus-simplement.
et plus économique vint-
the métalliques clic
-usy smadze
à l'uding par le fil de
retours you
régulatur.
CONMR-ka
ހއ
J'émission.
Paris, & 10 Jorin 1879.
4. PC Gravin.
Ligna damningand more!
Paris, to M and
1301
Peay expedition certifice anfilme.
Lelief du Puccauve la Promiété Industriel",
2560
Fig. 1
waisce fome
Come Profafina de Dition
Jilets jun 1881 par le
J. Gramin
Furier
ر
به شهریه
A
J
R
2
X
I
D
20
H
7
3 ht
X
Fig. 3
X
Translation of Gravier French Patent-1880-1. 2561
Complainant's Exhibit Official Transla-
tion of French Patent to M. Gravier,
and Certificates of Addition thereto.
[2—175a].
DEPARTMENT OF THE INTERIOR,
[Coat of Arms.]
UNITED STATES PATENT OFFICE.
TO ALL PERSONS TO WHOM THESE PRESENTS SHALL
COME, GREETING :
This is to Certify, That the annexed is a Translation
made by the Official Translator from the Bound Vol-
umes of the Library of this Office, of the Specification
of the French Letters Patent granted to Mr. Gravier,
June 3, 1880, No. 137,033, for a New Process of Dis-
tribution of electricity, and also of the first, second and
third Certificates of Addition to said Patent.
Attached hereto is a Tracing of the Drawing (Fig. 1)
of said Patent, and Tracings of the Drawings (Figs. 2
to 5) of said first Certificate of Addition; Tracings of
Drawings (Figs. 6 and 7) of said second Certificate of
Addition, and Tracings of Drawings (Figs. 8 to 10) of
said third Certificate of Addition.
[SEAL]
In testimony whereof, I, C. E. MITCHELL,
Commissioner of Patents, have caused
the Seal of the Patent Office to be
affixed this 5th day of March, in the
year of our Lord one thousand eight
hundred and ninety-one, and of the
Independence of the United States
the one hundred and fifteenth.
C. E. MITCHELL,
Commissioner.
E. Sz.
R. E. M.
2562 Translation of Gravier French Patent-1880-1.
FRENCH PATENT 137,033, JUNE 3, 1880.
To Mr. Gravier, for a new process of distribution of
electricity, applicable to the production of electric
light and other uses.
Pl. VI., Fig. 1..
I assimilate the distribution of electricity to that of
gas.
As in gas works, there are:
1° A factory, factory of electricity which, reduced to
its simples, is represented by a hydro-electric or
thermo-electric battery or a dynamo-electric machine;
2º A conduit of emission which I call, for the case of
electricity, emission conductor;
3° Distributing conduits which I call distributing
conductors or simply conductors;
4º Receivers, light apparatus, if it is a question of
lighting.
These various essential parts of an electric distribu-
tion must fulfil the same conditions as a gas distribu-
tion, that is:
The electric factory must produce and furnish the
electricity in proportion to the needs of consumption.
The emitting conduit must operate as a reservoir,
that is, with as little resistance as possible.
The distributing conductors should be so established
as to allow to pass only the amount of electricity neces-
sary for the apparatus served.
The receivers should act independently of each other,
that is, so that you could light or put out any number
of lights without troubling the service of the others.
All these conditions have been realized, starting from
the laws of Joule and Ohm.
According to Joule, the sum of energy transformed
into electricity which can be furnished by an electric
factory:
(1)
W=IE,
I expressing the number of webers;
E expressing the number of volts.
Translation of Gravier French Patent--1880-1. 2563
Evidently, to divide these products by n receivers, it
suffices to make
W IE,
(2)
whence
(3)
n
п
IE
W=n⋅
ጎ
The laws of Ohm give for I and E the following re-
lation:
(4)
I=
E,
R
If, in equation (1), we replace I by its value
shall have:
(5)
E2
W=
R.
E
we
R,
Consequently, equations (2) and (3) become respect-
ively:
W E2
(6)
(7)
N
n R
E 2
W=n
n R
Now, R represents the sum of the resistances trav-
ersed by the energy current IE, and which are :
1º The resistance of the generator Re;
2º The resistance of the emission conductor Re;
3° The resistance of the distributing conductors Ra;
4° The resistance of the voltaic arc in the lights Rª.
1
From this, equation (6), which represents the th
part of the total energy, becomes
n
W
E2
N
n (R® + Rº + Rª + Rª)
2564 Translation of Gravier French Patent-1880-1.
and indicates that we must multiply by n each of the
resistances Rº, Re, Rª, Rª, that is, make them n times
as great.
There are no other conditions to fulfil.
If they are filled for each receiver, the distribution
is perfect, except for losses, and moreover each receiver
operates independently of the others.
Experience has shown me the accuracy of the theory
for one, two, three or four Serrin regulators, fed, accord-
ing to the conditions of formula (8), by a single current
from a Gramme machine, type A.
Nothing prevents these conditions from being ful-
filled for any number of receivers.
Natural conditions for execution.-Lighting a work-
shop by means of a Gramme machine, for instance, and
three Serrin regulators.
According to formula (8) the conditions of distribu-
tion with three lights are for each :
W
3
E2
or
E2
3(Rɛ+Re+Rª +Rª ) ˜¯¯3 kº +3Rª +3R® +3 Rº,
which signifies that to divide into three equal parts the
E2
R,
product W or IE or it would be necessary:
1° That the circuit of the primary or inducing be
made of three wires instead of one, three wires of the
same length as the single wire, but of a cross-section of
one-third.
2º That the circuit of emission, as well as the circuit
of distribution, be composed of three wires, each having
three times as much resistance as the single conductor
it represents, when all three act at once.
3° In the lamps, that the carbon employed have a
section three times as small as that of the single carbon
to be burned by the total current.
But all these conditions are not practicably realiz-
able. In fact, we cannot touch the resistance of the
generator; we can make it more or less resistant, that
is all.
Translation of Gravier French Patent--1880-1. 2565
It is the same, in general, with the emission con-
ductor.
To render them as innocuous as possible, they must
be made as little resistant as possible, a thing that can
always be done.
The expression
W
(8)
n
E2
n (R² + R® + Ra + Rª)
becomes, since we can touch neither R nor Re,
(9)
W
n
<
E2
R® +R + n + nha
This will approach equality in proportion as R and
Re are made smaller.
Application. We have a Gramme machine, which has,
considering only the induced circuit, 0.10 ohm, and
which furnishes a current of 30 webers and of 100
volts.
We have, according to Joule, for the expression
W = EI = 30 webers x 100 volts = 3,000,
if the total circuit has
100 volts
R=
= 3.33 ohns.
30 webers
Then, R must be :
R = R +Re+ Rd + Rª.
We shall have, in the case in question:
0.10 ohms
Resistance of the generator Re..
Resistance of emission conductor Re..
Resistance of the distributing conductor Rd
Resistance of the arc Rª, † 3.33.
Total resistance R
0.15
1.42
1.66
((
((
3.33
2566 Translation of Gravier French Patent--1880-1.
The above conditions are those of the resistances of
a distribution which would have a lamp fed by the
total current of a Gramme machine.
In the case of two lamps utilizing all the source, we
shall have by formula (9), for one lamp:
W
1002
2
0.10 +0.15+ (2 × 1.42) + (2 × 1.66)
1,560 instead of 1,500.
In case of three lamps utilizing together all the
source, we shall have for one lamp :
W
1002
3
0.10 +0.15+ (3 × 1.42) + (3 × 1.66)
< 1,053 instead of 1,000.
In case of four lamps utilizing all the source, we
have for one lamp :
W
4
1002
0.10 +0.15+ (4 × 1.42) + (4 × 1.66)
< 795 instead of 750.
Fig. 1 represents the diagram of the material arrange-
ments for a distribution with three lamps.
A, B, clamp screws of the generator where R = 0.10
ohms.
A a, Bb, emission conductors where R = 0.15.
D, distributor formed of an insulating board on
which is placed :
1° The clamp screws for the entry and exit of the
current;
2° The interrupters, one for each distributing cir-
cuit.
c, d, distributing conductors fixed at one end of the
clamp screws of the distributor D, and at the other to
the lamps.
Translation of Gravier French Patent-1880-1. 2567
As the three lamps must each have the same in-
tensity, each has for resistance:
3Rd or 3 × 1.42 ohms = 4.26 ohms.
L, L¹, L', lamps, Serrin or otherwise.
The resistance of each, that is, of the arcs, is regu-
lated at:
3 x 1.66 4.98 ohms.
=
Experience has shown us that in a lamp utilizing all
the current we can burn carbon 16 millimeters in diam-
eter (Carre manufacture). Consequently the three
lamps forming the object of this distribution will have
carbons three times as small, that is, of about 9 mil-
limeters.
Operation. The induction machine makes 900 revo-
lutions a minute, I shall suppose. All the circuits are
open. The machine producing no electricity.
Let us close one of the three distributing circuits,
that of lamp L. This lamp will light and burn giving
a luminous intensity proportionate to the intensity of
the current furnished it, and which is:
W
1002
3 0.10 +0.15+ (3 × 1.42) + (3 × 1.66)
1,053
instead of
W
10,000
= 1,000.
3 3 x 3.33
10,000
9.49
Now, let us close the circuit of the two lamps,
L, L¹.
These two lamps light up together, and burn giving
a luminous intensity proportional to the energy fur-
nished them, and which is:
2568 Translation of Gravier French Patent-1880-1.
W
10,000
3
0.10 +0.15+ (3 × 1.42) + (3 × 1.66)
2
2
2
instead of
W
10,000
= 2,000
3
3 x 3.33
2
2
=
2,053,
When the three circuits are closed on the lamps L,
L¹, L², we have :
W
10,000
3,000
3
0.10+ 0.15 + 1.42 + 1.66
3
3
3
3
10
3
We see in this application that the conditions of the
programme are realized, that is:
1º Factory producing and emitting electricity in pro-
portion to the requirements of lighting;
2º Emission conductor operating very nearly as a
reservoir without resistance;
3° Distributing conductor giving electricity to the
receivers which they serve, according to the conditions
for which they were set up
4° Receivers operating with perfect independence.
In fact, in the most favorable case, that where only one
lamp is lighted, that lamp, instead of giving the third
of the light produced by the three together, gives an
intensity augmented by 5 to 6%; this variation is less
than that produced every day by gas lighting, where
we not infrequently find variations of 30, 40 or 50 %.
We can say that the distribution so made is prac-
tically satisfactory.
It is these exterior arrangements, independent of the
machines and also of the system of lamps, that we
Translation of Gravier French Patent.-1880-1. 2569
claim in our invention and which we intend to patent;
they have not been taken out by any one else before
us, since the division of light indicated by us has never
yet been realized.
The "Société pour L'exploitation des procédés Wer-
dermann" employs derived circuits just as we do, but
with the condition of using a second derivation of
equal resistance, a condition which has for result to
make the dynamo always work for the total illumina-
tion, whether one lamp or all are lighted.
Mr. Reynier uses different arrangements, but with
the same inconveniences; that is, that whether the
light were reduced to a single lamp or were complete
the machine always consumes the same work.
""
With alternative currents, the "Société générale
puts several candles on the same circuit or series, but
these candles are absolutely independent. One single
one going out carries along all the rest of the same cir-
cuit (??????).
Messrs. Siemens and Halske also practise the divi-
sion in the manner of the " Société générale ; " it gets
rid of the mutual independence by using a derived cur-
rent like that of Mr. Reynier.
We find in these ar-
rangements the same inconveniences. The machine
always works as if the illumination were complete, what-
ever the number of lamps burning.
Mr. Lontin also practices division; he uses several
circuits, but the lamps are dependent on each other.
None of these systems effect the division as it should
be understood, as we have defined it.
To resume, this invention consists in the application,
absolutely novel, of derived circuits, calculated accord-
ing to the laws of Joule and Ohm, and arranged as in
formula 8 and 9:
1º To distribute any source of electricity in deter-
mined proportions in an establishment containing a
certain number of apparatus.
2° To preserve to each apparatus the intensity
required.
3º To assure them their mutual independence, in
2570 Translation of Gravier French Patent-1880-1.
such manner that we can, at any instant and at will,
light or extinguish any without troubling the operation
of the others, in such manner that the production and
emission of electricity are always in proportion to the
needs of the lighting.
In our explanations we have always considered light-
ng as the object of the distribution, but it is well un-
derstood that we reserve the application of this
to all receivers utilizing electricity.
process
FIRST CERTIFICATE, NOVEMBER 9TH, 1880.
Plate VI., Figs. 2 to 5.
In the electric distribution, object of the patent, I
defined the conditions which each part must fulfil.
Practice having shown me their insufficiency, I have
been led to make the following modification :
1° Mode of Interruption.-The object of the inter-
rupter is simply to close and open the circuit which
it serves, to give passage to the current or to inter-
rupt it.
In practice this is not sufficient; it is absolutely
necessary that the lamp and its entire circuit should be
removed from the distribution; this is why: when you
open the circuit of one lamp to put it out there is pro-
duced in this circuit an induction current which reacts
momentarily on the rest of the distribution in a con-
trary direction to the current from the electric source;
it results from this that several lamps will go out if the
source is not more powerful than is necessary for the
service of lighting.
To obviate this inconvenience I entirely remove the
lamp and its whole circuit from the distribution.
Fig. 2, front view.
Fig. 3, section on line I-2 of an arrangement applied
for one lamp; it is composed of a piece P, prismatic or
cylindric, of ebonite or other insulating substance,
movable; about the centre o it carries two contacts, ca,
Translation of Gravier French Patent-1880-1. 2571
cb, of brass, of a such size that the two systems of
nickel-plated iron springs a a, b b′ can find room upon
them, and be sufficiently far apart for the spark of the
extra current not to be able to traverse the space.
The springs a, b are in electric communication with
the clamp screws A, B, where the outgoing conductors
end; the two other springs a', b' are fixed to the clamp
screws N, L.
Figs. 1, 2 and 3 show clearly that in the position indi-
cated of the prism P the current may pass, and that if,
by means of the handle m, we make a quarter of a turn
in one direction or the other, the lamp and its circuit
are placed out of the distribution.
In this manner the current induced on itself in the
circuit, being placed out of the distribution, has no
effect on the remaining apparatus.
Figs. 2 and 3 show only one cut-out. A certain num-
ber of these united on a single table constitute my dis-
tributor.
2° Distributing conductors.-The distributing con-
ductors have for object, by their resistances, which I
have fixed, to put a lamp in a determined position of
intensity, constancy and complete independence.
The first of the conditions is difficult to realize in
practice, because commercial wires are more or less
homogeneous, of more or less regular diameter.
If you
calculate the coarseness necessary for a given
resistance in length so as to obtain lights of equal in-
tensity, it almost always happens that we are obliged
to lengthen or shorten the circuit to obtain the desired
equality.
To avoid the necessity for repeated experiments,
which everybody is not in a condition to make, I place
in each distributing circuit a thumb switch which I call
a leveler, and which permits me to give more or less
electricity and to fix the level of the luminous intensity
in each lamp.
This arrangement is composed essentially of a resist-
ance box, Figs. 4 and 5, in the interior of which is ar-
ranged an iron wire, inned, nickeled or silvered, ser-
2572 Translation of Gravier French Patent-1880-1.
pentining from c to d, from d to c', . . . from cm to dº,
from d" to c", and ending in the clamp screw L.
This wire is placed in connection with the source by
the clamp screw A, the switch C, movable around the
center o, and which forms a contact on the small pieces
of brass c, c', cm, ch.
According to this description, we see the operation :
the current from the distributor, clamp screw N, arrives
at the clamp screw A of the leveler, passes through the
switch c through the clamp screw L, following the re-
sistance wire in all its circumvolutions, as far as the
contact of the switch, goes into the lamp, and comes
back to the distributor through the clamp screw L, and
to the source by the outgoing conductor B.
In these new conditions, as I have announced, the
electric source furnishes at each instant the electricity
necessary for each lamp, and in proportion to the num-
ber of lamps lighted.
The motive work done is in proportion to the num-
ber of lamps lighted and to their intensity.
Each light is proportional to the number of webers
multiplied by the volts which traverses the electrodes.
The independence of each apparatus is complete.
To resume, I claim:
1° The distributor so arranged as to remove each
lamp and its entire circuit from the distribution.
2° The light equalizer (leveler), that is to say, the
apparatus which, under the form described or any other
analogous one, allows of leveling the luminous intensity
of the lighting apparatus.
SECOND CERTIFICATE, MARCH 22D, 1881.
Pl. VI., Figs. 6 and 7.
In the patent we have considered only one case of the
distribution of electricity, that which corresponds to
the receiver state of the outgoing network.
We have shown by mathematics that the receiver
Translation of Gravier French Patent-1880-1. 2573
state is the condition necessary and sufficient to have a
distribution of electricity as simple as that of gas but
more nearly perfect.
The central station in this case produces and emits
the electricity under a constant tension, but in quanti-
ties varying with the consumption.
In practice a second case presents itself; it is that
which corresponds to an entirely different situation
from that which we have defined and characterized
under the name of receiver.
This situation begins when, in consequence of the
extension of the consumption of the electricity, the con-
ductors no longer suffice for the needs of the consump-
tion at certain points of the distribution.
After having passed the receiver (reservoir) state,
these conductors become veritable drainage canals, in
which, necessarily, the disposable electric energy is
more feeble down stream than up.
If in these conditions the central station continues to
produce under constant tension, there will be points
down stream insufficiently served at certain hours of
consumption, and this deficit will be the more accentu-
ated as the consumption up stream is greater.
As soon as this situation begins to subsist, the cen-
tral station must change its conditions, modify the out-
put to supply the deficit which tends to arise at the
most remote points; it should vary the electro-motive
force of the output so as to cause to arrive at the
feeblest points the sum of energy which is wanting
there.
This result can be attained by hand or automatically
by varying either the changes of the current for a con-
stant magnetic field or the inducing magnetic fiefd for
a constant rapidity of changes.
But in all cases the central station, in order to oper-
ate unfailingly at the proper time and to a useful de-
gree, should be informed at the very instant that dis-
turbance is produced; without this, nothing.
If at the exit and re-entry of the current at the cen-
tral station we place Deprez galvanometers with coarse
2574 Translation of Gravier French Patent-1880–1.
and fine wire, we shall have the exact state of con-
sumption at each moment, but no indication of the re-
quirements.
On the contrary, if at the feeblest point as recognized
in practice in the distribution we form a branch cur-
rent which we take back to the central station by
means of a special wire, and which we cause to pass
into a Deprez fine wire galvanometer, we shall have at
each instant the true situation at that point, hence the
head of the central station can act with all knowledge
of the case.
We call this special current the return current, and
the wire which brings it to the central station the re-
turn wire.
The employment of this current is the principal
feature of the distribution; when the outgoing conduc-
tors have ceased to act as reservoirs, without it emis-
sion is no longer possible; there would be the most
complete disorder.
By being satisfied with the indications of the galvan-
ometer furnished by the return current for varying the
electro-motive force of the central station, we should
have a plant very simple as an apparatus, but it would
require the most attentive watching te make the cor-
rections required.
To avoid this sustained attention, which is impossible
for human beings and which can therefore not be
counted on, we employ the following arrangement
which we are about to describe, and which we call
emission regulator; is composed of:
1º An electro-magnet A B, whose bobbin, provided
with fine wire, is traversed by the return current ;
2º A rocking armature a B, mounted like a balance
beam on a knife edge forming a prolongation of the
pole A.
A counter weight p serves to balance it when a cur-
rent of determined strength energizes the electro-
magnet; it bears at each side contacts ct, c't', ar-
ranged as shown in Fig. 2 of the diagram, whose object
Translation of Gravier French Patent-1880-1, 2575
is to close a local circuit over the rotary bobbins b s, first
in one direction and then in another.
3º A rotary armature bs (Siemens bobbins modified
by Mr. Trouve or otherwise.)
This bobbin, energized on one hand by the electro-
magnet A B, and on the other hand by a local current,
turns first to the right and then to the left, according
as the armature a B rocks to the right or to the left.
This bobbin bears upon its prolonged axis, on the
outside, an endless screw driving a toothed wheel and
acting by means of the same either on a steam engine
to moderate its speed, or on a series of resistances to
modify the intensity of the magnetic field.
Operation.—Three cases are presented :
1° The network acts as a reservoir ;
2° The network having ceased to act as a reservoir,
by reason of the increase of consumption, the remotest
points are feebly served;
3º The network operating all the time as a drainage
canal, the remotest points, by reason of the decrease
in general consumption, receive an excess of elec-
tricity.
In the first case, everything being in a normal con-
dition at the most remote point, the energy of the re-
turn current is constant, the armature a B remains in
equilibrium, and the central station produces and emits
electricity under constant tension, but varying in quan-
tity with the consumption itself.
In the second case, the consumption increasing there
comes a moment when the emission conductors become
insufficient; we then see the energy of the return cur-
rent decrease; the armature, no longer in equilibrium,
rocks under the influence of the weight p, closes the
local circuit on the left over the bobbin b s, and turns
in a suitable direction to turn the changes of current
more rapidly or to diminish the resistance of the in-
ducing circuit or circuits.
The electro-motive force of emission increases, and
you will soon see the action of the return current re-
establish the equilibrium of the armature a B; this
2576 Translation of Gravier French Patent-1880-1.
takes place until the moment when the emission con-
ductors become reservoirs again.
In the third case, the consumption decreases in con-
sequence of the extinctions or the cessation of the
work; the factory working always under the tension
required of it, the energy of return tends to rise; then
the electro-magnetism becomes predominant in its turn,
rocks the armature a B to the right, closes the local
circuit on this side, and turns the bobbin to the right
to diminish the rapidity of the changes of current or
increase the resistance of the inducing circuits.
The electro-motive force of emission lowers, and we
soon see the action of the return current re-establish
the equilibrium of the armature a B; this takes place
till the moment when the conductors of emission again
become reservoirs.
It is then that the central station resumes its original
conditions, operating under constant tension until the
cessation of all consumption, as is perfectly indicated
by registers of energy placed one on the outgoing cir-
cuit, at the exit from the central station, the other on
the return circuit.
When there is no more consumption in the city, if
there are no leaks the indications will be identical.
We have just seen that, when the emission circuit or
network does not operate as a reservoir, it is necessary
that the central station shall modify its electro-motive
force of emission in the direction indicated by the re-
turn current, to cause the amount of energy required to
reach the remotest point.
But would not this correction, necessitated by the
remotest point, introduce a certain amount of trouble
into the other points of the distribution? Evidently
it cannot be otherwise, because if we raise the electro-
motive force for this single point which is the feeblest
all the others are subjected to the consequences of this
fact.
To obviate this, each subscriber will have at his dis-
posal, to regulate his consumption, a means analogous
to that which the central station uses to regulate its
Translation of Gravier French Patent--1880-1. 2577
electro-motive force according to the requirements of
consumption. We shall use for this purpose the
apparatus shown in Fig. 6, and described above as
emission regulator. We shall call it energy or con-
sumption regulator of the same parts:
1° An electro-magnet A B, furnished with fine
wire;
2° A beam armature a B ;
3° A rotary armature bs (Siemens bobbin modified
by Mr. Trouve, or otherwise).
Here there is no return current; the correcting cur-
rent is set up in the subscriber's own house.
When the tension tends to rise, the electro-magnetic
energy of A B will attain the upper hand, will make the
armature a B rock and so close a local circuit which
will turn the bobbin b s in the direction desired to in-
troduce into the distributing circuit the resistance
necessary for the re-establishment of the equilibrium
of the armature a B, which corresponds to the rate of
consumption.
On the contrary, when the tension will have a ten-
dency to drop, the counter weight p will become pre-
dominant, will rock the armature a B to the left, and
will turn the bobbin bs in the opposite direction, to
take away from the distributing circuit the resistance.
necessary for the re-establishment of the rate of con-
sumption. All the distribution is in this.
To resume, we claim :
1º The use of the return wire and current which we
have defined and distinguished from the general return
of currents to the central station; this return current
has for single purpose to bring back to the central sta-
tion, from a point suitably chosen, indications without
which it will not be possible to give to the emissions a
regular direction subordinated to the requirements of
consumption.
2º The emission regulator which we have described,
and which has for object to regulate automatically the
electro-motive force of the central station;
3º The regulator of energy or consumption.
2578 Translation of Gravier French Patent-1880-1.
But what we aim at particularly in the present
addition, we repeat it, is the return current, starting
at one or more extreme points and ending at the cen-
tral station, to give the indications necessary for regu-
lating the emission according to the requirements
either by hand or automatically, by means of the ar-
rangement described.
THIRD CERTIFICATE, JUNE 10th, 1881.
Pl. VI., Figs. 8 to 10.
The present addition has for object various im-
provements which I have introduced in view of ob-
taining a good distribution and a better apportionment
of electricity.
I have supposed hitherto that the central station is
placed at the very centre of the network, that it sends
around it and in all directions electric currents for the
various applications to which the use of electricity may
give place. But it may be altogether otherwise. The
central station may have to satisfy other exigencies
than those of its destination; the price of ground, the
price of coal, the tariff, public security and other con-
siderations may have influence on the determination of
its position and place it outside of the city. This being
so, in order to fulfil the conditions necessary for a dis-
tributing network for creating and assuring its functions
as a reservoir, the expenses will evidently be greater; it
will require conductors of double the section to reach
the same conditions as before, that is, when the central
station was central.
I turn the difficulty by doing what Mr. H. Giroud
has taught us to do with gas: we employ the distribu-
ting receiver.
This distributing receiver will be a secondary battery
of Mr. Plante, or any other having the suitable im-
portance.
More simply, and, above all, more economically, the
distributing receiver or distributer will consist of a
mass of metal of the best possible conduction power.
Translation of Gravier French Patent-1880-1. 2579
Whichever is employed, this distributing receiver
will be placed in one or more points of the network,
according to the importance of the same.
I do not have to describe here the secondary battery
of Mr. Plante, which is universally known.
As to the mass of metal, its shape is rationally that
of half a sphere, or any other figures which have a
point equally distant from all the points of the exterior
surface. This shape allows the use of the minimum of
metal; it is therefore recommended by motives of
economy.
To fix one's ideas on the use and importance of our
distributing receiver, the drawing of the present addi-
tion shows several arrangements thereof.
In Fig. 8 I suppose a city enclosed in a circumfer-
ence A B CDEFGHIJK. The central station
has been placed outside at X; the mass of metal or
distributing receiver V is placed at the centre of distri-
bution, and connected with the factory (central station)
by a conducting cable c; this outgoing cable is alto-
gether independent of the distribution, has nothing else
to serve but the receiver V.
From V I start the return wire r, dotted in the draw-
ing; then from this point V there start in all directions
conductors a, having the dimensions necessary to act
as reservoirs.
These principal conductors a are connected by trans-
verse conductors b, which carry electricity in all direc-
tions and into all the streets.
I place at V the starting of the return current, and
by means of my emission regulator I fix the tension in
the receiver at the value t, a value which experience
shall have determined beforehand, and which I wish to
remain constant in all the network.
It is understood without difficulty that the electric
tension t will remain constant in V if the factory sends
to it in a unit of time a volume of electricity precisely
equal to that which goes out.
The distributing receiver V replaces not only the
factory which would be placed there, but it places the
2580 Translation of Gravier French Patent-1880-1.
point V, the sole point of departure of the distribution,
in the condition of an inexhaustible source without re-
sistance, which receives from the factory from one mo-
ment to another the quantity of energy required by the
consumption.
The principal role belongs to the distributing re-
ceiver; the factory has no longer anything but a passive
role; it must at once obey the orders sent from the
receiver by the return current.
This quality might be destroyed by the very fact of
the consumption; but even when this rupture takes
place by reason of the increase of the expenditure
required by a radiating conductor served by the dis-
tributor V, the communications established among them.
all will tend to re-establish the equilibrium by the ends
of the network, at the same time that the emission
regulator, warned by the return current, re-establishes
the tension t by increasing that of the emission in the
proportion necessary to send into V the volume required
by the consumption.
It is evident that in each conductor and at each
point, by reason of the movement, the service will be
made under a different tension, equal to t. t'.
t, tension of the source in the receiver V.
t', tension at the point where the service is ren-
dered.
This difference will be very small in fact, it being ad-
mitted that the conductors act as reservoirs, and, more-
over, is of no importance from the consumer's point of
view, for what he requires is a tension constant or vary-
ing within very small limits.
In a more important distribution, where it would be
difficult or onerous to serve the end of the networks
well, we should multiply, we should bring together the
receivers v of the localities of important consumption,
which would then be fed independently of each other,
either by a central receiver V or directly by the fac-
tory, as shown in the arrangement of Figs. 9 and 10.
In each case economy will decide.
In all cases each receiver V placed in communication
Translation of Gravier French Patent--1880-1. 2581
by the ends has its return wire and its emission regu-
lator at the factory or central receiver.
The intelligent use of the distributing receiver allows
of the use of large conductors only on short lengths,
and of placing them always where they are most
useful.
In one word, it assures a good apportionment of the
electricity in the network with the minimum of ex-
pense; it constitutes an important resource by placing
the factory at the point of consumption.
The use of the distributing receiver permits of dis-
pensing of the return wires in very many cases, but
there is no economical advantage in it. I mention it,
however, to prevent infringement.
I have said that at the point of V we must have con-
stant tension; but in the evening current the factory
must have a tension T, of varying magnitude, so that
Tt, under which the service of the factory is operated,
is variable.
By means of the return wire and the emission regu-
lator we obtain the variations at the factory.
To dispense with the return wire without risking bad
service, it would be necessary to maintain T t at its
highest value, which would be not at all economical as
regards production, as regards the losses by leakage or
defects of insulation.
To resume, according to the definition and sense that
I have given to the distributing receiver, I claim the
employment, for that special use, either of a Plante
secondary battery or, more simply and economically, a
mass of metal connected to the factory by the return
wire which controls the emission regulator.
2583
Bocédé De Distribution, Far M. Gravier
Serie J., Vol. 55, Bage 85, Plate 6.
Frig. 1.
Cond Dialedaleur joka
i
d
Fry. Q
Fig. 4.
a
3'
Fig. 5.
s
B
26
772
A
Z
Frig. 7
Courant isal
TW
22
Frig. 6.
Figs.
Frig 9.
Fig.10
a
a
A
Fig. 5.
Th
Edison Caveat of August 19, 1879. 2585
[2–175. |
Complainant's Exhibit Certified Copy of
Edison Caveat, filed August 19, 1879.
DEPARTMENT OF THE INTERIOR,
[Coat of Arms]
UNITED STATES PATENT OFFICE.
TO ALL PERSONS TO WHOM THESE PRESENTS SHALL
COME, GREETING:
This is to certify that the annexed is a true
copy from the Files of this Office of the Petition, Oath,
Specification and Drawing, in the matter of the Caveat
of Thomas A. Edison, filed August 19, 1879, for Im-
provement in Conductors and Apparatus for Electric
Lights.
[SEAL.]
In testimony whereof, I, C. E. MITCHELL,
Commissioner of Patents, have caused
the seal of the Patent Office to be
affixed this 18th day of June, in the
year of our Lord one thousand eight
hundred and ninety-one, and of the
Independence of the United States
the one hundred and fifteenth.
C. E. MITCHELL,
Commissioner.
2586
Edison Caveat of August 19, 1879.
TO THE HONORABLE COMMISSIONER OF PATENTS OF THE
UNITED STATES:
The petition of THOMAS A. EDISON, of Menlo Park,
in the State of New Jersey, respectfully represents that
your petitioner has invented a certain new and useful
improvement in conductors and apparatus for electric
lights, and that he is now engaged in making experi-
ments for the purpose of perfecting the same prepa-
ratory to his application for letters patent therefor.
He therefore prays that the annexed description of
his said invention may be filed as a caveat in the con-
fidential archives of the Patent Office, and he hereby
requests that all correspondence in said case be directed
to his agent, Lemuel W. Serrell, Box 4689, P. O. New
York City.
Respectfully yours,
Menlo Park, N. J.,
Aug. 14th, 1879.
THOMAS A. EDISON.
Edison Caveat of August 19, 1879. 2587
UNITED STATES OF AMERICA,
MIDDLESEX COUNTY,
State of New Jersey,
SS. :
On this fourteenth day of August in the year one
thousand eight hundred and seventy-nine, before the
subscriber a Notary Public in and for said State,
personally appeared the within named, Thomas A.
Edison, and made solemn oath that he verily believes
himself to be the original and first inventor of the
within described Impt. in Conductors and apparatus for
Electric Lights, and that he does not know and does
not believe that the same was ever before known or
used, and that he is a citizen of the United States, and
a resident of Menlo Park, N. J.
Sworn to before me the day
and year above written.
THOS. A. EDISON.
Stockton L. Griffin.
:Notary
: Public
•
Menlo Park, N. J. :
STOCKTON L. GRIFFIN,
Notary.
2588
Edison Caveat of August 19, 1879.
TO ALL WHOM IT MAY CONCERN:
Be it known that I, THOMAS A. EDISON of Menlo Park,
in the State of New Jersey, have invented an Improve-
ment in Conductors, and apparatus for Electric Lights,
of which the following is a specification:
The object of this invention is to economically sub-
divide the electric light.
The invention consists in devices for producing an
even or equal electromotive force in the circuit, to
moderate the power of the light without the interposi-
tion of devices wasteful of the electric energy.
The method of arranging the conductors is peculiar :
supposing that a section of a quarter of a mile is to be
lighted, and 1000 electric lamps are to be used all ar-
ranged in multiple arc. I first run two conductors the
&
distance from the central station of a certain size and
electrical resistance, to this point I put no lamps across
the two wires; the remaining distance I enlarge the
conductor commencing very large and tapering down to
the size of those from the station or below that size, on
these conductors of increased size, I place say 250
lamps; again from the central station I run two other
conductors to the distance or of a mile and there
connect enlarged conductors until a point is reached
where the large conductors commence on the first cir-
cuit, on this conductor I put 250 more lamps then
another circuit of a mile is run from the central station
of full size, thus up to the points where the lamps are
put on I am enabled to keep the pressure or electro-
motive force constant, hence the difference of fall in
electromotive between the lamps will not take place
gradually from the first lamp to the last lamp of the
1000 lamps as it would if they were all on one circuit,
but will only fall between 250 lamps in two cases of
500 lamps, in one case but if the circuit containing 500
lamps is split up into two circuits then the fall will be
only between the extreme of 250 lamps.
Figure 1 represents three circuits.
Edison Caveat of August 19, 1879. 2589
Fig. 1.
1 and 2d represents the lamp wires of the longest
circuit. N is the central station, c, c¹, are the smaller
leading wires connecting at B B1 with the enlarged
tapering conductors, x, x, x, are lamps, 3 and 4 the
second circuit, and 5 and 6 the shortest circuit.
The electromotive forces will be the same at B B¹,
K K¹, M M¹ hence the difference in the amount of light
given off by the lamp nearest the station and the one
furtherest from the station will only be 12 per cent.
under the most unfavorable condition. The drop in
the electromotive force, between the circuits with no
lamps upon them and when they are all on, is indepen-
dent of the unavoidable drop between the lamps and
may be controlled by hand, or by automatic devices.
When controlled by hand a small wire should be con-
nected to the end of every circuit and returned to the
central station and there connected permanently with
an electromotive by which any drop in the electro-
motive force can be seen at once, and the rise in the
electromotive force may be obtained either by increas-
ing the speed of the engine, or of the Dynamo Machine or
"Excitor" which serves to supply a permanent current
to the field magnets of the inductor bobbins of the
machines of the main conductors the rise may also to a
certain extent be effected automatically.
The field magnets being supplied with current from
an excitor, and the induction bobbin connected to the
line in multiple arc, the latter has one end disconnected
therefrom and the field magnet wound with a separate
coil, over the regular coil, and the bobbin wire con-
nected to one end the other end being connected to
the main conductor. This extra coil has but a fraction
of the resistance of the induction bobbin, thus without
this bobbin the current from the excitor, would, acting
in the field magnet coils, give sufficient magnetism to
cause the induction bobbin to show an electromotive
force of 95 volts which is raised to 100 when the extra
· 2590
Edison Caveat of August 19, 1879.
coil is in circuit. If now lamps are placed on circuit
they tend to cause a drop in the electromotive force of
the induction bobbin, but, the amount of current taken
from the machine being increased this reacts on the
extra coil to create a stronger field magnet and the
drop is prevented, this device is efficacious when the
field magnets do not approach anywhere near their
point of saturation.
Another method consists in winding an extra coil on
the field magnet of the excitor itself of very low resis-
tance, and interpolate it in one of the main conductors,
so that all the current which comes from the combined
bobbins shall pass through this extra coil.
Another plan consists in connecting all the extra
coils of all the main machines in multiple arc and inter-
polating the combined conductor in the main circuit
so that the whole current shall pass through the extra
coils.
The method of increasing and decreasing the amount.
of light from the lamp is as follows, and the device em-
ployed is shown in Fig. 2.
a is the burner, 6 c, the platina wire supports. X,
is an electric engine having resistance 200 times less
than the lamp when the latter is giving maximum light.
K, is the armature, which is kept in rotation by having
the magnet short circuited by break n. Spring m, and
shaft every time the armature approaches the poles, the
short circuit is by wire 22, and p (dotted line to repre-
sent the base).
Qis a break wheel on the revolving shaft, at the
bottom of this wheel there is but little metal the most
part of its circumference being insulating material the
amount of metal on the periphery gradually grows
greater until near its top when the whole circumference
is metal; on this rests permanently a contact spring or
roller h, connected to the lamps by wire 24, on the
lower part rests a spring f which by means of an
adjustant can be slid up or down Q, by the screw G,
the current entering at 23, passes through the lamp
Edison Caveat of August, 19, 1879. 2591
thence to h, through the metal of Q and if the engine
is revolving passes to ƒ each time the metallic portion
of Q comes in contact with f, thence by 20 through the
magnet and to 23 while the engine is revolving the
amount of metal on Q being 5 times less than the in-
sulating substance the lamp only receives of the
energy which it would receive were the surface of Q
wholly metal and this amount of energy is wholly in-
dependent of the speed with which Q revolves, this will
cause the lamp to be brought only to say a dull red.
If now the spring ƒ be raised the amount of total
contact will be increased and more energy will pass to
the lamp, and by this means the spring f may be
raised until it is at a point where the surface of Q is
wholly of metal.
In practice, I arrange Q, so that f, when down to its
lowest limit rests wholly in insulation and an extra
appliance or lever is arranged with the screw G,
whereby an initial motion or start is given the shaft of
the engine when the lamp is to be turned on. It is
obvious that any form of magnetic motor may be used
to give a constant rotation to Q. Even a clock work
would serve to give sufficient motion it being wound
up in the act of turning on the lamps, or a hot air
motor deriving its heat from the lamp might be used
or a vibrating fork-lever, reed may be employed.
My claims will probably hereafter be,
FIRST. The system of electric conductors substantially
as herein described.
SECOND. The method herein described for regulating
the electromotive force, in an electric lighting system.
THIRD. In combination with an electric burner of a
moving break wheel or analogous device of variable
conducting service, so that the circuit may be closed
for a greater or lesser period at each revolution or
movement by moving a contact spring over its periphery
whereby the total energy passing in a circuit may be
regulated substantially as specified.
2592
Edison Caveat of August 19, 1879.
FOURTH. The electric engine X, in combination with
the revolving break wheel Q for the purpose set forth.
Signed by me this 14th day of August, A. D. 1879.
Witnesses-
FRANK MCLAUGHLIN,
S. L. GRIFFIN.
M. P. H.
THOS. A. EDISON.
1
E. D. A.
2593
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Fig. 2.
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Johnson's Cyclopedia-Gas Lighting--1876. 2595
Complainant's Exhibit-Gas Lighting Ex-
tract. Johnson's New Universal Cyclopedia.
Vol. II., p. 456. New York, 1876.
Pressure. As already stated, a certain amount of
pressure is required to force the gas through the street
mains, house meters, pipes and burners. The pressure
is measured by the height of a column of water sup-
ported by the gas in a U-shaped tube, one end of which
is open to the air, while the other is connected with the
gas supply. It is estimated that there should be a
pressure of 1 inch at the entrance to the premises of
every consumer, 0.2 inch being required to force the
gas through the meter, 0.2 inch for the house pipes
and 0.6 inch for the burners. This pressure is exerted
by the weight of the great gas holders at the works.
Were the consumption of gas uniform during the entire
twenty-four hours, the holder could be properly bal-
anced once for all, and a uniform pressure would be ex-
erted at all times-four or five inches are found to be
necessary for large districts-but when no gas is
burned, no pressure is required; and, when little gas is
burned, four or five inches would be excessive. Conse-
quently, the pressure must be graduated according to
the hourly consumption. For this purpose the gov-
ernor, already mentioned, is employed at the works to
regulate the flow, and consequently the pressure, of the
gas from the holder to the street mains. The following
table exhibits the variation in pressure caused by
irregularities of consumption. The holders of the New
York Gas Lighting Company are on East Twenty-first
street; its district extends from Grand street to the
lower end of the island at Whitehall street; Hester
street is well within the district.
PRESSURE OF THE GAS IN INCHES OF WATER.
3 P.M. 4 P.M. 5 P.M. 6 P.M. 7 P.M. 10 P.M. 12 P.M.
Twenty-first street..
Hester street.
Whitehall street.
1.7
2.
5.5
4.2
2.9
1.9
1.0
1.6
1.7
2.4
2.2
1.9
1.6
1.2
1.0
1.
0.6
1.1
1.1
1.0
0.8
•
2596 Johnson's Cyclopedia-Gas Lighting-1876.
It is thus seen that a uniform pressure throughout
the district supplied is absolutely impossible. In order
to secure a sufficient pressure at the extremities of the
district, an excessive pressure must be produced at the
intermediate points; and as the pressure must be varied
from hour to hour at the works, it will vary at the prem-
ises of most of the consumers. The consumer must,
therefore, regulate the pressure for himself: (1) by care-
fully adjusting the main cock at the meter; (2) by ad-
justing the cock at each burner; (3) by using check
burners; (4) by attaching a regulator at the meter. It
sometimes happens that the consumer cannot get suffi-
cient pressure to supply his burners, when he, of course,
fails to get the light he requires, and concludes that the
gas is poor. This difficulty may be due to several
causes: (1) insufficient pressure at the works; (2) the
street mains are too small or are obstructed; (3) the
service pipe is too small or obstructed; (4) the meter is
too small or out of order; (5) the house pipes are too
small or obstructed; (6) the fixtures are obstructed; (7)
the burners are too small, defective, or obstructed. By
comparing notes with neighboring consumers, and con-
sulting an intelligent gas-fitter, the real cause of the de-
ficient light can generally be ascertained. In large
buildings there should be a separate cock and regulator
on each floor to prevent irregularity of pressure.
Regulators are constructed on the same principle as
the governor at the works. They contain automatic
valves, which partially close when the pressure in-
creases, and open when it diminishes. They may be
applied to the entire supply of gas at the meter or to
each burner.
Official Certificate of Transfer-1886. 2597
Complainant's Exhibit Official Certificate
of Transfer of U. S. Patents from "The Edi-
son Electric Light Co." to "Edison Electric Light
Co."
[2-175.]
DEPARTMENT OF THE INTERIOR,
[Coat of Arms.]
UNITED STATES PATENT OFFICE.
TO ALL PERSONS TO WHOM THESE PRESENTS SHALL
COME, GREETING:
This is to certify that the annexed is a true copy
from the Records of this Office of an Instrument of
Writing executed by The Edison Electric Light Com-
pany, and Recorded in Liber I 39, page 210, of Trans-
fers of Patents. Said Record has been carefully com-
pared with the Original and is a correct transcript of
the whole thereof.
[SEAL.]
In testimony whereof, I, Robert J. Fisher,
Commissioner of Patents, have caused
the Seal of the Patent Office to be
affixed this 7" day of August, in the
year of our Lord one thousand eight
hundred and ninety, and of the Inde-
pendence of the United States the
one hundred and fifteenth.
ROBERT J. FISHER,
Acting Commissioner.
2598
Official Certificate of Transfer-1886.
Liber I 39, Page 210:
WHEREAS, The Edison Electric Light Company and
The Edison Company for Isolated Lighting, corpora-
tions organized under the laws of the State of New
York, and having their principal place of business in
the City of New York, were on the 31st day of Decem-
ber, 1886. pursuant to and in conformity with an act of
the Legislature of the State of New York, entitled
"AN
ACT to authorize the consolidation of manufacturing
corporations," passed May 28th, 1884, and being Chap-
ter 378 of the Laws of 1884, consolidated into a single
corporation under the name of Edison Electric Light
Company, the said Edison Electric Light Company
being a corporation organized and existing under the
laws of the State of New York; and
WHEREAS, prior to such consolidation the Executive
Committee of the said The Edison Electric Light Com-
pany on the 30th day of December, 1886, at a meeting
of the said Committee duly called and held, passed the
following preamble and resolution.
"WHEREAS, an agreement of consolidation" between
this Company and the Edison Company for Isolated
Lighting, into a new Company to be called Edison
Electric Light Company has been entered into by the
Directors of this Company and confirmed by its stock-
holders.
(C
Now, THEREFORE, be it resolved, that to facilitate
the transfer to said new Company of the assets of this
Company the President and Secretary of this Company
be and they hereby are authorized and directed to sign
or endorse in blank to the said new Company all stocks,
bonds, notes, checks, drafts or other evidences of value
now held by or due to this Company, to execute
under seal of this Company and deliver to said
new Company all assignments of Patents and transfers
of contracts and rights of every kind, and generally to
do whatever may be necessary and may be deemed ex-
pedient to facilitate the transfer to said new Company
of all assets of this Company and all title to and in-
terest therein."
NOW THESE PRESENTS WITNESS: That The Edison
Official Certificate of Transfer-1886. 2599
Electric Light Company, being on the date of the said
resolution the owner of the several letters patent here-
inafter mentioned, or of undivided interests therein,
pursuant to and in accordance with the resolution here-
inbefore quoted and in accordance with the Statute of
the United States in such case made and provided, and
in consideration of the premises and of the sum of One
Dollar to it in hand paid by the said Edison Electric
Light Company, does hereby sell, assign, transfer and
set over unto the said Edison Electric Light Company,
its successors and assigns, all its right, title and in-
terests in and to each and every of the several letters
patent hereinafter mentioned, and in and to the inven-
tions covered thereby, to wit: Letters Patent of the
United States granted upon the inventions of the per-
sons hereinafter named and being dated and numbered
as follows to wit:
Inventor.
H. Woodward.
Number.
Date.
181,613. August 29th, 1876.
Thomas A. Edison... -214,636.April 22nd, 1879.
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__214,637__
218,166. August 5th, 1879.
__218,167__
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---_218,866__ August 26th, 1879.
219,393 September 9th, 1879.
219,628 September 16th, 1879.
--222,881 December 23d, 1879.
-- .223,998__January 27th, 1880.
1
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224,329 February 10th, 1880.
227,226. May 4th, 1880.
..__227,227..
___227,228. -
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227,229__
6.
-228,617. June 8th, 1880.
230,255..July 20th, 1880.
- _237,732_ _February 15th, 1881.
238,868. March 15th, 1881.
239,147. March 22nd, 1881.
____239,148_ _
239,149__
239,150.
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2600
Official Certificate of Transfer-1886.
Inventor.
Number.
Date.
Thomas A. Edison____239,151__March 22nd, 1881.
((
66
239,152__
__239,153__
Thomas A. Edison and
Charles Batchelor___239,372__March 29th, 1881.
Thomas A. Edison...239,373. March 29, 1881.
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__239,374..
-
--239,745. April 5th, 1881.
--240,678. April 26, 1881.
242,896. June 14th, 1881.
242,8 7..
.-242,898..
__242,899 _ _
242,900..
242,901..
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...248,416 October 18th, 1881.
____248,417__
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__248,418__
__248,419__
248,420.
_ .. 248,421 _ _
248,422
248,423_ _
.__.248,424-
____248,425__
248,426
_248,427__
1
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__248,428__
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__248,429
_248,433__
248,434..
-248,435
__248,436..
248,437.
248,565__
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__251,536__December 27th, 1881.
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__251,537_ _
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251,538..
251,539
--- .251,540..
Official Certificate of Transfer-1886.
2601
Inventor.
Number.
Date.
Thomas A. Edison. 251,541. December 27th, 1881.
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251,543__
._251,544__
_251,545
..251,546__
__251,547__
_251,548.-
251,549__
251,550__
..251,551..
__251,552.
-251,553.
251,554-
___251,555__
_251,556
__251,557__
_251,558__
_251,559__
12,631..
Edward H. Johnson_251,596_ _
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Sigmund Bergmann_-_257,276.. May 2nd, 1882.
..257,277..
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Edwin T. Greenfield_260,562.July 24th, 1882.
Thomas A. Edison_-_-263,132..August 22nd, 1882.
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263,134..
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_263,137__
263,138..
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_263,141__
_263,142__
____263,143_ _
__263,144._
__263,145__
263,146..
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Official Certificate of Transfer—1886. 2602
Inventor.
Date.
Edward H. Johnson_-_263,148. September 5th, 1882.
((
Number.
_263,149__
___263,150__
__263,878__
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264,298 September 12th, 1882.
__264,299_-
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Thomas A. Edison_-_-264,642_ _September 19th, 1882.
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-264,645__
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____264,647_.
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__264,655_ _
264,656__
__264,657__
264,658__
__264,659__
.264,660__
264,661..
264,662__
____264,663__
-264,664.
264,665__
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____264,667..
264,668__
264,669__
_264,670__
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264,672..
___261,673__
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William Holzer.
Samuel D. Mott...
_264,698__
.__264,737__
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Official Certificate of Transfer-1886. 2608
Inventor.
Number.
Date.
Thomas A. Edison....265,311 October 3rd, 1882.
__265,774--October, 10th, 1882.
66
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__265,777__
265,778 September 19th, 1882.
----265,779--
____265,780__
__265,781__
..265,782
___.265,783__
____265,784__
66
-265,785.
__265,786__
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John F. Ott___
_265,858__
-265,859__
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Thomas A. Edison____266,447-October 24th, 1882.
---_266,588.
66
____266,793__ October 31st, 1882.
Edwin T. Greenfield__266,808__
Thomas A. Edison..-_-268,205__November 28th, 1882.
_268,206__
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-271,613 February 6th, 1883.
__271,614__
"
____271,615__
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_271,616__
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Alfred Haid.
_271,628__
John F. Ott..
_271,654__
66
Thomas A. Edison____273,485. March 6th, 1883.
273,486..
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66
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__273,493.
____273,494__
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__273,828_ _March 13th, 1883.
2604
Official Certificate of Transfer-1886.
Inventor.
Number.
Date.
Thomas A. Edison..-_-274,290. March 20th, 1883.
"
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274,291..
_274,292.-
-274,293.
__274,294__
274,295
..274,296..
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__275,612__April 10th, 1883.
Sigmund Bergmann_-_275,749 --
Thomas A. Edison...276,232__April 24th, 1883.
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----278,413__May 29th, 1883.
____278,414.-
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Edwin T. Greenfield__278,535. May 29th, 1883.
Charles S. Bradley---280,563__July 3rd, 1883.
Thomas A. Edison. 280,727__
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-_-281,349-July 17th, 1883.
1
__281,350__
281,351.
__281,352__
___281,353_ _
Luther Stieringer.
Samuel D. Mott
__281,576__
-
283,270. August 14th, 1883.
Thomas A. Edison...283,984__August 28th, 1883.
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__283,986_ _
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Charles S. Bradley... 287,501-October 30th, 1883.
Thomas A. Edison____287,515__
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__287,518__
___287,519.
____287,520..
.___287,521 _ _
Official Certificate of Transfer.
2605
Inventor.
Number.
Date.
Thomas A. Edison-287,522 October 30th, 1883.
287,523.
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__287,524.
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Thomas A. Edison and
Charles L. Clarke___287,525__
Calvin Goddard_
...287,532. -
287,533..
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Thomas A. Edison....288,318_ _November 13th, 1883.
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288,318__November
-293,433. February 12th, 1884.
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-297,580__April 29th, 1884.
._297,581__
Sigmund Bergmann-298,658. May 13th, 1884.
Thomas A. Edison
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-298,679.
304,082 August 26th, 1884.
---307,029 October 21st, 1884.
Edward H. Johnson_-_314,582 March 21st, 1885.
William S. Andrews__317,610__ May 12th, 1885.
Thomas A. Edison_-_317,631..
<<
__317,632
__317,633__
William S. Andrews
317,700..
Thomas A. Edison_-_334,853 January 26th, 1886.
Frank J. Sprague.....335,045.-
Schuyler S. Wheeler__335,048__
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__335,099__
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Thomas A. Edison_-_339,278__ April 6th, 1886.
Edward H. Johnson--339,298__
Thomas A. Edison....341,644. May 11th, 1886.
William S. Andrews_-_348,371. August 31st, 1886.
Thomas A. Edison_351,855. November 2nd, 1886.
....351,856
-
Montgomery Waddell 353,649 November 30th, 1886.
Thomas A. Edison_-_353,783 December 7th, 1886.
Charles S. Bradley ----353,915. -
-
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Thomas A. Edison....358,599__March 1st, 1887.
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__358,600__
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---365,465__June 28th, 1887.
___365,509
2606
Official Certificate of Transfer.
Together with all claims for damages for infringe-
ment of such letters patent and each of them with the
right to sue for and recover such damages to its own
use.
The same and each thereof to be held, owned, pos-
sessed and enjoyed by the said Edison Electric Light
Company, in like manner as the same and each thereof
were held, owned, enjoyed and possessed by the said
The Edison Electric Light Company,. on the day of the
passage of the said resolution.
IN TESTIMONY WHEREOF, the said The Edison Electric
Light Company by its President and Secretary has
hereunto set its name and affixed its corporate seal, ast
of the date of the said resolution.
THE EDISON ELECTRIC LIGHT COMPANY,
By EDWD. H. JOHNSON,
President.
The Edison Electric
Attest:
Organized
1878.
F. S. HASTINGS,
Sec'y.
Light Company.
•
Recorded Oct. 18, 1888. J. F. F. L. C. G.
B
Stayton-Report of 1878.
2607
Complainant's Exhibit Stayton's Report
"The Electric Light"; Report by G. H.
Stayton, C. E., to the Vestry Parish of Chelsea.
TELEGRAPHIC JOURNAL AND ELECTRICAL REVIEW, LONDON
SEPTEMBER 1ST., 1878: PAGE 3.
Page 366. "Cost of Adoption. The distance between
the lamps in Chelsea being much greater than in
Paris, and there being only one lamp upon each col-
umn, greatly increases the comparative cost of the
systems. They are somewhat irregularly placed, but
the distance apart on each side averages about 55 yards
in Sloan street, 70 in Kings Road, 35 yards in Lowndes
Square, 35 yards in Cadogan Place, 28 yards on the
Chelsea Embankment. In Piccadilly the distance is
30 yards, and in Cromwell Road, South Kensington,
27 yards.
"To adopt the electric light for Sloane street, which
is 1,100 yards long and 20 yards wide, would necessi-
tate two electric stations, each of which would require
a 16 h. p. steam engine, including shafts, belts, &c., a
'Gramme' dynamo-electric machine, a shelter or
other buildings for the machinery and apparatus, the
alteration of 16 lamp columus, together with globes,
stands, connectors, and the necessary conducting wires,
the total expense of which would amount to the sum of
£3,200.
"The cost of lighting 32 electric candles, including
coal, oil, waste, wages, &c., per hour would be 16s.,
and 3,250 hours' consumption per annum would be re-
quired unless the lights were extinguished and gas
substituted at midnight, as in Paris, in which case the
annual cost would not be so great.
"The present cost of a gas lamp in Chelsea burning
3,850 hours per annum is £3 6s. 7d., therefore the ex-
pense of 40 lamps in Sloane street is 84d. per hour.
"To light the Chelsea Embankment, which is about
1,530 yards long, and has 109 gas lamps (including
2608
Stayton-Report of 1878.
those on the river wall belonging to the Metropolitan
Board of Works), would require a first outlay of £4,800
for 48 lights of 3,250 hours per annum, with an hourly
cost of £1 4s. The present cost of the gas lamps is
2s. 1 d. per hour for 3,850 hours per annum.
"To adopt the system in Sloane Square (where there
are but 17 lamps) would scarcely be practicable, even
if the motive power could be obtained from the pump-
ing engine of the Metropolitan District Railway Sta-
tion, or from the engine of any manufactory in the
locality after the close of the ordinary day's work.
"In connection with the foregoing estimates, it must
be remembered that in the case of Sloane street, the
amount of light would be 31 times greater than at
present, which might be considered an unnecessary
expenditure; but the electric current is said to lose 40
per cent. of power beyond a radius of about 250 yards,
consequently a 'station' for 16 lights has to be estab-
lished at about every 500 yards, which greatly increases
the expense. Probably half the above number of elec-
tric lights would be found sufficient for effectually light-
ing Sloane street, if the quantity of the current could
be maintained at double the distance, by which means
alone the cost would be reduced 50 per cent.
"GENERAL CONCLUSIONS.-I have arrived at the fol-
lowing conclusions, which may be thus stated briefly,
viz.: That the present arrangements for electric light-
ing are unsuitable for long distances (in this I am
supported by the City Engineer of Paris), especially
in London, where the lamps are so much farther apart
than in Paris. The close proximity of the electric
stations is a great drawback to the system, and their
establishment in business streets would be a matter of
considerable difficulty. These are the disadvantages
of the system. The following are the advantages:
"About 14 hours' daily consumption is saved in con-
sequence of instantaneous lighting and extinguishing;
the light is vastly superior to gas, and is not injurious;
there is an absence of noxious smells both in the pro-
duction and combustion; the heat in a room, so often
Stayton-Report of 1878.
2609
unbearable in the case of gas, is scarcely felt; the most
delicate colors are preserved; air is not consumed as
in the case of gas; there is no chance whatever of ex-
plosion, and although the light is so powerful in the
streets no accidents to horses have occurred.
'
"If the cost of producing the Gramme' machine
(10,000f.) could be reduced, or a less expensive one be
adopted; if hydraulic, or some other less expensive
power, such as a petroleum engine, could be utilized as
the motor in lieu of steam, or even a smaller amount
of power than one horse-power per lamp be rendered
sufficient; if the distance between the electric stations
could be greatly increased, the arrangements made
capable of minute subdivision, and by some simple
method the current could be branched off for household
or other requirements, I feel sure that the public would
gladly welcome such a change, and it would compete
with gas under highly advantageous conditions.
"The question is now largely occupying the atten-
tion of scientific men. At a recent meeting of the In-
stitution of Civil Engineers, its discussion occupied
three evenings. One speaker asserted that one of the
greatest advantages he saw in its introduction, was the
possiblity of its adding to the hygienic properties of
buildings, as fresh air could be preserved, because the
electric light consumes none, whereas gas consumes an
enormous quantity.' Another speaker (Sir William
Thomson) having made a suggestion as to the construc-
tion of a copper tube for producing the electric light at
a great distance, said that he believed it would be
possible to carry the electric energy to a distance of
several hundred miles. The theory appeared to be
that towns henceforth would be lighted by coal burned
at the pit's mouth, for which purpose the dross could
could be used.' On the other hand, another speaker
asserted, that in all probability, before the electric
light was perfected, the cost of manufacture of gas
would have been so far reduced as to lift it even fur-
ther beyond the reach of competition, and that gas mak-
(
2610
Stayton---Report of 1878.
ers' future promises in regard to improvement were as
bright as those of the promoters of electric light.'
"After a careful consideration of the whole question,
I am of opinion that at present the electric light is not
suitable for street lighting in the metropolis; that it is
suitable and can be utilized with splendid effect in
large quarters and places, such as Trafalgar Square or
Parliament Square; but although in each of these
places at the present time the lamps are numerous, the
cost would be greater than gas.
"I am also of opinion that so soon as the modifica-
tions alluded to can be effected (particularly as to the
electric current being carried to a much greater dis-
tance, thereby reducing the cost) the electric light will
very soon supersede gas to a considerable extent, the
attendant advantages being so great."
Geraldy--La Lumiere Electrique--1881.
2611
Complainant's Exhibit Geraldy's
Lumiere Electrique" Article.
LA LUMIÈRE ELECTRIQUE, PARIS, 1881.
Vol. V., pp. 253-255.
66
"La
NOTE SUR LA DISTRIBUTION DE L'ENERGIE PAR L'ELEC-
TRICITÉ, BY F. GERALDY.
"Nous l'avions prévu, et je m'honore d'avoir été des
premiers à l'annoncer d'avance, l'Exposition d'Electricité,
tout en étendant et en agrandissant les solutions déjà
acquises nous apporte une solution nouvelle, celle de la
question importante entre toutes, de la distribution de
l'electricité. Il est aujourd'hui certain, après une ex-
périence déjà prolongée et par l'examen de tous les
hommes de science et de pratique, que la difficulté
n'existe plus et que le système inventé et réalisé par M.
Marcel Deprez permet absolument de la surmonter.
Notre collaborateur se propose d'exposer lui-même
très prochainement toute cette question; il donnera
tout l'ensemble des principes et des théorèmes qui l'ont
amené a la résoudre. Il a paru qu'avant ce travail com-
plet il pourrait être utile déblayer un peu le terrain, et,
qu'il aurait avantage, M. Marcel Deprez se chargeant
de la théorie, à exposer d'avance les preliminaires et les
antécédents: c'est ce que je vais faire aussi brièvement
que possible.
La question est double, elle comprend le transport
de la force par l'électricité sans division, d'une part, et
de l'autre la division ou distribution de cette force.
L'idée de l'emploi des machines électriques comme
moteurs est très ancienne, anisi que me l'écrivais M.
Siemens dans une lettre que j'ai eu occasion de citer
dans ce journal, elle remonte incontestablement au
moins à Jacobi faisant marcher un petit bateau sur la
Néva vers 1839. Mais on s'égara longtemps pour la
construction des moteurs dans une voie qui n'était pas
2612 Geraldy--La Lumiere Electrique--1881.
la bonne; on cherchait á aimanter et désaimenter suc,
cessivement des electro-aimants d'une certaine masse-
de façon à produire une serie d'attractions successives
ayant chacune une intensité notable: dans cette voie
il n'y avait rien à faire, les alternatives électriques
dépensaient inutilement la plus grosse part de l'énergie ;
aussi était-il passé en chose jugée que l'électricité ne
pouvait fournir des quantités de travail sérieuses. La
question changea avec l'invention des machines magneto
et dynamo-électriques, elles apparurent bientôt, non
seulement comme des producteurs avantageux, mais
comme des moteurs capables de rendre beaucoup de
travail; elles résolurent anisi en même temps la ques-
tion dans les deux sens, donnant à la fois le moyen
d'obtenir l'électricité que la pile ne fournissait qu'avec
beaucoup de gêne et parcimonieusement, et le moyen
de la transformer en travail mécanique. Il est inutile
de faire remarquer à nos lecteurs pourquoi ces ma-
chines sont de meilleurs moteurs que les anciens, ils
savent bien qu'à une séries d'efforts distincts, procédé
employé dans les anciens moteurs, les machines nouvelles
substituent une succession d'attractions tellement
rapides qu'elles se présentent comme un effort continue
et régulier, ce qui évite les alternatives d'aimentation
obligées dans les machines anciennes et d'où provenait
leur grande perte d'énergie.
Qui a employé le premier les machines comme mo-
teurs, cella aussi est difficile à dire; il parait acquis
que la première expérience publique fut celle que furent
en 1873 M. M. Fontaine et Gramme à l'exposition de
Vienne en 1873. Il y en avait eu d'autres avant, sans
doute, mais elles ne sont pas, que je sache, authentique-
ment constatées. Il est assez singulier même que ce
fait ne se soit pas produit plus tôt ; il est curieux par ex-
ample que M. Siemens, qui avait crée dès 1854 sa bobine
a deux pôles, ne s'en soit pas servi comme moteur; M.
Marcel Deprez a montré depuis que les bobines faites
d'après ce principe fournissent des petits moteurs très
avantageux. Peut-être M. Siemens l'a-t-il fait, mais
sans que cette expérience ait éveillé l'attention. Il
?
Geraldy--La Lumiere Electrique-1881. 2613
semble que l'esprit public, il y a une vingtaine d'années,
ait refusé de s'intéresser à ce genre de recherches; la
machine de Pacinotti en est une preuve bien frappante;
elle a été crée en 1852, elle renferme tout l'ensemble
des principes que M. Gramme a retrouvés et appliqués
plus tard, et pendant près de vingt ans elle est resté
ignorée; il a fallu l'exposition pour en révéler toute la
valeur; que dire de la très curieuse machine d'Elias qui
est exposée dans la section hollandaise, elle date de
1842 et a déjà les éléments d'un moteur; les enroule-
ments, la commutation s'y trouvent en principe; per-
sonne ne la connaissait. Que de temps perdu! Il est
vrai qu'une fois lancé on s'est efforcé de le rattrapper;
depuis sept ou huit ans les essais de transport de force
par l'électricité n'ont cesser de se multiplier. On doit
beaucoup à M. M. Chrétien et Félix en France, qui ont
expérimenté avec persistance et crée des systèmes sus-
ceptibles de résultats pratiques sérieux. M. M. Sie-
mens, en Allemagne et en Angleterre, se sont surtout
attachés à la question des tramways et des chemius de
fer électriques et l'on sait les résultats qu'ils ont
obtenus. Je n'insiste pas sur ces applications; elles ont
été decrites trés complètement dans le journal, et d'ail-
leurs on a pu les voir à l'Exposition d'electricité.
Malgré ces efforts, la question restait embarrassée de
quelques difficultés; d'une part, au point de vue de la
perte entrainée par ce mode de transport de ce qu' on
appelle le rendement; de l'autre, au point de vue de la
dimension des organes nécessaires pour un grand trans-
port, et principalement de celle des conducteurs. Ces
points ont été éclaircis. En ce qui concerne le dernier,
M. Marcel Deprez, par des calculs simples qu'il avait
terminés vers le mois d'avril dernier, a montré dans
quelles conditions on pouvait se placer pour réaliser,
avec les moyens actuels, les résultats cherchés.
Nous renvoyons nos lecteurs aux numéros 38 et 42
de cette année, où ils trouveront ces études, on plutôt,
nous les invitons à vouloir bien attendre le numéro où
ces questions, seront reprises et complétement élucidées
par M. Deprez. On y trouvera également la solution
2614
Geraldy-La Lumiere Electrique-1881.
On sait en quoi
de la difficulté rélative au rendement.
elle consiste; deux machines étant placées sur un même
circuit, la première, mise en movement, produit de l'élec-
tricité, la seconde reçoit l'électricité ainsi engendrée et
produit du travail; on peut mesurer la valeur du tra-
vail électrique engendré par la première machine ainsi
que celle du travail utile rendu par la seconde, le rap-
port de ces travaux est la proportion entre la dépense
et le résultat, c'est le rendement. Comment varie-t-il,
et de quoi depend-il? La théorie, d'accord avec cer-
taines expériences, ayant fourni une proportion de 50
pour 100, on l'avait admise comme une proportion
générale et nécessaire; on admettait que le transport
électrique entrainait une perte de moitié. On vit bien-
tôt que ce rendement était un minimum, et qu'on
pouvait l'augmenter. Plusieurs savants, et particulière-
ment M. Ayrton signalèrent ce fait. M. Deprez qui
avait été un des premiers à le reconnaître, a démontré,
non-seulement que le rendement était arbitraire et dé-
pendait des dispositions adoptées, mais encore qu'il ne
dépendait pas de la distance du transport. Je n'entre-
prendrai pas ici la démonstration de ces vérités; on la
trouvera aussi simple que complète dans le travail
annoncé. Je n'ignore pas que beaucoup de bons esprits
ne peuvent se faire à l'idée du rendement independant
de la distance; cela tient, je pense à ce qu'on ne con-
sidère pas la question dans son ensemble; ce qui frappe
c'est que dans tout transport, il y a un travail perdu
en chemin, et il semble qu'avec longeur du chemin,
cette perte doit augmenter; elle varie, en effet, dans le
transport électrique, et on a raison dans ce sens, mais
il ne faut pas oublier que les travaux produits varient
aussi; l'on démontre que toutes ces quantités, si on
n'altère pas artificiellement leur mouvements, se modi-
fient dans la même proportion, en sorte que les valeurs
absolues peuvent changer sans que les rapports soient
modifiés, ce qui est fort compréhensible; au reste, je le
répéte, ces points trouveront bientôt un éclaircissement
complet.
La question du transport de la force doit donc être
Geraldy—La Lumiere Electrique—1881. 2615
considérée à peu prés complétement résolue, elle l'était
même avant l'exposition au moins expérimentalement,
il n'en est pas de même de celle de la distribution dont
la solution est plus récente et dont on a vu la première
expérience sérieuse à l'Exposition même.
La difficulté est ici d'un autre ordre, elle ne concerne
plus le transport mais la répartition de l'énergie élec-
trique suivant les appareils qui doivent l'utiliser.
On voit immédiatement le point difficile, c'est que la
quantité totale d'énergie à fournir est nécessairement
variable, s'il y a peu d'appareils en service, il ne leur
faudra qu'une faible quantité de travail; à mesure qu'on
introduit de nouveaux, il faut augmenter la production
de façon à satisfaire à leur besoins, sans diminuer le
service déjà réclamé par les autres.
De quelque façon qu'on s'y prenne, il faudra pour
réussir employer un système régulateur qui produise
les variations nécessaires. Le fait est même vrai pour
les piles dont la force électromotrice est invariable;
cela tient à ce que ces organes ont une résistance in-
térieure qui leur est propre, il s'en suit que lorsqu'on
attache des circuits aux deux bornes qui répresent les
pôles de la pile, la force qui amène la production du
courant dans ces circuits est la différence de potential
aux bornes, laquelle n'est pas égale à la force électro-
motrice et varie; en raison du rapport entre la résist-
ance de la pile et celle du reste du circuit; on serait
donc obligé de règler aussi avec ce genre de généra-
teurs.
Remarquez bien que c'est là un fait général; les piles
secondaires ou accumulateurs sont dans ce cas, comme
les autres appareils, puisque leur résistance intérieur
n'est pas nulle. Il s'ensuit qu'en se servant des accu-
mulateurs on serait également obligé de régler si l'on
voulait faire une distribution. Donc, l'accumulateur
ne résout pas la question; il peut en faciliter la solution
en réduisant les'oscillations de l'appareil; mais il ne
constitue pas un organe central suffisant.
On ne saurait non plus songer à les employer comine
moyen de transport; au moins dans l'état actuel leur
2616 Geraldy-La Lumiere Electrique-1881.
poids s'y oppose absolument. Ils peuvent, en effet
d'après les chriffres donnés, fournir pour 75 kilos de
pile un travail de cheval-vapeur pendant une heure;
il faudrait donc pour un travail de cheval pendant 10
heures faire un mouvement total de 1,500, ce qui est
inadmissible. La difficulté est la même si, l'accumula-
teur étant installé à domicile, on voulait l'y charger, il
faudrait alors déplacer la machine génératrice. La
solution serait de charger l'accumulateur avec un fil
venant d'une usine centrale, mais alors il faut régler
la dépense électrique du fil et on se trouve en présence
du problème de la distribution qu'il faut absolument
résoudre.
Nous avous donc à nous demander, quelles conditions
doit remplir une distribution pour qu'elle soit bonne,
complète ?
Une distribution pour être complète doit remplir trois
conditions.
1º. Il faut qu'elle puisse desservir, selon leurs be-
soins, des appareils quelconques, indépendamment les
uns des autres; en d'autres termes, il faut qu'en pla-
Sant sur le parcours de cette distribution, à un endroit
et à un moment quelconque, des machines dépensant
l'electricité, soit en lumière, soit sous forme de mouve-
ment ou sous toute autre forme de dépense l'une d'elles
puisse recevoir la quantité d'electricité qui lui est
nécessaire, sans que les autres placées sur le même cir-
cuit, en soient en aucune façon influencéss.
2º. If faut que ce résultat s'accomplisse automatique-
ment.
3º. Enfin, il faut que la machine génératrice ne donne
jamais que la quantité d'énergie qu'on lui demande et
pas davantage. En effet, la distribution ne serait pas
économique si, les machines produisant constamment
un maximum, l'on se contentait d'en perdre une moitié,
au moment où l'on n'aurait besoin que de l'autre moitié.
Telles sout les conditions indispensables à toute dis-
tribution pour qu'elle soit complète.
Deux dispositions électriques distinctes peuveut con-
duire à la solution; on peut placer les appareils en
Geraldy-La Lumiere Electrique-1881. 2617
série, c'est-a-dire sur un même circuit, où en dérivation,
c'est-à-dire sur des branchements opérés sur un circuit
primaire.
Dans la premiére disposition c'est l'intensité du cou-
vant qui doit rester constante et la difference de poten-
tial qui varie.
Dans la seconde, c'est au contraire l'intensité qui
varie et la différence de potentiel qui demeure con-
stante. Cette deuxième disposition est généralement
préférable; dans la disposition en série les appareils
sont dans une dépendance trop étroite les unes des
autres, un accident local entraine l'arrêt de tout le
système.
FRANK GERALDY.
"
2618
Translation of Geraldy's Article-1881.
of
Complainant's Exhibit Translation
Geraldy's "La Lumiere Electrique "
Article.
LA LUMIERE ELECTRIQUE, PARIS, 1881.
VOLUME V., pp. 253–255.
ARTICLE ON THE DISTRIBUTION OF ENERGY BY MEANS OF
ELECTRICITY. BY FRANK GERALDY.
"We had foreseen it, and I credit myself with hav-
ing been among the first to announce it in advance, the
Electrical Exposition, while extending and increasing
the solutions already acquired brings us a new solution,
that important one among all, the distribution of elec-
tricity. It is to-day certain, after an experiment
already prolonged, and by the examination of all scien-
tific and practical men, that the difficulty no longer
exists and that the system invented and brought to
perfection by Mr. Marcel Deprez absolutely allows us
to overcome it.
"Our colleague proposes to set forth himself very
shortly this whole question: he will give the summary
of the principles and theorems which have led him to
to the solution. It has seemed that before this com-
plete work it would be useful to clear the field a little,
and that it would be advantageous, since Mr. Marcel
Deprez takes charge of the theoretical part, to set
forth the preliminaries and antecedents; that is what
I am going to do as briefly as possible.
The question is a double one, it embraces the
transmission of power by means of electricity without
division, on the one hand, and on the other the division
or distribution of this power.
"The idea of employing electric machines as motors
is very old, as Mr. Siemens wrote me in a letter
which I have had occasion to cite in this journal, it
unquestionably goes back at least to Jacobi's making a
!
Translation of Geraldy's Article—1881. 2619
small boat travel on the Neva about 1839. But men
have been for a long time misled for the construction
of motors into a way that was not the good one; they
sought to magnetize and demagnetize successively
electro-magnets of a certain mass, so as to produce a
series of successive attractions having each a consider-
able intensity; in this way there was nothing to be ac-
complished, the electrical alternations expended use-
lessly the greater part of the energy; it had become an
established fact that electricity could not furnish con-
siderable quantities of work. The question changed
with the invention of magneto and dynamo-electric
machines, they soon appeared not only as advantageous
producers, but as motors capable of doing much work;
they thus solved the question in its two senses, giving
at once the means of obtaining electricity which the
battery could furnish only with much trouble and in
small quantities, and the means of transforming it into
mechanical work. It is useless to bring to the atten-
tion of our readers why these machines are better
motors than the old ones, they well know that for a
series of distinct efforts, the process employed in the
old motors, the new machines substitute a succession of
attractions so rapid that they present themselves as a
continuous and regular effort, a thing that avoids the
alternations of magnetization necessary in the old ma-
chines and from which arose their great loss of energy.
"Who has first employed the machines as motors is
difficult to say; it appears as accepted that the first
public experiment was that which Messrs. Fontaine and
Gramme made at the Vienna Exposition in 1873.
There were others before, without doubt, but they are
not, so far as I know, authentically verified. It is
singular enough even that this matter was not produced
earlier; it is strange, for example, that Mr. Siemens,
who had produced in 1854 his armature with two poles,
did not make use of it as a motor; Mr. Marcel Deprez
has since shown that armatures made in accordance
with this principle furnished very advantageous small
motors. Perhaps Mr. Siemens has done it, without
2620 Translation of Geraldy's Article-1881.
•
this experiment arousing any attention. It seems that
the public mind, a score of years ago, refused to inter-
est itself in this class of researches; the machine of
Pacinotti is a very striking proof of this fact; it was
produced in 1862, it embraced the whole of the princi-
ples that Mr. Gramme rediscovered and applied later,
and during more than twenty years it remained ignored,
the exposition was necessary in order to reveal all its
worth; what is to be said of the very curious machine
of Elias which is shown in the Dutch section, it dates
from 1842 and has already the elements of a motor;
the windings, the commutation are found in it in prin-
ciple; nobody knew it. What time lost! It is true
that once started men have tried to regain it; for
seven or eight years attempts to transmit power by
electricity have not ceased to multiply. Much is due
to Messrs. Chretien and Felix, in France, who have
perseveringly experimented and produced systems capa-
ble of serious practical results.
Messrs. Siemens, in
Germany and in England, have especially attacked the
question of tramways and electric railways and the re-
sults that they have obtained are known. I do not
dwell upon these applications, they have been described
very completely in this journal, and, moreover, they
can be seen at the Electrical Exposition.
Notwithstanding these efforts the question re-
mained hampered by some difficulties; on the one
hand, in view of the loss of that which is called the
output involved in this mode of transmission; on the
other hand, in view of the dimensions of the parts
necessary for a large transmission, and chiefly that of
the conductors. These points have been cleared up.
As regards the latter point, Mr. Marcel Deprez, by
simple calculations that he has finished about the end
of last April, has shown in what conditions one could
be placed in order to attain, with the present means,
the results sought for. We refer our readers to num-
bers 38 and 42 of this year, where they will find these
researches, or rather we invite them to be kind enough
to await the number in which these questions will be
Translation of Geraldy's Article - 1881. 2621
taken up again and completely elucidated by Mr.
Deprez. They will also find there the solution of the
difficulty relative to the output. It is known in what
it consists, two machines being placed upon the same
circuit, the first, set in motion, proluces electricity, the
second receives the electricity thus produced and pro-
duces work; the value of the work produced by the
first machine can be measured as well as the useful
work returned by the second, the relation of these
amounts of work is the proportion between the expendi-
ture and the result, that is the output. How does it
vary and upon what does it depend? Theory, in accord
with certain experiments, having given a proportion of
50%, it has been accepted as a general and necessary
proportion; it was admitted that the electrical trans-
mission involved a loss of a half. It was soon seen
that this output was a minimum and that it could be
increased Several scientists, and especially Mr. Ayr-
ton, called attention to this fact. Mr. Deprez, who
had been one of the first to recognize it, has shown,
not only that the output was arbitrary and depended
upon the arrangements adopted, but yet that it did not
depend upon the distance of the transmission. I will
not undertake here the demonstration of these truths;
they will be found as simple as they are complete in
the work mentioned. I am not ignorant that some
good minds cannot get accustomed to the idea of the
output being independent of the distance; that comes,
I think, from the fact that they do not consider the
question in its entirety; a striking fact is that in every
transmission there is work lost on the way, and it
seems that with the length of the route this loss should
increase; it varies, in fact, in electrical transmission,
they are right in this sense, but we must not forget
that the work produced varies also; it is shown that
all these quantities, if their movements are not artifi-
cially altered, are modified in the same proportion so
that the absolute values can change without the pro-
portions being modified, a fact that is very compre-
2622 Translation of Geraldy's Article--1881.
hensible; moreover, I repeat, these points will soon
have a complete elucidation.
"The question of the transmission of power should
then be considered almost completely solved, it was
even before the exposition, at least experimentally; it is
not the same with that of the distribution whose solu-
tion is more recent and of which we have seen the first
serious experiment at the exposition itself.
"The difficulty is here of another order, it has not
to do with the transmission, but with the division of
the electric energy according to the instruments which
are to use it.
"We see immediately the difficult point, which is
that the total quantity of energy to be furnished is
necessarily variable, if there are few machines in use,
they need only a small quantity of work; in proportion
as new ones are introduced, it is necessary to increase
the production so as to satisfy their needs, without
diminishing the service already demanded by the
others.
“Whatever method is adopted, it is necessary in
order to succeed to employ a regulating system which
produces the necessary variations. The fact is even
true for batteries whose electro-motive force is invari-
able, that is, because these parts have an internal re-
sistance which is peculiar to them, it follows that if
circuits are attached to the two terminals which
represent the poles of the battery, the force which
causes the production of the current in these circuits is
the difference of potential at the terminals, which is
not equal to the electro-motive force and varies on ac-
count of the relation between the resistance of the bat-
tery and that of the rest of the circuit; we should then
be obliged to regulate also with this class of gener-
ators.
It
"Notice well that that is a general fact; secondary
batteries or accumulators are in this case like other ap-
paratus, since their internal resistance is not nil.
follows that in making use of accumulators we should
be equally obliged to regulate if we wished to make a
Translation of Geraldy's Article-1881. 2623
distribution. The accumulator does not solve the
question; it can help to a solution of it by reducing
the oscillations of the apparatus, but it does not con-
stitute a sufficient central organism.
"One could no longer think of using them as a means
of transmission; at least in their present state their
weight opposes it absolutely. They can really, accord-
ing to the figures given, furnish for 75 kilos of battery,
a work of one steam-horse power for one hour; 10
hours would be necessary to move a total of 1,500,
which is inadmissible. The difference is the same if,
the accumulator being placed at the dwelling, we wish
to charge it, it would be necessary to move then the
generating machine. The solution would be to charge
the accumulator by a wire coming from a central sta-
tion, but then it would be necessary to regulate the
electrical waste of the wire and we should find our-
selves in the presence of the problem of distribution
which it is absolutely necessary to solve.
"We have then to ask ourselves what conditions a
system of distribution should fulfill in order that it
may be good, complete? A system of distribution in
order to be complete should fulfill three conditions:
"1st. It is necessary that it be able to serve, accord-
ing to their demands, any instruments whatever, inde-
pendent one of the other, in other words, it is necessary
that in placing in the circuit of this distribution, at any
place and at any moment whatever, machines consum-
ing electricity, whether in light or under the form of
chemical action, or under the form of movement or
under any other form of consumption, one of them may
be able to receive the quantity of electricity necessary
for it without that the others placed on the same cir-
cuit at the same time should be inflenced in any man-
ner.
"2d. It is necessary that these results should be ac-
complished automatically.
"3d. Finally it is necessary that the generating ma-
chine always produce only the quantity of energy that
is demanded of it and no more. In fact the distribu-
2624 Translation of Geraldy's Article---1881.
tion would not be economical if, the machines produc-
ing constantly a maximum, we were satisfied to lose half
of it, at the moment when we should only need the
other half.
'Such are the conditions indispensable to every
system of distribution in order that it may be com-
plete.
"Two distinct electrical arrangements can lead to
the solution: we can place the instruments in series,
that is to say, upon the same circuit, or in multiple arc,
that is to say, upon the branches operated upon a
primary circuit.
"In the first arrangement it is the strength of the
current which should remain constant and the differ-
ence of potential which varies.
"In the second it is on the contrary the current
strength which varies and the difference of potential
which remains constant. This second arrangement is
generally preferable; in the series arrangement the in-
struments are in a too strict dependence one upon the
other, a local accident involves the stopping of the
whole system."
Tyndall--Address--1879.
2625
Complainant's Exhibit Tyndall's Address,
“The Electric Light." A Discourse Deliv-
ered at the Royal Institution of Great Britain on
Friday, January 17, 1879.
THE FORTNIGHTLY REVIEW, TORONTO, FEBRUARY, 1879,
PAGE 197.
THE ELECTRIC LIGHT.1
THE subject of this evening's discourse was proposed
by our late honorary secretary. That word "late"
has for me its own connotations. It implies, among
other things, the loss of a comrade by whose side I have
worked for thirteen years. On the other hand, regret
is not without its opposite in the feeling with which I
have seen him rise by sheer intrinsic merit, moral and
intellectual, to the highest official position which it is
in the power of English science to bestow. Well, he,
whose constant desire and practice were to promote the
interests and extend the usefulness of this institution,
thought at a time when the electric light occupied so
much of public attention, a few sound notions regard-
ing it, on the more purely scientific side, might, to use his
own pithy expression, be "planted" in the public
mind. I am here to-night with the view of trying, to
the best of my ability, to realise the idea of our friend.
In the year 1800 Volta announced his immortal dis-
covery of the pile. Whetted to eagerness by the pre-
vious conflict between him and Galvani, the scientific
men of the age flung themselves with ardour upon the
new discovery, repeating Volta's experiments, and ex-
tending them in many ways. The light and heat of the
voltaic circuit attracted marked attention, and in the
(1) A discourse delivered at the Royal Institution of Great
Britain on Friday, January 17, 1879.
(2) Mr. William Spottiswoode, now President of the Royal
Society.
2626
Tyndall-Address-1879.
innumerable tests and trials to which this question was
subjected, the utility of platinum and charcoal as means
of exalting the light was on all hands recognised. Mr.
Children, with a battery surpassing in strength all its
predecessors, fused platinum wires eighteen inches
long, while "points of charcoal produced a light so
vivid that the sunshine, compared with it, appeared
feeble."3 Such effects reached their culmination
when, in 1808, through the liberality of a few members.
of the Royal Institution, Davy was enabled to con-
struct a battery of two thousand pairs of plates, with
which he afterwards obtained calorific and luminous
effects far transcending anything previously observed.
The arc of flame between the carbon terminals was four
inches long, and by its heat quartz, sapphire, magnesia,
and lime, were melted like wax in a candle flame
while fragments of diamond and plumbago rapidly dis-
appeared, as if reduced to vapour.4
The first condition to be fulfilled in the development
of heat and light by the electric current is that it shall
encounter and overcome resistance. Flowing through
a perfect conductor, no matter what the strength of the
current might be, neither heat nor light could be de-
veloped. A rod of unresisting copper carries away un-
injured and unwarmed an atmospheric discharge com-
petent to shiver to splinters a resisting oak. I send
the self-same current through a wire composed of alter-
nate lengths of silver and platinum. The silver offers
little resistrnce, the platinum offers much. The conse-
quence is that the platinum is raised to a white heat,
while the silver is not visibly warmed. The same holds
(3) Davy, "Chemical Philosophy," p. 110.
(4) In the concluding lecture at the Royal Institution in June,
1810, Davy showed the action of this battery. He then used iridium,
the alloy of iridium and osmium, and other refractory substances.
See Philosophical Magazine, vol. xxxv. p. 463. Quetelet assigns the
first production of the spark between coal-points to Curtet in 1802.
Davy certainly in that year showed the carbon light with a battery
of 150 pairs of plates in the theatre of the Royal Institution (Jour.
Roy. Inst. vol. i. p. 166).
Tyndall-Address-1879.
2627
good with regard to the carbon terminals employed for
the production of the electric light. The interval be-
tween them offers a powerful resistance to the passage
of the current, and it is by the gathering up of the force
necessary to burst across this interval that the voltaic
current is able to throw the carbon into that state of
violent intestine commotion which we call heat, and to
which its effulgence is due. The smallest interval of
air usually suffices to stop the current. But when the
carbon points are first brought together and then sep-
arated, there occurs between them a discharge of in-
candescent matter which carries, or may carry, the cur-
rent over a considerable space. The light comes al-
most wholly from the incandescent carbons. The space
between them is filled with a blue flame which, being
usually bent by the earth's magnetism, receives the
name of the Voltaic Arc.
For seventy years, then, we have been in possession
of this transcendent light without applying it to the
illumination of our streets and houses. Such applica-
tions suggested themselves at the outset, but there
were grave difficulties in their way. The first difficulty
arose from the waste of the carbons, which are dissi-
pated in part by ordinary combustion, and in part by
the electric transfer of matter from the one carbon to
the other. To keep the carbons at the proper distance
asunder regulators were devised, the earliest, I believe,
by Staite, and the most successful by Duboscq, Fou-
cault, and Serrin, who have been succeeded by Holmes,
Siemens, Browning, Carré, Gramme, Lontin, and
others. By such arrangements the first difficulty was
practically overcome; but the second, a graver one, is
probably inseparable from the construction of the vol-
taic battery. It arises from the operation of that in-
exorable law which throughout the material universe
demands an eye for an eye and a tooth for a tooth, re-
fusing to yield the faintest glow of heat or glimmer of
light without the expenditure of an absolutely equal
quantity of some other power. Hence, in practice, the
desirability of any transformation must depend upon
2628
Tyndall-Address—1879.
the value of the product in relation to that of the
power expended. The metal zinc can be burnt like
paper; it might be ignited in a flame, but it is possible
to avoid the introduction of all foreign heat and to
burn the zinc in air of the temperature of this room.
This is done by placing zinc foil at the focus of a con-
cave mirror, which concentrates to a point the diverg-
ent electric beam, but which does not warm the air.
The zinc burns at the focus with a violet flame, and we
could readily determine the amount of heat generated
by its combustion. But zinc can be burnt not only in
air but in liquids. It is thus burnt when acidulated
water is poured over it; it is also thus burnt in the voltaic
battery. Here, however, to obtain the oxygen neces-
sary for its combustion, the zinc has to dislodge the
hydrogen with which the oxygen is combined. The
consequence is that the heat due to the combustion of
the metal in the liquid falls short of that developed by
its combustion in air, by the exact quantity necessary
to separate the oxygen from the hydrogen. Fully four-
fifths of the total heat are used up in this molecular
work, only one-fifth remaining to warm the battery. It
is upon this residue that we must now fix our attention,
for it is solely out of it that we manufacture our elec-
tric light.
Before you are two small voltaic batteries of ten cells
each. The two ends of one of them are united by a
thick copper wire, while into the circuit of the other a
thin platinum wire is introduced. The platinum glows.
with a white heat, while the copper wire is not sensibly
warmed. Now an ounce of zinc, like an ounce of coal,
produces by its complete combustion in air a constant
quantity of heat. The total heat developed by an ounce
of zinc through its union with oxygen in the battery is
also absolutely invariable. Let our two batteries, then,
continue in action until an ounce of zinc in each of
them is consumed. In the one case the heat generated
is purely domestic, being liberated on the hearth where
the fuel is burnt, that is to say in the cells of the bat-
tery itself. In the other case, the heat is in part
•
Tyndall—Address-1879.
2629
domestic and in part foreign-in part within the battery
and in part outside. One of the fundamental truths to
be borne in mind is that the sum of the foreign and
domestic-of the external and internal-heats is fixed
and invariable. Hence, to have heat outside, you must
draw upon the heat within. These remarks apply to
the electric light. By the intermediation of the electric
current the moderate warmth of the battery is not only
carried away but concentrated, so as to produce, at any
distance from its origin, a heat next in order to that of
the sun. The current might therefore be defined as the
swift carrier of heat. Loading itself here with invisible
power, by a process of transmutation which outstrips
the dreams of the alchemist, it can discharge its load,
in the fraction of a second, as light and heat, at the
opposite side of the world.
Thus, the light and heat produced outside the battery
are derived from the metallic fuel burnt within the bat-
tery; and, as zinc happens to be an expensive fuel,
though we have possessed the electric light for more
than seventy years, it has been too costly to come into
general use. But within these walls, in the autumn of
1831, Faraday discovered a new source of electricity,
which we have now to investigate. On the table before
me lies a coil of covered copper wire, with its ends dis-
united. I lift one side of the coil from the table, and in
doing so exert the muscular effort necessary to overcome
the simple weight of the coil. I unite its two ends and
repeat the experiment. The effort now required, if ac-
curately measured, would be found greater than before.
In lifting the coil I cut the lines of the earth's magnetic
force, such cutting, as proved by Faraday, being always
accompanied, in a closed conductor, by the production
of an "induced" electric current, which as long as the
ends of the coil remained separate, had no circuit
through which it could pass. The current here evoked
subsides immediately as heat; this heat being the ex-
act equivalent of the excess of effort just referred to as
over and above that necessary to overcome the simple
weight of the coil. When the coil is liberated it falls
2630
Tyndall--Address-1879.
back to the table, and when its ends are united it en-
counters a resistance over and above that of the air. It
generates an electric current opposed in direction to
the first, and reaches the table with a diminished shock.
The amount of the diminution is accurately represented
by the warmth which the momentary current developes
in the coil. Various devices were employed to exalt
these induced currents, among which the instruments
of Pixii, Clarke, and Saxton were long conspicuous.
Faraday, indeed, foresaw that such attempts were sure
to be made; but he chose to leave them in the hands
of the mechanician, while he himself pursued the
deeper study of facts and principles. "I have rather,"
he writes in 1831, "been desirous of discovering new
facts and new relations dependent on magneto-electric
induction, than of exalting the force of those already
obtained; being assured that the latter would find their
full development hereafter."
For more than twenty years magneto-electricity had
subserved its first and noblest purpose of augmenting
our knowledge of the powers of nature. It had been
discovered and applied to intellectual ends, its applica-
tion to practical ends being still unrealised. The
Drummond light had raised thoughts and hopes of vast
improvements in public illumination. Many inventors
tried to obtain it cheaply; and in 1853 an attempt was
made to organize a company in Paris for the purpose of
procuring, through the decomposition of water by a
powerful magneto-electric machine constructed by M.
Nollet, the oxygen and hydrogen necessary for the lime
light. The experiment failed, but the apparatus by
which it was attempted suggested to Mr. Holmes other
and more hopeful applications. Abandoning the at-
tempt to produce the lime light, with persevering skill
Holmes continued to improve the apparatus and to
augment its power, until it was finally able to yield a
magneto-electric light comparable to that of the voltaic
battery. Judged by later knowledge, this first machine
would be considered cumbrous and defective in the ex-
44
Tyndall-Address-1879.
2631
treme; but judged by the light of antecedent events, it
marked a great step forward.
Faraday was profoundly interested in the growth
of his own discovery. The Elder Brethren of the
Trinity House had bad the wisdom to make him their
"Scientific Adviser;" and it is interesting to notice in
his reports regarding the light, the mixture of enthu-
siasm and caution which characterized him. Enthu-
siasm was with him a motive power, guided and controlled
by a disciplined judgment. He rode it as a charger,
holding it in by a strong rein. While dealing with
Holmes, he states the case of the light pro and con.
He checks the ardour of the inventor, and, as regards
cost, rejectiug sanguine estimates, he insists over and
over again on the necessity of continued experiment for
the solution of this important question. His matured
opinion was, however, strongly in favour of the light.
"I beg to state," he writes in his report to the Elder
Brethren, "that, in my opinion, Professor Holmes has
practically established the fitness and sufficiency of the
magneto-electric light for lighthouse purposes, so far as
its nature and management are concerned. The light
produced is powerful beyond any other that I have yet
seen so applied, and in principle may be accumulated
to any degree; its regularity in the lantern is great; its
management easy, and its care there may be confided
to attentive keepers of the ordinary degree of intellect
and knowledge." As regards the conduct of Professor
Holmes during these memorable experiments, it is only
fair to add the following remark with which Faraday
closes the report submitted to the Elder Brethren of
the Trinity House on the 29th of April, 1859 :—
"I must bear my testimony," he says, "to the perfect
openness, candour, and honour of Professor Holmes.
He has answered every question, concealed no weak
point, explained every applied principle, given every
reason for a change either in this or that direction,
during several periods of close questioning, in a manner
that was very agreeable to me, whose duty it was to
2632
Tyndall-Address-1879.
search for real faults or possible objections in respect
both of the present time and the future."1
Soon afterwards the Elder Brethren of the Trinity
House had the intelligent courage to establish the
machines of Holmes permanently at Dungeness, where
the magneto-electric light continued to shine for many
years.
2
The magneto-electric machine of the Alliance Com-
pany soon succeeded that of Holmes, and was in vari-
ous ways a marked improvement on the latter. Its
currents were stronger and its light brighter than those
of its predecessor. In it, moreover, the commutator,
the flashing and destruction of which were sources of
irregularity and deterioration in the machine of Holmes,
was, at the suggestion of M. Masson, entirely aban-
doned; alternating currents instead of the direct cur-
rent being employed. M. Serrin modified his excellent
lamp with the express view of enabling it to cope with
alternating currents. During the International Exhibi-
tion of 1862, where the machine was shown, M. Berlioz
offered to dispose of the invention to the Elder Breth-
ren of the Trinity House. They referred the matter to
Faraday, and he replied as follows :-" I am not aware
that the Trinity House authorities have advanced so
far as to be able to decide whether they will require
more magneto-electric machines, or whether, if they
should require them, they see reason to suppose the
means of their supply in this country, from the source
already open to them, would not be sufficient. There-
fore I do not see that at present they want to purchase
a machine." Faraday was obviously swayed by the de-
sire to protect the interests of Holmes, who had borne
the burden and heat which fell upon the pioneer. The
Alliance machines were introduced with success at
Cape la Héve, near Havre; and the Elder Brethren of
(1) Holmes's first offer of his machine to the Trinity House bears
the date February 2, 1857.
(2) Du Moncel," l'Électricité," Aug. 1878, p. 150.
Tyndall-Address-1879.
2633
the Trinity House, determined to have the best avail-
able apparatus, decided, in 1868, on the introduction of
machines on the Alliance principle into the lighthouses
at Souter Point and the South Foreland. These ma-
chines were constructed by Professor Holmes, and they
still continue in operation. With regard, then, to the
application of electricity to lighthouse purposes, the
course of events was this: The Dungeness light was
introduced on January 31, 1862; the light at La Héve
on December 26, 1863, or nearly two years later. But
Faraday's experimental trial at the South Foreland
preceded the lighting of Dungeness by more than two
years. The electric light was afterwards established at
Cape Grisnez. The light was started at Souter Point
on January 11, 1871, and at the South Foreland, Janu-
ary 1, 1872. At the Lizard, which probably enjoys the
newest and most powerful development of the electric
light, it began to shine on January 1, 1878.
I have now to revert to a point of apparently small
moment, but which really constitutes an important step
in the development of this subject. I refer to the form
given in 1857 to the rotating armature by Dr. Werner
Siemens, of Berlin. Instead of employing coils wound
transversely round cores of iron, as in the machine of
Saxton, Siemens, after giving a bar of iron the proper
shape, wound his wire longitudinally round it, and ob-
tained thereby greatly augmented effects between suit-
ably placed magnetic poles. Such an armature is em-
ployed in the small magneto-electric machine which I
now introduce to your notice, and for which the insti-
tution is indebted to Mr. Henry Wilde, of Manchester.
There are here sixteen permanent horse-shoe magnets
placed parallel to each other, and between their poles
a Siemens armature. The two ends of the wire which
surrounds the armature are now disconnected. In turn-
ing the handle and causing the armature to rotate, I
simply overcome ordinary mechanical friction. But
the two ends of the armature coil can be united in a
moment, and when this is done I immediately experi-
2634
Tyndall--Address-1879.
ence a greatly increased resistance to rotation. Some-
thing over and above the ordinary friction of the ma-
chine is now to be overcome, and by the expenditure
of an additional amount of muscular force I am able to
overcome it. The excess of labour thus thrown upon
my arm has its exact equivalent in the electric currents
generated, and the heat produced by their subsidence
in the coil of the armature. A portion of this heat may
be rendered visible by connecting the two ends of the
coil with a thin platinum wire. When the handle of
the machine is rapidly turned the wire glows, first with
a red heat, then with a white heat, and finally with the
heat of fusion. The moment the wire melts, the circuit
round the armature is broken, an instant relief from the
labour thrown upon the arm being the consequence.
Clearly realise the equivalent of the heat here devel-
oped. During the period of turning the machine a cer-
tain amount of combustible substance was oxidized or
burnt in the muscles of my arm.
Had it done no ex-
ternal work, the matter consumed would have produced
a definite amount of heat. Now, the muscular heat
actually developed during the rotation of the machine
fell short of this definite amount, the missing heat being
reproduced to the last fraction in the glowing platinum
wire and the other parts of the machine. Here, then,
the electric current intervenes between my muscles and
the generated heat, exactly as it did a moment ago be-
tween the voltaic battery and its generated heat. The
electric current is to all intents and purposes a vehicle
which transports the heat both of muscle and battery
to any
distance from the hearth where the fuel is con-
sumed. Not only is the current a messenger, but it is
also an intensifier of magical power. The temperature of
mny arm is, in round numbers, 100° Fahr., and it is by
the intensification of this heat that one of the most re-
fractory of metals, which requires a heat of 3,600°
Fahr. to fuse it, has been reduced to the molten condi-
tion.
Zinc, as I have said, is a fuel far too expensive to
permit of the electric light produced by its combustion
being used for the common purposes of life, and you
:
Tyndall-Address-1879.
2635
will readily perceive that the human muscles, or even
the muscles of a horse, would be more expensive still.
Here, however we can employ the force of burning coal
to turn our machine, and it is this employment of our
cheapest fuel, rendered possible by Faraday's discovery,
which opens out the prospect of our being able to ap-
ply the electric light to public use.
In 1866 a great step in the intensification of induced
currents, and the consequent augmentction of the mag-
neto-electric light, was taken by Mr. Henry Wilde. It
fell to my lot to report upon them to the Royal Society,
but before doing so I took the trouble of going to Man-
chester to witness Mr. Wilde's experiments. He oper-
ated in this way: starting from a small machine like
that worked in your presence a moment ago, he em-
ployed its current to excite an electro-magnet of a
peculiar shape, between whose poles rotated a Siemens
armature;¹ from this armature currents were obtained
vastly stronger than those generated by the small
magneto-electric machine. These currents might have
been immediately employed to produce the electric
light; but instead of this they were conducted round a
second electro-magnet of vast size, between whose poles
rotated a Siemens armature of corresponding dimen-
sions. Three armatures therefore were involved in this
series of operations; first, the armature of the small
magneto-electric machine; secondly, the armature of
the first electro-magnet, which was of considerable
size; and, thirdly, the armature of the second electro-
magnet, which was of vast dimensions. With the cur-
rents drawn from this third armature, Mr. Wilde ob-
tained effects, both as regards heat and light, enor-
mously transcending those previously known. 2
(1) Page and Moigno had previously shown that the magneto-
electric current could produce powerful electro-magnets.
(2) Mr. Wilde's paper is published in the Philosophical Transac
tions for 1867, p. 89. My opinion regarding Wilde's machine was
briefly expressed in a report to the Elder Brethren of the Trinity
House on the 17th of May, 1866: "It gives me pleasure to state that
the machine is exceedingly effective, and that it far transcends in
power all other apparatus of the kind."
2636
Tyndall-Address-1879.
But the discovery which, above all others, brought
the practical question to the front is now to be consid-
ered. On the 4th of February, 1867, a paper was re-
ceived by the Royal Society from Mr. William Siemens
bearing the title, "On the conversion of Dynamic into
Electric Force without the use of Permanent Mag-
netism." On the 14th of February, a paper from Sir
Charles Wheatstone was received, bearing the title,
On the augmentation of the Power of a Magnet by
thereaction thereon of Currents induced by the Magnet
itself." Both papers, which dwelt with the same dis-
covery, and which were illustrated by experiments,
were read upon the same night, viz. the 14th of Feb-
ruary. The whole field of science hardly furnishes a
more beautiful example of the interaction of natural
forces than that set forth in these two papers. You
can hardly find a bit of iron-you can hardly pick up
an old horse-shoe, for example-that does not possess
a trace of permanent magnetism; and from such a
small beginning Siemens and Wheatstone have taught
us to rise by a series of interactions between magnet
and armature to a magnetic intensity previously unap-
proached. Conceive the Siemens armature placed be-
tween the poles of a suitable electro-magnet. Suppose
(3) A paper on the same subject, by Dr. Werner Siemens, was
read on the 17th of January, 1867, before the Academy of Sciences
in Berlin. In a letter to Engineering, No. 622, p. 45, Mr. Robert
Sabine states that Professor Wheatstone's machines were constructed
by Mr. Stroh in the months of July and August, 1866. I do not
doubt Mr. Sabine's statement; still it would be dangerous in the
highest degree to depart from the canon, in asserting which Faraday
was specially strenuous, that the date of a discovery is the date of
its publication. Towards the end of December, 1866, Mr. Alfred
Varley also lodged a provisional specification (which, I believe, is a
sealed document) embodying the principles of the dynamo-electric
machine, but some years elapsed before he made anything pub-
lic. His brother, Mr. Cromwell Varley, when writing on this sub-
ject in 1867, does not mention him (Proc. Roy. Soc., March 14,
1867). It probably marks a national trait that sealed communica-
tions, though allowed in France, have never been recognised by the
scientific societies of England.
Tyndall- Address-1879.
2637
this latter to possess at starting the faintest trace of
magnetism; when the armature rotates, currents of in-
finitesimal strength are generated in its coil. Let the
ends of that coil be connected with the wire surround-
ing the electro-magnet. The infinitesimal current gen-
erated in the armature will then circulate round the
magnet, augmenting its intensity by an infinitesimal
amount. The strengthened magnet instantly reacts
upon the coil which feeds it, producing a current of
greater strength. This current again passes round the
magnet, which immediately brings its enhanced power
to bear upon the coil. By this play of mutual give and
take between magnet and armature, the strength of the
former is raised in a very brief interval from almost
nothing to complete magnetic saturation. Such a mag-
net and armature are able to produce currents of ex-
traordinary power, and if an electric lamp be introduced
into the common circuit of magnet and armature, we
can readily obtain a most powerful light. By this dis-
covery, then, we are enabled to avoid the trouble and
expense involved in the employment of permanent mag-
nets; we are also enabled to drop the exciting magneto-
electric machine, and the duplication of the electro-
magnets. By it, in short, the electric generator is so
far simplified, and reduced in cost, as to enable elec-
tricity to enter the lists as the rival of our present
means of illumination.
1
Soon after the announcement of their discovery by
Siemens and Wheatstone, Mr. Holmes, at the instance
of the Elder Brethren of the Trinity House, endeav-
oured to turn this discovery to account for lighthouse
purposes. Already, in the spring of 1869, he had con-
structed a machine which, though hampered with de-
fects, exhibited extraordinary power. The light was
developed in the focus of a dioptric apparatus placed
on the Trinity Wharf at Blackwall, and witnessed by
(1) In 1867 Mr. Ladd introduced the modification of dividing the
armature into two separate coils, one of which fed the electro-
magnets, while the other yielded the induced currents.
2638
Tyndall Address-1879.
the Elder Brethren, Mr. Douglass, and myself, from an
observatory at Charlton, on the opposite side of the
Thames. Falling upon the suspended haze, the light
illuminated the atmosphere for miles all round. Any-
thing so sunlike in splendour had not, I imagine, been
previously witnessed. The apparatus of Holmes, how-
ever, was rapidly distanced by the safer and more pow-
erful machines of Siemens and Gramme.
As regards lighthouse illumination, the next step for-
ward was taken by the Elder Brethren of the Trinity
House in 1876–77. Having previously decided on the
establishment of the electric light at the Lizard in
Cornwall, they instituted, at the time referred to, an
elaborate series of comparative experiments wherein
the machinery of Holmes, of the Alliance Company, of
Siemens, and of Gramme were pitted against each
other. The Siemens and the Gramme machines de-
livered direct currents, while those of Holmes and the
Alliance Company delivered alternating currents. The
light of the latter was of the same intensity in all azi-
muths round the place of observation; that of the
former was different in different azimuths, the discharge
being so regulated as to yield a gush of light of special
intensity in one direction. The following table gives
in standard candles the performance of the respective
machines:—1
Name of Machines.
Holmes.
Alliance
Gramme
(No. 1)
Maximum. Minimum.
1,523
1,523
1,953
1,953
6,663
4,016
(1) Observations from the sea on the night of November 21,
1876, made the Gramme and small Siemens practically equal to the
Alliance. But the photometric observations, in which the external
resistance was abolished, and previous to which the light-keepers
had become more skilled in the management of the direct current,
showed the differences recorded in the table. A close inspection of
these powerful lights at the South Foreland caused my face to peel,
as if it had been irritated by an Alpine sun.
Tyndall-Address-1879.
2639
Gramme
(No. 2)
Siemens
(Large)
Siemens
(Small, No. 1)
Siemens
(Small, No. 2)
Two Holmes's coupled..
Two Gramme's
Two Siemens'.
(Nos. 1 and 2)
1
1
6,663
4,016
14,818
8,932
5,539
3,339
6,864
4,138.
2,811
2,811
11,396
6,869
14,134
8,520
These determinations were made by Mr. Douglass
the engineer-in-chief, and Mr. Ayres the assistant
engineer of the Trinity House. After this contest,
which was conducted throughout in the most amicable
manner, Siemens machines of the smaller type were
chosen for the Lizard. 2
We have machines capable of sustaining a single
light, and also machines capable of sustaining several
lights. The Gramme machine, for example, which
ignites the Jablochkoff candles on the Thames Embank-
ment and at the Holborn Viaduct, delivers four cur-
rents, each passing through its own circuit. In each
circuit are five lamps through which the current be-
longing to the circuit passes in succession. The lights
correspond to so many resisting spaces, over which, as
already explained, the current has to leap; the force
which accomplishes the leap being that which produces
the light. Whether the current is to be competent to
pass through five lamps in succession, or to sustain only
a single lamp, depends entirely upon the will and skill of
the maker of the machine. He has, to guide him,
definite laws laid down by Ohm half a century ago, by
which he must abide.
Ohm has taught us how to arrange the elements of
(2) As the result of a recent trial by Mr. Schwendler, they have
been also chosen for India.
2640
Tyndall-Address-1879.
our battery so as to augment indefinitely its electro-
motive force that force, namely, which urges the cur-
rent forward and enables it to surmount external obsta-
cles. We have only to link the cells together so that
the current generated by each cell shall pass through
all the others, and add its electro-motive force to that
of all the others. We increase, it is true, at the same
time the resistance of the battery, diminishing thereby
the quantity of the current from each cell, bnt we aug-
ment the power of the integrated current to overcome
external hindrances. The resistance of the battery it-
self may, indeed, be rendered so great, that the external
resistance shall vanish in comparison. What is here
said regarding the voltaic battery is equally true of
magneto-electric machines. If we wish our current to
leap over five intervals, and produce five lights in suc-
cession, we must invoke a sufficient electro-motive
force. This is done through multiplying by the use of
thin wires the convolutions of the rotating armature as,
a moment ago, we augmented the cells of our voltaic
battery. Each additional convolution, like each addi-
tional cell, adds its electro-motive force to that of all
the others; and though it also adds its resistance,
thereby diminishing the quantity of current contributed
by each convolution, integrated current becomes en-
dowed with the power of leaping across the successive
spaces necessary for the production of a series of lights
in its course. The current is, as it were, rendered at
once thinner and more piercing by the simultaneous
addition of internal resistance and electro-motive power.
The machines, on the other hand, which produce only
a single light have a small internal resistance associ-
ated with a small electro-motive force. In such ma-
chines the wire of the rotating armature is compara-
tively short and thick, copper riband instead of wire
being commonly employed. Such machines deliver a
large quantity of electricity of low tension-in other
words, of low leaping power. Hence, though compe-
tent with their power is converged upon a single inter-
val, to produce one splendid light, their currents are
Tyndall-Address-1879.
2641
unable to force a passage when the number of intervals
is increased. Thus, by augmenting the convolutions of
our machines we sacrifice quantity and gain electro-
motive force; while by lessening the number of the
convolutions, we sacrifice electro-motive force and gain
quantity. Whether we ought to choose the one form
of machines or the other depends entirely upon the ex-
ternal work the machine has to perform. If the object
be to obtain a single light of great splendour, machines
of low resistance and large quantity must be employed.
If we want to obtain in the same circuit several lights
of moderate intensity, machines of high internal resist-
tance and of correspondingly high electro-motive power
must be invoked.
When a coil of covered wire surrounds a bar of iron,
the two ends of the coil being connected together, every
alteration of the magnetism of the bar is accompanied
by the development of an induced current in the coil.
The current is only excited during the period of mag-
netic change. No matter how strong or how weak the
magnetism of the bar may be, as long as its condition
remains permanent no current is developed. Conceive,
then, the pole of a magnet placed near one end of the
bar to be moved along it towards the other end. Dur-
ing the time of the pole's motion there will be an in-
cessant change in the magnetism of the bar, and accom-
panying this change we shall have an induced current in
the surrounding coil. If, instead of moving the magnet we
move the bar and its surrounding coil past the magnetic
pole, a similar alteration of the magnetism of the bar will
occur, and a similar current will be induced in the coil.
You have here the fundamental conception which led
M. Gramme to the construction of his beautiful ma-
chine. 1 He aimed at giving continuous motion to such
a bar as we have here described; and for this purpose
(1) Comptes Rendeus, 1871, p. 176. See also Gaugain on the
Gramme machine, Ann. de Chem. et de Phys., vol. xxviii. p. 324.
2642
Tyndall--Address --1879.
he bent it into a continuous ring, which, by a suitable
mechanism, he caused to rotate rapidly close to the
poles of a horse-shoe magnet. The direction of the
current varied with motion and with the character of
the influencing pole. The result was that the currents
in the two semicircles of the coil surrounding the ring
flowed in opposite directions. But it was easy, by the
mechanical arrangement called a commutator, to gather
up the currents and cause them to flow in the same
direction. The first machines of Gramme, therefore,
furnished direct currents, similar to those yielded by
the voltaic pile. M. Gramme subsequently so modified
his machine as to produce alternating currents. Such
machines are employed to produce the lights now ex-
hibited on the Holborn Viaduct and the Thames Em-
bankment.
Another machine of great alleged merit is that of M.
Lontin. It resembles in shape a toothed iron wheel,
the teeth being used as cores, round which are wound
coils of copper wire. The wheel is caused to rotate
between the opposite poles of powerful electro-magnets.
On passing each pole the core or tooth is strongly mag-
netised, and instantly evokes in the surrounding coil
induced current of corresponding strength. The cur-
rents excited in approaching and retreating, and in
passing different poles, move in opposite directions,
but by means of a commutator these conflicting electric
streams are gathered up and caused to flow in a com-
mon bed. The bobbins in which the currents are in-
duced, can be so increased in number as to augment
indefinitely the power of the machine. To excite his
electro-magnets, M. Lontin applies the principle of Mr.
A small machine furnishes a direct current,
which is carried round the electro-magnets of a second
and larger machine. Wilde's principle, it may be
added, is also applied on the Thames Embankment and
the Holborn Viaduct; a small Gramme machine being
used in each case to excite the electro-magnets of the
large one.
Wilde.
Tyndall--Address--1879.
2643
The Farmer-Wallace machine is also an apparatus of
great power. It consists of a combination of bobbins
for induced currents, and of inducing electro-magnets,
the latter being excited by the method discovered by
Siemens and Wheatstone. In the machines intended
for the production of the electric light, the electro-
motive force is so great as to permit of the introduc-
tion of several lights in the same circuit. A peculiarly
novel feature of the Farmer-Wallace system is the shape
of the carbons. Instead of rods, two large plates of
carbons with bevelled edges are employed, one above
the other. The electric discharge passes from edge to
edge, and shifts its position according as the carbon is
dissipated. The duration of the light in this case far
exceeds that obtainable with rods. I have myself seen
four of these lights in the same circuit in Mr. Ladd's
workshop in the City, and they are now, I believe, em-
ployed at the Liverpool Street Station of the Metro-
politan Railway. The Farmer-Wallace "quantity ma-
chine" pours forth a flood of electricity of low tension.
It is unable to cross the interval necessary for the pro-
duction of the electric light, but it can fuse thick cop-
per wires.
When sent through a short bar of iridium,
this refractory metal emits a light of extraordinary
splendour. 1
The machine of M. de Méritens, which he has gener-
ously brought over from Paris for our instruction, is the
newest of all. In its construction he falls back upon
the principle of the magneto-electric machine, employ-
ing permanent magnets as the exciters of the induced
currents. Using the magnets of the Alliance Company,
by a skilful disposition of his bobbins, M. de Méritens
produces with eight magnets a light equal to that pro-
duced by forty magnets in the Alliance machines.
While the space occupied is only one-fifth, the cost is
little more than one-fourth that of the latter. In the
de Méritens machine the commutator is abolished.
The internal heat is hardly sensible, and the absorption
of power, in relation to the effects produced, is small.
2644
Tyndall-Address-1879.
With his larger machines M. de Méritens maintains a
considerable number of lights in the same circuit.2
In relation to this subject, inventors fall into two
classes, the contrivers of regulators and the constructors
of machines. M. Rapieff has hitherto belonged to in-
ventors of the first class, but I have reason to know
that he is engaged on a machine which, when complete,
will place him in the other class also. Instead of two
single carbon rods, M. Rapieff employs two pairs of
rods, each pair forming a V. The light is produced at
the common junction of the four carbons. The device
for regulating the light is of the simplest character.
At the bottom of the stand which supports the carbons
are two small electro-magnets. One of them, when the
current passes, draws the carbons together, and in so
doing throws itself out of circuit, leaving the control of
the light to the other. The carbons are caused to ap-
proach each other by a descending weight, which acts
in conjunction with the electro-magnet. Through the
liberality of the proprietors of the Times, every facility
has been given to M. Rapieff to develope and simpify
his invention at Printing House Square. The illumi-
nation of the press-room, which I had the pleasure of
witnessing, under the guidance of M. Rapieff himself,
is extremely effectual and agreeable to the eye. There
are, I believe, five lamps in the same circuit, and the
regulators are so devised that the extinction of any
lamp does not compromise the action of the others.
M. Rapieff has lately improved his regulator.
Many other inventors might here be named, and
fresh ones are daily crowding in. Mr. Werdermann has
been long known in connection with this subject. Em-
ploying as negative carbon a disc, and as positive car-
bon a rod, he has, I am assured, obtained very satis-
(1) The iridium light was shown by Mr. Ladd. It brilliantly
illuminated the theatre of the Royal Institution.
(2) The small machine transforms one-and-a-quarter horse-power
into heat and light, yielding about 1,900 candles; the large machine
transforms five-horse power, yielding about 9,000 candles.
Tyndall-Address—1879.
2645
factory results. The small resistances brought into
play by his minute arcs enable Mr. Werdermann to in-
troduce a number of lamps into a circuit traversed by
a current of only moderate electro-motive power. M.
Reynier is also the inventor of a very beautiful little
lamp, in which the point of a thin carbon rod, properly
adjusted, is caused to touch the circumference of a car-
bon wheel which rotates underneath the point. The
light is developed at the place of contact of rod and
wheel. One of the last steps, though I am informed
not quite the last, in the improvement of regulators is
this: The positive carbon wastes more profusely than
the negative, and this is alleged to be due to the greater
heat of the former. It occurred to Mr. William
Siemens to chill the negative artificially, with the view
of diminishing or wholly preventing its waste. This he
accomplishes by making the negative pole a hollow cone
of copper, and by ingeniously discharging a small jet
of cold water against the interior of the cone. His
negative of copper is thus caused to remain fixed in
space, for it is not dissipated, the positive carbon only
needing control. I have seen this lamp in action, and
can bear witness to its success.
I might go on to other inventions, achieved or pro-
jected. Indeed, there is something bewildering in the
recent rush of constructive talent into this domain of
applied electricity. The question and its prospects are
modified from day to day, a steady advance being made
towards the improvement both of machines and regu-
lators. With regard to our public lighting, I strongly
lean to the opinion that the electric light will at no
distant day triumph over gas. I am not so sure that it
will do so in our private houses. As, however, I am
anxious to avoid dropping a word here that could in-
fluence the share market in the slightest degree, I limit
myself to this general statement of opinion.
To one inventor in particular belongs the honour of
the idea, and the realisation of the idea, of causing the
carbon rods to burn away like a candle. It is needless
for me to say that I here refer to the young Russian
•
2646
Tyndall-Address-1879.
officer, M. Jablochkoff. He sets two carbon rods up-
right at a small distance apart, and fills the space be-
tween them with an insulating substance like plaster of
Paris. The carbon rods are fixed in metallic holders.
A momentary contact is established between the two
carbons by a little cross-piece of the same substance
placed horizontally from top to top. This cross-piece
is immediately dissipated or removed by the current,
the passage of which once established is afterwards
maintained. The carbons gradually waste, while the
substance between them melts like the wax of a candle.
The comparison, however, only holds good for the act
of melting; for, as regards the current, the insulating
plaster is practically inert. Indeed, as proved by M.
Rapieff and Mr. Wilde, the plaster may be dispensed
with altogether, the current passing from point to point
between the naked carbons. M. de Méritens has re-
cently brought out a new candle, in which the plaster
is abandoned, while between the two principal carbons
is placed a third insulated rod of the same material.
With the small de Méritens machine two of these candles
can be lighted before you; they produce a very brilliant
light. In the Jablochkoff candle it is necessary that
the carbons should be consumed at the same rate.
Hence the necessity for alternating currents by which
this equal consumption is secured. It will be seen that
M. Jablochkoff has abolished regulators altogether, in-
troducing the candle principle in their stead. In my
judgment, the performance of the Jablochkoff candle
on the Thames Embankment and the Holborn Viaduct
is highly creditable, notwithstanding a considerable
waste of light towards the sky. The Jablochkoff
lamps, it may be added, would be more effective in a
street, where their light would be scattered abroad by
1
(1) Both the machines of M. de Méritens and the Farmer-Wallace
machine were worked by an excellent gas-engine, lent for the occa-
sion by the Messrs. Crossley, of Manchester. The Siemens machine
was worked by steam.
Tyndall-Address—1879.
2647
the adjacent houses, than in the positions which they
now occupy in London.
It was my custom some years ago, whenever I needed
a new and complicated instrument, to sit down besides
its proposed constructor, and to talk the matter over
with him. The study of the inventor's mind which this
habit opened out was always of the highest interest to
me. I particularly well remember the impression
made upon me on such occasions by the late Mr.
Darker, a philosophical instrument maker in Lambeth.
This man's life was a struggle, and the reason of it was
not far to seek. No matter how commercially lucrative
the work upon which he was engaged might be, he
would instantly turn aside from it to seize and realise
the ideas of a scientific man. He had an inventor's
power, and an inventor's delight in its exercise. The
late Mr. Becker possessed the same power in a very
considerable degree. On the Continent, Froment,
Breguet, Sauerwald, and others might be mentioned as
eminent instances of ability of this kind. Such minds
resemble a liquid on the point of crystallization.
Stirred by a hint, crystals of constructive thought im-
mediately shoot through them. That Mr. Edison pos-
sesses this intuitive power in no common measure, is
proved by what he has already accomplished. He has
the penetration to seize the relationship of facts and
principles, and the art to reduce them to novel and
concrete combinations. Hence, though he has thus
far accomplished nothing that we can recognise as new
in relation to the electric light, an adverse opinion as
to his ability to solve the complicated problem on
which he is engaged, would be unwarranted.
I will endeavour to illustrate in a simple manner Mr.
Edison's alleged mode of electric illumination, taking
advantage of what Ohm has taught us regarding the
laws of the current, and what Joule has taught us re-
garding the relation of resistance to the development
of light and heat. From one end of a voltaic battery
a wire, dividing at a certain point into two
runs
2648
Tyndall-Address-1879.
ance.
branches, which reunite in a single wire connected with
with the other end of the battery. From the positive
end of the battery the current passes first through the
single wire to the point of junction, where it divides
itself between the branches according to a well-known
law. If the branches be equally resistant, the current
divides itself equally between them. If one branch be
less resistant than the other, more than half the current
will choose the freer path. The strict law is that the
quantity of current is inversely proportional to the resist-
A clear image of the process is derived from the
deportment of water. When a river meets an island it
divides, passing right and left of the obstacle, and
afterwards reuniting. If the two branch beds be equal
in depth, width, and inclination, the water will divide
itself equally between them. If they be unequal, the
larger quantity of water will flow through the more
open course. And, as in the case of the water, we may
have an indefinite number of islands producing an in-
definite subdivision of the trunk stream, so in the case
of electricity we may have, instead of two branches,
any number of branches, the current dividing itself
among them, in accordance with the law which fixes
the relation of flow to resistance.
Let us apply this knowledge. Suppose an insulated
copper rod, which we may call an "electric main," to
be laid down along one of our streets, say along the
Strand. Let this rod be connected with one end of a
powerful voltaic battery, a good metallic connection
being established between the other end of the battery
and the gas-pipes under the street. As long as the
electric main continues unconnected with the gas-pipes,
the circuit is incomplete and no current will flow; but
if any part of the main, however distant from the bat-
tery, be connected with the adjacent gas-pipes, the cir-
cuit will be completed and the current will flow. Sup-
posing our battery to be at Charing Cross, and our rod
of copper to be tapped opposite Somerset House, a
branch wire can be carried from the rod into the build-
ing, the current passing through which may be subdi-
Tyndall-Address—1879.
2649
vided into any number of subordinate branches which
reunite afterwards and return through the gas-pipes to
the battery. The branch currents may be employed to
raise to vivid incandescence a refractory metal like
iridium or one of its alloys. Instead of being tapped
at one point, our main may be tapped at one hundred
points. The current will divide in strict accordance
with law, its power to produce light being solely limited
by its strength. The process of division closely re-
sembles the circulation of the blood; the electric main
carrying the outgoing current representing a great
artery, the gas-pipes carrying the return current repre-
senting a great vein, while the intermediate branches
represent the various vessels by which the blood is
distributed through the system. This, if I understand
aright, is Mr. Edison's proposed mode of illumination.
The electric force is at hand. Metals sufficiently re-
fractory to bear being raised to vivid incandescence are
also within reach. The principles which regulate the
division of the current and the development of its light
and heat are perfectly well known. There is no room
for a "discovery," in the scientific sense of the term,
but there is ample room for the exercise of that
mechanical ingenuity which has given us the sewing
machine and so many other useful inventions. Know-
ing something of the intricacy of the practical problem,
I should certainly prefer seeing it in Mr. Edison's
hands to having it in mine.¹
1
It is sometimes stated as a recommendation to the
electric light, that it is light without heat; but to dis-
prove this, it is only necessary to point to the experi-
ments of Davy, which show that the heat of the voltaic
arc transcends that of any other terrestrial source. The
emission from the carbon points is capable of accurate
analysis. To simplify the subject, we will take the
case of a platinum wire at first slightly warmed by the
(1) More than thirty years ago the radiation from incandescent
platinum was admirably investigated by Dr. Draper of New York.
2650
Tyndall—Address—1879.
current, and then, through the gradual augmentation of
the latter, raised to a white heat. When first warmed,
the wire sends forth rays which have no power on the
optic nerve. They are what we call invisible rays; and
not until the temperature of the wire has reached
nearly 1,000° Fahr., does it begin to glow with a faint,
red light. The rays which it emits prior to redness are
all invisible rays, which can warm the hand but cannot
excite vision. When the temperature of the wire is
raised to whiteness, these dark rays not only per-
sist, but they are enormously augmented in intensity.
They constitute about 95 per cent. of the total radia-
tion from the white-hot platinum wire. They make up
nearly 90 per cent. of the emission from a brilliant
electric light. You can by no means have the light of
the carbons without this invisible emission as an ac-
companiment. The visible radiation is, as it were,
built upon the invisible as its necessary foundation.
It is easy to illustrate the growth in intensity of
these invisible rays as the visible ones enter the radia-
tion and augment in power. The transparency of the
simple gases and metalloids-of oxygen, hydrogen,
nitrogen, chlorine, iodine, bromine, sulphur, phos-
phorus, and even of carbon, for the invisible heat rays
is extraordinary. Dissolved in a proper vehicle, iodine
cuts the visible radiation sharply off, but allows the
invisible free transmission. By dissolving iodine in
sulphur, Professor Dewar has recently added to the
number of our effectual ray-filters. The mixture may
be made as black as pitch for the visible, while remain-
ing transparent for the invisible rays. By such filters.
it is possible to detach the invisible rays from the total
radiation, and to watch their augmentation as the light
increases. Expressing the radiation from a platinum
wire when it first feels warm to the touch-when,
therefore, all its rays are invisible-by the number one,
the invisible radiation from the same wire raised to a
white heat may be five hundred or more. It is not,
then, by the diminution or transformation of the non-
luminous emission that we obtain the luminous; the
Tyndall--Address-1879.
2651
heat rays maintain their ground as the necessary ante-
cedents and companions of the light rays. When de-
tached and concentrated, these powerful heat rays can
produce all the effects ascribed to the mirrors of Archim-
edes at the siege of Syracuse. While incompetent to
produce the faintest glimmer of light, or to affect the
most delicate air-thermometer, they will inflame paper,
burn up wood, and even ignite combustible metals.
When they impinge upon a metal refractory enough to
bear their shock without fusion, they can raise it to a
heat so white and luminous as to yield, when analysed,
all the colours of the spectrum. In this way the dark
rays emitted by the incandescent carbons are converted
into light rays of all colours. Still, so powerless are
these invisible rays to excite vision that the eye has
been placed at a focus competent to raise platinum foil
to bright redness, without experiencing any visual im-
pression. Light for light, no doubt, the amount of
heat imparted by the incandescent carbons to the air is
far less than that imparted by gas flames. It is less
because of the smaller size of the carbons, and of the
comparative smallness of the quantity of fuel consumed
in a given time. It is also less because the air cannot
penetrate the carbons as it penetrates a flame. The tem-
perature of the flame is lowered by the admixture of a
gas which constitutes four-fifths of our atmosphere,
and which, while it appropriates and diffuses the heat,
does not aid in the combustion; and this lowering of
the temperature by the inert atmospheric nitrogen,
renders necessary the combustion of a greater amount
of gas to produce the necessary light. In fact, though
the statement may appear paradoxical, it is entirely
because of its enormous actual temperature that the
electric light seems so cool. It is this temperature
that renders the proportion of luminous to non-
luminous heat greater in the electric light than in our
brightest flames. The electric light, morever, requires
no air to sustain it. It glows in the most perfect air
Its light and heat are therefore not purchased
vacuum.
2652
Tyndall-Address-1879.
at the expense of the vitalising constituent of the atmos-
phere. It sheds its light without vitiating the air.
Two orders of minds have been implicated in the
development of this subject; first, the investigator and
discoverer, whose object is purely scientific, and who
cares little for practical ends; secondly, the practical
mechanician, whose object is mainly industrial. It
would be easy, and probably in many cases true, to say
that the one wants to gain knowledge, while the other
wants to make money; but I am persuaded that the
mechanician not unfrequently merges the hope of
profit in the love of his work. Members of each of
these classes are sometimes scornful towards those of
the other. There is, for example, something superb in
the disdain with which Cuvier hands over the discov-
eries of pure science to those who apply them: “Your
grand practical achievements are only the easy appli-
cation of truths not sought with a practical intent-
truths which their discoverers pursued for their own.
sake, impelled solely by an ardour for knowledge.
Those who turned them into practice could not have
discovered them, while those who discovered them
had neither the time nor the inclination to pursue them
to a practical result. Your rising workshops, your
peopled colonies, your vessels which furrow the seas;
this abundance, this luxury, this tumult "-"this com-
motion," he would have added, were he now alive,
"regarding the electric light "-" all come from discov-
eries in Science, though all remain strange to them.
The day that a discovery enters the market they
abandon it; it concerns them no more."
In writing thus Cuvier probably did not sufficiently
to take in account the reaction of the applications of
science upon science itself. The improvement of an
old instrument or the invention of a new one is often
tantamount to an enlargement and refinement of the
senses of the scientific investigator. Beyond this, the
amelioration of the community is also an object worthy
Tyndall-Address-1879.
2653
of the best efforts of the human brain. Still, assuredly
it is well and wise for a nation to bear in mind that
those practical applications which strike the public
eye, and excite public admiration, are the outgrowth of
long antecedent labours begun, continued, and ended
under the operation of a purely intellectual stimulus.
Few," says Pasteur, "seem to comprehend the real
origin of the marvels of industry and the wealth of
nations. I need no other proof of this than the free
quent employment in lectures, speeches, and official
language of the erroneous expression, applied science.'
A statesman of the greatest talent stated some time ago
that in our day the reign of theoretic science had
rightly yielded place to that of applied science. Noth-
ing, I venture to say, could be more dangerous, even
to practical life, than the consequences which might
flow from these words. They show the imperious
necessity of a reform in our higher education. There
exists no category of sciences to which the name of
applied science could be given. We have science and
the applications of science which are united as tree and
fruit."
A final reflection is here suggested. We have
amongst us a small cohort of social regenerators—men
of high thoughts and aspirations-who would place the
operations of the scientific mind under the control of a
hierarchy which should dictate to the man of science
the course that he ought to pursue. How this hier-
archy is to get its wisdom they do not explain. They
decry and denounce scientific theories; they scorn all
reference to æther, and atoms, and molecules, as sub-
jects lying apart from the world's needs; and yet such
ultra-sensible conceptions are often the spur to the
greatest discoveries. The source, in fact, from which
the true natural philosopher derives inspiration and.
unifying power is essentially ideal. Faraday lived in
this ideal world. Nearly half a century ago, when he
first obtained a spark from a magnet, an Oxford don
expressed regret that such a discovery should have
2654
Tyndall-Address-1879.
been made, as it placed a new and facile implement in
the hands of the incendiary. To regret, a Comtist hier-
archy would have probably added repression, sending
Faraday back to his bookbinder's bench as a more dig-
nified and practical sphere of action than peddling with
a magnet. And yet it is Faraday's spark which now
shines upon our coasts, and promises to illuminate our
streets, halls, quays, squares, warehouses, and, perhaps,
at no distant day, our homes.
JOHN TYNDALL.
Fontaine-1878-Chapter III.
2655
Complainant's Exhibit Extract from Fon-
taine's Electric Lighting.
ELECTRIC LIGHTING.
A PRACTICAL TREATISE,
BY HIPPOLYTE FONTAINE.
Translated from the French by Paget Higgs.
London.
E. & F. N. Spon, 1878.
Pages 38 to 52.
CHAPTER III.
ELECTRIC CARBONS.
WOOD CARBON RODS--RETORT CARBON-ITS INCONVEN-
IENCES--STAITE AND EDWARD'S CARBONS--LA
MOLT'S CARBONS--LACASSAGNE AND THIERS' CAR-
BONS--CURMER'S CARBONS-JACQUELAIN'S CAR-
BONS--PEYRET'S CARBONS--ARCHEREAU'S CAR-
BONS--CARRÉ'S EXPERIMENTS--HIS PROCESSES OF
MANUFACTURE--GAUDOIN'S EXPERIMENTS--HIS
PROCESSES OF MANUFACTURE--COMPARATIVE TRIALS
OF SEVERAL KINDS OF CARBONS.
In his experiments on the voltaic arc, Davy made use
of rods of wood carbon extinguished in water or mer-
cury. These rods burnt with great brilliancy, and in a
**
Fontaine-1878-Chapter III.
2656
very regular manner, but they wore away so rapidly
that their use was obliged to be reserved for laboratory
experiments. In replacing the wood carbon by the
deposits collected from the walls of gas retorts, Fou-
cault really opened up to the voltaic arc the epoch of
useful applications. Retort carbon is, in fact, much
more dense, and resists for a long time the destructive
action of the voltaic focus.
But, as M. Le Roux has observed with reason, the
last word has not been said upon this question, and
retort carbon will still offer grave inconveniences. Its
density is far from uniform, it sometimes splits, fre-
quently works irregularly, and produces considerable
variations in brilliancy. These variations chiefly
depend upon the presence of foreign matters, such as
alkaline or earthy salts, and also notable quantities of
silica. These matters are much less refractory than
the carbon; they pass into vapor, and form for a great
part the flame which envelopes the arc. This flame is
more conducting than the voltaic arc proper; more-
over, as it has a much greater section, it is less heated,
and besides, as it is a gaseous body, its power of radi-
ation is less than that of the particles of carbon which
constitute the arc.
Let us hasten to say that, by suitably choosing the
two rods which should furnish a regulator, retort car-
bon gives satisfactory results in most of its applica-
tions.
When the voltaic arc is enclosed in a globe of
frosted glass, the scintillations, intermittences, and va-
riations in the intensity of the focus are much less
felt; the shadows are much less marked, the light is
softer, more homogeneous, more agreeable. But the
globe causes a very considerable loss of light, and
whenever the small irregularities, due to the imperfec-
tion of the carbon, are supportable, the carbons should
be burned without a globe. Moreover, one gets readily
accustomed to the electric light; and the workmen
now, instead of complaining, seek factories lighted in
this manner.
Fontaine-1878-Chapter III.
2657
Several inventors have endeavored to substitute for
carbons cut directly from the deposits on the walls of
retorts, similar agglomerates, but purer; others have
merely purified retort carbons. Some have obtained
products very remarkable in respects of luminosity, but
practically inapplicable on account of their extreme
cost.
Among the processes proposed for the improvement
of electric carbons, we will cite those of Messrs. Staite
and Edwards, Le Molt, Lacassagne and Thiers, Cur-
mer, Jacquelain, Peyret, Archereau, Carré and Gau-
doin.
STAITE AND EDWARDS' CARBON.
In 1846, Messrs. Staite and Edwards patented a pro-
cess for the manufacture of carbons for the electric
light, which had for its base a mixture of pulverized
coke and sugar.
The coke is first reduced to a nearly impalpable
powder, and a small quantity of syrup added, the mix-
ture being purged, moulded, and strongly compressed,
Then the carbon is subjected to a first heating, and
plunged into a very concentrated solution of sugar
and again subjected to a white heat.
LE MOLT'S CARBON.
M. Le Molt, in 1849, patented a composition for
electric carbons, consisting of two parts of retort car-
bon, two parts of wood--charcoal or coke, and one
part of tar. The substances were in the first place
pulverized, pounded, mixed, and by much trituration
brought to the state of a stiff paste; then, by the aid
of powerful mechanical means, subjected to great com-
pression.
The moulded pieces were covered with a coating of
syrup, and placed beside each other in a vessel of re-
tort carbon. They were then subjected to a high tem-
2658
Fontaine-1878-Chapter III.
perature for a period of from twenty to thirty hours
and purified if necessary, by immersion in acids.
LACASSAGNE AND THIERS' CARBON.
In 1875, Messrs. Lacassagne and Thiers gave atten-
tion to the purification of retort carbons. They fused
a certain quantity of caustic potash or soda. When
this bath was at a red heat, they digested in it, for
about a quarter of an hour, the carbon rods which had
been previously cut from the walls of retorts.
This operation was intended to change into a solu-
ble silicate of potash or soda, the silica contained in
the carbons, which is so pernicious to the constancy of
the light. The carbon rods were then washed in boil-
ing water, and subjected for several hours (in a red-
hot tube of porcelain or fire-clay) to the action of a
current of chlorine, which had the effect of converting
the different earthy matters that the alkali had not at-
tacked, into volatile chlorides, as of silica, calcium, po-
tassium, iron, &c. Thus cleansed, these carbons gave
a somewhat more regular light.
CURMER'S CARBON.
Curmer's process consists principally in the calcina-
tion of lamp-black, benzine, and oil of turpentine, the
whole mixed and moulded in the form of cylinders; the
decomposition of these substances leaves a porous car-
bon, which is soaked with resins or saccharine matters
and again calcined. By repeating these operations, M.
Curmer scuceeded in producing carbons of small den-
sity, or conducting power, certainly, but extremely reg-
ular and free from all impurities.
JACQUELAIN'S CARBON.
M. Jacquelain, late chemist at l'Ecole Centrale, has
endeavored to imitate the circumstances which, during
Fontaine--1878-Chapter III.
2659
the manufacture of gas, gave birth to retort carbon.
These circumstances are the coming into contact with
the white-hot walls of the retort of very dense hydro-
carburetted matters, of which part is volatilized and
the rest decomposed, leaving as residue a layer of car-
bon. In retorts used in the manufacture of gas,
these hydro-carburetted matters carry away with them
a great number of the impurities that the coal contains.
By taking the tars resulting from true distilation,
cleared consequently of all the non-volatile impurities,
and realizing, in special apparatus, these conditions of
decomposition in contact with highly-heated walls, re-
tort carbons ought to be reproduced possessing perfect
purity. It is this that M. Jacquelain has done in
operating with a tube of refractory earth 0·15 metre
diameter, in an improvised furnace; and he has ob-
tained some plates which, cut into the rods with a saw,
have given a light perfectly steady, whiter, and of about
25 per cent. greater intensity, with an equal electric
current, than that given by the ordinary carbons.
The experiments made with these carbons, by the
Paris Administration of Lighthouses, have been so
conclusive that we had, about the commencement of
1876, the idea of putting the process in practice. But
M. Jacquelain, being consulted, explained to us that it
was impossible to calculate: 1st, the expenditure
necessary for the establishment of a continuous manu-
facture; 2nd, the approximate net cost price of the
carbons obtained. As another process by M. Gaudoin
has commenced to give good results, we had not con-
tinued our idea. We have long ago learnt what is the
cost of converting a very exact laboratory process into
an industrial operation, and we do not wish to launch
into an affair of this nature without some figures being
given.
The carbon of M. Jacquelain, once formed, has al-
ways the inconvenience of requiring a considerable
amount of manual labor before use can be made of it
(because the material is so hard, that it can with diffi-
2660
Fontaine-1878-Chapter III.
culty be cut by the saw), and of producing relatively
considerable waste.
PEYRET'S CARBON.
M. Peyret, a physicist of Lourdes, has prepared
carbons by soaking pieces of elder-tree pith or any
other porous body with liquefied sugar, and afterwards
decomposing the sugar by heat. By repeating the
operation a sufficient number of times, he obtained
very dense carbons, which he then submitted to a
current of sulphide of carbon.
We have had in our hands only very small fragments
of these carbons, and it has been impossible for us to
give an estimate of their worth; their high price is in
every case a very serious obstacle to the development
of an industrial manufacture.
ARCHEREAU'S CARBON.
M. Archereau, whose name frequently comes under
the pen in questions relating to agglomerates of car-
bon, or to electricity, has presented to the Academy of
Sciences some new rods for electric regulators, com-
posed of carbon mixed with magnesia, agglomerated
and pressed; the magnesia has, according to the au-
thor, the advantage of making the light more steady
and of augmenting its lighting power.
We have tried several samples of these carbons;
some were of good quality, others inferior to retort
carbons. Several carbons furnished a light of 150
burners, with a total consumption per hour of 0.03
metre. It is a manufacture that is capable of giving
good results, but needs very careful revision.
CARRÉ'S CARBON.
M. Carré has made a great number of experiments
for the electric light upon retort carbons impregnated
with different salts, and has combined a new product
Fontaine-1878—Chapter III.
2661
from the same usage. Some details of his labors are
necessary to make their importance and merit under-
stood.
By impregnating porous carbons, and by a prolonged
ebullition in concentrated solutions, M. Carré proves:
1st. That potash and soda at least double the
length of the voltaic arc, render it more silent, com-
bine themselves with the silica, and eliminate it from
the carbons by making it flow to six or seven milli-
meters from the points, in a state of vitreous globules,
limpid and often colorless; that these substances aug-
ment the light in the proportion of 1-25 to 1.
2d. That lime, magnesia, and strontia augment the
light in the proportion of 1-40 to 1, by the coloring
in different ways.
3d. That iron and antimony carry the augmentation
to 1-60 or 1-70.
4th. That boracic acid augments the duration of the
carbons by enveloping them with a vitreous layer
which isolates the oxygen from them, but without aug-
menting the light.
5th. That upon the whole the impregnation of pure
and regular porous carbons, with the solutions of dif-
ferent substances, is a convenient and economical
means of producing their spectra, but that the mixing
of the simple substances with the carbon compound is
preferable.
For the manufacture of carbons, M. Carré recom-
mends a composition of powdered coke, calcined lamp-
black, and a special syrup formed of 30 parts of cane-
sugar and 12 quarts of gum.
The following formula is recommended in the patent
of the 15th January, 1876:
Coke, very pure, in fine, nearly impalpable.
powder
Calcined lamp-black-
Special syrup
15 parts.
5
(C
-7 to 8
The whole is strongly triturated, and has added to
2662
Fontaine-1878-Chapter III.
it from 1 to 3 parts of water, to compensate for the
loss by evaporation, according to the degree of tough-
ness to be given to the paste. The coke ought to be
made with the best coals, pulverized and purified by
washings. (The coal powder may be likewise purified
by washings by decantation and maceration with heat
in acid baths). The coke dust of gas retorts is gener-
ally pure enough.
The paste is now pressed and passed through a draw-
plate, then the carbons are placed in tiers in crucibles,
and are subjected during a given time to a high tem-
perature.
The cooking comprehends a series of operations.
For the first, the carbons are placed horizontally in
the crucible, resting upon a bed of coke dust; every
layer is separated by a cover of paper to avoid any
adherence. Between the last layer and the cover is
put one centimetre of coke-sand, and one centimetre of
silicous sand upon the joint of the cover.
After the first operation, which ought to last from
four to five hours, and attain a cherry-red heat, the car-
bons should remain two or three hours in a very con-
centrated and boiling syrup of cane-sugar or caramel,
with two or three intervals of considerable cooling, in
order that the atmospheric pressure may force the
syrup into all the pores. The carbons are then left to
drain by opening a cock placed at the bottom of the
vessel, after which they are agitated for some instants
in boiling water to dissolve the sugar remaining on the
surface.
After desiccation the carbons are submitted to a
second cooking to the degree required; they are then
stood up in the crucible by filling up their intersti-
ces with sand.
They are thus manipulated from stage to stage, until
they have acquired the density and solidity requisite,
and the manipulation is facilitated by the use of an
oven having as many stages as there are cookings re-
quired.
The carbons are dried slowly. Their desiccation is
Fontaine--1878--Chapter III.
2663
completed in a stove, the temperature of which at-
tains gradually 80 degrees in twelve or fifteen hours.
To prevent their becoming deformed in drying, the
rods are placed on pieces of sheet iron having a V-
form.
The Carré carbons are more tenacious and are harder
than those of retort carbon. They are remarkably ac-
curate and regular. Rods of 0.01 metre diameter
and of 0.05 metre length can be employed without
fear of rupture. Their cylindrical form and their
homogeneity make the cones maintain as perfect shape
as if they were turned. They are also better con-
ductors than retort carbons. The only inconvenience
that we have remarked in their employment is a rapid
disaggregation, the production of small sparks, and
irregularity of the luminous brilliancy.
GAUDOIN'S CARBONS.
M. Gaudoin also has made numerous experiments
upon carbons containing foreign substances.
The following bodies have been introduced into the
carbons:
1st, phosphate of lime from bones; 2d, chloride of
calcium; 3d, borate of lime; 4th, silicate of lime; 5th,
pure precipitated silica; 6th, magnesia; 7th, borate of
magnesia; 8th, phosphate of magnesia; 9th, alumina ;
10th, silicate of alumina.
The proportions were calculated in such a manner
as to obtain five per cent. of oxide after the cooking of
the carbons. These were submitted to the action of
an electric current, always of the same direction, fur-
nished by a Gramme machine powerful enough to
maintain a voltaic arc of 10 to 15 Millimètres in length.
The negative carbon being placed at the bottom, M.
Gaudoin has observed the following results:
1st. The complete decomposition of the phosphate
of lime under triple influence of electrolytic action,
2664
Fontaine--1878--Chapter III.
The
calorific action, and reducing action of the carbon.
The reduced calcium goes to the negative carbon, and
burns in contact with the air with a reddish flame.
lime and phosphoric acid are diffused into the air, pro-
ducing abundant fumes. The light, measured by a
photometer, is double that which is produced by car-
bons of the same section cut from the residue of gas
retorts.
2d. Chloride of calcium, borate and silicate of lime
are also decomposed, but the boracic and silicic acids
appear to escape, by volatilization, from the electric ac-
tion. These bodies give less light than the phosphate
of lime.
3d. Silica introduced into the less conducting car-
bons, melts and volatilizes without being decomposed.
4th. Magnesia, borate and phosphate of magnesia
are decomposed; the magnesium in vapor goes to
the negative carbon and burns, in contact with the
air, with a white flame. The magnesia, boracic and
phosphoric acids diffuse into the air in a state of va-
por. The increase of light is less considerable than
with the lime salts.
5th. Alumina and silicate of alumina are decomposed
only with a very strong current and a very consider-
able voltaic arc, but under these circumstances the de-
composition of the alumina is well manifested, and the
alumina in vapor, is seen to go off from the negative
pole like a jet of gas, and burn with a blue flame of
little lighting power.
The flame and vapor which constantly accompany
these electro-chemical lights having appeared to him a
great obstacle to their utilization for illumination, M.
Gaudoin has not pushed these experiments further.
He has preferred to follow up his studies upon the
agglomeration of carbon.
Fontaine-1878-Chapter III.
2665
The products manufactured by M. Gaudoin being
superior to all others, we will expatiate a little upon
this mode of inanufacture.
The patent is dated 12th July, 1876.
As we have said above, the carbons intended for
the production of the voltaic arc ought to be chemi-
cally pure. Thus, the dust of retort carbon, though
containing only a small proportion of foreign matters,
is not sufficiently pure for this use, and its employ-
ment presents some inconveniences. The washings
in acids or alkalies to which the carbonaceous matters
may be submitted, with the aim of extracting the im-
purities they contain, are costly and insufficient.
Lamp-black is pure enough, but its price is high and
its management difficult. Owing to this, M. Gaudoin
had to seek elsewhere a better source of carbon, and
he has found a solution of the problem in decomposing,
by heat in closed vessels, the dried pitches, fats or
liquids, the tars, resins, bitumens, natural or artificial
essences or oils, organic matters capable of leaving be-
hind carbon sufficiently pure after their decomposition
by heat.
The apparatus employed to effect this decomposi-
tion are closed retorts or crucibles of plumbago.
These crucibles are placed in a furnace capable of be-
ing heated to a bright red. The lower parts of the
crucibles are furnished with two tubes, serving one for
the disengagement of gas and volatile matters, the
other for the introduction of the primary material.
The volatile products of decomposition may be con-
ducted under the hearth of the furnace and there
burnt for heating the crucibles, but it is more advanta-
geous to conduct them into a condensing chamber or
into a copper still, and to recover, after condensation,
the tars, oils, essences, aud hydro-carbons that are
produced in this operation.
M. Gaudoin utilizes these different sub-products
also in the manufacture of his carbons; he takes
great care to avoid for the worms and receivers the
use of iron, zinc, or any substances susceptible of be-
2666
Fontaine-1878-Chapter III.
ing attacked by these tars, because the whole value
rests in purity.
Whatever may be the primary material employed
for the manufacture of this carbon, the decomposition
by heat should be able to be conducted either slowly
or quickly, according to the nature of the sub-products
that it is proposed to obtain. For operating slowly it
suffices to two-thirds fill the retort and to heat gradu-
ally up to a clear red, avoiding as much as possible
the boiling over of the substances. For operating
quickly, the empty retort is heated to a deep red, and
the primary material thrown into the bottom in small
quantities, in a thin stream if it is liquid, and in small
fragments if it is solid. The slow distillation gives
most tars and heavy oils and little gas. The quick de-
composition gives more light oils and gas.
When the primary material has been properly
chosen, there remains in the retort, carbon more or less
compact. It is pulverized as finely as possible, and
agglomerated alone or with a certain quantity of lamp-
black by means of the carbides of hydrogen obtained as
secondary products.
Thus prepared, those carbides are completely free
from iron, and are much preferable to those found in
commerce, not only in the agglomeration of the carbon,
but also in the impregnation or soaking of the manu-
factured objects. (The last operation, by filling up
the pores, introduces oxide of iron when affected with
commercial products.)
The objects made in agglomerated carbon are, for
one variety of carbon, as much more combustible as
they are porous, and as much more porous as they are
moulded with less pressure. The inventor himself
uses for his manuracture, steel moulds capable of re-
sisting the highest pressure of a strong hydraulic press.
Although the draw-plate or moulding apparatus,
used long since in the manufacture of ordinary graph-
ite carbons, may be used, without any modification, for
the manufacture of carbons for the electric lamp, M.
Gaudoin has added to this apparatus certain important
Fontaine-1878-Chapter III.
2667
improvements. Thus, instead of causing the carbons
to issue, from top to bottom, vertically, he places the
orifice or orifices of the mould upon the side, and in
such a manner that the issuing carbons form with the
horizon a descending angle of 20 to 70 degrees. This
arrangement allows of emptying the whole of the mat-
ter contained in the mould without interrupting the
work, and as the carbon is constantly supported it does
not break under its own weight, which frequently hap-
pens when issuing vertically.
We have made, at different times, numerous trials
with all kinds of carbons, and those of M. Gaudoin's
manufacture gave the best results. It has necessitated
much time and considerable expense to remove this
manufacture from the merely scientific domain to that
of the practical, but success has crowned the efforts of
the inventor. (Table A.)
2668
Fontaine-1878--Chapter III.
TABLE A.
TABLE OF EXPERIMENTS MADE WITH SEVERAL ELECTRIC CARBONS, 6TH NOVEMBER, 1876.
Consumption.
Name of
Carbon.
Dimensions.
Speed of Machine.
Of negative carb.
Of positive carb.
Total per hour.
Mean of two ex-
periments.
Regularity.
Observation.
m.m.m.m.m.m.m.m.
Retort
9 m.m. square...! 800.
19
36
55
63 Irregular.
9 m.m. square... 920 23 48 71
Archereau .. 10 m.m. diam.. 800 20
... 10 m.m. diam
Sufficiently regular.
Scintillating, eclipsed for a short time, a slight disag-
gregation.
920 30
6880
80
90
88
Carré..
10.4 m.m. diam. 800
10.4 m.m. diam
920
Gaudoin
11.3 m.m. diam
800
11.3 m.m. diam
920 38 50
88 88
∞ ∞ 2008080
26 80 106
58
38
8888 82
18 60 78
92 Irregular.
73
Very regular.
Very regular.
85 Sufficiently regular. A slight disaggregation; a few sparks. Cinders of
Sufficiently regular. Oxide of Iron in rather large quantity. White light.
Cones good.
Regular enough.
A slight disaggregation; a few sparks. More cinders
than the preceding; reddened for a greater length.
Neither disaggregation nor sparks; less cinders than
the Carré and Archereau carbons.
Fontaine-1878-Chapter III.
2669
The light produced with the retort carbons was equal
to 103 burners, and that produced by the artificial car-
bons varied between 120 and 180 burners for the Arch-
ereau and Carré carbons, and between 200 and 210 for
the Gaudoin carbons. The mean of 150 burners may
be applied without appreciable error to the Archereau
and Carré carbons, and that of 205 to the Gaudoin car-
bons.
Brought to a uniform section of 0.0001 square metre,
the consumption of the carbon was respectively.
For retort carbons-
Archereau..
Gaudoin.
Carré
_51 millimetres.
__66
""
73
_77
"(
In proportion to the light produced, this consump-
tion was:
For the Gaudoin carbons, 35 mills. per 100 burners.
"(
Archereau
(C
((
Carré
Retort
44
51
(C
49
These experiments were made with a Gramme ma-
chine constructed by M. Bréguet and a Carré lamp by
the same maker. The carbons were taken at hazard
from a lot of several metres for each series.
At the request of one of the inventors we made some
fresh experiments, with the co-operation of Messrs.
Gramme and Lemonnier, with a more powerful Gramme
machine and a Serrin lamp.
The following table (B) contains the mean of three
series of experiments made with the greatest precision.
The electric lamp was placed, quite vertically, at the
same level as the oil-lamp and photometer. Every
precaution was taken that there should not be any
sensible error in the measurements of the luminous in-
tensity.
Brought to a uniform section of 0.0001 square metre,
2670
Fontaine-1878-Chapter III.
the consumption of the carbons was respectively in these
new experiments:
For the Carré carbons,
Retort,
Archereau
((
44 millimetres.
49
53
"(
Gaudoin (wood carbon), 61
Gaudoin, No. 1,
78
((
In proportion to the light produced, the consumption
was:
For the Gaudoin (wood carbon) 32 mills. per 100 burners.
""
Archereau
39 ((
66
Carré
40
((
Gaudoin, No. 1
40
("
""
((
Retort
50
The light given by the Gaudoin carbons was a little
less regular than that observed 6th November, 1876.
That given by the Carré carbons varied in less than a
minute from 100 to 250 burners; the arc rotated posi-
tively round the points, the same as if alternating cur-
rents were being used. The Archereau carbons ap-
peared to us less effective than at the first trial; they
were consumed slowly, but they produced a light so
variable that it was difficult to take photometric meas-
urements. Only the retort carbons maintained their
duration, luminous intensity, and, unfortunately, their
irregularity.
Fontaine--1878--Chapter III.
2671
TABLE B.
RESULTS OF EXPERIMENTS UPON SEVERAL CARBONS, 4TH APRIL, 1887.
Section in square
millimetres.
hour in milli-
Total consumption
per
metres.
Mean light in Car-
Length of the arc
Revolutions per
in millimetres.
cel burners.
minute of the ma-
chine.
Name of
Carbon.
Form and
dimensions.
Regularity.
Observations.
Retort carbon
Square.
good quality. 9m.m. in the
men.
Carré's Carbons,
new specimen.
Round.
81 60 120 2.5 820 Passable.
side.
Archereau's car-
Round.
78
68 173 3 820 Null.
bons, new speci-
10 m. m. di-
ameter.
64
69 175 3
820 Middling.
9 m. m. di-
ameter.
Gaudoin's type,
No 1.
Round.
98
80
203
3
820 Good.
11.2m.m. di-
ameter.
78
240
3
820 Sufficiently good.
Gaudoin's [Ag-
glomeration of
wood carbon].
Round.
Splinters numerous. Separation of a small piece.
Scintillation. Carbons were shaped very irregularly.
Disaggregation. Sparks. Light very variable in in-
tensity at periods. Shaping into small facets.
Small sparks. Light running round. Very variable
in intensity. Good shaping of the carbons.
Neither sparks nor splinters. Light a little red, but
pretty constant.
Light very white. Less steady than with Gaudoin's
carbons, No. 1. No sparks. Small variations.
2672
Fontaine -1878—Chapter III.
We shall describe, in terminating this chapter, the
improvements that M. Gaudoin has made in his process,
and patented 7th April, 1877.
Instead of carbonizing wood, reducing it to powder,
and then submitting it to mixture, the inventor takes
dried wood, properly chosen, to which he gives the defi-
nite form of the carbon, then he converts it into hard
carbon, and finally soaks it, as in the manufacture we
have described.
The distillation of the wood is effected slowly, in such
manner as to drive out the volatile substances, and the
the final desiccation is made in a reducing atmosphere,
at a very high temperature. A previous washing in
acids or alkalies, removes from the wood any impurities
that it possessed.
M. Gaudoin points out also the means of filling up
the pores of the wood, by heating to redness, and sub-
mitting it to the action of chloride of carbon and differ-
ent carbides of hydrogen. He hopes thus to produce
electric carbons of small consumption and giving an ab-
solutely steady light.
!
Pontaine-1877--Preface First Edition. 2673
Complainant's Exhibit Preface First Edi-
tion of Fontaine, Higgs' Translation.
PREFACE.
Our purpose in publishing this work is to show what
are, in the present state of science, the judicious appli-
cations of electric lighting; as much as to record the
services that this new light is capable of rendering a
multitude of industries, as to combat false ideas
founded on the possibility of its universal use.
Few questions have at the present time the ad-
vantage of exciting public attention to the extent of
this one; trials have been made in France, England,
Germany, Russia, Belgium, Sweden, Austria, Spain,
America; on vessels, quays and dock-yards; in work-
shops, harbors, fortifications, railway stations, &c.
It is of general interest.
In this century, when progress is so rapid, many per-
sons do not await the sanction of experience before ex-
alting a new invention to the detriment of all others;
these persons have scarcely had time to admire the
marvelous effects of gas-lighting than they salute the
dawn of electric lighting by proclaiming that it is a
hundred times more econmical than the former, that we
can employ it everywhere, distribute it indefinitely,
and that its light is as beautiful and intense as that of
the sun itself.
Other persons, unfortunately more numerous than
the former, wish no departure from routine, and hinder
by their inertia the march of progress. For them, the elec-
tric light has no industrial existence; it is a will-o'-the-
wisp, dazzling those who regard it, and so fatiguing the
eye that its use is materially impossible.
We ignore surprises that the future may reserve for
us; but our knowledge of the subject leads us to affirm
that the rôle of electricity is far from its full develop-
ment, especially from the point of view of the transfor-
2674
Fontaine-1877-Preface First Edition.
mation of motion into light. It is not of so much im-
portance to know what will be, as to know what is.
And it is to this end that we present a study of the
elements of electric lighting that have definitely en-
tered the domain of practice, and of the best conditions
for its use. Later, as perfections are more nearly at-
tained, we shall put them so much better to profit that
we can better appreciate the advantages; it appears to
us irrational to neglect the use of what is already
good, under the pretext that we shall one day arrive at
something more nearly perfect.
The electric light may be utilized in two ways, either
by powerful foci illuminating or visible at great dis-
tances or by less intense foci giving a light suitable to
all kinds of night work. In the first case, nothing can
equal the services rendered by electricity; in the sec-
ond case there is no longer comparison, the advantage
being sometimes in favor of gas, oil, petroleum, &c.,
sometimes in favor of electricity.
Thus for lighthouse service, fortifications, maritime
service, shores, armies and campaign, the electric light
is superior to all others; for show-rooms and manufact-
ories, for open air yards and large work shops it is
equally suitable; for domestic household illumination,
and for certain trades carried on under low roofs, where
there are numerous local subdivisions, gas, oil or pe-
troleum is preferable. In many establishments lighted
by gas it has been advantageous to substitute elec-
tricity.
In any case, the number of applications would be
very limited if we should continue to deprive ourselves
of light, as it is the custom to do in the majority of
manufactures, where during the night superintendence
is impossible where the work produced during the
night is much less than in the day. But we hasten to
add, this statu quo is not to be feared; some intelligent
manufacturers—and their number is great--will re-
place their present system of lighting by a system of
lighting four or five times more intense, and they will
not hesitate to admit that their products are better, in
Fontaine-1877-Preface First Edition. 2675
larger quantities, and consequently more economical;
this example will not be lost, and to sustain competition
their fellow-manufacturers will imitate them.
In support of this opinion it is sufficient to recollect
that the Gramme machine, with which the electric
light is practically obtained, had not last year* more
than a dozen applications, whereas to-day it numbers
more than two hundred. However, this new machine
has not failed to receive criticism. It has been said to
become heated, difficult to work, clumsy, capricious,
that it could not be worked ten hours without repairs.
The truth is, it works perfectly, and, instead of deterio-
rating, improves by use.
The first
Our work is divided into twelve chapters.
six are devoted to the study of the voltaic arc, the car-
bons, the lamps or regulators, and some magneto-elec-
tric machines; the last six treat of realized applications,
the comparative costs of several sources of illumination,
of lighting by incandescence, and of the division of the
electric light.
Those persons simply seeking for information as to
the possibility of utilizing the electric light for them-
selves, should read Chapters VII., VIII. and IX., which
contain all the necessary information for planning and
appreciating the advantages to be gained by this sys-
tem of illumination.
We have dwelt somewhat on experiments made by
scientific men to determine the nature and properties
of the voltaic arc; this was the origin of the new
method, and it is important to explain thoroughly the
phenomena which have given birth to the remarkable
applications that we subsequently cite, in order to ad-
mit of the better exercise of judgment.
The study of regulators or lamps could have been
made the subject of a special work as regards the pro-
posed and attempted types; but most of these appara-
tus have numerous drawbacks, and we have preferred
* M. Fontaine writes in 1877.-Trans.
2676 Fontaine-1877--Preface First Edition.
to mention only those presenting originality, such as
might serve as basis for a new invention, or warn
seekers against combinations judged impracticable. M.
Serrin's apparatus should have, and in effect has, the
honors of our record, as being to the present time
the only one susceptible of advantageous use in in-
dustry.
The manufacture of carbon rods, intended to supply
the regulators and to become heated under the influence
of the electric fluid, has an exceptional importance;
upon this, perhaps, depends the success of electric light-
ing. To this we have devoted a long chapter, and have
minutely detailed the processes of Messrs. Carré and
Gaudoin, which are the most perfect. Some exact ex-
periments on the quantity of light produced by several
carbons complete these descriptions.
Before attempting the study of the Gramme machine,
we have passed in review the principal magneto-electric
machines that have preceded it, and, with the aid of nn-
merous engravings, we hope to have made clear, even
to those little initiated in modern physics, the principle
of these marvellous machines that create such torrents
of electricity without acid or consumption of metal-
with nothing more than the influence of magnets and
coils of copper in relative motion.
The Gramme machine being applied only in con-
structive workshops, it is useful to speak of it at
length; to well distinguish its principle, its mode of
construction, and its multiple effects. Here again it
has been necessary to make use of drawings in order
to explain the apparatus and show the several forms it
has assumed.
But it is especially in the part devoted to the appli-
cations that we have entered into precise detail, by in-
sisting particularly on the motive force expended, and
on the true cost price of the electric light. To evalu-
ate the motive force, we have at our disposal the reports
of Messrs. Tresca, Member of the Institute (of France);
Hagenbach, Professor at the University of Bâle; and
Schneider, Professor of Physics at Mulhouse. For the
Fontaine-1877-Preface First Edition. 2677
comparison of the cost prices of several lights, we have
drawn upon some sources of authority, chiefly from
persons who have for several years employed this new
system of lighting. The applications to marine, artil-
lery, or civil purposes have not been signalized by great
development; for the several Governments who have
experimented with the Gramme machine have kept
secret all the results observed. Nevertheless, numer-
ous and important orders, obtained after prolonged
trials, authorise us in saying that success has been
complete.
Mechanical workshops have been the first to make
use of the electric light; also dyers, who need a very
white light; and sugar refineries, where steam is pro-
duced very economically. Railway companies have
adopted it for the illumination of their goods depots;
contractors for public works, for the execution during
the night of earthworks or mason-work; finally it has
been introduced with success into spinning mills, smith-
ies, foundries, &c.
Three years ago much was said about a new system
of electric lighting, the invention of a Russian professor,
which consisted in causing the incandescence of a small
rod of carbon. It was for some time believed that by
the aid of this invention the light could be in some
way indefinitely divided, and introduced everywhere
for nearly nothing. Deeper study of this subject, and
numerous directed experiments have enabled us to re-
duce this system to its real value, which, if it be de-
fective when we consider it as capable of causing a
revolution in present lighting, is very remarkable, on
the other hand, when we have in view only a small
number of special applications.
The Jablochkoff candles, about which also much was
said, appear to us to merit the same appreciation. If
they result in anything practical, which is very possi-
ble, they will be useful in certain cases, but will be
substitute for nothing absolutely. In spite or our sym-
pathy for the inventor, we have to guard the reader
against the exaggerations founded on some experiments
2678
Fontaine-1877-Preface First Edition.
made in a Paris warehouse, and bring to their true
value the consequences that may be logically deduced
from these experiments.
Finally, we conclude our analytic review with the de-
scription of means attempted for the division of the
light, and with some consideration of the present state
of the question.
We have consulted the following special works, and
borrowed from them several interesting notes:-The
physical treatises of Messrs. Jamin, Daguin, Ganot,
Pouillet; the electrical treatises of Messrs. Becquerel,
de la Rive, du Moncel, Jenkin, Guthrie; the treatises
on light of Messrs. Tyndall, Becquerel, Moitessier; M.
Cazin's 'L'Étincelle Electrique,' M. Niaudet-Breguet's
'Machines Gramme,' M. Figuier's Merveilles de la
Scienc,' Abbé Moigno's Les Mondes,' M. Leroux
'Machines Magnéto-Electriques Françaises,' the col-
lection of the 'Comptes Rendus de l'Académie des
Sciences,' 'Les Bulletins de la Société d'Encourage-
ment,' and the collections of French and English
patents.
Our searches in the collection of French patents
have procured some very curious information; we have
abstracted thence more than one hundred descriptions
of apparatus, of which we have published only a very
small part, giving, preferably, favor to practical appli-
cations, as the principal object of our labor.
Among these old inventions are a goodly number
now represented under other names, and that we have
believed to be new. It would be easy to cite more
than one patent that is a rejuvenation of old combina-
tions, and of which it may be said, in the words of a
certain inventor, "The people of former times had lit-
tle honesty; they have stolen all my ideas."
Fontaine-1877-Chapters XI and XII. 2679
Complainant's Exhibit Chapters XI. and
XII., First Edition of Fontaine, Higgs'
Translation.
CHAPTER XI.
LIGHTING BY INCANDESCENCE.
Use of Geissler Tubes-Report presented to the Academy of Sciences
by M. Coste, in the name of M. Gervais-King's Invention—
Lodyguine's Lamp-Wild's Report to the St. Petersburg
Academy-Konn's Lamp-Bouliguine's Lamp-Experiments by
the Author on Lighting by Incandescence-Chérémeteff and
Fontaine's Lamp.
As we have said, the voltaic arc is eminently con-
venient for the lighting of large uncovered spaces, or
large halls without interior partitions, but when it is
required to light small places or very subdivided locali-
ties, it is much more advantageous to employ gas, pe-
troleum, or even ordinary oil.
There are numerous works on the construction of
small electric foci, but to the present day none of the
means devised have given practical results. It has been
endeavored to use Geissler tubes, and small incandes-
cent carbons, and if these two means have not been
successful, they offer nevertheless sufficient interest
that we should devote some pages to their descrip-
tion.
It is well known that Geissler, an artist at Bonn,
constructed the first tubes blown in various forms,
closed hermetically and containing only traces of vari-
ous vapours. These tubes put into communication
with a current, by means of platinum wires fused into
the glass, from a Ruhmkorff coil, produce a stratified
light, that is to say, composed of fine transverse layers.
separated by dark layers continually agitated. At
the same time the sides of the tubes present a brilliant
appearance, to which the term fluorescence has been
applied.
On March 27, 1865, M. Coste presented to the
Academy of Sciences, in the name of M. Gervais, the
following report:
2680
Fontaine-1877-Chapters XI and XII.
"The apparatus was constructed by M. Ruhmkorff,
who has acquitted himself of his task with his usual
care and ability. It is a case or box in bronze, mounted
on four feet, and its cover or lid is hermetically closed
by means of a press-screw, and between the two sur-
faces thus brought into contact is a caoutchouc washer.
To the cover is attached a ring, serving as a suspension.
to the optical apparatus. The case contains two bi-
chromate of potash elements closed in their turn by
plates to which strips of copper are solidly screwed. The
poles of the current furnished by these two elements may
be put at will into communication with the bobbin, and
the induced current is transmitted to a Geissler tube by
two wires covered with india-rubber. This tube, of
proper form and filled with carbonic acid, is enclosed
in a glass cylinder with thick sides, furnished with cop-
per armatures, and into which water cannot penetrate.
This is the lighting part of the apparatus. With this in-
strument a soft light is obtained, similar to that now em-
ployed by miners. It resembles in certain respects that
given by phosphorescent animals, but is more intense.
It can be seen even when the apparatus is several
mètres under water. It would doubtless serve to at-
tract fish, as does the phosphorescence of certain
species, and it would also serve to light limited spaces,
situated beneath the surface of the water, or for float-
ing signals. The captain of the 'Devoulx,' command-
ing the southern coasts of France, employed this ap-
paratus in the port of Cette, in September last.
It re-
mained immersed for nine hours, and it gave light for
six hours, under these conditions, as well as when
charged at Montpellier. The phosphorescence may be
of longer duration. A second trial, made at Port
Vendres, on board the 'Favori' (Captain Trotabas),
was equally successful."
The light obtained by the Geissler tube is so feeble,
that it can never be utilized practically, and numerous
trials made in mines and powder mills have been with-
out result.
Lighting by incandescence has been studied for a
long time, but its application generally presents so
Fontaine-1877-Chapters XI and XII. 2681
great difficulties, that at the present day it may be con-
sidered as within a purely scientific domain, although
a certain number of apparatus exist working moderately
well.
The first document on the question that we have
found, is an English patent of the 4th November,
1845.
Mr. King, the inventor, enters into some exact details
of his idea, and presents some considerations which
tend to prove that magneto-electric machines, powerful
enough to produce light, already existed in 1845.
The following are the principal passages from this
patent:
The invention has for its basis the use of metallic
conductors, or of continuous carbons, heated to white-
ness by the passage of an electric current. The best
metal for this purpose is platinum, the best carbon is
retort carbon.
D
C
B
FIG. 45.
When carbon is employed, it is useful
on account of its affinity for oxygen at
high temperatures to cover it from air and
moisture, as indicated in Fig. 45. The
conductor C rests on a bath of mercury;
the bar B is in porcelain, it serves to sup-
port the conductor C; the conductor D is
fixed on the bell by a hermetically sealed
joint. The carbon rod A rests at top and
bottom on conducting blocks and becomes
incandescent by the passage of an electric
current.
A vacuum is previously established in
the bell, and the apparatus veritably
forms a barometer with one of the poles
of the battery in communication with the
column of mercury, and the other with the
conductor D.
In order to obtain an intermittent light,
the circuit can be periodically interrupted
by a clockwork movement.
The apparatus properly closed may be
KING'S LAMP. applied to submarine lighting, as well as
2682
Fontaine-1877-Chapters XI and XII.
to the illumination of powder mills and of mines,
especially where the danger of explosion is feared, or
the rapid inflammation of very combustible substances.
When the current is of sufficient intensity, two or a
larger number of lights may be placed in the same cir-
cuit, care being taken to regulate the power of the mag-
neto-electric machines, or the elements of the battery
producing the current.
In 1846, Greener and Staite filed a patent for a lamp,
analogous to King's, pointing out that they freed the
carbon, before use, from impurities by treatment with
nitro-muriatic acid.
In 1849, Petrie concludes the description of a patent
for a lamp with the following remark :-"A light may
be produced by passing an electric current through a
short and thin conductor, which heats and becomes
luminous; but the majority of substances fuse and burn
rapidly however, I obtain a good light by using
iridium, or one of its alloys. Iridium may be fused so
as to produce an ingot whilst it is submitted to the
heat of the voltaic arc; afterwards it may be decarbon-
ised and rendered more malleable. It can be cut into
small pieces of 0·001 mètre diameter and 0·010 to 0·020
mètre length, that can be fixed upon two insulated me-
tallic supports, which are in connection with the two
wires of a proper galvanic battery. There is then ob-
tained a beautiful light."
Several other patents have been taken out in Am-
erica, France, and England for the same kind of idea;
but none of these appear more complete, more explicit,
and more practicable than King's; it is then useless to
continue our nomenclature.
Lighting by incandescence, and the principle of its
production, had for a long time fallen into oblivion,
when in 1873 a Russian physicist, M. Lodyguine, re-
suscitated both, and invented a new lamp, which has
since been perfected by Messrs. Konn and Bouliguine.
In 1874, the St. Petersburg Academy of Sciences.
awarded a high prize to M. Lodyguine. The following
includes some extracts from the report presented on
Fontaine-1877-Chapters XI and XII. 2683
the occasion by M. Wild, director of the Imperial Ob-
servatory; this report, as we shall see, includes several
capital errors:
"It has long been known that we can employ the
heating faculty of the electric current, even without the
aid of gas, as in the luminous galvanic arc, to heat a
solid body to whiteness. On this principle there are
often thus heated thin platiuum wires, which are bad
conductors, by causing them to be traversed by a pow-
erful electric current. The light obtained by this pro-
cess is much more feeble and more constant than the
electric light from carbon; it can also be extended
further, and may be increased or diminished at will;
nevertheless it has never found practical use, because
it is too feeble compared with its cost, and because
when it is desired to give greater intensity, there re-
sults fusion of the platinum wire, which in general is
not homogeneous throughout.
"M. Lodyguine was the first who had the idea of re-
placing the platinum wire, in these combustion experi-
ments, by small bars of carbon (coke) analogous to
graphite, that is to say, a good conductor, and thus re-
solved the problem of electric lighting.
"The advantages of this substitution of the carbon
for platinum are so obvious from a theoretical point of
view, that it is astonishing, as is always the case with
important inventions, that no one had the idea sooner.
Carbon possesses at equal temperature much greater
power of radiation than platinum; the capacity for
heat of platinum is superior (nearly double) that of the
carbon in question, so that the same quantity of caloric
raises the temperature of a small bar of carbon to a de-
gree nearly twice that attained by a platinum wire of
the same volume. Besides the resistance of the carbon
in question, as a conductor of electricity, is nearly 250
times greater than that of platinum; it results that the
small rod of carbon may be fifteen times thicker than a
platinum bar of the same length, and that the current
traversing it will engender the same quantity of heat.
Finally the carbon may be heated to the most extreme
2684 Fontaine-1878- Chapters XI and XII.
white heat without fear of fusion, as is the case with
platinum. It is to these important theoretical advant-
tages that is evidently due the great success of the
mode of electric lighting proposed by M. Lodyguine.
"The sole inconvenience of the use of carbon instead
of platinum consists in the fact that, in the combustion
the carbon combines with the oxygen of the air, and is
thus gradually consumed. M. Lodyguine has avoided
this inconvenience by enclosing the carbon heated to
whiteness by the electric current in a glass receiver
hermetically sealed, and from the interior of which the
oxygen is expelled by a most simple process.
((
'It is not within the province of the Academy of
Sciences to give its judgment on the technical
and other difficulties which will present them-
selves in the extended application of M. Lodyguine's
invention, nor on the other hand, upon the numerous
practical advantages of this mode of lighting above all
others; it will suffice to the Academy to state that,
thanks to this invention, there is resolved in the sim-
plest possible manner the great problem of subdivision.
of the electric light, and of rendering it constant,* in
order to recognise M. Lodyguine as worthy, in consid-
eration of the numerous applications of his invention,
to obtain the Lomonossow prize."
In his lamp, M. Lodyguine employs carbon in a
single piece by diminishing the section at the point of
the luminus focus, and he places two carbons in the
same apparatus with a small exterior commutator, in
order to pass the current into the second carbon, when
the first has been consumed. Nothing is less practical
nor less studied than the apparatus of this inventor.
M. Kosloff, of St. Petersburg, who went to France in
the hope of working the Lodyguine patent, perfected
his lamp slightly, without, however, bordering upon
anything passable.
*We shall see subsequently how the problem has been resolved
by M. Lodyguine.
Fontaine--1877--Chapters XI and XII. 2685
In 1875, M. Konn, also from St. Petersburg, pa-
tented a more practicable lamp, represented in Fig. 46,
which was constructed for the first time in Paris by M.
Duboscq.
This lamp consists of a base A in copper, on which
are fixed two terminals N for fastening the conductors,
two bars C, D in copper, and a small valve K opening
only from within outwards. A globe B, widened at its
upper part, is retained on the base by means of a
bronze collar L pressing on an india-rubber ring
exactly as occurs with the level-gauges of steam boilers.
One of the vertical rods D is insulated electrically
from the base, and communicates with a terminal also
insulated. The other rod C is constructed in two parts:
(1) of a tube fixed directly upon the base without insu-
lation, and (2) of a copper rod split for a part of its
length. This split gives elasticity, and admits of the
rod sliding in the tube with only a small effort.
The retort carbons E, to the number of five, are
placed between two small plates which crown the
rods.
Each carbon is introduced into two small blocks,
also of carbon, which receive the copper rods at their
extremities. The rods also are equal in length at their
lower ends, and of unequal length at their upper ends.
A hammer I is hinged on the bar C, and rests only on
a single rod of carbon at once. If this lamp is placed
in circuit by attaching the two conductors from a bat-
tery to the terminals N, N' (the terminal or binding
screw N' is hidden by the terminal N; but it is identi-
cal, and is not insulated from the base), the bar of car-
bon E is traversed by the current which passes by the
aid of the hammer I, from the copper bar F, the two
carbon blocks O, O, the copper bar G, and the plate
crowning the bar D.
The vacuum has previously been made by putting
the cock K in connection with an air-pump or other
known pneumatic machine.
The rod E reddens, whitens, and becomes luminous.
Its light is colourless, steady, and constant; but grad-
2686 Fontaine-1877-Chapters XI and XII.
ually the section diminishes, the rod breaks, and the
light disappears. The hammer I then falls on another
rod, and nearly instantaneously lighting is re-estab-
lished.
When all the carbons are consumed the hammer rests
upon the copper rod H, and the current is not inter-
rupted. In this manner when several lamps are fed by
the same electric generator, extinction of one does not
cause that of the others.
To avoid the projection of small pieces of carbon and
their blocks against the glass, M. Konn has placed at
the lower part of his lamp a small copper tub M, which
receives the débris until the plates are refurnished.
Three of these lamps were introduced two years ago
at the house of M. Florent, a merchant of St. Peters-
burg, and put in action with an "Alliance" machine.
Each carbon lasts about two hours, with the exception
of the first, which is consumed nearly immediately;
the light is very agreeable, but its cost considerably ex-
ceeds that of gas. M. Florent, whom we have had oc-
casion several times to see, has informed us that the
great advantage he has found in the employment of
electric lighting was its cleanliness. His store-rooms
contain much white linen that gas rapidly impairs, and
on which electricity exercises no injurious influence.
The bleaching economised fully compensates the sup-
plementary cost necessitated by an important introduc-
tion, with but little regard to the light obtained.¸
M. Florent has not made any photometric measure-
Fontaine--1877--Chapters XI and XII. 2687
H
B
M
G
D
K
FIG. 46. KONN'S LAMP.
ment; but, by comparison with gas, each Konu lamp
has been valued at about 20 Carcel burners.
2688
Fontaine--1877--Chapters XI and XII.
The principal cause of the great expense that the use
of the light from incandescence entails, rests in the diffi-
culty of preparing small carbons, which cost, as fitted,
more than 5 francs per mètre.
A Russian officer, M. Bouliguine, has constructed a
lamp (Fig. 47), which attains nearly the same end as
that by M. Konn with a single carbon. It consists,
like the preceding, of a copper base or socket, two ver-
tical bars, two bars carrying the current, and an exhaust
valve.
One of the bars is pierced with a small hole from top
to bottom, and has nearly throughout its length a slot
admitting the passage of two small lateral lugs.
The carbon is introduced into this bar like the lead
of an ordinary pencil-case, and it is assisted to rise by
a counterweight connected by two microscopic cables
to lugs in the transverse support on which the carbon
rests.
The part of the carbon which is to become incandes-
cent is held between the lips of two conical blocks of
retort carbon.
A screw placed on the base admits of increasing or
diminishing the length of the bar which carries the
upper conical block, and consequently of giving to the
luminous part greater or less length.
The closing of the globe is effected by the lateral
pressure of several india-rubber washers.
When the lamp is placed in circuit, the carbon rod
reddens and illuminates until it is about to break.
At this moment a small mechanism* commanded by an
electro-magnet opens the lips of the carbon holders,
the counterweight above drives out the fragments that
would remain in the notch; and the counterweight be-
low raises the carbon rod which penetrates the upper
block, and re-establishes the current. The mechanism
*The mechanism in question, which the scale of the engraving
will not admit of showing, consists substantially of an iron arma-
ture placed in the interior of the lamp, and of two metallic rods
acting on two cross levers jointed on to the ring surrounding the
carbon-holders.
Fontaine--1877--Chapters XI and XII. 2689
again acts, but in contrary direction to its first man-
œuvre, the carbon-holders contract, and the light is re-
newed.
FI
JE. BOURDELIN
FIG. 47. BOULIGUINE'S LAMP.
2690
Fontaine--1877--Chapters XI and XII.
We have several times tried this lamp, but we have
never obtained good results. It includes too many
moving parts, and the least obstacle prevents the
play of the mechanism. However, we have observed
that when by chance it works regularly, the contacts
being better and less numerous than those of Konn's
lamp, it needs less intense currents for the production
of a given light. With a Gramme machine of 100
burners we have obtained with a single lamp as much
as 80 burners, whilst with a Konn lamp we could never
exceed 60 burners.
In order to realise the actual value of the system of
lighting by incandescence, we have made a series of ex-
periments with several Konn's lamps and a Bunsen bat-
tery of 48 elements, of 0.20 mètre height.
The first operation consisted in measuring the resist-
ances of retort carbon of square section. The samples
tested were 0.002 mètre in the side. The following re-
sults are from eight experiments:
Number of
Experiment.
Length
of Samples.
Resistance in
Mètres of Telegraph
Wire.
mètre.
1234 LOZ∞
0.100
0.100
16
14
0.100
15
0.100
14.50
5
0.100
6
0.050
19
77
0.050
9
8
0.050
7
Total
0.650
101.50
Whence it results that the mean linear resistance of
the retort carbon of 0·002 mètre is about 172, that of a
telegraph wire of 0.004 mètre being taken for unity.
We subsequently rounded the carbons, so as to re-
duce their diameter to 0.0016 mètre, and regulated the
length in such a manner as to obtain 0.018 mètre in-
candescent part. The vacuum was carried to about
0.70 mètre mercurial pressure.
Fontaine-1877-Chapters XI and XII. 2691
Circuit.
The following results represent the mean of more
than twenty series of experiments:
State of
the
Circuit.
Methods of Coupling the Battery.
2 Series paral-3 Series parallel of 4 Series parallel of 121 Single Series of 48
lel of 24 Ele-
Galvanometer]
deflection.
ments.
Luminous
Intensity
of each
Lamp.
16 Elements.
Galvanometer
deflection.
Lumincus
Intensity
of each
Lamp.
Galvanometer
denection.
Elements.
Luminous
Intensity
of each
Lamp.
Galvanometer
Elements in
deflection.
Tension.
Luminous
1ntensity
of each
Lamp.
Circuit
closed 47
70
70
50
on itself
5 lamps
28 Reddish-
white
17
Cherry-red 10 or 11 Dull red
35
burner
4 lamps
29 burner
22
Reddish-
white! 16
Orange red
38
2 burners
3 lamps
38 1 to 2
2 lamps
1 lamp
burners
40 3 burners 41 to 42 2 to 3
43 4 to 5
38
burner
26
burner
41
3% burners
burners 40 to 45 3 to 5
44
5 burners
burners
49
11 to 12
Lurners 60
burners
40 burners 45 to 46 6 to 7
burners
The lamps were grouped like the elements of a bat-
tery in tension, then forming a single series.
In the following table are given the results obtained
with lamps arranged in batteries, that is to say, on dis-
tinct circuits derived from the battery. Because of the
considerable differences observed in the intensities of
the light of each lamp during the same experiment, we
give the total light instead of that produced by each
lamp:
Galvanometer|
deflection.
Total light
State of
the
Methods of Coupling the Battery.
16 Elements.
12 Elements.
2 Series parallel of 3 Series parallel of 4 Series parallel of 8 Series parallel of
24 Elements.
6 Elements.
emitted by the
whole of the
lamps.
Galvan ometer]
deflection.
Total light
emitted by the
whole of the
lamps.
Galvanometer
deflection.
Total light
emitted by the
whole of the
lamp.
Galvadometer
deflection.
Total light
emitted by the
whole of the
lamps.
Circuit
closed
on itself 58
5 lamps
57
4 lamps 56
68
64%
burner
69
632 burners
70
60
529 burners
633 burner
612 burners
606½ burners
57% 54 burners
63
3 burners
59
62
4 burners
58 34 burner
59 15 burners
55 1 burner
55 65 burners
3 lamps 56 1 burner
2 lamps 55 5 burners
1 lamp
46 8 burners
Several important observations were made during
these experiments.
When the receivers are sealed and the contacts care-
2692
Fontaine--1877-Chapters XI and XII.
fully put in line, the carbons last for a satisfactory
period. The first carbon of a lamp never lasts for less
time than a quarter of an hour; sometimes it breaks at
the end of thirty to thirty-five minutes, but that
is very rarely; its average duration is twenty-one min-
utes. The succeeding carbons last upon an average
for two hours, so long as the luminous intensity does
not reach 40 burners, in which case the average dura-
tion is only half an hour. In the experiment of four
parallel series of 12 elements, the five lamps being col-
lected in batteries and one only lighted, the carbon,
which gave 65 burners, lasted only twenty-three min-
utes as an average.
Attentive examination of incandescent carbons,
through a strongly coloured glass, has shown that they
are not uniformly brilliant. They present obscure
spots, indicative of non-homogeneity, and the position
of cracks which rapidly disintegrate the carbon.
The vacuum never being perfect in the receivers, the
first carbon is in greater part consumed. It would ap-
pear that consequently upon the little oxygen contained
in the lamp being transformed into carbonic acid and
carbonic oxide, the carbon should be preserved indefi-
nitely. But there is then produced a kind of evapora-
tion which continues to slowly destroy the incandes-
cent rods. This evaporation is besides clearly proved
by a pulverent deposit of sublimed carbon, that we have
found on the interior surface of the bells, on the sev-
eral interior parts: rods, contacts, hammers, &c.
No bell has been cracked by heating or cooling dur-
ing the whole of the experiments, extending over sev-
eral months, but several of the necks have been broken
by the two energetic closing of the joint.
The delicate part of the lamp is in the series of con-
tacts which precede the incandescent rod. The carbons
are got into straight line, which is indispensable to
their duration, only with minute and long precau-
tious. After rupture, the contact does not always oc-
cur automatically, and two or three times we have been
obliged to shake the lamp to cause the lighting of the
next carbon.
Fontaine-1877-Chapters XI and XII. 2693
The maximum efficiency has occurred with a single
lamp and with four elements in quantity; by employ-
ing two lamps and descending to two elements in quan-
tity, the results were considerably diminished.
We have recently made similar trials with Gaudoin
artificial carbons of the same section, and the results
have been more satisfactory. Thus the total light pro-
duced with 48 elements in four series and a single lamp,
reached 80 burners, and that produced with the same
battery and three lamps, attained 30 burners.
The same battery coupled in tension and actuating a
Serrin lamp gives a voltaic arc of 105 burners; but the
light obtained by incandescence is much steadier and
more agreeable to the eye.
From what precedes, it appears to result that King
and Lodyguine's system is much more favourable to
large foci than to the divisibility of the electric light;
however it is proper to remark that when 10 burners
per lamp are not exceeded, the carbons have a very
long duration, whilst they are consumed very quickly for
an intensity of 60 to 80 burners.
Only carbons of 0.0016 mètre diameter and 0·018
mètre luminous length were until theu those tried;
these behave very well with a strong current, but give
no light with 12 elements. It became interesting to
learn what light could be obtained with 12 elements
by diminishing the length of the carbons. This was the
object of a new series of experiments.
Five different combinations were attempted, by vary-
ing in turn the coupling of the battery, the diameter of
the carbon and its length.
The best results were obtained with a single lamp
furnished with Gaudoin carbons of 0·0016 mètre diam-
eter, and of 0.015 mètre length, in the incandescent
portion.
The light varied betwees 2 and 8 burners, but it was
often 5 burners. Each carbon lasted on average fifteen
minutes.
We were about to repeat all these experiments, sub-
stituting for the battery a Gramme machine constructed
to give the best useful effect; but the imperfections of
2694
Fontaine-1877-Chapters XI and XII.
the lamps, the difficulty of obtaining good contacts,
the too minute care to be taken at the commencement
of each operation, led us to decide to previously design
a lamp more commodious and slightly more practical
than that of M. Konn.
FIG. 48. FONTAINE'S LAMP.
Fontaine-1877-Chapters XI and XII. 2695
This lamp, which we represent in Fig. 48, is at pres-
ent under construction by M. Bréguet. It is character-
ized by the following points: (1) the carbons are set in
a groove at each of their extremities in rigid contacts
and kept fixed, which admits of the lamp being placed
in all positions; (2) the electric current passes auto-
matically from one carbon to the other by the action
of an electro-magnet interposed in the circuit.
A description, even summary, would not be of great
interest, since the lamp is not yet finished; the engrav-
ing sufficiently indicates the arrangement we have
adopted.
CHAPTER XII.
DIVISIBILITY OF THE ELECTRIC LIGHT.
General Remarks on the Divisibility of the Electric Light-Impos-
sibility of establishing very small Luminous Centres with the
means actually known-De Changy's Invention-Report of M.
Jobart — Lacassagne and Thiers' Dividing Regulator — M.
le Roux' Experiments-M. de Mersanne's Apparatus-M. Jab-
lochkoff's Experiments at the Magasius du Louvre-A Recent
Communication made by M. Denayrouse to the Academy of
Sciences.
The remarkable effects of the voltaic arc were no
sooner foreseen than the idea arose of dividing the
electric light, and even before the existence of a good
regulator for a single light, King took out a patent for
a lamp on the divisible system. The steps, however,
that were being taken to perfect the single luminous
centre had advanced so rapidly, that with an expendi-
ture of 10 horse-power an artificial sun of an intensity
of 4000 burners was produced. This grand result was
due to the carbons of Foucault, Carré, and Gaudoin ;
to Serrin's lamps, Gramme's machines, and Sautter and
Mangin's projectors. On the other hand, the plan of
dividing the light made no advance, but remained still
an object of experimental and speculative inquiry.
2696
Fontaine-1877-Chapters XI and XII.
The merits of the system of King in 1845, and of
Jablochkoff in 1877, are of an exceptional character,
and it would be a matter of difficulty to decide which
of them approaches nearest to the true solution of the
difficult problem of dividing the electric light. It must
not, however, be thought that in face of these obstacles
the idea of replacing gas by electricity will have to be
entirely renounced, for science is far from having at-
tained the last of its conquests by means of this
mysterious fluid, which has already annihilated dis-
tance, and may also be said to have suppressed night;
but despite the remarkable labours of M. Jablochkoff,
and the no less remarkable initiative of M. Denayrouse,
there exists at the present time no sufficiently practical
system of so dividing the light as to render it generally
available for the purposes for which gas is used. Each
decade gives birth to a new idea, the importance of
which is exaggerated by rumor until, after a few unsuc-
cessful trials, public interest abates, and nothing more
is heard of the matter. In 1847, King's discovery of
incandescent carbons was announced in England; iu
1857, M. de Chaugy, in Belgium, substituted platinum
for the carbon, and employed a regulator; in 1867, M.
Le Roux published in France a method of passing a
current alternately, and with great rapidity, through
several ordinary regulators; and lastly, M. Jablochkoff,
in 1877, caused sparks to pass through plates of kaolin,
and by this means obtained a series of small lights.
There is no doubt that each of the systems pro-
posed is capable of rendering important service in spe-
cial cases, but the error that inventors have fallen into
has been the claiming of too great a scope for their ap-
paratus as leading immediately to the supplanting of
gas. The electric light has already a vast field of ap-
plication open to it, and Chapters VII. and VIII. treat
of the great advantages attaching to its employment in
a number of cases, but that it will some day entirely
take the place of gas is extremely improbable. It has,
in fact, only been since the introduction of electric
lighting that our admiration for the facility with which
Fontaine-1877-Chapters XI and XII. 2697
gas can be divided and distributed has been fairly
aroused.
By the term " divisibility of the electric light" we
do not mean the production of several intense lights by
means of one machine or battery, but simply the main-
taining of a few small luminous centres, each equal to
1 to 15 Carcel burners. It has been proved beyond
a doubt that several lamps can be kept in action by one
magneto-electric machine, but the question is, whether
the first cost and maintenance of such apparatus is not
greater than that of a series of small machines each in
circuit with a lamp. We have always favoured the lat-
ter method of lighting, although the other plan has re-
ceived a large share of our attention, and there is a
liklihood that M. Gramme will still have the honor of
making it a practical success. At present, however, the
means proposed for attaining this divisibility of the
light have been practically without success*.
We will now glance at the various systems devised
for the solving of this problem. It has been shown that
the invention of King, reinvented by M. Lodyguine,
and improved by M. Konn, was better suited to
a single light than to a divisible system. There are,
however, some advantages connected with the burning
of small carbons in a vacuum, inasmuch as the light is
steady and the expense moderate. Before abandoning
this method, some new experiments should be made.
with shorter and thinner carbons of various qualities.
Where a single lamp and great regularity of the light
is needed, this system may come into use. The mode
of operation adopted by M. de Changy have never been
thoroughly known, but to judge from the following
communication made by M. Jobart to the Academy of
*This opinion must be taken to refer entirely to the present time,
and in no way to prejudge the future; from time to time we have
drawn attention to the experiments which have been made in this
direction, with a view to the placing of a fair statement before every
one who wishes for our opinion on the subject.
2698
Fontaine-1877-Chapters XI and XII.
Sciences on the 27th of February, 1858, M. de Changy's
laboratory experiments must have been perfect:
"I hasten to announce to the Academy the import-
ant discovery of the dividing of an electric current for
lighting purposes. This current from a single source
traverses as many wires as may be desired, and gives
a series of lights ranging from a night lamp to a light-
house lamp.
The luminous arc between two carbons produces,
as is well known, a very intense, flickering and costly
light. M. de Changy, who is a chemist, mechanician
and physicist, is thoroughly conversant with the latest
discoveries, and has just solved the problem of divid-
ing the electric light.
"In his laboratory, where he has worked alone for
the past six years, I saw a battery of twelve Bunsen
elements producing a constant luminous are between
two carbons in a regulator of his own invention, this
regulator being the most simple and perfect I
have ever seen. A dozen small miner's lamps
were also in the circuit, and he could at
pleasure light or extinguish either one oľ the
other, or all together, without diminishing or increas-
ing the intensity of the light through the extinction of
the neighboring lamps. The lamps, which are enclosed
in hermetically sealed glass tubes, are intended for the
lighting of mines in which there is fire-damp, and for
street lamps, which would by this system be all lighted
or put out at the same time on the circuits being opened
or closed. The light is as white and pure as Gillard's
gas, with which it has one point in common, namely,
its production by the incandescence of platinum. The
gaspipes are replaced by simple wires, and no explos-
sions, bad smells, or fires can take place.
The trials that have been hitherto made with the
object of producing an electric light by means of heated
platinum, have failed on account of the melting of the
wires. This difficulty has been overcome by M. de
Changy's dividing regulator. The cost of the light is
estimated to be half that of gas. A lamp placed at the
Fontaine--1877--Chapters XI and XII. 2699
masthead of a ship, would form a permanent signal for
about six months, without the necessity of changing the
platium. With several such lights placed in tubes of
colored glass, it would be easy to telegraph by night, as
they could be extinguished and relighted rapidly from
the deck. For lighthouse purposes considerable am-
plitude can be given to the light. I also saw a lamp
so arranged in a thick glass globe that it could be im-
mersed to considerable depths without being overturned
by any movement. This lamp had already been used
in the taking of fish, which were attracted towards the
light.
"The above slight description will suffice to show to
what a variety of applications this discovery can be
put. The communication which I have the honour of
laying before the Academy is founded upon no illusion,
a lamp was to my astonishment lit in the hollow of my
hand and remained alight after I had put it in my
pocket with my handkerchief over it."
It must be borne in mind that the above communica-
tion was made by (M. Jobart*, of Brussels) a thor-
oughly skilled man of science, and one not likely to be
carried away by the enthusiasm of an inventor.
We have not seen any drawings of the regulator in-
vented by M. de Changy, but we have seen that of MM.
Lacassagne and Thiers, patented by them in 1854.
The theory of this apparatus is explained in the fol-
lowing description taken from the patent:
When in any part of the circuit the current has to
pass through a liquid of less conductivity than that of
the reophores, the intensity or quantity of electricity
passing in a given time is inversely proportional to the
* M. Jobart was born at Bourgogne. He was, at the time this
communication was made, Director of the Royal Museum of Bel-
gium Industry, Chevalier of the Legion of Honor and of the Order
of Francis the First of Naples, President of the Society of French
Inventors, President of the National Academy of Agricultural and
Manufacturing Industry, besides being a Member of the Scientific
Institutions of the United States, France, &c.
2700
Fontaine--1877-Chapters XI and XII.
resistance of the interposed liquid. This resistance
may be increased or diminished, either by an increase
or decrease of the conducting power of the liquid or of
the surface immersed. The magnetic force of an elec-
tro-magnet varies with the intensity of the current. If
the surfaces of the conductors immersed in the liquid
are of an unchangeable metal, we obtain in a free state
the gas arising from the decomposition of the liquid;
the quantity of this gas in a given time being in a di-
rect proportion to the intensity of the current.
MM. Lacassagne and Thiers divided one of the con-
ductors of a battery in action into two parts, attached
a plate of platinum to each extremity, and suspended
the plates in the interior of a glass gasometer contain-
ing acidulated water. The bell of the gasometer was
raised or lowered by the inlet or outlet of the gas, pro-
duced by the current. The ascent of the bell produced
of course a diminution of the galvanic intensity, whilst
its descent produced the opposite effect. An electro-
magnet, with an armature in the form of a lever and an
opposing spring completed the arrangement.
The ap-
paratus worked in the following manner :
•
The spring was first adjusted to the strength of the
current determined upon. As long as the magnetic at-
traction was greater than the tension of the spring, the
armature remained in contact, and as the gas which
was developed had no outlet, the bell of the gasometer
was raised, thereby diminishing the surface of the plati-
num in contact with the liquid, and consequently the
intensity of the current. There would occur a moment
of equilibrium and also when the force of the spring
exceeded that of the magnet; the armature receded,
and in so doing opened a trap which allowed of the es-
cape of a portion of the gas until the normal position of
the bell was again obtained. When such a regulator was
accurately adjusted, the tap remained.constantly partly
open, and the armature very close to the electro-mag-
net without touching it. This regulator, if applied to
each of the small lamps of M. de Changy, would pre-
vent the combustion of the platinum wires, but the
Fontaine-1877--Chapters XI and XII. 2701
complication which would arise from this arrangement
would render it inapplicable, even if no other practical
defects had been found to arise from its use.
MM. de la Rive and Elie Wartman, both physicists
of Geneva, observed that with a very sensitive regula-
tor, and a battery in good working order, a current
could be interrupted for the thirtieth of a second with-
out any variation of the arc; but with an interruption
of longer duration the arc became enfeebled and van-
ished altogether after the current had ceased for the
tenth of a second. M. Le Roux, profiting by this ob-
servation, has obtained some very beautiful results,
which he has thus described in a communication to the
Academy of Sciences, dated the 30th of December,
1867:
The spark from an electric battery is in general ca-
pable of passing between two separated conductors.
(A battery of 3,500 elements insulated with the greatest
care is necessary for the production of a spark having
the length of only a fraction of a millimètre.) The in-
duction currents from magneto-electric machines have
a much higher tension, and this accounts for the light
produced by alternate-current machines. I have ob-
tained the same effects with a battery of fifty Bunsen
elements, and with the current interrupted during the
twenty-fifth part of a second, a spark leaped over an in-
terval of about three millimètres. This fact led me to
a solution of the problem of divisibility. When a cur-
rent passes between two conductors, so as to produce a
voltaic arc, it has hitherto appeared probable that this
passage was due to the elevation of the temperature,
and not to the arc itself. The conductibility of the in-
terposed medium is perhaps only an extension of the
fact noted by M. Edouard Becquerel in the case of
heated gases, whose conductibility was considerably in-
creased by the enormous elevation of the temperature.
"The carbon electrodes form perhaps a vapor of con-
siderable tension at this high tempurature, and this
vapor tends to increase the conductibility of the arc."
By means of a distributing wheel, revolving with great
1
2702 Fontaine--1877--Chapters XI and XII.
rapidity, M. Le Roux sent the current of a Bunsen bat-
tery alternately into two regulators, in such way that
it traversed each of them during the same number of
fractions of a second, and he thus succeeded in divid-
ing the light. The lights were under these conditions
perfectly equal.
M. de Mersanne, in 1873, took out a patent for the
dividing of electric currents on the same principle as
that of Le Roux. The mechanical construction of the
invention is of so elementary a nature and so little worth
patenting that we should have made no mention of it
had not M. de Mersanne in the following year made an
addition to the patent, which, if not practical, is at
least original. The distributing wheel of M. Le Roux
he has replaced by a horizontal spindle carrying a ser-
ies of cams. By means of these cams a reciprocating
motion is given to some rollers jointed to vertical me-
tallic arms which are plunged into and withdrawn from
cups filled with mercury. When the spindle revolves
at a high rate of speed several lamps are put succes-
sively into contact with the electric current, whereby a
single source of electricity is divided into equal or un-
equal portions, according to the combination given to
the interruptors.
•
Last year, when traveling through the principal
towns of the United States, we endeavored to discover
what progress had been made in America in the matter
of electric lighting, but we were unable to see anything
of a practical nature. Many physicists had been ex-
perimenting with a view to the division of the light, but
none of them were in a position to show us an appara-
tus worthy of even being mentioned. We will only re-
fer here to a patent taken out by Mr. Henry Wood-
ward in 1876.
This invention relates to the incandescence of a car-
bon in a rarefied gas, having the property of not com-
bining chemically with carbon heated to redness.
We have already mentioned the arrangement of par-
allel carbons forming the candles of M. Jablochkoff
and will now give some account of the experiments ac-
Fontaine-1877-Chapters XI and XII. 2703
tually made at the Grands Magasins of the Louvre,
and also of the note presented by M. Denayrouse to
the Academy of Sciences on the 17th of April, 1877.
At the Magasins the object was to increase the light in
the Marengo Hall, which was supplied with eleven
lustres, and also received light from the halls surround-
ing it. Around the Marengo Hall, at about two-thirds
of the height, there is a gallery on which the electric
lights were placed. Two "Alliance" machines worked
six candles, and by an ingenious arrangement the can-
dles when burned out were replaced by others, without
causing a sensible diminution of the light. The can-
dles were arranged in diffusing globes, and the light
was projected forward by means of reflectors. Two
sticks of Carré's carbons, 4 mm. in diameter and 12 cm.
long, insulated with a thin plate of silicious matter, and
fixed in two copper tubes, which were united by a plug
of asbestos, formed the candles. A slip of carbon laid
across the top of the two carbon sticks served to light
them. It was difficult to judge of the intensity of the
electric light, as the gas was not entirely extinguished,
and the neighboring galleries added their light also,
but with a pocket photometer each candle was found to
give about 20 to 25 Carcel burners. The irregularities
were not great, but of tolerable frequency. A slight
and continual fiickering was perceptible in all the lights,
arising from the nature of the carbons and changes of
speed of the motor. An effect of a special kind, which
was no doubt due to the ebullition of the silicious sub-
stance interposed between the carbons, gave a singing
sound to the diffusing globe. We were told that the
candles would last three-quarters of an hour; at the
Louvre they were renewed every half hour. The ad-
vantages of this mode of lighting can only be decided
by knowing the cost of machines, motor, &c., the ex-
pense of erecting them, and the cost of maintenance
per hour for each unit of light.
then be made with the cost of other existing electric
lights, such as those erected at M. Ménier's chocolate
factory at Grenelle.
A comparison could
$1
2704
Fontaine--1877-Chapters XI and XII.
The labors of M. Jablochkoff have, from a purely
scientific point of view, an undoubted value, as he has
demonstrated that these voltaic arcs can be maintained
in the circuit of a single current, and that two parallel
carbons separated by a silicious plate produce a light
less intense, it is true, than that of a regulator with or-
dinary retort carbons, but quite as regular and less in-
termittent. The possibility of dividing the electric
light experimentally, or for purposes of scientific
demonstration, was proved by M. Florent at St. Peters-
burg with Konu's lamp, but the novelty of the newer
experiments is that the carbons are burned in the air,
and not in a vacuum, as in M. Konn's arrangement.
There is no doubt that M. Jablochkoff, with the ac-
tive co-operation of M. Denayrouse, will succeed in
making the light more economical, and in considerably
reducing the large outlay which his system necessitates;
but as far as the application of the light to industrial
purposes is concerned, the experiment at the Magazine
of the Louvre proves nothing whatever. In fact, the
only inference to be drawn therefrom is that the cost
of this new method of electric lighting is much higher
than that of the old system.
The two "Alliance" machines and the six standards
for carrying the candles employed in the Jablochkoff
arrangement cost at least as much as six Gramme ma-
chines and six Serrin lamps. The six candles give 240
Carcel burners*, whereas six Gramme machines with
Gaudoin's carbons give 3,000 Carcel burners. Taking,
then, the first cost of plant as equal, the system with
regulators gives twelve times more light than that with
candles.
*These figures must be taken as absolute. Our estimate was 20
to 25 Carcel burners, and observations made independently by two
other persons gave 22 and 30 Carcel burners. But as it is difficult to
take exact measurements, we will reckon 40 burners to one Jab-
lochkoff candle. Even if we double this number, the result of our
comparison will not be altered to any appreciable extent.
Fontaine-1877- Chapters XI and XII. 2705
Taking the horse-power absorbed by the two "Al-
liance" machines at a minimum, namely, 5 horse-power,
two Gramme machines with the same power would pro-
duce 1,000 Carcel burners, in place of the 240 burners
given by the six Jablochkoff candles. In this respect.
the advantage is again considerably in favor of lighting
by means of regulators. The superiority of the old
system is established in the most convincing manner
by comparing the consumption of carbons.
An electric candle, costing at least half a franc, lasts
half an hour, being at the rate of 1 franc per hour for
40 burners and 12½ francs for 500 burners. With ordi-
nary carbons, the same quantity of light is produced at
M. Ménier's for a quarter of a franc; the cost of the
candles is therefore fifty times greater than that of regu-
lator carbons. We cannot repeat too often our opinion
that M. Jablochkoff will soon succeed in reducing in a
certain degree the heavy expenses to which we have
just drawn attention.
For instance, the "Alliance" machines are dear, but
it is possible to manufacture them at a lower cost, and
the candles can also be made more economically. The
only fact which we insist upon is, that it is materially
impossible to replace advantageously the regulators by
candles.
The experiment made at the Grand Magasins of the
Louvre was very interesting; it attracted the public,
and the journals spoke of it in terms of praise. If not
absolutely practical, it yet deserves public attention as
being the germ out of which in future a great success
may grow. In a word, neither a favorable nor an un-
favorable conclusion can be deduced from this experi-
ment, which is perhaps a step towards the solution, but
certainly does not satisfactorily solve the problem.
The difference of color between the electric light
and gas-light was plainly shown, but this difference was
also observed some years ago on the Boulevard des
Italiens, when M. Tessié du Motay made some experi-
ments with the oxy-hydrogen light.
2706
Fontaine-1877-Chapters XI and XII.
M. Denagrouse's note to the Academy related to the
complete suppressing of the carbon in the production of
the electric light. M. Jablochkoff conceived the idea of
introducing into the circuit of a magneto-electric ma-
chine the primary wire of a series of induction coils; in
the secondary wire of each bobbin is placed a plate of
kaolin, through which the induction sparks pass. The
interposed plate of kaolin gets hot, reddens, and at last
becomes luminous. Around the edge of the plate is
placed a priming of a better conducting substance than
the kaolin itself. By this arrangement M. Jablochkoff
hoped to produce fifty lights with a single magneto-
electric machine. The aspirations of MM. King, Lody-
guine, Konn, Kosloff, and De Changy were of a like
nature, and we wish M. Jablochkoff better success than
his predecessors obtained.
!
Thompson--Letter of 1878.
2707
Complainant's Exhibit Thompson's En-
gineering Letter of Oct. 25, 1878.
“ENGINEERING," VOL. 26, p. 341. LONDON, Oct. 25, 1878.
DIVISIBILITY OF THE
THE ELECTRIC LIGHT
FROM A DYNAMICAL POINT OF VIEW.
TO THE EDITOR OF ENGINEERING
SIR-Much vagueness appears to exist in the minds
of men upon the possibility of dividing the electric light
indefinitely, and much has recently been said and
written upon the question which, if tested by sober
reasoning, and by the application of elementary dy-
namical principles, will be found to be sheer nonsense.
The idea that the electric current can be indefinitely
subdivided and the number of small lights indefinitely
multiplied, by the employment of a substance more
suitable in its conducting properties than carbon, is
one that has been freely indulged on many hands
during the past fortnight. The reporter of the New
York Sun, in his enthusiam to repeat the claims of
Mr. Edison, puts into his mouth statements which ex-
hibit the most airy ignorance of the fundamental prin-
ciples both of electricity and of dynamics. If there
be one truth more than another to which scientific
credence must be given in the present day, that truth
is the dynamical principle of the conservation of energy,
which asserts that work cannot be done by a force ex-
cept by the expenditure of a precise equivalent of some
other form of energy, actual or potential.
The work done by the steam engine necessitates the
expenditure of fuel in the boiler; the light of the gas
implies the use of chemical energies stored up in the
coal beds; the motion of the telegraphic needle, or of
the rotating wheel of the electric pen, involves the con-
sumption of zinc in the battery where the electricity is
generated. In a precisely similar manner the heat and
light of the voltaic arc-the electric light, par excellence
2708
Thompson-Letter of 1878.
-represents a certain equivalent of energy which is
transformed into light and heat by the intermediate ac-
tion of electricity. The battery, or the dynamo-electric
machine, with its steam or gas motor, provides a
source of energy. The electric current is the conven-
ient method of transferring that energy from the source
to the distant point of application. The "strength
of the current is another expression for the rate of
transference, and represents the quantity of energy
conveyed in a given time.
""
Let us consider an analogy between this transference
of energy by electricity and the transference of energy
by the motion of moving bodies. A ball shot from a
cannon possesses a certain energy of motion, or "kin-
etic" energy, by virtue of which it will, when it strikes
an obstacle, do work, and that of a powerful kind. It
has had work done upon it to set it in motion. The
principle of the conservation of energy teaches us that
just as much energy as must be spent upon it in set-
ting it in motion, just so much will it be capable of
exerting by virtue of its motion. The name "force "
should accurately be assigned to the rate at which
energy is transferred in the act of setting a body in mo-
tion. Hence it is inaccurate to speak of the "force
that must be spent upon a cannon ball to set it in mo-
tion, we ought to speak of the energy that must be ex-
pended.
Now, it is one of the stubborn facts of dynamics
(though one that hundreds of people refuse to see be-
cause they have never examined the question experi-
mentally, or thought it carefully out) that the velocity
of a moving body is not proportional in any simple
ratio to the work that can be done by it, or to the
energy that must be imparted to it to give it that
velocity. The energy which has been imparted to it,
and by virtue of which it can do work, is proportional,
not to the simple velocity, but to the square of the
velocity. An example will illustrate our meaning. Sup-
pose a cannon ball weighing 1 lb. to be shot out of a
gun with the velocity of 100 feet per second. A certain
Thompson-Letter of 1878.
2709
quantity of energy in the form of the explosive activities
of the gunpowder must be expended on it to give it that
velocity; and by virtue of its velocity and weight
(which together we call its "momentum ") it is capable
of doing a certain amount of destructive work. And it
will obviously require the explosion of twice as much
gunpowder to shoot two such cannon balls at the same
rate of 100 ft. per second, and they will do twice as
much damage. Now instead of sending two cannon
balls with a velocity of 100 ft. per second, let us attempt
to send one cannon ball at the rate of 200 ft. per second.
Will the same quantity of gunpowder suffice? Will the
effective work done be the same? Nothing of the kind.
Experience shows that a mass of 1 lb. moving at the
rate of 200 ft. per second will do more than twice as
much damage as the same mass moving with a velocity
of 100 ft. per second, double the weight and you double
the destructive energy, exactly, it is true. But instead,
double the velocity and you increase the destructive energy
fourfold. Treble the velocity while the weight remains
the same and you increase the destructive forces nine-
fold; but then you will require a ninefold charge of
powder to produce that trebled velocity. The effective
work done by the moving mass and the energy that must
be imparted to it, both increase, therefore, not as the ve-
locity but as the square of the velocity. The necessity of
having a clear idea of this quantity which we term
energy, by virtue of which work can be done, has been
tacitly recognized by physicists ever since Newton
spoke of measuring the action of an agent " by the prod-
uct of its force into its velocity;" where the word
force is used for what we now term momentum (the prod-
uct of mass into velocity) the "action of an agent "
here expressing the capacity to do work, what has also
been termed vis viva.
Now in the electric current you have a transfer of
energy from the battery to some other point of the cir-
cuit. The real source of energy in the battery is the
zinc that is oxidized, the energy of its chemical separa-
tion being transformed into electricity. If the current
2710
Thompson-Letter of 1878.
does no work on the external circuit, the energy of the
current fritters itself away in heating the liquids and
plates of the battery. If the external circuit contains a
portion that conducts badly, say a short length of thin
platinum wire, presenting a resistance (which we may
look at as a species of friction in the movement of the
current), then the energy of the current will be trans-
muted at that point into heat and light instead of being
transmuted into heat within the battery. The heat al-
ways is developed at that point of the circuit where the
resistance is greatest. In the production of the ordi-
nary electric light between two carbon points special
care is taken by using stout conductors to avoid all re-
sistance to the circuit except just at the point where
intense heat is required. And now, observe, the law of
the production of heat from a current of electricity is a law
similar to that which expresses the relation between the
work done by a projectile and the velocity of the pro-
jectile. The heat produced in a conductor of high re-
sistance is proportional not to the simple strength of the
current, but is proportional to the square of the strength
of the current. This analogy goes even further. Suppose
the current to be produced from a single cell whose in-
ternal resistance is negligibly small as compared with
the external resistance of the circuit. If we link on a
second shell we shall double the strength of the current,
and shall produce four times as much heat in our wire
of high resistance. But mark this: we shall consume
four times as much zinc in so doing; for we shall use
up twice as much zinc in each of the two cells. Simi-
larly, by linking three cells, we shall treble the current
strength, and shall produce nine times as much heat;
but we shall use up nine times as much zinc, three
times as much in each of the three cells. Now the in-
tensity of the electric light between the carbon points fol-
lows precisely the same law. It is proportional, not to the
strength of the current, but to the square of the strength
of the current. This has been accurately determined
by the photometric measurements of Masson, and is
also a necessary consequence of dynamics, for the cur-
Thompson-Letter of 1878.
2711
rent strength, as indicated by a galvanometer, repre-
sents the rate of transfer of energy, and is therefore a
fluxional quantity, of which the integral is the energy
expended, or its equivalent where it reappears as heat,
light, &c.
Now apply these matters to the problem of subdivis-
ion of the electric light. Suppose we have a current
of a certain strength which we will reckon as unity.
Let us divide that current into two equal parts by di-
viding the resisting part of the circuit into two branches,
whose resistances are equal. A current of half the
strength passes through each branch, producing at the
point of resistance an effect of heating and illumination.
We shall not get in each branch half the light of the
previous case; we shall only get a quarter, because the
effect follows the square of the current strength. If we
had divided the circuit into three branches, in each
branch we shall get but one-ninth part of the original
light. This diminution becomes serious when we con-
sider a case of large subdivision. Suppose an electric
light equal in luminosity to 1000 candles, and we want
instead to divide that light into ten smaller lights. If we
introduce ten equal branches, each will carry one-tenth
part of the original current, and the intensity of light
in each will be one one-hundredth part only of the
original light, or 10 candles. We shall get 10 lights of
10 candles each, instead of 1 light of 1,000 candles.
Clearly it might not pay to subdivide the light at this
rate, though it might for particular cases pay to use
the undivided current to mass the light in one bright
spark of 1,0 0 candle brilliancy.
Where in place of a battery a dynamo-electric or
magneto-electric machine is used in connection with a
steam engine or gas engine to generate a current of
electricity, the case is a little more involved. It was
recently stated by M. Boutemps, of Paris, as the result
of his experiments with the Gramme machine, that the
strength of current produced by that instrument was
directly proportional to the velocity of rotation of the
armature. The figures given in Fontaine's "Electric
2712
Thompson-Letter of 1878.
Lighting," on the authority of M. Hagenback, bear out
this statement. But as yet no statistics have been pre-
sented on the amounts of fuel used in running the ma-
chine at different velocities, and it is not hard to pre-
dict that, other things being equal, this quantity will be
proportional to the square of the number of revolutions.
per minute. The arrangement of the dynamo-electric
machines, whereby a part of the current is diverted to
excite the electro-magnets, introduces an element of
difficulty here, since the proportion so diverted varies
with the nature of the external circuit, and depends
upon its resistance. Whatever Mr. Edison's new dis-
covery may prove to be, it is understood that it refers
to a mode of procuring incandescence in a circuit of
many branches, and that it does not refer to the ques-
tion of the source of the current. Yet here, it would
on a priori grounds appear, lies the most hopeful field
for the discovery of a practicable method of distrib-
uting the light. As yet we have not the data to en-
able us to say whether the steam power which now
gives us in the dynamo machine a current of great
strength, might by any arrangement be as economically
employed in giving us one hundred currents of one-
tenth the strength each; yet this seems not an im-
probable view. The recent improvements of M.
Jablochkoff in the dynamo machines, whereby each
machine generates electricty for four separate circuits,
capable of working four "candles
candles" on each circuit
point to a solution in this direction. Happily the
question is now in a fair way to be sifted in the
most thorough manner, and even if Mr. Edison's al-
leged discovery brings us no nearer to a solution of the
problem than we had before been, the reckless state-
ments attributed to him in the public press will have
done the public the service of showing the true bases
upon which the settlement of this great and absorbing
scientific problem must depend.
Bristol, October 23, 1878.
SYLVANUS P. THOMPSON.
Fontaine-1879-Preface Second Edition. 2713
Complainant's Exhibit Preface Second
Edition of Fontaine.
ELECTRIC LIGHTING.
(Translation.)
BY
HIPPOLYTE-FONTAINE.
2d Edition-Paris, 1879.
PREFACE.
The first edition of this work was placed on sale in
May, 1877, just two years ago. It has been translated
into English and German, and all the impressions have
been rapidly exhausted.
This success, very rare in respect to technical works,
is particularly due to the important character of the
subject considered and to the practical information
which we have succeeded in collecting together and in
arranging in an orderly manner.
To-day, as in 1877, the electric light is the order of
the day. A considerable number of inventors are occu-
pied in improving its operation and manufacturers are
beginning to make a common use of it. Personally, we
have made, in two years, several hundred installations
and have collected a great number of notes concerning
the labors of French and foreign electricians; thus en-
abling us to considerably increase the size of this new
edition and to embrace in it a large number of unpub-
lished data.
In a few words, the following is the present state of
lighting by electricity:
The invention by Mr. Gramme has brought about the
large introduction of the electric light into factories and
machine shops; Messrs. Sautter and Lemonnier have
brilliantly started it in navigation and the art of war;
2714 Fontaine-1879--Preface Second Edition.
Mr. Breguet has made it specially known in labarato-
ries and in England; Mr. Jasper is occupied in promot-
ing it in Belgium; Mr. Siemens in Prussia, Mr. Mercier
in Austria, Mr. Konn in Russia, Mr. Dalman in Spain,
etc.; and all at once the candle of Mr. Jablochkoff,
aided by the Gramme machine, sheds its light in shops,
in hotels and also upon the public ways.
Has this development appeared to increase forever
as electricians hope, or are the existing installations
going soon to disappear as gas companies affirm? To
this it is easy to reply.
An industry is transient when its only foundation is
fashion and when it does not meet a general want.
On the other hand, when it is of real service and is
based upon truly economic principles, it grows.
Now, it is incontestable that when there is need of a
very intense light at one point, as in the case in forts, to
watch the enemy, in harbors to combat the destructive
intent of torpedo boats, in lighthouses to guide mariners,
the electric light is not only the most economical of all
lights, but it is quite often the only light which is ap-
plicable.
It is equally certain that for a large dockyard like
that of the outer port of Havre, or for a vast enclosure
like that of the Hippodrome of Paris, where it is im-
possible to suspend lighting apparatus and place lamp
posts on the track, the electric light is alone possi-
ble, the only light which can take the place of the absent
sun.
First of all it can be affirmed that lighting by
electricity has a field which is peculiar to it and where
it does not even fear the competition of other systems.
This alone is sufficient to assure to it a great future,
as also that it will not answer for many other applica-
tions.
For lighting private dwellings, gas offers the most
desirable, the most convenient and the most economical
means (solution). Electricity will indeed be able here
and there to penetrate into some large drawing-rooms
or into some costly mansions, but this will be an
Fontaine--1879-Preface Second Edition. 2715
exception so rare that it is not necessary to take ac-
count of it.
For lighting public ways, gas also answers better.
Still the large avenues and open squares are already
able to avail of the Jablochkoff candles, and this in
spite of the slight imperfections which are always en-
countered at the beginning of a new enterprise and
which will soon disappear.
For large shops, large cafés, and in general for
establishments which seek to attract custom by the
fine appearance of the merchandise placed on sale or by
the richness of their decorations, the electric light in
part is a means for lighting (solution) which will force.
itself upon them in all the important cities.
For lighting factories, machine shops, forges, found-
ries and mills, the electric light presents itself with its
advantages and its inconveniences in competition with
gas, oil and petroleum. Most frequently gas and elec-
tricity are alone in competition.
Gas possesses, as a luminous agent, some remarkable
properties; it produces a very uniform lighting result-
ing from its division into a large number of low power
lights; its use is convenient and easy, because it is
sufficient to open a cock for it to come to the burners;
once lighted, it burns indefinitely without requiring
attention; it can be lighted and extinguished as often
as is necessary; its flame can be increased or diminished
at will according to requirements and fade from the
splendor of the most beautiful lamp to the glimmer of
the most unpretending watch-light; finally, in almost
all cities, it is always at the disposal of the consumer,
night and day.
Its inconveniences are particularly in the disagreeable
odor given out by the least leakage, in the yellow color
of its flames which alters the tint of objects lighted, in
the considerable heat which accompanies its combustion,
which renders it unhealthy in poorly ventilated and
crowded habitations; and especially in fires and explo-
sions which it frequently causes.
The electric light possesses advantages likewise very
2716 Fontaine-1879--Preface Second Edition.
remarkable; it gives out a feeble heat, and takes from
the surrounding air only a small part of its oxygen,
which renders its use very healthful; it preserves the
tints of colors as they are in daylight, and permits the
distinguishing of shades almost alike; it produces in
factories a powerfully diffused (ambient) light which
facilitates inspection, diminishes the chances of acci-
dents and simplifies the labors of management; it can
furnish foci of an extraordinary power to illuminate
spaces far away from the place of their production, and
to shed around it a splendid diffused light; it removes
dangers of fire, and its cost is extremely small in pro-
portion to its lighting power.
Its inconveniences, which are especially the con-
sequence of its recent introduction (mise en pratique),
and which the experience of some years will certainly
partly overcome, can be summed up as follows: It loses
much of its intensity when it is divided into small foci,
which renders it difficult of application to small apart-
ments; it is liable to extinction for a short time it is true,
but with a disagreeable effect upon public ways; it neces-
sitates the use of an engine; its production causes a
noise often very fatiguing, and it requires some hand-
ling for renewing the carbons or candles.
If the workshops are made up of comparatively small
rooms, if the ceilings are low, the machine tools large
(élevé) and crowded together, gas is generally preferable
to electricity. If the rooms are large, the ceilings suf-
ficiently high, the tools well apart, electricity is gener-
ally preferable to gas. In each particular case condi-
tions are to be taken into account which depend
especially upon the price of gas in the locality, and
upon the class of work to be done in the shops.
But in spite of the rivalry which will be established
in certain cases between lighting by electricity and
lighting by gas, the gas industry will never be arrested
in its development by the electrical industry.
We have said at a meeting of the British Institute of
Mechanical Engineers, and we cannot repeat it too
often, that the electric light can neither injure gas nor
Fontaine-1879-Preface Second Edition. 2717
oil lamps, nor candles, but on the contrary. It will not
change, as certain financiers pretend, the question of
lighting from foundation to roof, destroy that which ex-
ists, monopolize to itself alone all the industrial appli-
cations, domestic and public.
The electric light has its place fixed by a multitude
of circumstances, but far from causing the end of other
lights it will develop the use of them by demonstrating
the advantages of a more intense and more perfect
lighting.
The field for exploiting this new industry is immense,
but it certainly does not represent the one hundredth
part of the general lighting, and it may be predicted,
without the least exaggeration, that general lighting will
soon be increased.
Electricians may, therefore, pursue their researches,
because their labors will receive, without any doubt,
their just reward; on the other hand, the managers of
the gas companies can remain tranquil, their rights are
most certainly sheltered from a fall.
At least this is the humble opinion of the author.
2718
Fontaine-1879--Chapter XIII.
Complainant's Exhibit Extracts from
Chapter XIII., Second Edition of Fon-
taine.
(Translation.)
ELECTRIC LIGHTING,
BY
HIPPOLYTE FONTAINE,
2d Edition, Paris, 1879.
CHAPTER XIII.
LIGHTING BY INCANDESCENCE.
While, thanks to the efforts of M. M. Gramme and
Jablochkoff, lighting by the voltaic arc has received
considerable development, lighting by incandescence
has likewise made rapid progress, which has even
recently caused a great disturbance in the investments
of the gas industry, although it has not yet been de-
veloped into anything practical. An American Jour-
nal, having stated that Mr. Edison was going to light
an entire section of New York by electricity, a large
number of the share-holders of gas companies, of the
Old World as well as of the New World, hastened to
sell their holdings, and threw the market for these ex-
cellent investments into a veritable panic.
To-day tranquility is restored, the statement of the
journal is justly considered as a hoax, and shares have
returned to their old value. But the market remains
very sensitive, and we would not be surprised to soon
see it again agitated by reports also devoid of founda-
tion.
The truth is that the celebrated inventor of the
phonograph has only re-edited a platinum wire lamp,
which has already been experimented with, perfected
Fontaine-1879-Chapter XIII.
2719
and finally confessed to be unsuited to industrial use by
several electricians of great merit.
We will rapidly examine the devices which have been
proposed for producing the electric light by the use of
a badly conducting body, raised, by the current, to a
temperature near the point of fusion.
These devices can be divided into three classes: 1st,
metallic spiral lamps; 2d, lamps with carbons held in
clamps or sockets (charbons encastres); 3d, semi-incandes-
cent lamps (lamps a contact imparfait). We will men-
tion, particularly in the 1st class, the lamps of De Mol-
eyns, Petrie, de Changy and Edison; in the 2d class
the lamps of King, Lodyguine, Konn, Bouliguine and
Fontaine, and in the 3d class the lamps of Varley,
Reynier, Werdermann and Ducretal.
1st. Lamps with metallic spirals.
(Translator's note. Here follows a description of the
lamps of de Moleyns, Petrie and de Changy.)
Edison's lamp. The experiments in lighting by in-
candescence of platinum continued after 1858, and
several electricians attempted to render it practical; but
none of them succeeded in advancing a single step in
the matter. It was even believed that it had been aban-
doned forever when this famous American note arose
which attributed to Mr. Edison the honor of having
solved completely the problem of the divisibility of the
electric light by means of platinum spirals.
(Translator's note. Here follows a short account of
Edison's French patent for a platinum spiral lamp.)
But all this does not constitute an invention suscepti-
ble of immediate applications and, still more so, to in-
fluence a market as important as that of gas invest-
ments.
2d. Lamps with carbons held in clumps or sockets.
Lighting with carbons held in clamps or sockets has
been studied for a very long time; but its usual appli-
2720
Fontaine-1879-Chapter XIII.
cation has met with such great difficulties that to-day
they are still to be considered as in a purely scientific
stage, although to-day a certain number of devices exist
which work pretty well.
(Translator's note. Here follows a description of the
carbon lamps of King, Konn, Bouliguine and Fon-
taine.)
3d. Semi-incandescent lamps.
(Translator's note. Here follows a description of the
lamps of Varley, Reynier and Werdermann.)
Of all the physicists who have occupied themselves
with incandescence, M. de Changy has made the best
spiral lamp, M. Konn the best lamp with carbons held
in clamps or sockets, and M. Reynier the best semi-in-
candescent lamp. The last would, without doubt, ar-
rive at a practical solution of the problem of lighting
by small electrical foci, did it not present some difficul-
ties almost insurmountable.
In the actual state of affairs, with the electrical gen-
erators in use and the lamps proposed for utilizing the
electricity, we do not believe that lighting generally by
electricity can be made to succeed.
Circumstances may present themselves where its ap-
plication will be interesting and even useful, but to de-
velop them, it is necessary to invent a gas engine of
moderate price or thermo-electric batteries must be-
come really practical. In the meantime we can recom-
mend incandescent lamps, particularly that of M.
Reynier, in laboratories and in factories which already
have electrical lamps for powerful foci, and which can,
without inconvenience, interpolate one or several semi-
incandescent lamps in the circuit.
!
Engineering Editorial—1880.
2721
Complainant's Exhibit "Engineer" Article
of February 13, 1880.
Extracts from "The Engineer," February 13, 1880,
p. 126. Under the heading :
"MR. EDISON ON ELECTRIC LIGHT."
*
*
*
*
X
*
Either, as we have said, Mr. Edison and Mr. Upton
know little or nothing of electric lighting or else they
have put forward statements which are in advance of
facts, and that knowingly and of set purpose.
""
*
*
*
"But he understands so little the questions involved in
the production of the electric light that he has failed to
see the consequences which must ensue from the fact
that if the resistance be increased, the power must be
increased also."
*
C
*
*
*
*
*
"We have said nothing of Mr. Edison's schemes for
lighting towns from central stations, as set forth by
Mr. Upton. It is proposed,' he says, ' to establish
'
such stations in the course of a few months in the
heart of several of our large cities. These will supply
houses for quite a distance around them; 1000 horse-
power is thought to be sufficient amount for a unit, and
the stations will be at such distances from one another
that each district will require about this amount. The
engines will be divided into four groups of 250 horse-
power each, with a spare one in each station of the
same power.' Seeing that five lights would require
one-horse power indicated, and that twenty 16 can-
dle burners per horse is certainly not a high aver-
age, it is evident that engines of 1000 horse-power
could not supply more than 200 houses, or say a single
street of very moderate dimensions. Thus at every
turn the moment Mr. Upton's statements are sub-
mitted to the test of calculation they break down or ap-
pear in the light of wild vaticinations, hardly deserving
serious attention."
*
*
-X-
*
*
*
2722
Fontaine-1888-Chapter XIII.
Complainant's Exhibit Extracts from
Third Edition of Fontaine.
(Translation.)
ELECTRIC LIGHTING.
BY
HIPPOLYTE FONTAINE.
3d Edition, Paris, 1888, p. 396.
Chapter XIII.
INCANDESCENT LAMPS.
INDUSTRIAL LAMPS. Although they have only been
introduced into general use for a very few years,
incandescent lamps have quickly attracted the attention
of inventors, and the number of types of different
makes is increasing without ceasing. For this reason,
it would be difficult, if not impossible, for us to
establish to-day a complete nomenclature of the types
used in the industry, and also give the names of all the
manufacturers.
We have limited our inquiries to the lamps most val-
ued, beginning of course with Mr. Edison; because we
consider Mr. Edison, we cannot repeat it too often, as
the true creator of incandescent lighting, and as one of
the benefactors of mankind.
Concerning several systems, we have only been able
to obtain very incomplete information, because of the
mystery which still surrounds their manufacture; but
the description of the customary methods in the large
factories will suffice to give to the reader a correct idea
of this new and great industry.
As far as possible we have completed our descrip-
tion with a table of the lamps at present known in
France * *
*
(pp. 404-405).
Fontaine-1888-Chapter XIII.
2723
SWAN LAMPS. In England, Mr. Swan is considered to
be the true inventor of the incandescent lamp. The
fact is, that long before the Edison lamp had been
heard of, he attempted the construction of a practical
apparatus, and he had even shown, in a public meeting,
lamps sealed with a blow pipe and containing a small
incandescent carbon.
But it is certain that these lamps were not yet suffi-
ciently perfected to be utilized industrially when the
Edison fibrous filament lamp appeared.
It is after the glorious success of this lamp that Mr.
Swan renewed his labors and brought them to a useful
end by following the road marked out by the American
inventor.
*
*
*
*
*
*
2724
Edison Caveat of April 21, 1879.
Complainant's Exhibit, Certified Copy of
Edison Caveat, Filed April 21st, 1879.
[2-175.]
DEPARTMENT OF THE INTERIOR,
| Coat of Arms.]
UNITED STATES PATENT OFFICE.
TO ALL PERSONS TO WHOM THESE PRESENTS SHALL COME,
GREETING:
This is to certify that the annexed is a true copy
from the Records of this Office of the Petition, Oath,
Specification and Drawing, in the matter of the Caveat,
of Thomas A. Edison, Filed April 21, 1879, for Im-
provement in Electric Lights.
[SEAL.]
In testimony whereof I, W. E. Simonds,
Commissioner of Patents, have caused
the Seal of the Patent office to be
affixed this 18th day of September,
in the year of our Lord one thousand
eight hundred and Ninety-one, and
of the Independence of the United
States the one hundred and six-
teenth.
W. E. SIMONDs,
Commissioner.
TO THE HONORABLE COMMISSIONER OF PATENTS OF THE
UNITED STATES :
The Petition of Thomas Alva Edison, of Menlo Park,
New Jersey, Respectfully Represents That your peti-
tioner has invented certain new and useful improve-
Edison Caveat of April 21, 1879.
2725
ments in Electric Lights, and that he is now engaged
in making experiments for the purpose of perfecting
the same preparatory to his application for Letters
Patent therefor.
He therefore prays that the annexed description of
his said invention may be filed as a caveat (No. 89) in
the confidential archives of the Patent Office, and he
hereby requests that all correspondence in said case be
directed to his agent, Lemuel W. Serrell, Box 4689,
P. O., New York City.
Respectfully yours,
Menlo Park, N. J.)
April 16th, 1879. )
THOMAS A. EDISON.
UNITED STATES OF AMERICA.
MENLO PARK
New Jersey
}
SS.
On this sixteenth day of April in the year one thou-
sand eight hundred and seventy nine before the sub-
scriber, a Notary Public in and for said State, person-
ally appeared the within named Thomas Alva Edison
and made solemn oath that he verily believes himself
to be the original and first inventor of the within de-
scribed Impt. in Electric Lights, and that he does not
know and does not believe that the same was ever
before known or used, and that he is a citizen of the
United States, and a resident of Menlo Park, N. J.
THOMAS A. EDISON.
Sworn to before me, the day
and year above written.
STOCKTON L. GRIFFIN,
[SEAL.]
Notary.
!
Edison Caveat of April 21, 1879.
2726
TO ALL WHOM IT MAY CONCERN:
Be it known that I, THOMAS ALVA EDISON of Menlo
Park in the State of New Jersey, have invented an Im-
provement in Electric Lights of which the following is
a full clear and exact description of the same so far as
perfected.
The object of this invention is to economically and
practically produce light by electricity.
The invention consists in various devices which I
propose to use in my system of electric lighting, and
which devices I am now engaged in experimenting
with.
Fig. 1. shows a burner. a is a cylinder of lime, mag-
nesia, zircon, or other infusible oxide. Upon this is
wound platina-iridium wire B. coated with a pyro-in-
sulation such as magnesia reduced by heat to an oxidė
from an acid combination such as the acetate of mag-
nesia. The two ends of the wire are connected to the
two platina wires cd, which act both as conductors
and as supports to the lime cylinder. By winding the
wire round or in a spherical form, the total heat energy
is concentrated to the greatest extent.
In fig. 2 the bobbin of pyro insulated wire B is pre-
viously wound upon a mandrel between heads and then
removed therefrom: pyro insulated wires n. x. bend
the bobbin of wires together; it is then laid upon a
horizontal disk of lime a. supported by the wires c. d.
to which the ends of the coil are attached. By this
method the upper surface of the coil serves to give
light and does not require to be brought to as high
temperature as it would if it had to heat the lime and
render that incandescent.
In fig. 3. the bobbin is suspended in a sealed vacuum
globe v. by the ends of the wires of the bobbin B:
these ends are fastened to lugs n. m. projecting from
the lime disk, the ends of these wires pass through a
washer of lime x. The use of small wires prevents
loss of heat by conduction to a greater extent than if
Edison Caveat of April 21, 1879.
2727
large wires were used to support the bobbin, besides
the saving in expense.
Fig. 4. shows a flattened piece of lime over which
the wire is coiled.
Fig. 5. is a top view of the same.
Fig. 6. shows a bobbin separated in the center by
lime n. and placed horizontal.
Fig. 7. shows a method of preventing the fusion of
the bobbin when the current becomes too strong. B. is
the coil. The current passes through the coil thence
through the magnet c. thence through the magnet d.
thence to the lever e. through the point . thence by
wire k to the lever f. point g. and out. If now the
levers f. and e. are provided with retractile springs and
their tension is arranged so that the magnets will not
attract the levers until the current has brought the
bobbin B to the proper incandescence, the lever will
start vibrating if the current is increased beyond that
amount and thus weaken it. Two magnets are used,
as the amount of spark at the point is reduced as the
square of the number of breaks-i. e. the spark on the
point will be of what it would if but one point was
used and the current broken in but one place. The
lamps of course are to be worked in multiple arc.
Fig. 8. shows the arrangement with the single point.
Fig. 9. shows an extra lever h. which has consider-
able friction placed on its bearings: when the lever k.
throws it against the point g. the circuit is closed and
the magnet attracts the lever : when coming in con-
tact with the bottom part of the prong of h. it separates
from the point g and thus opens the circuit. When
the current diminishes in intensity the lever returns to
the upper prong g again closing the circuit to the
burner.
Fig. 10. shows an extra lever h. which serves to open
the circuit quicker than if the lever k. was used direct
and thus prevent a prolongation of the spark.
Fig. 11. shows the burner shunted with the magnet
which in this case has several thousand ohms resist-
ance: it is adjusted so that when the lamp has a proper
2728
Edison Caveat of April 21, 1879.
current it will not attract the lever, but if this is ex-
ceeded, the lever is attracted and opens the circuit with
great rapidity. Of course the devices of figs. 7. 9 &
10. may be used in this connection.
Fig. 12. shows a magnet provided with two coils the
current passing through in opposite directions. The
coil a is of large wire and is in the main circuit with
the burner, while the coil B. is of great resistance and
shunts both the lamp and the coil a. The inequality
of the resistance of the lamp produced by the rise of
temperature serves to disturb the balance and the mag-
net becoming magnetic, attracts the armature and
opens the circuit by means of its lever and point.
Fig. 13. shows a small electric engine which is wound
with very coarse wire this is included in the circuit
with the lamp: when the current becomes too strong
the engine commences to rotate and thus puts in a
counter-acting force as well as breaking the circuit. It
is obvious that a small miniature engine might be kept
running as long as the current passes and the shaft
provided with a governor which would open the circuit
when the engine obtained a certain velocity-this would
produce a very even regulation.
Such a device is shown in Fig. 14. The governor
balls n. fly outwardly and raise a collar which in its
turn raises a lever x from the contact point and opens
the circuit.
Fig. 15. shows several magnets machines arranged
in multiple arc and supplying the main conductors 1
and 2. with current. At the extremity of the main
conductors two smaller wires 3 & 4 return to the sta-
tion and a lamp is placed across or included in the
circuit, by this means the state of the circuit is shown
at the central station.
In Fig. 16. is shown a safety device for working ma-
chines in multiple arc. If one of any number of mag-
neto electric machines worked in multiple are should
stop for any reason and thus produce no energy, its
wire would act as a single resistance, hence the whole
power of the other machines would pass through it and
Edison Caveat of April 21, 1879.
2729
tend to destroy it as well as cause a momentary reduc-
tion in the amount of light given by the lamps supplied
by the machine hence it becomes very important that
such accidents should be guarded against. a. a. a. are·
magneto machines arranged in multiple arc and con-
nected to the main conductors 1 & 2.
Before the wires connect to the main conductor 1.
they pass through electro magnets wound with very
large wire so as to offer very slight resistances and
prevent waste of energy in heat. These electro-mag-
nets are provided with levers which are kept away from
the magnets by retractile springs: the levers rest
against points c c c. and thus preserve the continuity of
the circuit.
The tension on the springs is such that the lever will
only be attracted when a current passes through the
machine greater than it produces. When it is attracted
the lever is attracted with great force and opens its
own circuit but cannot return as it is provided with
catches d. x. which locking, hold the lever against the
magnet.
In Fig. 17. is shown another device for accomplishing
the same object. The current which in cases of acci-
dent will tend to destroy the dynamo machine, will flow
in an opposite direction to the current generated by
the machine, hence I used polarized armatures a. a. a.
between two electro magnets. If the current from the
machine is passing, the levers remain in contact with
the points c. c. c. and preserve the continuity of the
circuit, but if a reverse current is attempted to be sent
the levers will be attracted to the opposite point and
open the circuit, but only in that machine which is out
of order.
Fig. 18. shows a method of opening the circuit when
the current becomes stronger than it should be to work
the lamp at its proper point.
B. is the burner. A. a tube containing mercury: the
mercury forms part of the circuit and becomes heated
by the passage of the current through it. A lever a.
having a float at its end is lifted or lowered as the
2730
Edison Caveat of April, 1879.
!
mercury expands or contracts. The current passes
from the mercury through a. to the point upon the
lever d: when the mercury expands the lever a. is
raised and the spiral spring of lever d. causes it to
follow with it and preserve the continuity of the circuit,
but when a. reaches a certain point, the lever d. is
stopped from passing upwards by coming in contact
with the point x hence the circuit opens.
In Fig. 19. is shown a magnet for opening and closing
the circuit with great rapidity and by which the strength
of the current passing through the lamp may be regu-
lated, without the use of resistance which consumes
energy and is uneconomical.
X. is an adjusting post; upon one extremity is a
block n. which moves up and down as the screw is
worked to the right or left.
Upon the block is a flat spring c. which serves to lift
the lever of the magnet against the back point and
close the circuit. If the screw x. is turned so that the
lever will just be lifted and placed in contact with the
back point and no more, the vibrations will be slow
and the circuit will only be closed 1/10 of the time:
if x. is now adjusted so that the spring passes the lever
with greater force upwards, the rapidity of the vibra-
tions and time of closing will be increased and this ac-
tion will take place in proportion to the pressure, hence
the temperature of the burner can be increased and
decreased. If it is so adjusted and the current is in-
creased, this is immediately weakened in the same
manner as it would be if the pressure on the spring c.
was lessened.
Fig. 20 shows how the lever may be made to vibrate
slow or fast according to the distance which the adjust-
able magnet is from the lever it gives motion to.
Fig. 21. shows the thermal regulating spiral separate
from the burner and within a case containing flexible
aneroid chambers which latter are expanded by the
heated air and operate the circuit controlling devices:
this allows of the regulator being quite small and out
of sight.
A
Edison Caveat of April, 1879.
2731
Fig. 22. shows a device for measuring the amount of
current consumed in a given period m is an electro
magnet-d a lever-g. a cylinder a. a piston head
working tightly within said cylinder-x is glycerine or
oil.
This cylinder is connected with a reservoir n. by a
tube with a capillary core at the end. The measure-
ment is obtained by the pressure produced by the
magnet upon the piston forcing oil into the reservoir
very slowly but in proportion to the attraction of the
mag-
net which is as the square of the electro-motive force
of the current.
Fig. 23. shows a pipe through which hot water
passes, and the whole of the circumference of the pipe
is covered with thermo electric couples.
It is known that one half of the theoretical energy of
combustion of coal in a steam boiler furnace is wasted
through the medium of the hot water condensed after
passing through the best condensing engine.
Now as a river will flow with a fall of 1/10 of an
inch per mile, I propose to arrange many hundred feet
of pipe passing over a room back and forth many times.
and pass the hot water from the condenser through the
entire length of this pipe to the cistern, and I propose
to extract the heat energy from it by covering the
entire surface of the pipe with thermo-electric batteries,
the hot junctures to rest upon the painted non-electro-
conducting surface, and if necessary to obtain an in-
creased effect, to place the other junctures in contact
with another set of pipes through which cold water is
passing. These thermo couples are connected together
in the proper manner so that their current can be used
for maintaining a constant field magnet for magneto
electric machines which I employed in my electric
lighting system.
A certain section of pipe is reserved for each magnet.
x. x x. Fig. 24. are such field magnets. Thermo batteries
are admirably adapted for this peculiar service as the
resistance of the field magnet can be very slow. I am
now engaged in a great number of experiments to de-
2732
Edison Caveat of April 21, 1879.
termine the best metals or conducting substances to be
used for this purpose: heretofore temperatures so low
as that of hot water have not been used commercially
with thermo batteries and it becomes very essential to
discover some combination giving great electro motive
force and low resistance which can be made cheaply.
I shall probably claim hereafter as my invention
FIRST. The burners for electric lights shown in Figs.
1, 2, 3, 4, 5 and 6.
SECOND. The thermal regulators shown in Figs. 7, 8,
9, 10, 11, 12, 13 and 14.
THIRD. The device shown in Fig. 15 for showing the
state of the current on the line at a central station.
FOURTH. The devices shown in Figs. 16 and 17 for
working magneto machines in multiple arc.
FIFTH. The thermal regulators shown in Figs. 18, 19,
20 and 21.
SIXTH. The device shown in Fig. 22 for measuring the
amount of current consumed.
SEVENTH. To the means for generating electric cur-
rents, described in connection with Figs. 23 and 24.
Signed by me this 16th day of April, A. D. 1879.
THOMAS A. EDISON.
Witnesses.
J. F. RANDOLPH
S. L. GRIFFIN.
!
A. J. J.
A. E. R.
[ENDORSED:] Rec'd. & filed April 21, 1879. 19,651
D/91.
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2735
(No Model.)
T. A. EDISON.
CURRENT REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 248,421.
Patented Oot. 18, 1881.
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D.D. Mort
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J. A. Edison
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THE NORRIS-PETERS CO., PHOTO-LITHÓ,, WASHINGTON, D. 0.
attys.
2736
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
CURRENT-REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming- part of Letters Patent No. 248,421, dated October 18, 1881.
Application filed March 5, 1881. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Current-Regulators for
Dynamo-Electric Machines; and I do hereby
declare that the following is a full and exact
description of the same, reference being had to
the accompanying drawing, and to the letters
10 of reference marked thereon.
In a system for supplying electricity from
one source for a number of trauslating devices
it is desirable that there be such an arrange-
ment as will insure the generation of the proper
15 amount of current, no matter how many devices
be in circuit, so that the proper amount be
supplied to each such device in circuit without
regard to the increase or decrease of the total
number in circuit, and the proper pressure or
o electro-motive force be maintained constant in
the circuit.
The object of this invention is to attain such
a result. In prior applications it has been
shown how this object may be accomplished
5 by varying the current energizing the field-of-
force magnets, either by shunting more or less
of such current or by interposing in the field-
circuit more or less resistance.
I have discovered another method, which
30 consists in causing a greater or less electro-
motive force from a magneto-machine used as
an engine to traverse the field-circuit of the
generator, the counter electro-motive force hav.
ing the function of a resistance. This method
35 may be put into practice in the following way:
An electro-motor of small or proportionately
much less resistance and power than the gen-
erator is included in the circuit of the field-of-
force magnets of the generator. Upon the
40 shaft of the revolving armature of the electro-
motor is mounted a copper disk, which rotates
between the polar extensions of an electro-
magnet included in the field-circuit, and also
in the circuit leading to the translating devices
45 to be supplied, which are arranged upon mul-
tiple-arc circuits. This electro-magnet is wound
with coarse wire, so as to have but little re-
sistance. When no translating devices are in
circuit, the exterior circuit of the generator is
only through the motor-engine and the mag. 50
net, and there is but little current therein,
energizing but feebly the magnet, so that it
offers little resistance to the rotation of the
disk cutting the lines of forces between its po-
lar extensions. This feeble retardation allows 55
the engine to ruu at high speed, giving a coun-
ter electro motive in the field-circuit, weaken-
ing the energizing-current. If, now, the cir
cuit of translating devices be closed, so that
the exterior circuit of the generator is through 60
them, the resistance of the exterior circuit is
decreased, causing a greater flow of current
therethrough, which intensifies the magnetiza-
tion of the magnet referred to, which now of
fers increased resistance to the rotation through 65
its lines of force of the disk, causing the elec-
tro-motor to run at a less rate, diminishing the
counter electro-motive force in the field-circuit,
thereby strengthening the field, with the nec-
essary resultant of increased generation. Up- 70
on devices being cut out of circuit, the reverse
takes place. This is illustrated in the draw-
ing, in which G is the generator, and 1 2 the
conductors leading thence for the supply of
translating devices, (represented by T T.) 75
While only one generator and two translating
devices are indicated, it is evident that any
number may be used. As shown, G is a dy-
namo-electric machine, whose field-circuit 3
passes as a derived circuit from the commuta- 80
tor brushes or springs 4 5 around the field, and
includes au electric motor, M, and a magnet,
A, the latter being also included in one branch,
2, of the exterior or supply circuit.
•
Upon the shaft of M is a copper disk, C, which 85
rotates between the polar extensions a a of
magnet A, its rotation being opposed by the
magnetic field between a and a, whose lines of
force it is obliged to cut, and opposed propor-
tionately to the strength of that maguetic field. 90
If, now, no translating devices be in circuit,
the entire resistance of the exterior circuit of
the generator is only that of A and M, which
is comparatively large. Consequently A has
but a weak magnetization, offering but little re- 95
sistance to the rotation of C, allowing the mo-
tor M to run at high speed, the result being
that considerable counter electro-fmotive force
2737
2
248,421
therefrom is thrown into the field circuit of the
generator. If, now, translating devices T be
put in circuit, the resistance of the external
circuit is decreased, resulting in greater flow
5 of current in the exterior circuit, a stronger
megnetization of A, and a retardation of O,
slowing the rate of the motor M, and dimin-
ishing the counter electro-motive force thrown
therefrom into the field - circuit, so that the
10 field-circuit is strongthened substantially, the
essential result being that aimed at an in-
crease in the generative capacity of the gene-
rator G and a uniform pressure or electro-mo-
tive force throughout the system.
15
By this arrangement the generators may be
automatically controlled, so that the genera-
tion of current is kept just adequate to the de-
mand of the supply or consumption circuit,
and the pressure or electro-motive force inain-
20 tained constant.
While the generator herein shown is a dy-
namo, it is evident that the method and means
may be applied to magneto-machines, or to
that class in which the field is energized from
25 an exterior source of energy.
What I claim is-
1. The method of controlling or regulating
the generative force of a dynamo or magneto
electric machine consisting in throwing into
30 the field-magnet circuit a variable and con-
|
trollable counter electro-motive force, substan-
tially as set forth.
2. The combination, with a generator, of an
electro-motor included in and regulating the
field-magnet circuit by its counter electro-mo- 35
tive force, substantially as set forth.
3. The combination of a generator, an elec-
tro-motor included in the field-magnet circuit,
and a magnet in the supply or consumption
circuit controlling the rate of rotation of the 40
motor, substantially as set forth.
4. The combination, with a motor, of a disk
driveu thereby, and a magnet, between whose
poles or in whose field the disk rotates to vary
and control the rate of rotation of the motor, 45
substantially as set forth.
5. The combination of a generator, an elec-
tro-motor in the field-magnet circuit, carrying
a disk upon its rotating shaft, and a magnet
in the supply-circuit in whose field the disk 50
rotates, whereby the rate of the motor and the
strength of the field-circuit are varied and con-
trolled, substantially as set forth.
This specification signed and witnessed this
25th day of February, 1881.
Witnesses:
S. D. MOTT,
H. W. SEELY.
THOS. A. EDISON.
2738
2
(No Model.)
T. A. EDISON.
MAGNETO OR DYNAMO ELECTRIC MACHINE.
No. 251,550.
1
D
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6
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Attest
Sam D. Mott
Law Phyre
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Patented Dec. 27, 1881.
N. PETERS. Photo-Lithographer. Washington, D. C.
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Inventorz
Thos. A. Edison.
Dyenolither
attys.
2739
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
MAGNETO OR DYNAMO ELECTRIC MACHINE.
SPECIFICATION forming part of Letters Patent No. 251,550, dated December 27, 1881.
Application filed March 3, 1881. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Faradic or Magneto or
Dynamo Electric Machines; and I do hereby
declare that the following is a full and exact
description of the same, reference being had
to the accompanying drawing, and to the let-
IO ters of reference marked thereon.
D, and consequently the generative capacity
of those machines, may be readily controlled.
Upon the first using of D C as generators
their field-of-force coils are connected to any 50
suitable source of energy-for instance, a gal-
vanic battery or to a dynamo or magneto ma-
chine, the current from either serving to mag-
netize their cores. After this first magnetiza-
tion the cores retain enough residual magnet- 55
ism to start at least a weak initial current,
which excites A, causing B to become active,
its current passing through the field-circuit of
DC and strengthening it, causing an increased
current through 1 and 2 and through A, the 60
increased current in the latter reacting upon
the generators themselves, this sequence con-
tinuing until the maximum magnetization is
attained.
The object of this invention is to furnish an
arrangement of means whereby the field-of-
force magnets of a number of Faradic machines
may be readily and controllably energized. To
15 this end, in a derived circuit from the main or
consumption circuit of the Faradic machines or
generators, is placed an electro-motor, which
gives motion to a generator whose circuit is,
by multiple arc, through all the field-of-force By A may be so controlled that its speed 65
20 circuits of the generators. In the circuit of is varied to cause B to generate current enough
the motor is an adjustable resistance, so that only for the magnetization of the field to the
its action may be varied, which, in turn, con- degree necessary for the production of current
trols the generative capacity of the Faradic requisite for the demands of the circuit 1 2;
machines. In the circuit leading around the or the circuit 3 4 may be left constant and the 70
25 field-of-force coils is an adjustable resistance, current through the field-circuit controlled by
so that that circuit may be controlled inde-R to affect and regulate the generative capac-
pendently, if desired, of the motor-circuit, but
with the same ultimate result. This is illus-
trated in the drawing, in which D C are the
30 Faradic machines or generators, with their
bobbins connected in multiple arc to the main
or supply or consumption circuit 1 2. These
generators D C are driven by any suitable mo-
tive power, and in a manner well understood
35 in the art.
In a derived circuit, 34, is the motor A,
which gives motion to the generator B. In
this circuit 3 4 is an adjustable resistance, î',
so that the amount of current energizing A
40 may be controlled. The motor A gives mo-
tion to the Faradic machine or generator B,
whose circuit 5 leads by multiple arcs 6 around
the field-of-force magnets of C D, energizing
them. In this circuit is an adjustable resist-
45 ance, R, so that, other things remaining equal,
the force of the current around the field of C
ity of C D.
What I claim is—
1. The combination, with a battery of Far- 75
adic machines, of an electric motor in a de-
rived circuit to the main circuit, and a genera-
tor driven thereby and supplying the current
for the fields of the battery of Faradic ma-
chines, substantially as set forth.
80
2. The combination of a battery of Faradic
generators, a separate generator for supplying
the field-current thereto, and an independent
motor for the latter, said independent motor
being actuated by current from the battery of 85
Faradic generators, substantially as set forth.
This specification signed and witnessed this
26th day of February, 1881.
Witnesses:
S. D. MOTT,
H. W. SEELY.
THOS. A. EDISON.
2740
•
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 251,555.
5.
P.
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2.
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Attest=
D. D. Mott
HOW. Howard
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Patented Dec. 27, 1881.
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Inventor
Thos. A. Edison
Dyer Milber
Attys.
N. PETERS. Photo-Lithographer, Washington, D. C.
2741
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 251,555, dated December 27, 1881.
Application filed May 27, 1881. (No model.)
Te all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Dynamo or Magneto
Electric Machines; and I do hereby declare
that the following is a full and exact descrip-
tion of the same, reference being had to the ac-
companying drawings, and to the letters of
10 reference marked thereon.
This invention relates to means for automati-
cally controlling the generative force of a mag-
neto or dynamo electric machine, so that the
amount and only the amount of current needed
15 in the circuit may be supplied thereto, and the
pressure or electro motive force maintained
constant in the ciruuit. To accomplish this a
resistance and switch or lever, by which the cir-
cuit may be made independently of or through
20 more or less of the resistance, are included in |
the circuit energizing the field-of-force mag-
nets. The switch or lever is attached to a mag-
net playing within a longitudinal opening in a
helix, the magnet and helix preferably being
25 longitudinally the segment of a circle and form-
ing an axial magnet, the interior magnet tend-
ing, when both are at a maximum of intensity,
to place itself so that its center and the center
of the coil correspond, in which position it
30 places the switch or lever so that the field-cir-
cuit is through all the resistance, while a spring
attached to the switch serves, when unresist-
ed, to hold the switch or lever so that it cuts
the resistance out. Both coils of this axial
35 magnet are in a circuit derived from the main
or consumption circuit. No translating devices
being in circuit, the entire exterior circuit is
through the coils of the axial magnet only, and
it acquires a maximum magnetization, putting
40 all the resistance in the field-circuit, thereby
keeping production or generation down to a
given point. If, now, translating devices be
put in circuit, more exterior circuits are closed
and the amount of current flowing through the
45 axial-magnet circuit is lessened, weakening the
force of the electro-magnet so that the spring
causes the lever or switch to move so as to cut
out a portion of the resistance, which is equiv-
alent to strengthening the field-circuit, thus
arresting the diminution of current due to put 50
ting on more lamps. This is illustrated in the
drawings, in which one generator of the dy
namo type is shown; but it is to be understood
that the principle and means are equally ap
plicable to any type of generator, and to them 55
used singly, or to a number used as a battery.
G is a generator, from whose commutator
brushes or springs 1 2 leads the main or con-
sumption circuit 3 4, a derived circuit, 5, there-
from being led around the field-magnets of the 60
generator, in which circuit are included a re-
sistance, R, and switch or lever L.
In a derived circuit, 6, is included the helix
M, in which plays, forming the core thereof,
the magnet m, attached to and moving in oné 65
direction the switch or lever L against the re-
silience of the spring S.
In derived circuits 7 lamps or other trans-
lating devices are placed. If these latter cir-
cuits be open, whatever current is generated 70
finds its only exterior circuit through 6 M m,
magnetizing them strongly. Hence m is drawn
up within M, causing L to contact with R at
about a or b, so that all or nearly all of R is in-
cluded in the field-circuit 5, so weakening it 75
that the generative force of G is kept at a
given point. If 7 be closed, it takes a part of
the current, lessening the amount through 6,
weakening the force of M m, the spring pulls
L to, say, c, cutting out part of the resistance, 80
strengthening the field-circuit, which results
in a proportionate increase of generation of
current. As more circuits are closed L is car-
ried from contact to contact of R until finally all
or nearly all or as much of R is cut out as is 85
necessary to compensate for the increased de-
mand.
Upon cutting out of 7 the reverse operation
takes place.
What I claim is-
90
1. The combination, with a generator, of a
variable resistance in its field-circuit, a mag-
net in a derived circuit to the main or supply
circuit of the generator, and a movable con-
tact-arm controlled by the magnet for effect- 95
ing an automatic regulation of the field of the
generator, substantially as set forth.
2. The combination of a generator, a resist
2742
2
251,555
ance in its field-circuit, an axial magnet com-
posed of a helix and an electro-magnet as a
core thereto, both included in one circuit de-
rived from the main or supply circuit, and a·
5 movable contact-arm controlled by the mag-
net and contacting with the resistance, sub-
stantially as set forth.
This specification signed and witnessed this
26th day of February, 1881.
Witnesses:
H. W. SEELY,
THOS. A: EDISON.
RICHD. N. DYER.
2743
(No. Model.)
T. A. EDISON.
REGULATOR FOR MAGNETO OR DYNAMO ELECTRIC MACHINES.
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No. 251,556.
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Inventorz
Thos. A. Edison
per
Byer and Wilber
N. PETERS. Photo-Lithographer. Washington. D. C.
Olttys
2744
UNITED STATES PATENT OFFICE.
сл
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR MAGNETO OR DYNAMO ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 251,556, dated December 27, 1881.
Application filed October 30, 1880. (No model.)
To all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Magneto or Dynamo
Electric Machines, (Case No. 258;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to the
Io letters of reference marked thereon.
As explained in a prior application for pat-
ent by me made, the current used in my sys-
tem is generated at and distributed from a
central station to and through the district of
15 such station. At the central station is massed
a number of generators sufficient to supply
the wants of the entire district. As shown in
the application referred to, these generators
are connected in multiple arc, and the genera-
20 tive capacity of those in use is regulated and
controlled by regulating and controlling the
current passing through the coils of the field-
of-force magnets by introducing into a circuit
common to all the field-of-force coils more or
25 less resistance. In this instance the invention
consists in arranging equal resistances in the
circuit of each field-of-force coil and cutting
in or out equal portions of each simultane-
ously by hand or automatically, the result be-
30 ing accomplished in the latter case by the use
of a special electric engine placed in a derived
circuit to the main circuit, and provided with
a governor which, on lessening or increase of
speed, actuates a switch, cutting in or out a
35 portion or all of the resistances.
In the drawings, which are mainly diagram-
matic, Figure 1 is a view of the automatic ar-
rangement, and Fig. 2 a view of the arrange-
ment wherein the resistances are controlled by
40 hand.
1 2 represent the main-circuit conductors at
and leading from a central station, where is
shown a battery of four dynamo-electric ma-
chines, A A' A" A", which number may be
45 greater or less, as desired.
14 14 are the connections from the armature
of each generator to the main circuit 1 2, for
throwing thereinto the current generated in
the coil of the revolving armature. From
50 each field coil one conductor, 3, leads directly
to main conductor 2. From conductor 1 a
wire, 4, leads, in one instance to the hand-
Switch S, in the other to the switch-lever L.
Sets of resistances R R' R"R"" are used, one
for each generator, a conductor leading from 55
each set of resistances to its appropriate gen-
erator-for instance, 10 from R to A, 11 from
R' to A', 12 from R″ to A", and 13 from R"" to
A"". Each set of resistances may consist of as
many resistance-boxes as desired. For illus- 60
tration, four only are shown, r'"'""', con-
ductors being arranged, in connection with the
hand-switch S or switch-lever L, to cut more
or less out of circuit. If either be turned to
9, all the resistances are cut out of circuit; at 65
8, only is placed in circuit; at 7, and r'; at
6,, ', and ", while at 5 all are thrown into
circuit. The path of the circuit to the field-
coils then is from 1, via 4, to S or L, thence
through one of the conductors 5, 6, 7, 8, or 9, 70
when it divides and passes by 10, 11, 12, and 13
to A, A', A", and A"" to 2. By this arrange-
ment the resistance of all the exterior field-
circuits is always equally increased or dimin-
ished, their relative resistances remaining un- 75
changed, while each field is rapidly, accu-
rately, and delicately adjusted, correspond-
ingly affecting the generative capacity of the
machine.
In Fig. 1, B is an electric engine in a derived 80
circuit, bb, to the main circuit. Upon the
shaft of its armature is a governor, G, to which
is connected the switch-lever L, pivoted at 7.
The speed of the armature and of its attached
governor depends upon the current passing 85
through bb. If an insufficient amount is gen-
erated, the speed falls, the governor-balls drop,
moving L, so that it contacts with 8 or 9, caus-
ing an increased current through the field-
coils, and a consequent increase of strength of 90
magnetic field and of generative capacity. If
an excessive amount of current is generated,
the reverse takes place.
While the generators here shown are con-
nected as dynamos, it is evident that the same 95
arrangement is equally applicable to and effi-
cacious with magneto-electric generators, and
that the wire 3 might lead to a special genera-
tor set apart for the work of supplying cur-
rent for the fields only, the wire 4 of course be- 100
ing led to the same machine.
What I claim is-
2745
2
251,556
1. The combination, with each generator of
a battery of magneto or dynamo electric ma-
chines arranged in multiple arc, of a resistance
in its field circuit and a switch controlling
5 equally and simultaneously all the resistances
of the generators of the battery, substantially
as set forth.
2. The combination of a battery of dynamo
or magneto electric machines, a series of equal
IO resistances, one series for each generator, a
switch, a circuit to the switch, and resistances
and special circuits, one for the field of each
generator, from the resistances to the field-of-
force coils of the generators, substantially as
15 set forth.
3. The combination of a battery of magneto
or dynamo generators, a series of resistances
in the field-circuits, one for each generator,
and means for automatically controlling equal-
ly and simultaneously the resistances of the 20
field-circuits of all the generators, substan-
tially as set forth.
This specification signed and witnessed this
21st day of October, 1880.
Witnesses:
THOS. A. EDISON.
CHAS. BATCHELOR,
WM. CARMAN.
¡
2746
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
No. 263,134.
6.
A:
B
Fig.1.
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Patented Aug. 22, 1882.
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Inventor:
J. A. Edison
Dyer & Wilber
Attys.
THE NORAIS PETERS CO,
HOTO-LITHO..
WASHINGTON, D. C.
2747
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 263,134, dated August 22, 1882.
Application filed May 28, 1881. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON; of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Dynamo and Magneto
Electric Machines, (Case No. 314;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to the
10 letters of reference marked thereon.
only within certain definite limits, the yoke al- so
ways being complete to a greater or less ex-
tent, independent of the position of the mova-
ble piece.
In the drawings, Figure 1 is an end elevation
of a dynamo or magneto electric machine and 55
connectious, with the yoke partly broken away
to disclose the magnetic-circuit regulator; and
Fig. 2, a similar view, showing the magnetic.
circuit regulator operated automatically by the
electro-motive force of the main or consump- 60
tion circuit through an electro-magnet.
Like letters denote corresponding parts in
both figures.
A A'are the helices of the field-of-force mag-
net; B B', the pole ends of the same; C, the 65
yoke or bar connecting the helix-cores; D, the
revolving armatures of the machine, and E the
commutator-block. The commutator brushes
or springs 1 2 lead from the block E to the
main or consumption circuit 3 4. The field-of- 70
force magnet may be energized by the derived
circuit 5 6 or by the main circuit of another
generator. The yoke C has a central conical
opening, F, passing vertically through it, in
which plays the conical block G, forming the 75
magnetic-circuit regulator. This cone is sup-
ported by bars a b, secured to the yoke, and
separated therefrom by brass plates. The stem
c of the conical block may be screw-threaded
and receive above the bar a a hand-wheel, d, Ec
having an internal screw - thread, by turning
which hand-wheel the position of the cone with
relation to the yoke can be adjusted.
The object I have in view is to produce sim-
ple and efficient means for regulating the gen-
erative force of a dynamo or magneto electric
machine, so that only the amount of current
15 needed in a circuit may be supplied thereto
and the pressure or electro-motive force main
tained constant in the circuit. For this pur
pose I make use of the principle that the power
of an electro-magnet can be weakened by di-
20 minishing the mass of the yoke connecting the
cores, and that such power can be strength-
ened by increasing the mass of said yoke un-
til the maximum power is attained. In apply-
ing this principle I provide the yoke of the
25 field-of-force magnet of a dynamo or magneto
electric machine with a movable portion, the
position of which can be varied so as to effect
the mass aud conducting-power of such yoke,
said movable portion acting as a magnetic-cir-
30 cuit regulator. This movable portion is pref-
erably situated in the center of the yoke, and
is of conical shape, being supported by a spin-
dle which passes through bars connected with
the top and bottom of the yoke, and separated
35 therefrom by plates of brass or other non-mag- The translating devices represented by e are
netic material. The position of this movable in derived circuits, while an electro-dyuamom- 85
cone may be adjusted by meaus of a hand- eter, H, is also situated in a circuit derived
wheel working on the screw-threaded stem of from the main circuit 3 4, and serves to guide
the cone; or the cone may be drawn into the the attendant in his adjustment of the mag-
40 yoke by an electro-maguet (preferably an ax- netic-circuit regulator. When the electro-mo-
ial magnet) the coils of which are in a shunt tive force increases beyond the desired inten- 90
or derived circuit from the main or consumpsity the attendant retracts the cone, and vice
tion circuit, or directly in the main circuit. versa, and thereby diminishes or increases the
This magnet forms means for adjusting the energy of the field-of-force magnet, and con-
45 cone automatically. Were the yoke entirely sequently the electro-motive force of the cur-
cut through, the uniting piece or part varying ent induced in the bobbin of the revolving ar- 95
the mass might become entirely displaced, so mature. It is possible, therefore, by these
that there would be no effect. The construc- meaus to maintain a nearly-constant pressure
tion noted then varies the mass of this yoke or electro-motive force in the main circuit 3 4.
2748
ΙΟ
15
20
2
263,134
In Fig. 2 an axial magnet, I, is used to draw
the cone into the yoke, the same being retracted
by a spring, f, and by its own weight. The
coil of this magnet is in the main or consump-
5 tion circuit. When the magnet I is used it is
not necessary to employ an electro-dynamom-
eter; but one may be used to check the oper-
ation of the magnet.
What I claim is-
1. In a dynamo or magneto electric machine,
the yoke of the field-magnet, having an open-
ing through the same, in combination with a
block adjustable in and out of said opening,
substantially as set forth.
2. In adynamo or magneto electric machine,
the combination, with the yoke of the field-mag-
net, provided with a conical opening, of a coni-
cal block adjustable in and out of said opening,
substantially as set forth.
3. In a dynamo or magneto electric machine,
the field-of-force magnet, the yoke of which has
an adjustable portion acting as a magnetic-cir-
cuit regulator, in combination with means op-
erated by the current generated for automati-
cally adjusting said adjustable portion, sub- 25
stantially as set forth.
4. The combination, with the yoke of the
field-magnet of a dynamo or magneto electric
machine provided with an adjustable portion
for regulating the generation of current, of au 30
electro-magnet placed in the main circuit from
said machine for adjusting said adjustable por-
tion according to variations in the current re-
quired, substantially as set forth.
This specification signed and witnessed this 35
19th day of May, 1881.
Witnesses:
THOMAS A. EDISON.
RICHD. N. DYER,
H. W. SEELY.
2749
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 1.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
No. 263,136.
Patented Aug. 22, 1882.
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Fig 1
A
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WITNESSES:
Thomas E. Birch.
Frank Ni Hall
INVENTOR:
ToA.
BY
A. Edrim
заживет
ATTORNEY.
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
2750
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 2.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
No. 263,136.
7.
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9
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Attest;
Fr. W. Howard
JH Hall
A.
Fig. 2.
M.
M.
Patented Aug. 22, 1882.
c.
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
8.
6.
4.
10
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·Inventor;
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​J.st. Edison pr
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2751
(No.Model.)
T. A. EDISON.
3 Sheets-Sheet 3.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
No. 263,136...
5.
B.
Fig.3.
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Patented Aug. 22, 1882.
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B.
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9.
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Attest;
B. W. Howard
GH Hall
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THE NORRIS PETERS.CO., PHOTO-LITHO., WASHINGTON, D. C.
6.
8.
10
Inventor;
F.A. Edirne for
Atty.
2752
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR DYNAMO OR MAGNETO ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 263,136, dated August 22, 1882.
Application filed May 27, 1881. (No model.) Patented in England October 18, 1881, No. 4,552; in Canada November 20, 1881, No.
13,734, and in France December 7, 1881, No. 145,598.
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Dynamo and Magneto
Electric Machines, (Case No. 312;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to the
Io letters of reference marked thereon.
The object of my invention is to produce sim-
ple and efficient means, operating either auto-
matically or by hand, for regulating the gen-
eration of current by a dynamo or magneto
15 electric machine by increasing or diminishing
at will the strength of the lines of force in the
magnetic field in which the induction-bobbin
rotates. This I accomplish by the use of le-
vers or bars of iron adapted to be adjusted
20 close to or farther away from the pole ends
and yoke of the maguet or the pole ends alone,
which partially shunt the magnetic current or
lines of force away from the field in which the
armature revolves. These levers or bars I
25 may arrange in either of two ways.
First. I may pivot to the outer sides of the
pole ends of the magnet two vertical soft-iron
levers rising above the ends of the yoke and
making contact with such yoke when in line
30 therewith. The yoke supports two brass seg-
ments, which are secured thereto and project
some distance off from the same in the line of
the play of the shunting-lever. To these seg-
ments are connected the said levers by means
35 of suitable latches or clamps, so that such le-
vers, at their upper ends, can be adjusted toward
or away from the yoke or brought into con-
tact with the ends of the same.
Second. I may, in place of or in addition to
40 the first construction, pivot upon the base of
the machine, close to one of the pole ends of
the magnet, one or two horizontal soft-iron
levers. The lever used extends across the
pole ends of the magnet, being pivoted at one
45 end and adjustable back and forth at the
other.
In both constructions the effect of the le-
vers depends upon their mass and their posi-
•
tion with relation to the magnet. In the first
construction the vertical levers become mag- 50
netized, diminishing thereby the strength of
the lines of force in the magnetic field, the
free end of each lever having a polarity oppo-
site to that of the end of the magnet to which
it is attached. Consequent poles are thereby 55
established in the yoke of the maguet oppo-
site the ends of the levers, which poles are
increased in power by the approach of the le-
vers to the yoke, from which it will be seen
that the lines of force are shunted away from 60
the field in which the induction-bobbin rotates,
more or less, according to the distance of the
vertical levers from the yoke. In the second
construction, supposing one lever only is used,
the approach of this lever to the pole ends of 65
the magnet will have the effect of partially
bridging or connecting (more or less) the poles
of the magnet and shunting the lines of force
or magnetic current around or away from the
magnetic field. With two levers, one on each 70
side of the magnet, the effect would be in-
creased. The proper size or mass of the le-
vers having been determined to accomplish
the effect desired, the adjustment of such le-
vers will diminish or increase the strength of 75
the lines of force in the magnetic field, and in
consequence thereof the current generated in
the bobbiu. Either of these arrangements
may be worked automatically by means of au
electro-magnetic device actuated by the cur- 80
rent generated for moving the levers in the
proper direction. For this purpose I use pref-
erably an axial magnet whose core is attached
to some portion of the pivoted lever in such
way as to move said lever forward or back- 85
ward according to the degree of magnetiza-
tion, the arm being provided with a spring or
weight to assist its backward motion.
In the drawings, Figure 1 is an elevation
of a generator provided with that form of my 90
invention in which the pivoted bars connect
the yoke and the polar extensions of the field-
magnet; Fig. 2, a perspective view of the
same, arranged to operate automatically; Fig.
3, a perspective view of the form in which a 95
pivoted bar crosses the polar extensions of the
2753
2
263,136
field-magnet, this also being so arranged as
to operate automatically.
Like letters denote corresponding parts in
all three figures.
5 A is the base of the machine, B B' the pole
BB'
ends of the magnet, C C' the helices, D the
yoke, and E the revolving armature, all of
which are constructed in any suitable or usual
way employed in dynamo or magneto electric
to machines.
In Fig. 1, F F' are two vertical soft-iron lev-
Fare
ers, which are pivoted to the outer sides of
the pole ends B B' of the magnet and rise
above the yoke D. Two brass segments, G,
15 are secured to the yoke at opposite ends
thereof, (only one being shown,) with which
the levers are locked by any suitable means,
the segments being shown as toothed and
the levers being provided with latches for
20 this purpose.
In Fig. 2 the armature is omitted for con-
venience of drawing. Main conductors 1 2
are, however, shown.
The derived circuit 3 4 includes the arma-
25 ture, the circuit 5 6 the field-coils, and the cir-
cuit 7 8 the coils of the axial magnet M. The
movable core of this magnet is attached to the
bar N, connecting the levers FF. In derived
circuits 9 10 are placed electric lamps, or other
30 translating devices a a. When more of these
are placed in circuit the current in the derived
circuit 7 8 decreases and the magnet M
weakens in power. The levers F are then
drawn back by means of the spring b. Instead
35 of adjusting the spring b, a weight, c, sliding
on an arm projecting from the lever, may be
used, so that the force acting against the
spring may be readily varied. The levers be-
ing drawn back, the magnetic field is strength
40 ened and the generation of current propor.
tionately strengthened. A reverse operation
of course occurs as transitory devices are
thrown out of circuit.
In the modification shown in Fig. 3 the
45 horizontal soft-iron lever H is pivoted to the
base A close to B', and extends across such
base to the other side. A similar lever may
be situated upon the opposite sides of the poles,
if desired. The shunting effect of these levers,
50 the diminishing thereby of the strength of the
lines of force in the magnetic field, and the con-
sequent effect upon the current generated in-
ductively in the bobbin will be understood from
the foregoing description. The movement of
the levers is automatically accomplished by 55
means of the magnet M, located in the desired
circuit 7 8, its movable core being attached to
the lever H and the latter being retracted by
a spring, d. The operation in this case is simi-
lar to that described with reference to Fig. 2.
What I claim is-
60
1. In a dynamo or magneto electric machine,
the combination, with the field-magnet, of a bar
or lever adapted to magnetically connect the
polar and yoke ends of the magnet, being piv- 65
oted to or upon one end and adjustable to or
from the other end, substantially as set forth.
2. In a dyuamo or magneto electric machine,
a shunting lever or bar for shunting the lines
of force away from or around the magnetic 70
field in which the induction-bobbin rotates,
said bar or lever being automatically adjusta-
ble to and from the magnet, substantially as
set forth.
3. In a dynamo or magneto electric machine, 75
a magnetic shunting lever or bar operating
as described, pivoted at one end close to or
upon a portion of the magnet and automati-
cally adjustable from the other end to and from
another portion of the magnet, substantially 80
as set forth.
4. In a dynamo or magneto electric machine,
the combination, with the field-magnet, of a
magnetic shunting lever or bar operating as
described, and an electro-magnet energized by 85
the current generated for automatically ad-
justing said lever to and from the magnet,
substantially as set forth.
5. In adyuamo or magneto electric machine,
a bar or lever adapted to magnetically con- 90
nect the polar aud yoke ends of the field-mag-
net, being pivoted to or upon one end and ad-
justable to or from the other end, in combina-
tion with an electro-magnet energized by the
current generated for automatically accom- 95
plishing such adjustment, substantially as set
forth.
This specification sigued and witnessed this
17th day of May, 1881.
Witnesses:
THOMAS A. EDISON.
WM. H. MEADOWCROFT,
H. W. SEELY,
2754
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,658.
5
Patented Sept. 19, 1882.
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Edward CRowland
Hitely
INVENTOR:
J. A. Edeim
BY Rich & M. Dijer.
ATTORNEY
N. PETERS. Photo-Lithographer, Washington, D. C.
2755
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,658, dated September 19, 1882.
Application filed August 7, 1882, (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in the Regulation of Dy-
namo or Magneto Electric Machines, (Case No.
407;) and I do hereby declare that the follow-
ing is a full and exact description of the same,
reference being bad to the accompanying draw-
10 ing, and to the letters of reference marked
thereon.
In an application for a patent of even date
herewith I have set forth a means of regulat-
ing the generation of current by dynamo or
15 magneto electric machines by the use of a vi-
brating circuit-controller for regulating the eu-
ergy of the field-magnet of the machine.
reference to the drawing, which is a diagram
illustrating the same.
A is a dynamo-electric machine, from which 55
lead main conductors 1 2, the field-magnet be-
ing energized by a derived circuit, 3 4. In the
circuit 3 4 is placed a vibrating circuit-con-
troller, b, actuated by the movement of the ar-
mature-lever B of the electro-magnet C, the 60
latter being in a derived circuit, 5 6. In a
shunt-circuit, 7 8, around the circuit-controller
b are constant resistances DEF. Around re-
sistance D is a shunt, 7 10, including the arma-
ture-lever c of the magnet G, while a shunt, 10 65
12, around E includes armature-leverd of mag-
net H. The magnets G H are in multiple arc
to each other in the shunt-circuit 13 14.
The operation of these devices is as follows:
This invention relates to the same subject; Each of the resistances D E F is proportioned 70
and it consists in the use, in connection with for one-third of the lamps a a supplied by the
20 this vibrating circuit-controller, of resistances machine. As shown, only a few lamps are in
|
for reducing the spark, so arranged in the field- circuit, and the resistances D E F are all in
circuit that when a certain definite proportion use for reducing the spark caused by the vi
of the lamps or other translating devices sup-brations of the circuit-controller b, which reg- 75
plied by the plant are in circuit a certain con- ulates the machine, a suitable device, I, being
25 stant resistance for reducing the spark will be used to adjust the tension of the spring B, and
in the field. To do this I place in the field-so regulate the candle-power of the lamps;
circuit a vibrating circuit-controller, prefera- but when more than one-third of the entire
bly one constructed so as to break circuit at number of lamps is placed in circuit the in- 80
several points simultaneously. This is prefer- crease of current in the shunt13 14 causes the
30 ably actuated by an electro-magnet placed in magnet G to attract its armature, which closes
a multiple arç-circuit from the main line, and the shunt-circuit 7 10 and cuts out the resist-
regulates the generation of current, as set forth auce D, for as more current must now flow in
in the application above referred to. In a the field, it is desirable to decrease the resist- 85
shunt around the circuit-controller is placed a ance in the shunt so as to reduce the spark at
35 series of equal resistances, around which are the breaking-points. The magnet H and ar-
formed shunts including the armatures of elec- matured are so arranged that a greater amount
tro-magnets placed in a shunt or shunts from of current is required to attract the armature
the main conductors. When only a few lamps than is the case with magnet G. When more go
are in circuit and little current passes in the than two-thirds of all the lamps are placed in
40 main line the last-mentioned magnets are but circuit the armature 7 is attracted and the re-
slightly energized, and the shunt circuits sistance E cut out of circuit, leaving in only
around the resistances in the field are open; the resistance F for reducing the spark. The
but when the certain predetermined number resistances, by reducing the spark at the break- 95
of lamps is exceeded and a greater current ing-poiuts, and thus preventing sudden fluctu-
45 flows in the main line one of the electro-mag- ations of current, prevent any sudden varyings
nets attracts its armature and closes the shunt of candle-power or flickerings in the lamps
around a portion of the spark-reducing resist- which might otherwise ensue. The throwing
ance, for it is now unnecessary to have so in and out of these resistances has, however, 100
large a resistance in the circuit; and this op- no direct effect upon the lamps, but simply and
50 eration continues according to the number of solely affects the spark caused by the break-
parts into which the resistance is divided. ing of circuit.
The invention may be better understood by
•
Instead of using the maguet C to operate
א:
264,2756
the circuit-controller directly, it, being wound
to respond quickly to variations of current,
could be used to open and close the circuit of
another magnet which would do the work, this
5 magnet being placed in any convenient loca-
tion, but preferably in a shunt around the re-
sistance in the main line or around the resist-
ance F in the field.
It is evident that this invention is as well
10 adapted to magneto as to dynamo electric ma-
chines, or to machines in which the main cur-
rent energizes the field-magnet, in which case
the circuit-controller b would be in a shunt
around the field.
15
It is also evident that the number of spark-
reducing resistances and of electro-magnets
connected therewith and the proportion of
lamps required to be in circuit in order that
these magnets will operate might be varied in
20 any desired manner.
I do not claim broadly the use of a vibrating
circuit-controller for regulating the generation
of current, or a spark-arresting shunt around
such a circuit-controller, or providing such a
25 circuit-controller with an adjustable retractor,
since such invention forms the subject-matter
of claims in my application No. 68,627, of even
date herewith.
30
What I claim is-
1. The combination, with a dynamo or mag-
neto electric machine, of a vibrating circuit-
controller for regulating the generation of cur-
rent, and a shunt around said circuit-control-
ler containing a series of constant resistances
for reducing the spark, and means adapted to 35
cut each of such resistances into or out of cir-
cuit by the removal or addition of a definite
predetermined number of translating devices,
substantially as set forth.
2. The combination, with the vibrating cir- 40
cuit-controller and spark-reducing resistances
in a shunt around the circuit-controller, of the
electro-maguets in a shunt from the main line,
each adapted, upon the addition or removal of
a certain number of translating devices, to cause 45
the throwing in or out of circuit of a portion
of the spark-reducing resistances placed in a
shunt around the vibrating circuit-controller,
substantially as set forth.
3. The combination of the vibrating circuit- 50
controller placed in the field-circuit, the elec
tro-magnet for operating the same, placed in a
derived circuit from the main line, the series
of constant spark-reducing resistances placed
in a shunt around the circuit-controller, and 55
the series of electro-magnets in a shunt from
the main line, for throwing said resistances out
of circuit one after another, as desired, sub-
stantially as set forth.
This specification signed and witnessed this 60
28th day of February, 1882.
Witnesses:
THOS. A. EDISON.
II. W. SEELY,
THOMAS JOHNSTON.
2757
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,659.
Patented Sept. 19, 1882.
Fig. 1.
Fig. 3.
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WITNESSES:
Edward C. Rowland
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​INVENTOR:
J. A. Edison
BY Rich? At. Dyer,
ATTORNEY
N PETERS. Photo-Litographer, Washington, D. C.
2758
UNITED STATES PATENT OFFICE.
5
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,659, dated September 19, 1882,
Application filed August 7, 1882. (No model.)
To all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
useful Improvement in the Regulation of Dy-
namo or Magneto Electric Machines, (Case No.
406;) and I do hereby declare that the follow-
ing is a full and exact description of the same,
reference being had to the accompanying draw
10 ings, and to the letters of reference marked
thereon.
In multiple-are circuits 5 6 and 7 8 are placed
respectively the electro-magnets B and C. The
magnet B is provided with a pivoted arma-
ture-lever, b, retracted by a spring, d, its free 55
end making and breaking contact at e, and
thus opening and closing the shunt-circuit f
around the magnet C, of which circuit the ar-
mature-lever b forms a part. The maguet C
has pivoted armature c, retracted by spring g. 60
The movement of this armature causes the vi-
bration of the circuit-controller h, which, in
The object of this invention is to produce order to reduce the spark, is made to break
means for automatically regulating the genera circuit simultaneously at points i i, k being
tion of current by a dynamo or magneto electric an insulating-pin. This circuit-controller reg. 65
15 machine supplying current to a mutiple-arc sys-ulates the machine as in the application above
tem of electrical distribution, which shall not referred to.
referred to. A shunt-circuit, 9 10, is formed
vary the resistance of or the current flowing in around this circuit-controller, containing a
the field-circuit of the machine, and shall be high resistance, preferably an incandescent
exceedingly and unusually sensitive in their electric lamp, D, in order that the spark may 70
20 action, responding instantly to the slightest be still further reduced; or the shunt-circuit
variation in the current on the main line. This may include a portion of the field-magnet coils
I accomplish in the following manner: Two with the same result. The opening and clos-
electro-magnets are placed each in a derived ing of the shunt f, controlling the energy of the
circuit from the main conductors of the gen- magnet C, increases the sensitiveness of the 75
25 erator, and each actuating a vibrating circuit- action of the circuit-controller h. All the
controller. The circuit-controller of one mag- movements of the armatures c and b are simul-
net opens and closes a circuit whose opening taneous, and thus a double effect, both in in-
and closing controls or assists in controlling crease and decrease of energy, is produced in C.
the energy of the other magnet, whose vibrat- In Fig. 2 the magnet B is used to close and 80
30 ing circuit-controller is placed in the field-cir- open directly the circuit 7 8 through the mag-
cuit, so as to regulate the energy of the field-net C, instead of a shunt around it. The cir-
magnet of the machine, as explained in an-
other application made by me of even date here-
with; or where the main circuit includes the
35 field-coils the circuit-controller would be placed
in a shunt-circuit around such coils. One or
more shunt-circuits may be formed around the
last-mentioned circuit-controller, (which is
preferably one which makes and breaks cir-
40 cuit at several points simultaneously,) such
shunts having a high resistance, and being
used to decrease the spark which might other-
wise ensue.
In the drawings, Figures 1, 2, and 3 are dia-
45 grams of different forms of my invention.
50
Referring to Fig. 1, A is a dynamo-electric
machine, from which lead main conductors 12,
having lamps or other translating devices, a a,
placed in multiple arc upon them.
34 is a multiple-arc circuit including the
field-magnet of the machine.
cuit-controller F here shown is one in which
the flat springs 7 bear on the cross-piece m,
and so keep the contacts n n and o o always 85
in line. With the exception of the points
above noted, this form is similar to that of
Fig. 1.
In the form shown in Fig. 3 two incandesc-
ing electric lamps, D D, are used as resist- 90
ances for decreasing the spark, and placed di
rectly in the field-circuit 3 4, a shunt being
formed around each, and both shunts being
opened or closed simultaneously by the move-
ment of the vibrating circuit-controller h. The 95
magnet B is used to open and close a shunt,
f, around the magnet C, as in Fig. 1, and the
movement of the armature-lever c throws the
lamps or other suitable high resistances, D D,
in or out of circuit. In this case the magnets 100
B C are placed in series in the same multiple-
arc circuit, 5 6.
2759
2
264,659
It is evident that in all these forms the field- 3. The combination, with a dynamo or mag-
circuit 3 4 might be a circuit supplied from an neto electric machine, of two electro-magnets 35
external source, or a shunt instead of a derived placed in a multiple-arc circuit or circuits from
circuit from the main line; or the vibrating cir- the machine, and each provided with a vibrat-
5 cuit-controller could be placed in a shunt ing circuit-controller, one for regulating the
around the field in those machines in which generation of current by the machine, the other
the main current energizes the field-magnet. for controlling or assisting to control the.sup- 40
I do not claim broadly the use of a vibrat-ply of current energizing the first, substan-
ing circuit-controller for regulating the genera- tially as set forth.
10 tion of current, or a spark-arresting shunt
around such a circuit-controller, or providing
such a circuit-controller with an adjustable re-
tractor, since such invention forms the sub-
ject-matter of claims in my application No.
15 68,627, of even date herewith.
What I claim is-
4. The combination, with the two vibrating
circuit-controllers, one for regulating the gen-
eration of current, the other for controlling the 45
supply of current to the first, of the spark-ar-
resting shunt around the first circuit-controller,
substantially as set forth.
5. The combination, with an electro-magnet
1. The combination, with a dynamo or mag-placed in a multiple-arc circuit from a dynamo 50
neto electric machine, of a circuit-controller or magneto electric machine, and a vibrating
operated by the current generated for regulat- circuit-controller operated thereby and placed
20 ing the generation of current by the machine, in the field circuit of the machine, of an elec-
and a second circuit-controller, also operated tro-magnet placed in the same or another mul-
by the current generated for controlling or as- tiple-arc circuit, and a vibrating circuit-con- 55
sisting in controlling the current operating the troller for controlling the current energizing
first circuit-controller, as desired, substan- the first-mentioned electro-magnet, placed in
25 tially as set forth.
the circuit of said first-mentioned magnet or
in a shunt around the same, substantially as ·
set forth.
This specification signed and witnessed this
28th day of February, 1882.
2. The combination, with a dynamo or mag.
neto electric machine, of a vibrating circuit-
controller adapted to make and break circuit
at several points simultaneously, and another
30 vibrating circuit-controller for controlling or
assisting in controlling the current operating
the first circuit-controller, substantially as set
forth.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
THOMAS JOHNSTON.
60'
2760
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No 264 660
А
WITNESSES:
D. DD. Mott
Phomas E. Birch.
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2761
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,660, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Means for Regulating
the Generative Capacity of Dynamo or Mag-
neto Electric Machines, (Case No. 375;) and
I do hereby declare that the following is a
full and exact description of the same, refer-
10 erence being had to the accompanying draw-
ings, and to the letters of reference marked
thereon.
My invention relates to means for automat-
ically varying the resistance of the field-cir-
15 cuit of a dynamo or magneto electric machine
for the purpose of regulating the generation
of current by the machine, the object I have
in view being to produce a continuously-act-
ing mechanism for this purpose, and one in |
20 which the increase or decrease of resistance
is not limited by the movement (necessarily
small) of the armatures of electro-magnets,
and which mechanism, further, will be efficient
in operation, will maintain the lamps at a
25 practically-constant candle-power, and pre-
vent the light from flickering.
1
taining an electro-magnet and a resistance for
turning current into the shunt. The pivoted 55
spring-armature of this magnet forms a part
of the shunt-circuit, and its free end is placed
between contact-points. A pivoted spring-
arm is also placed between these contact-
points in such manner that the forward move- 60
ment of the armature-forces is against one of
them and completes one of the divisions of the
shunt-circuit, while the armature, when drawn
back a sufficient distance, strikes the other
contact-point and completes the other divis- 65
ion. Normally, however, the armature and
spring-arm are held by the resilience of their
springs and by a properly-placed stop mid-
way between the contact-points, and either
circuit is completed only by an increase or 70
decrease in the force of the electro-magnet.
When too much current is in the main circuit
it is desirable to decrease the generative ca-
pacity of the machine by placing more resist-
ance in the field-circuit. The magnet in 75
the multiple - arc circuit of course has its
energy increased by the excessive quantity
of current in the main line, and attracts
its armature, which pushes the spring-arm
Generally speaking, my arrangement is as against a contact-point, thus closing a di- 80
follows: In the field-circuit of a dynamo-ma vision of the shunt, including one of the first-
chine is placed a circular adjustable resist- mentioned electro-magnets, whose vibrating
30 ance, having its contact-points arranged in- armature is set in motion, moving the pawl
side, portions of the resistance being cut in and turning the ratchet-wheel and contact-arm
and out by a contact-arm forming part of the in such a direction that more resistance is 85
circuit and pivoted in the center of the resist-placed in the field-circuit. The current in the
ance. The contact-arm is turned by ratchet- main circuit then decreases, and the magnet
35 wheels, one adapted to be moved by a pawl in the multiple-arc circuit weakens in power
in one direction, the other by another pawl in until the armature is drawn away by the
the opposite direction, so that resistance is spring and the circuit of the electro-magnet 90
placed in or thrown out of circuit as one or which actuates the contact-arm is broken; but
the other pawl is in operation. Each of these if the current is very much decreased, so that
40 pawls is moved by the vibrating armature of it becomes necessary to throw out resistance,
an electro-magnet. To effect the make and the first armature-lever is drawn back by its
break of circuit which causes the vibration of spring and closes the other division of the 95
the armature, one end of the latter extends shunt-circuit through the other electro-mag-
between the sides of a pivoted U-shaped piece, net, whose pawl-arm turns the contact-arm in
45 which is driven by the movement of the arma- the opposite direction and throws out a por-
ture in one direction to complete the circuit tion of the resistance.
and in the other direction to break it, the U- The controlling electro-magnet of the mech- 100
piece being weighted, so that its motion is as-anism, as before explained, is placed in a mul-
sisted by gravity; or a spring may be used for tiple-arc circuit. In this location it is effected,
50 this purpose. Each of the electro-magnets exactly as is a lamp, by variations caused by
operating these vibrating armatures is placed changes in the number of translating devices
in a circuit which is a division of a shunt-cir- and in the speed of the engine. To prevent 105
cuit from a multiple-arc circuit, the last con- the light from flickering it is necessary to pro-
|
2762
2.
264,660
vide means for determining the central posi- | wheel r and turns the contact-arm a, so that
tion of the armature-lever of the controlling it places more of the resistance B in the cir-
electro-magnet. This is done by the spring-cuit 3 4. A similar arrangement is placed on 70
arm, against which the armature-lever strikes, the opposite side of the resistance, F' being
5 the armature-lever bearing normally against the magnet, G' its armature, k' the U-shaped
this arm with such pressure that it is not af- circuit-reverser, and H' the pawl actuating
fected by small magnetic changes. The two
The two the ratchet-wheel r', so that the contact-arm a
magnets, vibrating armature-levers, and cir- is turned in the opposite direction and cuts 75
cuit-controllers for working the contact-arm of out instead of putting in resistance.
Io the resistance form two electro-moters, which
act oppositely upon the resistance, and are
brought into action separately by the control-
ling-magnet.
The accompanying drawing is a diagram
15 showing an appropriate manner of carrying
out my invention.
A is a dynamo-electric machine, from which
lead the main conductors 1 2 of a multiple-arc
system.
20 3 4 is a multiple-arc circuit, including the
field-magnets of the dynamo. The wire 4 in-
cludes the circular adjustable resistance B,
while the wire 3 terminates in a pivoted con-
tact-arm, a, adapted to make contact with the
25 points bb of the resistance B.
35
56 is another multiple-arc circuit, including
an electro-magnet, C, and a resistance, D.
Around the latter is formed a shunt-circuit, 7
8, which is divided into two circuits 9 x c and
30 9 x'd, cand a being contact-points. Either or
both of the wires 7 8 may, if desired, be made
adjustable, so that they may be connected with
different parts of the resistance D, and thus
shunt more or less current into the circuit 7 8.
The magnet Cis provided with an armature,
E, pivoted at e and forming part of the cir-
cuit 78. At its free end it is provided with two
contact-points, one on each side. The arma-
ture has also a spring, f, whose tendency is to
40 withdraw it from the magnet C. A pivoted
spring-arm, g, is so placed that normally it is
midway between c and d, but may be pressed
over by the armature, so as to contact with c
and close the circuit 9 x c. When the press-
45 ure is removed the circuit is broken until the
magnet becomes so weak that the armature is
drawn back against d and closes the circuit 9
x'd. The spring-arm g determines the central
position of the armature-lever E, as before ex-
50 plained, and prevents the lever E from being
vibrated by small magnetic changes in C.
The circuit 9c includes a magnet, F, having
an armature, G, pivoted at h, and having a
spring, i. The lower end of the armature en-
55 ters between the sides of the U-shaped metal
piece k, which is pivoted at 7 and placed be-
tween stops m n. The wire x is attached at
and the wire 9 to the stop n, so that when k is
thrown against n the circuit 9 x c is closed at
60 this point and when it is thrown against m
the circuit 9 x c is opened. A ball or weight,
o, assists the motion of the piece k. Thus the
movement of the armature G causes the make
and break of the circuit, and the armature is
65 made to vibrate. At the other end of the ar-
mature G is pivoted a pawl, H, which, when
the armature G vibrates, moves the ratchet-
It is evident that this invention is applica-
ble to magneto-electric machines as well as to
dynamos, and to a battery as well as to a sin-
gle machine.
What I claim is—
80
1. The combination, with a dynamo or mag-
neto electric machine and translating devices
arranged in multiple arc, of an adjustable re-
sistance in the field-circuit of such machine, 85
an electrically-operated mechanism for ad-
justing said resistance, and an electro-magnet
located in a multiple-are circuit and con-
trolling such electrically-operated mechan-
ism, substantially as set forth.
90
2. The combination, with a dynamo or mag-
neto electric machine and translating devices
arranged in multiple-arc, of a mechanism for
regulating such machine, an electro-magnet
located in a multiple arc circuit, and closing- 95
circuits at the contacts of its armature-lever
for controlling such regulating mechanism,
and means for determining the central posi-
tion of the armature-lever of said controlling
electro-magnet, substantially as set forth.
100
s. The combination, with a dynamo or mag-
neto electric mechine and translating devices
arranged in multiple arc, of an adjustable re-
sistance in the field-circuit of such machine, a
mechanism for adjusting such resistance, an 105
electro-magnet located in a multiple-arc cir-
cuit and controlling such adjusting mechan-
ism by closing-circuits at the contact of its
armature-lever, and means for determining the
central position of the armature-lever of said 110
controlling electro-magnet, substantially as
set forth.
4. The combination, with an electro-magnet
energized by the current generated by a dy-
namo or magneto electric machine or battery 115
thereof, of an armature-lever adapted to close
by its forward and backward movement the
branches of a divided shunt, which contain
mechanism for varying the resistance of the
field-circuit of the generator, substantially as 120
set forth.
5. The combination, with a multiple-arc cir-
cuit, of a divided shunt therefrom, each divis-
ion containing an electro-magnet provided
with a vibrating armature, said vibrating ar- 125
mature being adapted to operate a pawl and
a ratchet-wheel, substantially as set forth.
This specification signed and witnessed this
5th day of December, 1881.
Witnesses:
T. A. EDISON.
H. W. SEELY,
WM. H. MEADOWCROFT.
2763
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 1.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,661.
Patented Sept. 19. 1882.
Fig. 1
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Thomas & Birch
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INVENTOR:
J.A. Edison
Rich.
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ATTORNEY
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BY
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
2764
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 2.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,661.
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Patented Sept. 19, 1882.
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WITNESSES:
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Thomas E. Birch.
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BY
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
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INVENTOR:
J. A. Edison
Rich M. Dyer.
ATTORNEY
2765
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 3
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,661.
Patented Sept. 19,. 1882.
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D. D. Mott
Murderly
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INVENTOR:
J. A. Edison
BY
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
Rich M. Dyer.
ATTORNEY.
2766
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,661, dated September 19, 1882,
Application filed August 7, 1882. (No model.)
To all whom it may concern:
which cause variations in the current produced;
Be it known that I, THOMAS A. EDISON, of but when such maguets are in a shunt or in the
Menlo Park, in the county of Middlesex and main line this is not the case, and I therefore
State of New Jersey, have invented a new and provide other means for this purpose. A mag- 55
5 useful Improvement in Regulating the Gener- net or magnets are placed in one or more mul-
ative Capacity of Dynamo or Magneto Elec-tiple-arc circuits from the mains. Each mag-
tric Machines, (Case No. 399;) and I do hereby net is provided with an armature-lever re-
declare that the following is a full and exact tracted by a spring and provided with contact-
description of the same, reference being had points, so that when attracted by its magnet 60
Lo to the accompanying drawings, and to the let the armature will close a circuit whose closure
ters of reference marked thereon.
causes a decrease in the amount of current
flowing through the magnets which control
the field of force of the generator. Such cir
cuit brings a shunt around the resistance, which 65
turns current into the shunt containing the
last-mentioned magnets, or a new branch of
the main line passing around said magnets..
Thus, if a sudden increase of speed in the en-
gine causes an unusual flow of current, the mag- 70
net in the multiple-arc circuit causes less cur-
rent to flow through those in the shunt, whose
energy, being diminished, will cause a decrease
in the current energizing the field-magnet of
the generator, as before set forth.
of different forms thereof.
75
The object of this invention is to produce
new and efficient means for varying the cur-
rent energizing the field-magnet of a dynamo
15 or magneto electric machine supplying a mul-
tiple - arc system of electric distribution for
the purpose of regulating the generation of
current by such machine. This I accomplish,
first, by the use of several electro-magnets,
20 each provided with an armature-lever, the re-
lation between each armature-lever and its
magnet being different from that of the others-
that is, different currents being required to en-
ergize each magnet sufficiently to cause it to
25 move its armature—this being accomplished The invention may be better understood by
by employing, in connection with the armature, reference to the accompanying drawings, Fig-
different springs or weights by different wind-ures 1, 2, 3, 4, and 5 being diagrammatic views
ings of the various magnets, by varying the
normal distances between the magnets and their
30 armatures, or in any other suitable manner.
The energy of these magnets is varied by va-
riations in the current flowing in the main cir-
cuit from the dynamo or magneto electric ma-
chine, caused by the addition or removal of
35 lamps or other translating devices in the sys-
tem. The movements of the armatures above
mentioned cause the opening and closing of
circuits, the closure of each of which causes
a greater amount of current to flow through
40 the field-magnet of the generator. The elec-
tro-magnets may be placed directly in the main
circuit of the generator, or in multiple-arc or
derived circuits, or iu a shunt-circuit therefrom,
the circuits and contact-points connected with
45 their armatures being arranged differently, ac-
cording to the different conditions arising from
the different positions in which the magnets
are placed. When the magnets are placed in
multiple-arc circuits from the mains their ac-
50 tion compensates also for differences in the
speed of the engine actuating the generator,
In Fig. 1 electro-magnets A B C are placed 80
in a shunt, 3 4, around the resistance R from
the main conductor 2, which leads from the
dynamo-electric machine D.
|
5 6 is the field-circuit of such machine, and
contains a series of resistances, E E E². The 85
field-circuit is here shown as a multiple-arc cir-
cuit from the main line; but it is evident that
it may be a circuit supplied from an exterual
source, such as another dynamo or magneto
electric machine or a battery.
90
A shunt-circuit, a b, is formed around each
of the resistances E E' E2, a portion of each
shunt being formed by one of the armature-
levers ccc² of the magnets E E' E². These
pivoted armatures are provided with springs 95
d d' d², which differ in tension.
When only a few lamps or other translating
devices, e e, are placed in multiple-arc circuits
on the main line, all the resistances E E' E² may
be in the field-circuit 5 6. As more lamps are 100
turned on a greater electro-motive force is
produced in the shunt-circuit in consequence
1
2767
2
264,661
|
of the decrease in resistance of the main line. | ances E are closed by the making of the back
Therefore the armature c, which has the weak contacts instead of their forward ones. With
est spring, is attracted by the magnet A and this exception the operation is similar to those
closes the shunt a b' around the resistance E, previously described. Instead of closing shunt- 70
5. thus cutting the latter out of circuit and al- circuits around resistances in the field-circuit,
lowing more current to pass through the field- the magnets A B C may be used to close ad-
magnet of the generator, so that enough cur- ditional circuits around the field-magnet, which
rent is supplied for the additional translating is wound in bobbins or sections of wire, each
devices. A still further addition to the num- of which forms part of a circuit, including one 75
10 ber of the last causes the successive drawing of the pivoted armature-levers c c c.
forward of the armature c' c² and the throwing
out of the resistances E' E2. It is evident that
any desired number of electro-magnets, arma-
tures, and resistances may be used.
15 M is another electro-magnet, placed in a
multiple-arc circuit, m m, aud provided with a
pivoted armature, l, which forms part of a shunt-
circuit, N N, around the resistance R. A sud-
den increase of current, caused by an increase
20 in the speed of the engine or by any unusual
cause, increases the energy of the maguet M,
which draws forward its armature l and com-
pletes the circuit 3 n, which, by opening a new
path for the current, causes a less portion of
25 it to pass through the magnets A B C, so that
their energy is decreased, and the resistances E
E' E² are successively placed in the field-cir-
cuit as desired.
A resistance, r, may be placed in the circuit
30 N N, so that it shall not take too large a por-
tion of the current. It is evident that any de-
sired number of magnets M and circuits N N
of different resistances may be provided, in
order that successive paths may be opened for
35 the current, and that in the circuit 3 4 be grad-
ually diminished. In the form shown in Fig.
2 the magnets A B C are all placed directly in
the main line in multiple-arc relation to each
other.
40
Another similar branch of the maiu con-
ductor contains a resistance, R', and the ar-
mature-leverl of the electro-magnet M, the lat-
ter being in a multiple-arc circuit, m m, from
the main line. The successive drawing for
45 ward of the armatures c c'e² cuts out the re-
sistances E E' E2 from the field-circuit 5 6 of
the generator D. An increase of current in
the multiple-arc circuit m m, caused not by the
condition of the translating devices, but by an
50 increase in the speed of the motor driving the
armature of the generator, causes an increase
in the attractive force of the magnet M, which,
by drawing forward its pivoted armature-1,
completes the circuit containing the resistance
55 R, and thus by a further division of the cur-
rent that flowing through the magnets A B
C is lessened, and the resistances E E' E2 are
placed in circuit. It is evident in this case as
well as in the preceding that the number of
60 magnets M and of different paths for the cur
rent may be increased as desired.
In Fig. 3 the magnets A B C are placed in
a multiple-arc, circuit, 7 S. Being in a multi-
ple-arc circuit, such magnets are weakened by
65 the addition of translating devices e e, and
therefore the shunt-circuits ab around resist-
C
In Fig. 4 the magnets are placed in the shunt-
circuit 3 4 around resistance R. While here
shown, for convenience, as in multiple are
across the wires of the shunt, it is evident that 80
they may be placed as in Fig. 1. The pres-
ent arrangement of the magnets is similar to
that in Fig. 2. Instead of springs of different
tensions, the armatures cc' c² are here provided
with different weights f. A field-circuit of a 85
constant high resistance, 9 10, is used to pri-
marily energize the field-magnet of the gen-
erator D. This circuit may, if desired, be sup-
plied from any external source instead of from
the machine itself. The attraction of the arma- 90
ture c by the magnet A causes the closure of
the circuit 9g; that of the armature c' causes
the closure of 9 h, while 9 i is closed by the
attraction of the armature c². It is evident
that g, h, and i might be connected directly to 95
the conductor 2 instead of reaching it through
a wire, l. In this case, also, a maguet, M,
k.
in
a derived circuit, m m, is used to close a shunt-
circuit around the resistance R.
•
The form shown in Fig. 5 is similar to the 100
preceding, except that now the magnets A B C
are placed in a multiple-arc circuit, 7 8, and
the circuits through the field are completed
through the back instead of the front contacts
of the armature, as before explained.
What I claim is-
105
1. The combination, with a dynamo or mag-
neto electric machine and translating devices
arranged in multiple-arc circuits therefrom, of a.
series of independent devices operated by the 110
current generated and arranged to act succes-
sively as more translating devices are placed
in circuit to increase the current energizing
the field-magnet of the generator, substantially
as set forth.
115
2. The combination, with a dynamo or mag-
neto electric machine and translating devices
arranged in multiple-arc circuits therefrom, of a
series of electro-magnets energized by the cur-
rent generated and arranged to operate suc- 120
cessively as more translating devices are placed
in circuit to close circuits, whereby the current
energizing the field-maguet of the generator
is increased, substantially as set forth.
3. The combination, with a dynamo or mag- 125
neto electric machine and translating devices
arranged in multiple-arc circuits therefrom, of a
series of electro-magnets energized by the cur-
rent generated, and each provided with a piv-
oted armature-lever, the relation between each· 130
magnet and its armature differing from that
of each other magnet and armature, as ex-
2768
264,661
plained, and circuits, as described, the move-
ment of each armature opening or closing a
circuit whose closure increases the current en-
ergizing the field-magnet of the generator,
5 substantially as set forth.
|
3.
4. The combination, with a dynamo or mag.
neto electric machine and translating devices
arranged in multiple-arc circuits therefrom, of a
series of electro-magnets energized by the cur-
10 rent generated, and armature therefor, different
amounts of current being required to cause each
magnet to attract its armature, and circuits
and resistances, as described, the movement
of each armature causing the throwing of a
15 resistance in or out of the field-circuit, sub-field magnet of a dynamo-electric machine
stantially as set forth.
·
45
arranged in multiple-arc circuits therefrom, of a
number of electro-magnets placed in divisions
of the main line or in a shunt therefrom, and 35
arranged to act successively as more trans-
lating devices are placed in circuit to increase
the current energizing the field-magnet of the
generator, and an electro-magnet placed in a
multiple-arc circuit from the main line, aud 40
arranged to act upon an increase of the cur-
rent generated to close circuits which shall
draw off a portion of the current energizing
the magnets in the shunt-circuit or divisions
of the main line, substantially as set forth,
7. The combination of the following: the
placed in a multiple-arc circuit, the armature.
5. The combination, with a dynamo or mag- of said machine placed in another multiple-
neto electric machine and translating devices arc circuit, lamps or other translating devices 50
arranged in multiple-arc circuits therefrom, of a placed in other multiple-arc circuits, (all such
20 series of devices operated by the current gen- multiple-arc circuits being derived from the
erated, and arranged to act successively as same main conductors,) and a series of inde-
more translating devices are placed in circuit pendent devices operated by the current geu-
to increase the current energizing the field-erated, and arranged to act successively as 55
magnet of the generator, and a device or series
25 of devices, also operated by the current gener-
ated, and arranged to act upon an increase of
said current to decrease the current affecting
the first-mentioned series of devices, thereby
decreasing the current in the field-circuit of
30 the generator, substantially as set forth.
6. The combination, with a dynamo or mag
neto electric machine and translating devices
more translating devices are placed in circuit
to increase the current energizing the said
field-magnet, substantially as set forth.
This specification signed and witnessed this
10th day of February, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
WM. H. MEADOWCROFT.
2769
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,662.
5.
B
WITNESSES:
E. C. Rowland
F. W. Howard
3.
A.
Oa
a.
-0°
Оа
a.
Oa
о
Oa
Oa
Patented Sept. 19, 1882.
4.
N. PETERS, Photo-Lithographer. Washington, D. C.
B.
2.
6.
INVENTOR:
J. A Edison
BY
Rich H. Dyer.
ATTORNEY.
2770
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION 'forming part of Letters Patent No. 264,662, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in the Regulation of Dy.
namoor Magneto Electric Machines, (Case No.
410;) and I do hereby declare that the follow-
ing is a full and exact description of the same,
reference being had to the accompanying draw-
Io ing, and to the letters of reference marked
thereon.
The object of my invention is to produce
simple and efficient means for regulating the
generation of current by a dynamo or mag.
15 neto electric machine supplying a multiple-arc
system of electrical distribution, according to
variations in the number of translating devices
in circuit in such system; and my invention
consists in winding the field-magnet of the
20 machine in two separate portions, the direc-
tion of the winding in one portion being the
reverse of that in the other, so that the two
parts of the magnet will oppose each other in
their attractive energy. The main portion of
25 the wire is included in the field-circuit, which
is preferably a multiple-arc circuit from the
main conductors of the machine, or which may
be supplied from any suitable external source.
The oppositely-wound portion is included in
30 another multiple-arc circuit derived from the
main conductors. When only-a few translat-
ing devices are in circuit in the system a
large amount of current will pass in this sec-
ond multiple-arc circuit, which, by opposing
35 the inductive action of the rest of the magnet,
allows the generation of only a small amount
of current; but as more translating devices
are brought into action the current through
the reversed coils decreases, and this portion
40 of the magnet becoming less powerful the gen-
eration of current increases.
The drawing is a diagram illustrating my
invention.
A is the field-magnet of a dynamo-electric
45 machine, each limb of which is wound in two
bobbius or sections, B C, the section B being
wound in one direction and the section C in
the opposite one.
1 2 are the main conductors leading from
the machine, and having multiple-arc circuits 50
derived from them, in which are placed lamps
or other translating devices, a a.
A derived circuit, 3 4, includes the portions
B B of the field-magnet coils, and a derived
circuit, 5 6, the portions C C, the latter start- 55
ing from a point beyond the translating de-
vices.
The operation of these circuits is as before
explained.
What I claim is-
бо
1. A dynamo or magneto electric machine
having a small portion of its field-magnet so
wound as to oppose the actiou of the main por-
tion, in combination with means for varying
the current passing in said smaller portion ac- 65
cording to the number of translating devices
in circuit, whereby the generative capacity of
the machine is regulated, substantially as set
forth.
2. The combination, with a dynamo or mag. 70
neto electric machine and translating devices
arranged in multiple arc, of a multiple-arc
circuit from said machine, including a portion
of the coils of its field-magnet, such portion
being arranged to have a circuit in a direction 75
opposite to that of the coils included in the
primary field-circuit, substantially as and for
the purpose set forth.
3. The combination, with a dynamo or mag-
neto electric machine and translating devices 80
arranged in multiple arc, of a multiple-arc cir-
cuit iucluding the main portion of its field-
maguet coils and another multiple-arc circuit
including the remaining portion, these two
portions being arranged to have their currents 85
in opposite directions, substantially as and for
the purpose set forth.
This specification signed and witnessed this
1st day of May, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
P. B. WILBer.
2771
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,663.
Patented Sept. 19, 1882.
A
WITNESSES:
7.
E. C. Kowland
J. W. Howard
a.
R.
24
2:
17. B.
2.
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
d.
یشه
5.
B.
1-8
dy
གཟ
B.. d.
INVENTOR:
J. A. Edison
BY Rich? It. Oyer
ATTORNEY.
2772
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,663, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
by reference to the annexed drawing, which il- 50
lustrates my invention diagrammatically.
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and A is the field-magnet of a dynamo-electric
State of New Jersey, have invented a new and machine, energized by the derived circuit 3 4
5 useful Improvement in the Regulation of Dy- from the main conductors 12. On these main
namo or Magneto Electric Machines, (Case No. conductors electric lamps or other translating 55
411;) and I do hereby declare that the follow-devices, a a, are placed in multiple arc. A re-
ing is a full and exact description of the same, sistance, R, is placed in the main conductor
reference being had to the accompanying draw-2, around which is formed a shunt,5 6. In mul-
10 ing, and to the letters of reference marked
thereon.
tiple-arc circuits across this shunt are placed
electro-magnets B B B, each having an arma- 60
ture, d, retracted by a spring, c, the springs
differing in tension. Each armature is included
in a shuut-circuit, 7 8, around a resistance, r,
in the main line. As more and more translat-
ing devices are placed in circuit the armatures 65
d are successively drawn forward by the in-
creased energy of their magnets B, and the re-
sistances are successively thrown out of
circuit. A reverse operation takes place as
the number of translating devices is decreased. 70
What I claim is—
The object of this invention is to produce
means for regulating the generation of current
by a dynamo or magneto electric machine by
15 automatically varying the resistance of the
main circuit leading therefrom, according to
variations in the number of translating devices
in circuit in the multiple-arc system supplied
by the machine. To do this I place in one or
20 both of the main conductors a series of resist-
ances, around each of which is formed a shunt-
circuit, a portion of which is formed by a piv-
oted armature-lever. Each of these armature- 1. The combination, with a dynamo or mag-
levers is actuated by an electro-magnet, and neto electric machine and translating devices
25 these electro-magnets are preferably placed in arranged in multiple arc, of a series of resist-
multiple arc across a shunt-circuit around an- ances in the main circuit from said generator 75
other resistance in the main line, though they and a number of independent devices actuated
might be placed in series in such shunt. The by the current generated, for successively
armature-levers are retracted by springs, the throwing such resistances into or out of circuit,
30 springs of the different levers varying in according to variations in the number of said
strength; or other means may be provided translating devices, substantially as set forth. 80
whereby different amounts of current will be 2. The combination, with a dynamo or mag-
required to cause each magnet to attract its neto electric machine and translating devices
armature, such as placing each armature at a arranged in multiple are, of a series of resist
35 different distance from its magnet, winding the ances in the main circuit and a series of elec-
magnets in different ways, &c. The forward tro-magnets in a shunt from said main circuit, 85
movement of an armature closes the shunt-each magnet being provided with an armaturo-
circuit in which it is placed, and so cuts out lever, the motion of which opens and closes a
of circuit one of the resistances in the main shunt around one of the said resistances im
40 line. When the number of translating devices the main line, and the armatures being so ar-
in circuit is increased the current in the shunt- ranged as to operate successively, substan- 90
circuit, which contains the magnets, becomes tially as set forth.
greater, and one or more of the magnets at-
tracts its armature, which, being drawu for-
45 ward against a contact-point, short-circuits a
resistance in the main line, and thereby allows
a greater amount of current to pass from the
machine to the translating devices- supplied
thereby. This may be better comprehended
This specification signed and witnessed this
1st day of May, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
P. B. WILBER.
•
2773
Patented Sept. 19, 1882.
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,664.
9
&
7
4
9
WITNESSES:
D. D. Mott
Thomas E. Birch,
x
L
6
7
2 (
9
2
N. PETERS, Photo-Lithographer, Washington, D. C.
5
5
L
INVENTOR:
I.A. Edison
Rich. A. Dyer,
ATTORNEY.
BY
2774
UNITED STATES PATENT OFFICE.
5
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,664, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new
and useful Improvement in Regulating the
Generative Capacity of Dynamo or Magneto
Electric Machines, (Case No. 393;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
To had to the accompanying drawing, and to the
letters of reference marked thereon.
The object I have in view is to produce sim-
ple and efficient means for regulating the gen-
erative capacity of a dynamo or magneto elec-
15 tric machine, which will be wholly dependent
upon and controlled by the throwing in and
out of the translating devices, arranged in
multiple-arc or derived circuits, without the use
of actuating mechanism other than the usual
20 circuit-controllers at the individual translating
devices.
►
This invention is an improvement upon that
described in my Patent No. 248,422, in which
only part of the current furnished the lamps
25 passes through the circuit of the field-magnet,
and circuit-controllers, in addition to the usual
ones at the individual translating devices, are
employed to make and break separate field-cir-
cuits.
30
In carrying out the present invention one of
the main conductors is divided into a number
of parts, each of which parts is connected with
bobbins on the limbs of the field-magnet be-
tween the commutator-brush and the lamp-
35 circuits. Between each part of the divided
conductor and the undivided main conductor
is located one set of conductors in multiple-
arc or derived circuits, from which last con-
ductors the lamps or other translating devices
40 are arranged; but a number of such sets of
conductors may be connected with each part
of the divided main conductor; or the sepa-
rate lamp-circuits may be connected directly
with each part of such divided main conductor.
45 In addition to the bobbins spoken of, a portion
of the field-magnet is wound with wire, which
forms part of a field circuit, which has such re-
sistance produced by the winding itself or by
extra resistance as to supply only a small |
50 amount of current, enough to primarily ener-
gize the magnets. This circuit is preferably a
derived or multiple-arc circuit from the main
conductors; but it may be one supplied from
a battery, a dynamo or magneto electric ma-
chine, or other external source.
When the 55.
multiple-arc circuits of part or all of the trans-
lating devices connected with any division of
the main conductor are closed by the usual
circuit-controllers the current flowing through
them will also flow through the bobbins of the 60
field-magnet connected with the particular di-
vision of the main conductor, and the energy
of the field-magnet will be increased in direct
proportion to the number of translating de-
vices in circuit, and as the other divisions are 65
closed by the addition of other lamps or groups
of lamps the field-magnet becomes more and
more energized, increasing to the desired ex-
tent the electro-motive force of the machine.
This may be better understood by reference to 70
the drawing, which is a diagrammatic view of
a dynamo-electric machine with its circuits.
A is the field-magnet of the machine, and 1
2 are the main conductors leading therefrom.
3 4 is the field-circuit of constant resistance. 75
At the point a the main conductor 2 is divided
into a number of conductors, 55, each of which
includes a portion of the coils of the field-mag-
net A. From each of the circuits 1 5 a circuit,
6 7, is derived, on which translating devices b 89
b, having the usual circuit-controllers, c, are
placed in multiple arc.
It is evident that as fast as more translat
ing devices or groups thereof are placed in cir 85
cuit the current will pass through a greater
portion of the coils of the field-maguet, and the
latter will therefore be more and more ener-
gized.
I do not claim broadly the combination,
with a multiple-arc system of electric lighting, 90
of a portion of the coils of the field-magnet
formed by one of the main conductors, as this
forms the subject-matter of a claim in applica-
tion No. 68,621 of even date herewith.
What I claim is-
95
1. The combination, with a dynamo or mag-
neto electric machine, of a divided main con-
ductor therefrom, each division of which in-
cludes a portion of the coils of the field-mag-
net of the machine, and forms, with the other 100
main conductor, a circuit ou which translating
devices are placed in multiple arc, substan-
tially as set forth.
2. The combination, with a multiple-arc cir
2775
2
264.664
cuit of constant resistance from the main con-
ductors of a dynamo or magneto electric ma
chine for primarily energizing the field-magnet
of such machine, of the divisions of one of such
5 main conductors, each including a portion of
the coils of said field-magnet for increasing the
strength of the same, substantially as set forth.
3. The combination of a multiple-arc circuit
containing a portion of the coils of the field-
10 maguet of a dynamo-electric machine, a mul-
tiple-arc circuit containing the armature of
said machine, multiple-arc circuits containing
|
groups of translating devices, (all such mul.
tiple-arc circuits being derived from the same
main conductors,) and a portion of the coils I
of the field-magnet formed by divisions of one
of such main conductors, substantially as set
forth.
This specification signed and witnessed this
10th day of February, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
WM. H. MEADOWCROFT.
2776
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,665.
о
о
С
a.
4.
Patented Sept. 19, 1882.
A.
d
13.
B.
c.
2
WITNESSES:
E. C. Kouland
H. W. Howard
N PETERS, Photo-Lithographer, Washington, D. C.
E.
-0
F
INVENTOR:
J. A. Edison
BY lich? A. Dyer.
ATTORNEY.
2777
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,665, dated September 19, 1852.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in the Regulation of Dy.
namo or Magneto Electric Machines, (Case No.
414;) and I do hereby declare that the follow-
ing is a full and exact description of the same,
reference being had to the accompanying draw-
ro ing, and to the letters of reference marked
thereon.
lating material. The adjustable resistance F
is connected in the field-circuit of the machine,
as shown, so that when an arm, f, is in contact
with its stop g the corresponding portion of the 55
resistance is short-circuited.
Directly in the main circuit 1 2 is placed an
electro-magnet, E, the poles of which are op-
posite the arm D, so that it will attract said
arm when sufficiently energized, and thus allow 60
the.contact-levers ff to make contact with the
points gg. Normally-that is, when few lamps
The object of this invention is to produce a a are in circuit and the engine is running at
regulating apparatus for dynamo and mag- its proper speed-a portion of the resistance.
neto electric machines which shall regulate Fisin circuit, as shown in the drawing. Should 65
15 the generation of current either for variations this small number of lamps be still further re-
in the number of trauslating devices in circuit duced, the magnet E will weaken and release
from the machine or for variations in the speed the arm D, so as to open circuit at more of the
of the steam-engine or other motor used to ro- points g and throw more of the resistance F
tate the armature of the machine. Such ap- into the field circuit; or should the speed of 70
20 paratus consists, generally speaking, of an ad- the engine suddenly increase from any cause
justable resistance in the field-circuit of the the same effect would be produced, the drawing
machine and a movable arm, by means of which up of the governor-balls pulling forward the arm
portions of such resistance are placed in or D. Should, however, the number of translat-
taken out of circuit, the means for moving such ing devices in circuit be increased, the energy of 75
25 arm being, first, a centrifugal governor at- the magnet E will also become greater, and
tached to and operated by any moving part of the arm D will be drawn back, closing one or
the generating apparatus, thus regulating for more circuits at g around portions of the re-
variations of speed; and, second, an electro- sistance F and properly increasing the energy
magnet placed directly in the main circuit of the field-maguet. The same effect is pro- 80
30 from the generator, or else in a shunt there- duced by a decrease in the speed of the engine
from, and in such position as to attract the actuating the armature, the governor C push-
movable arm when sufficiently energized. ing the arm D back, so as to close circuits
A convenient form of my invention is shown around portions of the resistance. It is evi-
diagrammatically in the accompanying draw-dent that the governor C could be run from 85
35 ing.
A is a dynamo-electric machine, from which
lead main conductors 1 2, having translating
devices a a arranged upon them in multiple
arc. The multiple-arc circuit 3 4 (shown in
40 dotted lines) is the field-circuit energizing, the
magnet of the machine.
45
On the armature-shaft B is mounted a pul-
ley, b, from which a belt, c, passes over the pul-
ley'd on the shaft of a centrifugal governor, C.
Attached to the governor C, and moved back
and forth by it, is an arm, D, whose lower end,
e, is opposite the free ends of the series of
spring-retracted contact-levers ff. These open
and close circuit at points g g, according as
50 they are thrown forward by the arm Dordrawn
back by their springs, h h being pins of insu-
the engine-shaft instead of from that of the ar-
mature, or, if desired, from any other moving
portion of the apparatus.
The circuit 3 4, instead of being a multiple-
arc circuit from the main, could be a shunt 90
therefrom, or a circuit supplied from another
dynamo-machiue or other suitable external
source.
The arrangement of resistances and contact-
arms could of course be varied in many ways, 95
if desired.
What I claim is-
1. The combination of a dynamo or magneto
electric machiue, an adjustable resistance in
its field-circuit, a movable arm for varying such 100
resistance, mechanical means connected with
and actuated by a moving portion of the ma-
:
2778
2
264,665
electric machine, an adjustable resistance in
its field-circuit, a movable arm for varying such
resistance, a centrifugal governor connected
chine or of the motor which drives it, for mov-
ing said arm to vary said resistance, and means
actuated by the current generated, also for
moving said arm to vary the resistance, sub-with and actuated by some moving portion of 20
5 stantially as set forth.
2. The combination of a dynaino or magneto
electric machine, an adjustable resistance in
its field-circuit, a movable arm for varying such
resistance, mechanical means connected with
10 and actuated by some moving portion of the
apparatus for moving said arm to vary the re-
sistance, and an electro-magnet in the main
circuit or in a shunt therefrom, also for moving
said arm to vary the resistance, substantially
15 as set forth.
3. The combination of a dynamo or magneto
the apparatus, and also connected with said
arm, so as to move it back and forth, and an
electro-magnet energized by the current gen-
erated, and also adapted to move said arm
back and forth, substantially as set forth.
This specification sigued and witnessed this
1st day of May, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
P. B. WILBER.
25
2779
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIO MACHINES.
No. 264,666..
Patented Sept. 19, 1882.
B.
A.
e.
a.
a.
A
G.
E
X
d
C.
3.
FAAAAA
c. c.
A
2.
1.
WITNESSES:
E. C. Kowland
F. W. Howard
e.
THE NORRIS PETERS CO., PHOTO-LITNO., WASHINGTON, D. C.
A.
INVENTOR:
J. A. Edison
BY Rich N. Dayer.
ATTORNEY
2780
UNITED STATES PATENT OFFICE.
5
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,666, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
useful Improvement in the Regulation of Dy-e
namo or Magneto Electric Machines, (Case No.
415;) and I do hereby declare that the follow-
ing is a full and exact description of the same,
reference being had to the accompanying draw-
10 ing, and to the letters of reference marked
thereon.
The object of my invention is to produce an
automatic regulating apparatus for dynamo
and magneto electric machines which shall act
15 on variations in the number of translating de-
vices in circuit from the machine, or in the
speed of the engine driving said machine, to
adjust the speed of rotation of the armature to
the point necessary to produce the generation
20 of current required. This I do by connecting
the pulley over which the belt from the engine
is placed to the armature shaft through a fric-
tion - clutch, the latter being adjustable by
means of an electro-magnet energized by the
25 current generated, so as to convey more or less
power to the armature-shaft, according to the
current required.
A convenient form of my invention is shown
in the drawing, which is a view of a regulating
30 apparatus in elevation, with the friction-clutch
shown in section and the circuits in diagram.
A is the armature-shaft of a dynamo or mag
neto electric machine, and B the commutator-
cylinder mounted thereon, the armature being
35 omitted for convenience in drawing. 12 are
the main conductors leading from the commu-
tator, and having translating devices a a placed
in multiple arc upon them.
C is an electro-magnet, so mounted near the
40 end of the armature-shaft A as to revolve there.
with. The conductor 2 is broken and formed
into contact-springs b b,which bear on the metal
collars cc, these being insulated from the shaft
A. From these metal collars a circuit, 34, runs,
45 which includes the magnet C, the latter being
thus placed directly in the main circuit 1 2. A
sleeve, d, is keyed also to the armature-shaft,
so that it revolves with it, but has a longitudi-
nal movement upon it, on which sleeve are
50 mounted the armature D of the magnet C and
•
55
the friction-clutch E. A spring, F, is secured
to the sleeve d, so that such sleeve is retracted
from the magnet by the spring. The friction-
clutch consists of arms carrying friction-shoes
e and united by a toggle or elbow joint, f.
G is the pulley over which the belt from the
engine which drives the armature passes. The
pulley G is sleeved to the shaft A so as to turn
loosely upon it, and motion is therefore com-
municated from the belt to the shaft only 60
through the friction-clutch, more or less power
being communicated, according to the position
of the friction-shoes within the pulley G.
The operation of this apparatus is as follows:
When more translating devices a a are placed 65
in circuit the increased current in the main line
causes an increase in the energy of the magnet
C, which attracts its armature D, and thus
throws the friction-shoes e e into greater con-
tact with the pulley G, thereby conveying more 70
power from the engine to the armature-shaft
and causing the latter to revolve with greater
rapidity, thus increasing the generation of cur-
rent to the desired degree. A decrease in the
number of translating devices in circuit causes 75
a decrease in the energy of the magnet C, the
spring F throws the armature back, and the
friction shoes e e are partly removed from con-
tact with the pulley. Should a sudden increase
occur from any cause in the speed of the en- 80
gine which drives the armature—an increase
too great to be taken up immediately by the
governor of the engine-the friction-shoes e e
will slip on the surface of the pulley, and the in-
crease will not be communicated to the arma- 85
ture-shaft. It is evident that other forms of
friction - clutch might be used, though that
shown is found most convenient for the purpose.
The magnet C might be placed in a shunt
from the main line, instead of directly therein, 90
with the same effect.
What I claim as my invention is-
1. In a dynamo or magneto electric machine,
the combination, with the armature-shaft and
a loose pulley mounted thereon, of a friction- 95
clutch for conveying motion from said pulley
to said shaft, and means actuated by the cur-
rent generated for moving such friction-clutch
so as to vary its contact with the pulley, sub-
stantially as set forth.
100
2781
2
264,666
2. In a dynamo or magneto electric machine,
the combination, with the armature-shaft and
a loose pulley mounted thereon, of a friction-
clutch for conveying motion from said pulley
5 to said shaft, and an electro-magnet in the maiu
line from the machine for moving such friction-
clutch so as to vary its contact with the pul-
ley, substantially as set forth.
3. The combination of the loose pulley on the
10 armature-shaft, the electro-magnet mounted on
said shaft and revolving with it, and the sleeve
keyed to said shaft and carrying the armature
of said electro-magnet, and the friction-clutch
making frictional contact with the inside of
said pulley, substantially as set forth.
15
This specification signed and witnessed this
1st day of May, 1882.
Witnesses:
H. W. SEELY,
P. B. WILBER.
THOS. A. EDISON.
2782
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,667.
Patented Sept. 19, 1882.
5
WITNESSES:
E.C. Rowlands
skelig
A
B
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2
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C
INVENTOR:
J. A. Edison
•
· BY Rich. A. Dyer.
ATTORNEY
2783
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,667, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern :
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Means for Regulating
Electrical Generators, (Case No. 425;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to the
10 letters of reference marked thereon.
This invention relates to means for regulat.
ing the generative capacity of a dynamo or
magneto electric machine by throwing into
the circuit of the field-maguet a variable and
15 controllable counter electro-motive force, and
is an improvement upon the special means for
this purpose described in my Patent No.
248,421.
The object I have in view is to produce a
20 simple and efficient mechanism operating upon
this principle which will regulate both for va-
riations in the speed of the engine and in the
number of translating devices. This I accom- |
plish by arranging a motor directly in the
25 field-circuit, and by regulating it or control-
ling its regulation by an electro-magnet ar-
ranged in multiple arc, so that it will be af-
fected both by variations in speed and in num-
ber of translating devices. A friction-brake
30 is arranged to bear upon a large wheel located
'directly on the shaft of the motor-armature or
on a shaft connected with such armature-shaft,
and having a higher rate of speed than the
armature-shaft. This friction-brake is forced
35 upon the wheel by a spring or weight, which
is made adjustable to give more or less press-
ure normally, so that the candle-power of the
lamps can be adjusted. The magnet arranged
in multiple arc from the main conductors of
40 the machine operates against the spring or
weight, and tends to relieve the pressure of
the brake and allow the motor to run with
greater speed and throw a greater counter
electro-motive force into the field - circuit,
45 thereby weakening the field-magnet. As the
magnet grows weaker it allows the spring or
weight to force the brake with greater press-
ure upon the wheel, reducing the speed of the
motor and the counter electro-motive force gen-
50 erated by it. The electro-magnet which op-
poses the action of the spring or weight of the
brake may be placed in a local circuit, as in a
shunt from the main line or from the field-cir-
cuit, and have its circuit closed and opened
by the armature of a controlling relay-magnet 55
placed in a multiple-arc circuit from the main
conductors. The electro-magnet in the mul-
tiple-arc circuit being affected in the same way
as are the lamps by changes in speed and in
number of lamps, the local circuit will be opened 60
and closed accordingly, and the regulation
will be efficient in all respects.
The foregoing will be better understood from
the drawing, which is a view, partly diagram-
matic, of apparatus embodying the invention. 65
A is a dynamo or magneto electric ma-
chine, from which run the main conductors 1
2 in multiple-arc circuits, from which are lo-
cated the lamps or other translating devices,
B. The field-circuit 3 4 of A is preferably a 70
multiple-arc circuit from 1 2, and in it is lo-
cated the electro-dynamic motor C. Upon the
armature-shaft of the motor is a large wheel,
D, upon which bears a pivoted brake-lever, E.
This lever, at its other end, carries an armature 75
attracted by an electro-magnet, F, located in
a multiple-arc circuit, 5 6, from the main con-
ductors 1 2. The brake-lever is lifted off of
the brake-wheel by the attraction of this elec
tro: magnet, the force of which is opposed by 80
a spring, G, made adjustable in its tension by
a nut, a, or other suitable means, so that the
candle-power of the lamps can be adjusted.
If the magnet F were in a local circuit con-
trolled by a relay-magnet. arranged in multi- 85
ple arc, as before explained, and as shown in
Fig. 2 of Case No. 68,628, of even date here-
with, the means for adjusting the candle-power
would be used in connection with the relay-
magnet.
What I claim is—
90
1. The combination, with a dynamo or mag-
neto electric machine, of an electromotor lo-
cated in the field-circuit and varying the
strength of the field-maguet by variations in 95
its counter electro-motive force, and an elec-
tro-magnet arranged in a multiple-arc circuit
from the conductors of the generator, for con-
trolling the speed of the motor, whereby the
generator will be regulated to meet changes in 100
speed, as well as the varying conditions of the
external circuit, substantially as set forth.
2784
2
264,667
2. The combination, with a dynamo or mag.
neto electric machine, of an electromotor lo-
cated in its field-circuit and adjustable means
for regulating or controlling the speed of such
5 motor, substantially as set forth.
3. The combination, with a dynamo or mag-
neto electric machine, of an electromotor lo-
cated in its field-circuit and a friction-brake
controlled by an electro-magnet for regulating |
10 the speed of such motor, substantially as set
forth.
4. The combination, with a dynamo or mag
neto electric machine, of an electromotor lo-
cated in its field-circuit, a friction-brake forced
by a spring or weight upon a wheel mounted 15
upon or connected with the motor-shaft, and
an electro-magnet opposing the action of such
spring or weight and located in a multiple-arc
circuit from the main conductors of the gen-
erator, substantially as set forth.
This specification signed and witnessed this
22d day of May, 1882.
Witnesses:
THOMAS A. EDISON.
EDUARD C. ROWLAND,
C. P. MOTT.
20
2785
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,668.
करी
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WITNESSES:
D. D. Mott
Thomas & Birch
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Patented Sept. 19, 1882.
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
INVENTOR:
J. A. Edison
BY Rich W. Dyer.
ATTORNEY.
2786
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,669, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
the energy of the magnet is lessened by the
decrease of current in the conductor 1.
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Regulating the Gener-matically by the throwing in and out of circuit
ative Capacity of Dynamo-Electric Machines,
(Case No. 398;) and I do hereby declare that
the following is a full and exact description of
the same, reference being had to the accom-
10 panying drawings, and to the letters of refer-
ence marked thereon.
It will thus be seen that the regulation of the 50
machine is accomplished instantly and auto-
The object of this invention is to produce
means by which the addition or removal of
translating devices in the multiple-arc circuits
15 of a system of electrical distribution shall cause
immediately a proper regulation of the current
energizing the field-magnet of the dynamo-
electric machine supplying such system, and
this without the use of adjustable resistances,
20 or of any, mechanism whatever, except the or-
dinary circuit-controllers of the lamps.
The drawing is a diagram illustrating views
of my invention.
A is a dynamo-electric machine, from which
25 lead the main conductors 1 2, in multiple-arc
circuits from which are placed lamps or other
translating devices, a, each provided with a cir-
cuit-controller, c. The lower portion of the
field-maguet of the generator A is wound with
30 wire, forming part of a multiple-arc circuit, 34,
from the main conductors 1 2. This circuit is
of high resistance, so that only a small amount
of current sufficient to primarily energize the
field-magnet will pass through it. It may, if
35 desired, be a circuit supplied from an external
source instead of from the conductors 12. The
main conductor 1 is brought up on one side and
wound around the magnet, afterward extend-
ing out parallel with the conductor 2. When
40 translating devices are first put in circuit the
magnet is sufficiently energized by means of
the circuit 3 4; but as their number is in-
creased the resistance of the main circuit is
lowered, so that more current flows through the
15 conductor 1 and the magnet becomes more and
more energized. As devices are thrown out
and the resistance of the main circuit increases,
|
of single translating devices, the addition or
removal of each device having an immediate
effect on the current passing through the field- 55
magnet.
What I claim is-
1. The combination, with a dynamo-electric
machine and translating devices arranged in
multiple arc, of a field-circuit of constant re- 60
sistance for primarily energizing the field-mag-
net, and another field circuit whose resistance
is varied by the addition and removal of traus-
lating devices, substantially as set forth.
2. The combination, with a dynamo-electric 65
machine, of one of its main conductors forming
a portion of the coils of its field-magnet, a cir-
cuit for primarily energizing such field-magnet,
and translating devices arranged in multiple-
arc or derived circuits, whereby the addition of 70
each individual translating device causes a
corresponding increase in the energy of the
field-magnet, substantially as set forth.
3. The combination of a multiple-arc circuit
containing a portion of the coils of the field- 75
magnet of a dynamo-electric machine, a mul-
tiple-arc circuit containing the armature of said
machine, and multiple-arc circuits containing
lamps or other translating devices, all such
multiple-arc circuits being derived from the 8ɔ
same main conductors, and another field-cir-
cuit whose resistance is varied by the addition
and removal of translating devices, whereby
the addition or removal of any translating de-
vice causes an instant and corresponding reg- 85
ulation of the current energizing the field-mag-
net of the machine, substantially as set forth.
This specification signed and witnessed this
10th day of February, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
SAMUEL INSULL
2787
(No Model:)
2 Sheets-Sheet 1.
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,669.
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Patented Sept. 19, 1882.
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WITNESSES:
Thomas &. Birch
Д.Р. Мон
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
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INVENTOR:
J. A. Edison
Rich. St. Dyer.
ATTORNEY.
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2788
(No Model.)
T. A. EDISON.
2 Sheets-Sheet 2.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,669.
Patented Sept. 19, 1882.
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WITNESSES:
Thomas &. Birch
D. D. Mort
BY
INVENTOR:
J. A. Edison
Rich & A. Dyer.
ATTORNEY
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. F.
2789
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,669, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new aud
5 useful Improvement in Means for Regulating
the Generative Capacity of Dynamo or Magneto
Electric Machines, (Case No. 395;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
Io had to the accompanying drawings, and to the
letters of reference marked thereon.
The object of this invention is to furnish sim-
ple and efficient means whereby the addition
or removal of translating devices in a multiple-
15 arc system of electrical distribution will auto-
matically vary the current energizing the field-
magnet of the dynamo or magneto electric ma-
chine supplying such system. From the main
conductors which lead from the machine mul-
20 tiple-arc circuits are ruu, across which are
placed lamps, also in multiple arc. Separate
groups of translating devices are thus formed.
In each of the multiple-arc circuits from the
mains is placed an electro-magnet, provided
25 with a pivoted armature-lever retracted by a
spring, which acts to open and close a circuit,
which, by its closure, causes more current to
pass through the field-magnet, such circuit be
ing either a shunt around a résistance in the
30 field-circuit or a division of the field-circuit, in-
cluding a portion of the coils of the field-magret.
In the annexed drawings, Figure 1 is a dia-
gram showing the arrangement in which the
magnet cuts out resistance from the field, and
35 Fig. 2 a diagram showing that in which addi-
tional circuits are closed through the field-coils.
While the invention is here shown as applied
to a dynamo-electric machine, it is evident that
it is equally applicable to magneto-electric ma.
40 chines in which the field-circuit is supplied
with current from an external source, such as
another magueto or dynamo machine or a
battery.
A is a dynamo-electric machine, and 12 are
45 the main conductors leading therefrom.
3 4 is the multiple-arc circuit energizing the
field magnet of the machine..
5 6, 78, and 9 10 are multiple-arc circuits
from the main line, containing lamps or other
50 translating devices, a a, each of which is pro-
vided with a circuit-controller, c.
R RR" are resistances placed in the circuit
3 4. Shunt-circuits bde are formed around
these resistances. A part of each shunt-cir-
cuit consists of an armature-lever, f, controlled 55
by an electro-magnet, B, placed in the multi-
ple-arc circuit containing lamps a. It is evi-
dent that when these shunt-circuits are all
closed at i i uone of the resistances will be in
the field-circuit, and when these shunts are 60
open all the resistances R R R" will be in cir-
cuit. All the lamp-circuits in the multiple-
arc circuit 5 6 being open, no current flows
through the magnet of that circuit, and the
shunt-circuit b is therefore open at i, so that 65
the resistance R is in the field-circuit; but in
the circuit 7 8 a number of lamps are ou, and
sufficient current passes through the circuit to
cause the armature f to be attracted, closing
the shuute, thus short-circuiting the resistance 70
R'. While in the circuit 9 10, though a few
lamps are ou, yet they are not enough to cause
the passage of sufficient current to energize
the magnet B enough to close the shuut d and
cut out the resistance R".
75
In Fig. 2 the coils of the field-magnet of the
dynamo-electric machine A are divided into a
number of parts or bobbins, each of which is
included in a division of a multiple-arc circuit
from the main conductors 1 2. One of these 80
divisions, 3 g, returns directly to the main con-
ductor 2, being iutended as a circuit for pri-
marily energizing the field, and is made of high
resistance, either by the fiueness of its wire or
by a resistance placed in it, so that only a small 85
amount of current will pass through it. Each
of the other divisions, 3 h and 3 k, of the field-
circuit includes an armature-lever, f, which is
actuated, according to the current flowing
through its magnet B, to make or break the 90
circuit in which it is placed. Thus, when a
circuit through a magnet, B, is closed by the
addition of a sufficient number of translating
devices it attracts its armature-lever and closes
a circuit through a greater portion of the field- 95
magnet coils.
What I claim is—
1. The combination, with a dynamo or mag-
neto electric machine and groups of translat-
ing devices arranged in multiple arc upon 100
multiple-arc circuits from the main conductors
of such machine, of means other than the cir-
2790
2
•
264,669
cuit-connections in connection with each group neto electric machine and groups of translat-
for regulating the current energizing the field. ing devices, arranged as described, of a mag
magnet of the machine, acting automatically net energized by the current supplying each
upon the addition or removal of translating group and provided with an armature-lever
5 devices in the group, substantially as set forth. whose motion opens or closes a circuit to vary 30
2. The combination, with a dynamo or mag- the current energizing the field-magnets of said
neto electric machine and groups of translat-machine, substantially as set forth.
ing devices, arranged as described, of means
in connection with each group, operated auto-
10 matically by the current, whereby the addi-
tion or removal of translating devices in the
group causes the closing or opening of a cir-
cuit, whose closure or opening varies the cur-
rent energizing the field-magnet of the gener
15 ator, substantially as set forth.
3. The combination, with a series of resist
auces in the field-circuit of a dynamo or mag-
neto electric machine and a number of groups
of translating devices, arranged as described,
20 of means in connection with each group, op-
erated automatically by the addition or re-
moval of translating devices in such group, for
throwing one of said series of resistance in or
out of circuit, substantially as set forth.
25
4. The combination, with a dynamo or mag-
5. The combination of the field-magnet of a
dynamo-electric machine placed in a multiple-
arc circuit, the armature of said machine placed 35
in another multiple-arc circuit, groups of
translating devices placed in other multiple-
arc circuits, said multiple-arc circuits being
all derived from the same main conductors,
and means in connection with each group for 40
regulating the current energizing the field-
magnet of the machine, acting automatically
upon the addition or removal of translating
devices in the group, substantially as set forth.
This specification signed and witnessed this 45
10th day of February, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
WM. H. MEADOWCROFT.
2791
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,670.
WITNESSES:
E. C. Kowland
пливи
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Patented Sept. 19, 1882.
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INVENTOR:
T. A. Edison
by
Rich A. Dyer,
THE MORAIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
៩
2792
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,670, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, bave invented a new and
5 useful Improvement in Means for Regulating
Electrical Generators, (Case No. 442;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawing, and to the
10 letters of reference marked thereon.
·
The object I have in view is to produce sim-
ple and efficient means for automatically regu- |
lating the generative capacity of dynamo or
magneto electric machines supplying lamps
15 or motors arranged in multiple arc, which
means will regulate both for chauges in the
speed of the engine, as well as in the number
of translating devices, and will keep the can-
dle-power of the lamps constant and prevent
20 flicker. This I accomplish by providing a mech-
auism operated by the current generated aud
throwing resistance into and out of one of the
main conductors. This mechanism is con-
trolled by an electro-magnet located in a mul-
25 tiple-arc circuit beyond the resistance, and af-
fected exactly as are the lamps themselves by
changes in the speed of the engine and in the
number of lamps or motors in circuit, and also
by the throwing in and out of the resistance.
30 When the lever of this magnet makes its for-
ward contact a circuit is completed through the
resistance - adjusting mechanism and resist-
ance is thrown into the main line or conductor,
and when this lever makes its back contact an-
35 other circuit through the resistance adjusting
mechanism is completed and resistance is cut
out of the main line. When the candle-power
is normal the lever of the controlling electro-
magnet is held in a central position by spring.
40 fingers or equivalent means. The resistance
adjusting mechanism is composed of two elec-
tro-magnets, whose armature - levers carry
pawls engaging with two ratchet-wheels, the
forward movement of which throws the con-
45 tact-arm in opposite directions. The divided
circuit running through these electro-magnets
may be a multiple-arc circuit, a shunt-circuit,
or other circuit having always, when closed,
sufficient energy to work the mechanism. This
go circuit passes through a circuit-breaker com-
mon to both magnets, which is preferably a
mechanical circuit-breaker operated by some
moving part, and may be a wheel riding on
the armature-shaft and carrying a circuit-
breaking cylinder, or there may be two cir- 55
cuit-breakers operated in this way-one for
each electro-magnet. The field-circuit of the
generator is also a multiple-arc circuit from
the main conductors, and is connected with
such main conductors beyond the resistance, 60
so that it will be affected by such resistance,
like the lamps, and will receive more current
when resistance is cut out of the main line and
less current when resistance is thrown into the
main line.
The foregoing will be better understood from
the drawing, which is a view, partly diagram -
matic, of apparatus embodying the invention.
65
A is a dynamo or magneto electric machine,
from which run the main conductors, 1 2, in 70
multiple-arc circuits 3 4 from which are ar-
ranged the lamps or motors B.
R is the resistance, located in either 1 or 2,
between the lamps and the generator. This
resistance is thrown into and out of circuit by 75
the arm a, which is moved in one or the other
direction by two ratchet-wheels, one of which
is shown at b.
C D are electro-magnets, the armature-le-
vers c d of which carry pawls e f, working 80
the ratchet-wheels.
E is an electro-magnet in a multiple-arc cir-
cuit, 5 6, connected with 12 beyond the re-
sistance R. Its armature-lever g is in another
multiple-arc circuit, 7 8, which is divided at 85
the frout and back contacts, hi, of this lever.
The divisions of this circuit pass through the
coils of the two electro-magnets C D and are
again joined. The lever g is held in a central
position by spring-fingers k. The retracting 9ɔ
spring l of the lever g is made adjustable, so
that the candle-power of the lamps may be
adjusted at this point. The circuit 7 8 has a
mechanical circuit-breaker arranged in its line.
This may be a wheel, m, riding upon the arma- 95
ture-shaft n, a detached portion of which is
shown for clearness of illustration. The wheel
m carries a breaking-cylinder, o, composed of
metal and insulation, upon which cylinder.
rest spring-fingers p q. The circuit-wires ruu
to these spring-fingers, the revolution of the
cylinder alternately making and breaking the
electrical connection between such fingers.
The field-of-force circuit of the machine is a
I 00
2793
5
2
264,670
multiple-arc circuit, 9 10, from 12, the con-
nection being made beyond the resistance R,
as shown, for the purpose already explained.
What I claim is-
1. The combination, with a dynamo or mag-
neto electric machine, of translating devices
located in multiple-arc circuits from its main
conductors, an adjustable resistance in one of
such main conductors, an electro-magnet lo-
10 cated in a multiple-arc circuit, and mechan-
ism operated or controlled by said electro-
magnet for throwing such resistance into and
out of the main line, substantially as set forth.
2. The combination, with a dynamo or mag-
15 neto electric machine and translating devices
in multiple arc-circuits, of an adjustable resist-
ance in the main line, an electro-magnet in a
multiple-arc circuit, circuits closed at the front
and back contacts of the armature-lever of
20 said electro-maguet, and mechanism included
in said circuits for throwing such resistance
into and out of the main line, substantially as
set forth.
3. The combination, with a dynamo or mag-
25 neto electric machine and translating devices
in multiple-arc circuits, of an adjustable re-
sistance in the main line, two electro-magnets,
pawl-and-ratchet mechanism worked by such
electro-magnets, a contact-arm moved thereby
30 in opposite directions, an electro-magnet in
multiple arc, the armature of which closes at
its front and back contact a circuit through
one or the other of such two electro-magnets,
and a circuit breaker or breakers in circuit
35 with said two electro-magnets, substantially
as set forth.
4. The combination, with a dynamo or mag-
neto electric machine and translating devices
in multiple arc, of an adjustable resistance in
the main line, an electro-magnet, and mechan- 40
ism operated or controlled by said electro-mag-
net for throwing such resistance into and out
of the main line, said electro-magnet being lo-
cated in a multiple-arc circuit connected with
the main conductors beyond such resistance, 45
substantially as set forth.
5. The combination, with a dynamo or mag-
neto electric machine and translating devices
in multiple arc, of an adjustable resistance in
the main line and the field-of-force circuit of g
the machine connected with the main conduet-
ors beyond such adjustable resistance, substan-
tially as set forth.
.5.0
6. The combination, with a dynamo or mag.
neto electric machine and translating devices 55
in multiple arc, of an adjustable resistance in
the main line, an electro-magnet located in a
multiple-arc circuit beyond the resistance,
mechanism operated or controlled by said elec-
tro-magnet for throwing such resistance into 60
and out of the main line, and the field-of-force
circuit of the machine connected with the main
conductors beyond such resistance, substan-
tially as set forth.
This specification signed and witnessed this 65
9th day of June, 1882.
Witnesses:
THOS. A. EDISON.
RICHD. N. DYER,
EDWARD H. PYATT.
2794
1.
(No Model.) ·
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,671.
Fig. 7.
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5
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WITNESSES:
D. D. Mott.
Thomas E. Birch
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
Patented Sept. 19, 1882.
INVENTOR:
T.A. Edison
BY Rich? A. Dyer
ATTORNEY.
2795
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,671, dated September 19, 1882.
Application filed August 7, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Regulating the Gen-
erative Capacity of Dynamo or Magneto Elec-
tric Machines, (Case No. 392;) and I do hereby
declare that the following is a full and exact
description of the same, reference being had
10 to the accompanying drawings, and to the let-
ters of reference marked thereon.
the main line causes a greater amount of cur-
rent to flow through the shunt, so that the
field-magnet becomes stronger and the electro-
motive force is increased. If, now, translating 55
devices are removed, the difference of poten-
tial becomes less and the field-magnets are
weakened by the decrease of current in the
shunt. Instead of a shunt-circuit depending
upon the drop iu pressure on one of the main 60
conductors, a shunt around a resistance placed
in one of the main conductors may be used for
The object of my invention is to produce the field-circuit of the machine. This may
means for regulating the energy of the field-be better understood by reference to the draw-
maguet of a dynamo or magneto electric-ma- ings, in which-
15 chine supplying current to a multiple-arc sys-
tem of electrical distribution, which shall op-
erate automatically on the addition or removal
of translating devices, and shall not require
any mechanism whatever for varying the
20 strength of the field-circuit
In carrying my invention into effect the field-
magnet is partly wound with wire, the coils
being preferably in a multiple-arc circuit from
the main line. This circuit has a comparatively
25 high resistance, which remains constant, and
may be obtained by the winding itself or by
means.of an additional resistance placed in
the circuit. The resistance of the circuit is
such that the requisite electro-motive force
30 will be given only when a few translating
devices are in circuit. In addition to this
In addition to this
winding, a portion of the magnet is wound with
a conductor formed of bunched wires, to give
flexibility for winding, preferably equal in con-
35 ductivity to one of the main conductors leading
from the machine, and these coils are in a
shunt-circuit from one of the said main con-
ductors, which circuit starts at a point near
the machine, preferably between the machine
40 and the first translating device, and returus to
the main conductor at a point beyoud the far-
thest translating device. There is of course
a difference of potential between these two
points, and the greater the uuinber of trans-
45 lating devices between them the greater be-
comes the difference of potential. When only
a few translating devices are in circuit the
constant field-circuit errergizes the magnet
sufficiently; but as more devices are placed
in circuit and the electro-motive force becomes
too weak the fall of potential at the end of
50
65
Figure 1 is a diagrammatic view of the pre-
ferred form of connectious, and Fig. 2 a view
showing modified connections.
A represents the field-magnet, and 1-2 the
main circuit therefrom, in which translating 70
devices a a are placed in multiple-arc circuits.
3 4 is the constant field-circuit, and 5 6 the
shunt-circuit. The wire 3 4 may be wound on
a portion of the limbs of the magnet and the
wire 5 6 on the remaining portiou, as shown; 75
or the wire 3 4 may cover the whole of the
cores, while the thicker wire is placed over it.
It is evident that the circuit 3 4 could be sup-
plied from an exterual source, such as a bat-
tery or another dynamo or magueto electric 80
machine. The shunt 56 may be around a re-
sistance, R, Fig. 2, in 1 or 2.
What I claim is-
1
1. The combination, with the field-magnet
of a dynamo or magneto electric machine and 85
translating devices in multiple-arc or derived
circuits from the main conductors thereof, of
a shunt-circuit from one of the main conduct-
ors for energizing said field-magnet, the cur-
rent in such shuut being dependent upon the 90
number of translating devices in circuit, sub-
stantially as set forth.
2. The combination, with a dynamo or mag-
neto electric machine, of a circuit for primarily
energizing the field-magnet and another field- 95
circuit formed by a shunt from one main con-
ductor, the current in which is controlled by
the number of translating devices in circuit,for
automatically regulating the strength of the
field-circuit in direct proportion to the number 100
of translating devices, substantially as set
forth.
2796
2
264,671
3. A dynamo or magneto electric machine magnet of a dynamo-electric machine, a mul-
supplying translating devices arranged in multiple-arc circuit containing the armature of 20
tiple-arc circuits, in combination with a shunt- said machine, multiple-arc circuits containing
circuit from one of the main conductors of the lamps or other translating devices, (all these
5 machine around the multiple-arc connections multiple-arc circuits being derived from the
therewith, for increasing the strength of the same main conductors,) and a shunt-circuit
field-magnet, and another circuit for primarily from one of said main conductors, including a 25
energizing the field-magnet, substantially as portion of the coils of said field-magnet, the
set forth.
current in said shunt being dependent upon
the number of translating devices in circuit,
substantially as set forth.
IO 4. The combination of a multiple-arc circuit
from the main conductors for primarily euer-
gizing the field-magnet and the shunt-circuit
from one of such main conductors around the
multiple-arc connections therewith for increas-
15 ing the strength of such field-magnet, sub-
stantially as set forth.
5. The combination of a multiple-arc circuit
containing a portion of the coils of the field-
This specification signed and witnessed this 30
10th day of February, 1882.
Witnesses:
THOMAS A. EDISON.
H. W. SEELY,
SAMUEL INSULL
(No Model.)
2 Sheets-Sheet 1
2797
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,672.
3
Patented Sept. 19, 1882.
Fig. 1.
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WITNESSES:
E. C. Rowland
Wensely
2
THE HORRIS PETERS 00., PHOTO-LITHO., WASHINGTON, D. C.
>
|
INVENTOR:
T. A. Edison
BY Rich ? A. Dyer.
ATTORNEY..
2798
1
(No Model.)
T. A. EDISON.
2 Sheets-Sheet 2.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,672.
Witnesses;
Mark.
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Patented Sept. 19, 1882.
*!!!!!!!!!!!!!!!!!
Inventor
1.
2.
homas S. Edizan
By Rich. A. Dyer.
Attorney.
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. 0.
2799
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,672, dated September 19, 1881.
Application filed August 7, 1862. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Means for Regulating
Electrical Generators, (Case No. 426;) and I do
hereby declare that the following is a full and
exact description of the same, reference being
had to the accompanying drawings, and to the
10 letters of reference marked thereon.
The object I have in view is to produce sim-
ple and efficient means for regulating the gen-
erative capacity of a dynamo or magneto elec-
tric machine by the counter electro-motive
15 force of an electromotor located in its field-of-
force circuit, and for governing or controlling
the counter electro-motive force generated by
such motor, so as to counteract variations in
speed of engine, as well as number of lamps
20 or other translating devices.
This invention is an improvement upon the
special means described in my Patent No.
248,421. I accomplish the object sought by ar-
ranging the armature-coils of the motor directly
25 in the field-circuit of the generator and the field-
magnet coils of the motor in a circuit which
is controlled by a vibrating circuit-controller
operated directly or controlled by an electro-
magnet arranged in a multiple arc circuit from
30 the main conductors of the generator. The
field-circuit of the motor may be a shunt from
the field-circuit of the generator around the
armature-coils of the motor; or it may be a mul
tiple-arc circuit from the main conductors of
35 the generator; or the field-coils of the motor
may be arranged in series with its armature-
coils in the field-circuit, and the field-magnet of
the motor be weakened and strengthened by
closing and opening a shunt around the same.
40 A shunt of high resistance is preferably formed
around the vibrating circuit-controller, so that
the motor will always have sufficient strength
of field to run at a low speed. The armature
of the operating or controlling electro-magnet
45 in the multiple-arc circuit is provided with an
adjustable retractor, so that the candle-power
of the lamps can be adjusted.
The foregoing will be better understood from
the drawings, in which Figure 1 is a view,
50 partly diagrammatic, of an apparatus embody-
ing the invention, and Figs. 2 and 3 similar
views of modified connections.
|
A represents a dynamo or magneto electric
machine, from which run main conductors 1 2,
iu 'multiple-arc circuits from which are located 55
lamps or other translating devices, B. The field-
circuit 3 4 of the generator is preferably a mul-
tiple-arc circuit from the main conductors 1 2.
In this field-circuit are located the armature-
coils of an electro-dynamic motor, C. The field- 60
circuit 5 6 of the motor C is shown in Fig. 1
as a shunt from 3 4 around the armature-coils
of the motor. This circuit 5 6 runs to the
armature-lever a and its frout contact, b. Said
lever carries an armature attracted by an elec- 65
tro-magnet, D, located in a multiple-arc circuit,
7 8, from 1 2, and the lever is retracted by au
adjustable spring, c. The maguet and lever
form a vibrating circuit-controller, which, when
closed, allows the field-magnet of the motor to 70
strengthen, increasing the speed of the motor
and its counter electro-motive force, and when
open breaks the field-circuit of the motor, re-
ducing its speed and counter electro-motive
force. The motor is not, however, stopped en- 75
tirely, since a shunt, 9 10, containing resist-
ance R, is formed around the vibrating circuit-
controller, and allows some current always to
flow through the field of the motor. This re-
sistance also reduces the spark at the points 80
of the vibrating circuit-controller. It will be
seen that the speed of the motor is increased
by the strengthening of the magnet D and less-
ened by the weakening of such magnet, which
is affected both by variations in speed and 85
number of translating devices. If desired, the
vibrating circuit-controller may break circuit
at a number of points simultaneously in order
to reduce the spark. This circuit-controller
may be operated by the magnet D, arranged 90
in multiple arc; or this magnet D may be used
to open and close the circuit of another mag-
net, E, arranged in a shunt from one of the
main conductors, Fig. 2, or from the field-cir.
cuit of the generator, which latter magnet will 95
operate the vibrating circuit-controller.
As before explained, the field-circuit of the
motor, instead of being a shunt from the field-
circuit of the generator around the armature-
coils of the motor, may be a multiple-arc cir- 100
cuit, 11 12, from 1 2, opened and closed by the
electro-magnet D, or by an electro-magnet, E,
in a local circuit controlled by D as a relay,
Fig. 2; or the field-coils of the motor may be
2800
2
264,672
arranged in series with its armature-coils and
a shunt-circuit, 13 14, be formed around the
field-magnet of the motor, Fig. 3, which shunt
will be opened and closed by D'or a magnet
5 controlled by it, the operation, however, being
the reverse of the other constructions.
What I claim is-
1. The combination, with a dynamo or mag-
neto electric machine, of an electro-dynamic
10 motor arranged in the field-circuit of such gen-
erator, and means in a separate multiple-arc
circuit operated by the current for controlling
the field-circuit of the motor, substantially as
set forth.
15
2. The combination, with a dynamo or mag.
neto electric machine, of an electro-dynamic
motor arranged in the field-circuit of the gen-
erator, and an electro-magnet located in a mul-
tiple-arc circuit from the main conductors of
the generator, and arranged to control directly 26
or indirectly the field-circuit of the motor, sub.
stantially as set forth.
3. The combination, with a dynamo or mag-
neto electric machine, of an electro-dynamic
motor arranged in the field-circuit of the gen- 25
erator, a vibrating electro-magnetic circuit-
controller controlling the field-circuit of the
motor, and a shunt of high resistance around
such vibrating circuit-controller, substantially
as set forth.
This specification signed and witnessed this
22d day of May, 1882.
Witnesses:
THOMAS A. EDISON.
EDW. C. ROWLAND,
C. P. MOTT.
30
2801
(No Model.)
T. A. EDISON.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 264,673.
A
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WITNESSES:
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D. D. Mort
J. Jeu Blark.
12
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Patented Sept. 19, 1882.
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C. ´
BY
INVENTOR:
J.A.Edison
Dyer & Wilber
ATTORNEYS.
2802
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.
SPECIFICATION forming part of Letters Patent No. 264,673, dated September 19, 1882.
Application filed November 28, 1881. Renewed August 14, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Regulating the Genera-
tive Capacity of Dynamo or Magneto Electric
Machines, (Case No. 366;) and I do hereby de-
clare that the following is a full and exact de-
scription of the same, reference being had to
To the accompanying drawing, and to the letters
of reference marked thereon.
My invention consists in regulating the
strength of the field-magnets of a dynamo or
magneto electric machine and the current
15 generated by such machine by reversing the
current passing through more or less of the
field-coils. This I do by winding the magnets
in sections or bobbins, each section being pro-
vided with means for reversing the direction
20 of its current. A convenient arrangement for
this purpose is shown in the annexed draw-
ing.
A A' are the helices of the field-magnet of a
dynamo-electric machine. 12 is the main cir-
25 cuit from such machine, having translating de-
vices a a arranged in multiple arc upon them.
3 4 is the field-circuit by which the magnet
A A' is energized. The helix A' is wound in
separate sections b b, each end of the wire of
30 each section extending out from the magnet.
The arrangement of the lowest section, b, will
illustrate that of the rest.
35
cc' are the wire ends, each divided into two
branches, ee' and ff'.
B is a circuit-reversing lever moving the
pivoted arms h h!.
As shown in the drawing, the current is pass-
ing through all the coils of the helix in the
same direction-viz., by wire 4, pivoted arm h',
40 wires f'c' b c e, pivoted arm h, by a wire, i, to
the next circuit-reverser, and so on; but if it
is desired to reduce the current generated by
the machine the lever B is moved so as to
•
bring in contact with ƒ and h' with e'. The
direction of the current in the bottom section 45
is thus changed, being now by arm h', wires
e' cbcf, arm h, &c. The strength of the
field-magnet is thus reduced. If a still further
reduction is necessary, more of the sections b
are reversed, as desired.
50
While only one of the helices is shown as
wound in sections, it is evident that this may
be done with both, and where the wire is wound
upon the core in layers one above another one
or more of the layers may be arranged to have 55
their current reversed.
It is evident, also, that other forms of circuit.
reversers may be used, and that they may be
worked automatically without departing from
the spirit of my invention.
This invention is of course equally applica-
ble to dynamo or to magneto electric machines.
What I claim is—
60
1. The method of regulating the generative
capacity of magneto or dynamo electric ma- 65
chines, consisting in reversing the polarity of
the current in a greater or less portion of the
coils of their field-magnets, substantially as set
forth.
2. The combination, with a field-magnet of 70
a dynamo or magneto electric machine, of
means for reversing the polarity of the current
in a greater or less portion of the coils of the
magnet, substantially as set forth.
3. A dynamo or magneto electric machine 75
having one or both of the limbs of its field-
magnet wound in separate sectious of wire,
each section including a circuit-reverser, sub-
stantially as set forth.
This specification signed and witnessed this 80
3d day of November, 1881.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
RICHD. N. DYER.
Telegraphic Journal Editorial, Oct. 15, 1878. 2803
Complainant's Exhibit “Gas vs. Electric
Lighting."
THE TELEGRAPHIC JOURNAL (LONDON), OCTOBER 15,
1878, VOL. VI., No. 137, PAGE 413.
The most important practical scientific question of the
hour, and the one of greatest public interest, is that of
illumination by means of electricity. Every day the sub-
ject is developing and attracting more and more attention.
As we predicted long ago, the Paris Exposition, and
the fine display of the power and beauty of the electric
arc which has been this year made patent to all the
world in that city, have given an incalculable impetus.
to the progress of this mode of lighting. It has been
said, doubtless by some timid holder of gas shares with
whom the wish was father to the thought, that with the
Paris Exhibition so would the electric light pass away
again, and sink into the darkness from whence it sprung;
but there is now no fear of that. It has made too great an
impression on the public mind, and gained too wide-
spread a footing for itself in practical usage now, to
lapse into obscurity. Inventors, too, are giving their
ingenuity to the solution of the difficulties which still
bar its advancement, a great many patents relating to
it are being taken out in all civilised countries, it is one
of the present tides in the affairs of men which may
lead to fortune-in short "there is money in it,” and its
ultimate success is undoubted.
It has hitherto been the habit of gas investors to
dread, and of gas directors to repudiate, the electric
light as a promising rival of gas. It would seem in-
deed as if colour blindness was unusually common
amongst the directors of gas companies, for few of these
gentlemen have been able to see the superior excellence
2804 Telegraphic Journal Editorial, Oct. 15, 1878.
of the electric light over gas light. To them it has ap-
peared a weird, ghastly glow, reminding them of corpse-
lights and mortal decay. If it be true that gas directors
are particularly subject to jaundiced vision, a philosophic
oculist might, with some show of reason, attribute
the fact to the meretricious influence of the yellow gas-
light they have been so long habituated to. From
recent meetings, however, we are happy to see that a
change has taken place in the attitude of the leading
London gas companies towards the new illuminator. It
is no longer pooh-poohed by them, but wisely regarded
as a declared rival, which must be fairly competed
against if gas-lighting is to hold its ground. The cost
of electric lighting for street purposes is at the present
so much more than gas that, although the superiority
of the light is unquestionable, there will be no hurry to
supersede gas by it. But even if all the streets of the
metropolis were lit by electricity, we are told that it
would only cause a reduction of about 1 per cent. on
the gross revenues of the companies who get their prin-
ciple receipts from domestic lighting. If this be so,
there is no immediate cause for a panic among gas
shares, and gas shareholders may use the statement as
a prop to their tottering faith. But we would advise
them not to trust too implicitly to consolation of this
kind.
It is true that at present an invention, by which the
electric current supplying the electric lamps can be
subdivided so as to feed a great many light centres, and
thus at the same time moderate while it distributes the
light, is a desideratum necessary to the complete suc-
cess of electric lighting even for general street purposes,
let alone household uses. But tried inventors are at
work on the problem, and any day may see its accom-
plishment. Some comfort may be derived from reflec-
tions that gas lighting will never be driven from the
field, that gas will be more and more used for heating
purposes, that it will even be used in gas engines for
generating powerful electric lights, and that at least for
Telegraphic Journal Editorial, Oct. 15, 1878. 2805
many years to come it will keep its impregnable position
as a domestic illuminator. But at the same time it
should not be forgotten that an invention may come any
day which will dispel these dreams of security, and
banish gas lighting to a secondary place. In proof of
this we have only to cite the report from America
(published on another page) that the indefatigable Mr.
Edison has succeeded in solving the problem of gen-
eral electric illumination in the most thorough and
sweeping manner. While the gas companies were in
the act of laying the soothing unction to their souls,
and congratulating themselves on their safe position
even against electric street lighting, the news was being
flashed across the Atlantic that Edison had invented a
means of subdividing the electric current indefinitely,
so as to produce 1,000 lights if need be from one ma-
chine, and of bringing it into homes for household pur-
poses, such as lighting, heating, and driving sewing
machines, at half the cost of gas and without disturb-
ing the existing brackets and chandeliers.
The Napoleon of invention delights in startling sur-
prises, and his fertile and daring imagination runs at
once through the whole gamut of possibilities as soon
as the key-note of a new idea is struck. Future de-
velopments are to him as if they already existed; but
for all that the great mechanical genius of Mr. Edison
is so well attested, that any report of the kind is to be
taken seriously. It is a sign of the uncanny reputation.
of this inventor, that on the publication of the said an-
nouncement in London on October 8th, the gas shares
fell seven per cent. No opinion can be passed on the
merits of the new invention until a description of it is
made public, which will not be until the patents are
secured. Meanwhile, both inventors, gas shareholders
and the general public will be interested to learn what
the coming disclosure is to be. We trust that Mr. Edi-
son, for his own as well as others sake, has made him-
self certain of the success of his invention before
sending forth the telegrams proclaiming it. It is a fine
2806 Telegraphic Journal Editorial, Oct. 15, 1878.
thing, no doubt, to assume the god and shake the
spheres with a nod; but it must not be forgotten that
the disturbance may cost heavily to humbler beings.
In conclusion, we would remark that the announcement
that the problem of dividing the light has been com-
pletely solved by Mr. Edison need not deter other in-
ventors from giving their minds to this matter. We
have yet to learn what the new system is, and although
Mr. Edison is admittedly a great inventor, he cannot
be supposed to monopolize all ideas on the subject, nor
even always to hit upon the best.
Telegraphic Journal Editorial Apr. 15, 1878. 2807
Complainant's Exhibit “Electric Light-
ing."
THE TELEGRAPHIC JOURNAL (LONDON) APRIL 15, 1878,
VOL. VI., No. 125, p. 157.
The last words of the expiring poet Goëthe are said
to have been a cry for "more light." We remember
hearing a few years ago, the eminent Scotch divine,
Principal Caird, preach one of his famous sermons to
the students of Glasgow University. It was a dismal
November Sunday, and the college chapel was dimly
lit by coal gas, half turned on. As the orator waxed
mightier in the pulpit, the winter day waned, and the
darkness deepened. When at the climax of his elo-
quence, he suddenly rehearsed the closing prayer of
Goëthe, "More light-more light!" In an instant the
chapel blazed with light. The janitor, a matter-of-fact
old Scotchman, had promptly turned on the gas. This
practical answer somewhat discomfitted the preacher;
but it was none the less appreciated by the congrega-
tion.
If in these times, as some think, the higher spiritual
light which Goëthe sought is waning and becoming
more and more uncertain, the same cannot be said for
that material light supplied by the Macpherson. A
source of illumination, of a power and brilliancy before
unheard of, and rivalling the beams of the sun himself,
is already in our hands. The electric light, as M. Jamin
pointed out, at one of the recent conferences of the
Sorbonne, which correspond to our Friday evening
meetings at the Royal Institution, has now entered its
practical stage. It has been so fully developed, now
that in regard to cost, convenience, and effectiveness, it
completely eclipses, for certain purposes, the ordinary
coal-gas in general use. These purposes are the light-
ing of large areas by a few powerful lamps. As yet,
the electric light cannot be said to be fitted for the
lighting of streets and private dwellings. In a practi-
2808 Telegraphic Journal Editorial Apr. 15, 1878.
cal sense it is not so divisible as gas, a d cannot be so
easily conducted into all the multifarious ramifications
of houses and cities. For the present, at least, gas will
hold its own in this department; but for the lighting
of factories, large commercial establishments, ware-
houses, shops, and wide public thoroughfares, the elec-
tric light is ready to be adopted with profit and
advantage. "Gas," said M. Jamin, "should be the re-
tail purveyor, electricity the wholesale merchant."
Besides its cheapness, the electric light is superior to
gaslight in many respects for such purposes. It has
been complained that the light is too white and ghastly.
It would be as reasonable to quarrel with daylight itself
as to quarrel with it on this account, for the electric
light is the nearest approach we have made to the per-
fection of sunlight, and it is only because we have been
so long accustomed to the sickly yellow hue of gas that
we cannot yet fully appreciate the purer brilliance of
electricity. Under the electric light the most delicate
colours preserve their tints, and this fact especially
recommends it to dyers, and also to manufacturers of
cloth, for with it even the darkest colours can be woven
by night as well as by day. The safety of the electric
light against fire is another point in its favour. No luci-
fers are required to kindle it; each lamp is enclosed in
a glass shade, and takes of itself the place of fifty or
more scattered jets of gas. This consideration has
caused insurance companies to insure works lit by
electricity at a lower rate than the ordinary. The elec-
tric light is healthier than gas, inasmuch as it consumes
little or no oxygen, and consequently gives off no foul
and pernicious exhalations of carbonic acid and other
poisonous gases. There is little or no burning in con-
nection with it, and therefore it does not raise the
temperature of the factory. It is handy, for the neces-
sary apparatus, magneto-electric machines, lamps and
connections, can be set up in a very short time; and
the due lubrication and supply of carbon wicks, are the
only further cares necessary. It has been objected to
the electric light that it is too intense and not suffi-
Telegraphic Journal Editorial, Apr. 15, 1878. 2809
ciently diffusive, that it throws black shadows and is
therefore unsuited to the illumination of factories where
there is a multiplicity of shafts, pulleys and belting.
But this defect, if it be a defect, can be overcome by
the use of reflectors, or even by whitening the walls
and ceilings, so that the light is mixed up and blended
into a soft diffused radiance, which fills the whole.
apartment uniformly and casts no shadow at all. The
cost of maintaining the light, apart from the initial ex-
penses of installation, is at present only about one-fifth
of the cost of gas.
On the Continent, and especially in France and Ger-
many, where the machines of Gramme and Siemens
have originated, the application of the electric light to
large buildings, railway stations and public places, is
proceeding apace. England, which is considered by
our Continental neighbours to be one large workshop, is
somewhat behindhand in the matter; nevertheless,
owing to our busy industries, and to the naturally ob-
scure character of our remarkable climate, and the re-
tiring disposition of our sun, England is a country
which has more to gain by adopting the electric light
than any other. The recent Trinity House trials of
dynamo-electric machines clearly demonstrated that of
those experimented upon the Siemens' form was the
best. But further, and probably more crucial, because
more extensive, experiments are, we believe, about to
be made at the forthcoming Paris Exhibition, with a
view of determining the relative advantages of existing
machines. It appears to be agreed that all the latest
forms are capable of outdoing gas-light for illumination
on a large scale; and it only remains to discover their
order of merit. These trials will be witnessed by visi-
tors from all parts of the world, and no doubt the sub-
ject of electric lighting will receive an impulse from
such a display of its capabilities. Let us hope that the
impulse will be felt in England.
2810 Telegraphic Journal, Nov. 1, 1878.
Complainant's Exhibit, Progress of the
Electric Light.
THE TELEGRAPHIC JOURNAL (LONDON), NOVEMBER 1,
1878, VOL. VI.—No. 138, P. 435.
·
Siemens' Regulator.-The following account of Sie-
mens' new regulator for keeping the resistance
in circuit of an electric light constant, is taken
from Dr. C. W. Siemens' letter to the Times
of October 12th: "In passing an electric circuit
from a main conductor into several or any num-
ber of branches, the current divides itself between those
branches, according to the well-known law of Ohm, in
the exact inverse ratio of the electrical resistance pre-
sented by each branch. A current may thus be divided,
for instance, into ten separate currents of precisely
equal force, if each branch is made to consist of a
wire of the same length and conductivity; but if one
of these wires was again to be slit into ten wires,
presenting in the aggregate the same conductivity
each of these wires would only convey 100th part of
the total current. In the same way one of the minor
wires might again be subdivided into branches each of
which would convey an amount of electric current
which would be accurately expressed by the relative
resistance of the branch in question, divided by the
total resistance of all the branches put together. It
would thus seem that nothing could be more easy than
to divide a powerful electric current among as many
branches of varying relative importance as might be
desired; but in the case of electric lighting a difficulty
arises in consequence of the varying resistance of each
electric light or candle, due to the necessarily some-
Telegraphic Journal, Nov. 1, 1878.
2811
what varying distance of the carbon points from each
other, upon which the length of the luminous arc de-
pends. In order to work a number of lights upon dif-
ferent branches of the same current, it is necessary to
furnish each branch with a regulator so contrived that
an increase of current corresponding to too near an ap-
proach of the carbon points will produce automatically
an increased resistance in that branch circuit, whereas
an accidental increase in the distance between the car-
bon points of any lamp will cause the regulator to re-
duce the extraneous resistance of the circuit to a mini-
тит. Such a mode of regulating currents was present
in my mind when, in addressing the Iron and Steel In-
stitute in March, 1877, I ventured to express my con-
viction that natural forces, such as represented by large
waterfalls, could be utilized for the production of
motive power and electric light, in towns at a distance.
even of 30 miles from such source, by means of a large
electric conductor. This suggestion gave rise to a good
deal of discussion and criticism, especially in the United
States; but I replied to some of these criticisms in de-
livering one of the Science Lectures at Glasgow, in
March last, having already referred to the matter in
a discussion that was held before the Institution of
Civil Engineers on the 29th of January last. Having
in the meantime perfected the regulator, I showed it in
operation at the soirée of the Royal Society on the 19th
of June, and have only been waiting to get experi-
mental data complete, in order to bring the whole sub-
ject before one of the scientific bodies. The arrange-
ment may be said to consist simply of a thin strip of
copper or silver, say six inches long and half an inch
broad, stretched horizontally between two supports
with a weight or spring exerting a certain pressure in
the middle. The branch current to be regulated is
passed through this strip of metal, which is thereby
heated to a certain moderate extent, depending upon
the amount of current passing, and upon the rate of
radiation of the heat produced in the strip to surround-
2812
Telegraphic Journal, Nov. 1, 1878.
ing objects. Suppose that when the normal condition
of things obtains, the strip of metal is maintained at
the temperature of say 100 degrees Fahrenheit, and
suppose by an accidental approach of the carbons of a
lamp the resistance of the circuit is suddenly decreased,
an almost instantaneous increase of temperature of the
thin strip will ensue, which will cause it to elongate
slightly, and allow the weight resting in the middle to
descend, which in its turn causes an increase in the re-
sistance of a small rheostat, through which the branch
current in question has to flow.
Siemens-Iron and Steel Inst.-1877. 2813
Complainant's Exhibit, "President's In-
augural address."-C. W. Siemens before the
Iron and Steel Institute.
[From the Journal of the Iron and Steel Institute,
No. 1, 1877, London, E. & F. N. Spon, pages 6 to 34.]
The Iron and Steel Institute was called into existance
in 1869, by a few of those leading members, who,
assisted throughout by our energetic General Secretary,
are still giving it their zealous and disinterested sup-
port. At their head stood His Grace, the Duke of
Devonshire, who, as its first president, pointed out to
the young society the useful results that would be
realized through a judicious combination of natural
science with practical experience, and by attention to
the progress in metallurgical processes effected in other
countries. He thus implanted upon this institute a
vitality which has resulted in a rapid increase of its
members and a career of usefulness, such as scarcely
any other society for the promotion of applied science
can boast of.
With regard to the progress of the institute in the
numerical strength of its membership, the number has
risen from 292 in 1869, to 960 in 1876, and the pro-
posals of candidates coming in, show that the interest
in the society has not abated. This numerical progress,
however, cannot be expected to continue, because
the institute has now arrived at a point where it
counts among its members those gentlemen who can
best aid us in the objects we have in view, and it can
thus afford to restrict the privilege of membership to
candidates who, by their previous training and actual
position, have qualified themselves to join profitably in
our discussions.
During last year, as the report shows, meetings were
held in London and Leeds, at which numerous papers
were brought before you regarding subjects of consider-
2814 Siemens-Iron and Steel Inst.-1877.
able interest, and which gave rise to important discus-
sions.
But besides the reading and discussion of papers,
there has been much other useful work done by the
Institute; I refer to the several committees that have
on various occasions been appointed by the Council
for the purpose of investigating questions of impor-
tance relative to the production of iron and steel, and
the interest evinced in those special inquiries proves
how much more may yet be accomplished by more
systematic organization for the attainment of similar
objects.
Another branch of useful action of this Institute has
been to place before the members, through its Journal,
the latest results obtained in other countries, which
work was ably performed by our late Foreign Secretary,
Mr. David Forbes, F. R. S. The death of this distin-
guished gentleman must be a matter of deep regret to
every member of the Institute.
Out of our still young society has grown another—
the British Iron Trade Association—which, under the
able presidency of Mr. Geo. T. Clark, already gives
promise of useful results in supplying us with reliable
statistics regarding the extent and progress of the iron
trade of this and other countries, and in calling the at-
tion of our legislators to questions of tariffs, and to
other measures likely to affect the interests of the Brit-
ish iron trade.
Educational.-Intimately connected with the interests
of this Institute, and with the prosperity of the iron
trade, is the subject of technical education. It is not
many years since practical knowledge was regarded as
the one thing requisite in an iron smelter, whilst
theoretical knowledge of the chemical and mechanical
principles involved in the operations was viewed with
considerable suspicion. The aversion to scientific
reasoning upon metallurgical processes extended even
to the authors who professed to enlighten us upon these
subjects; and we find, in technological works of the
early part of the present century, little more than eye-
Siemens-Iron and Steel Inst.-1877. 2815
:
witness accounts of the processes pursued by the oper-
ating smelter, and no attempt to reconcile those opera-
tions with scientific facts. A great step in advance
was made in this country by Dr. Percy, when, in
1864, he published his remarkable "Metallurgy of
Iron and Steel." Here we find the gradual processes.
of iron smelting passed in review, and supported by
chemical analysis of the fuel, ores, and fluxing materials
employed, and of the metal, slags, and cinder produced
in the operation. On the Continent of Europe, the
researches of Ebelmann, and the technological writings
of Karsten, Tunner, Grüner, Karl, Akermann, Wedding
and others have also contributed largely towards a more
rational conception of the processes employed in iron
smelting.
It must be conceded to the nations of the Continent
of Europe that they were the first to recognize the
necessity of technical education, and it has been chiefly
in consequence of their increasing competition with the
producers of this country that the attention of the
latter has been forcibly drawn to this subject. The
only special educational establishment for the metallur-
gist of Great Britain is the School of Mines. This
institution has unquestionably already produced most
excellent results in furnishing us with young metallur-
gists qualified to make good careers for themselves, and
to advance the practical processes of iron making; but
it is equally evident that that institution is still sus-
ceptible of great improvement, by adding to the
branches of knowledge now taught at Jermyn Street,
and I cannot help thinking that a step in the wrong
direction has recently been made in separating geo-
graphically and administratively the instruction in pure
chemistry from that in applied chemistry, geology, and
mineralogy. If properly supported the School of Mines
might become one of the best and largest institutions
of its kind, but it would be an error to suppose that,
however successful it might be, it could be made to suf-
fice for the requirements of the whole country. Other
similar institutions will have to be opened in provincial
2816 Siemens-Iron and Steel Inst.-1877.
centres, and we have an excellent example set us by
the town of Manchester, which, in creating its Owen's
College, has laid the foundation for a technical univer-
sity, capable of imparting useful knowledge to the tech-
nologist of the future.
Technical education is here spoken of in contradis-
tinction to the purely classical and scientific education
of the Universities, but it must not be supposed that I
would advocate any attempt in compromising in its
curriculum a practical working of the processes which
the student would have to direct in after life. This has
been attempted at many of the polytechnic schools of
the Continent with results decidedly unfavorable to the
useful career of the student; the practice
taught in such establishments is devoid of the com-
mercial element, and must of necessity be objection-
able, as tending to engender conceit in the mind of the
student, which will stand in the way of the unbiassed
application of his mind to real work. Let technical
schools confine themselves to teaching those natural
sciences which bear upon practice, but let practice.
itself be taught in the workshop and in the metallurgi-
cal establishment.
Labour.-Equal in importance to an enlightened
direction of metallurgical works is the obtaining of
labour upon reasonable terms. The wages paid in this
country are, as a rule, higher than those prevailing on
the continent of Europe, and I do not belong to those
who would wish to see them materially reduced. The
late Mr. Brassey found as the result of his experience.
that the cost of labour, that is, the co-efficient resulting
from the division of the work done per day, by the
day's wage, was a constant quantity for all countries.
This rule would lead to the conclusion that the more
costly but effective labour, as measured by a day's
wage, must be the cheaper in the end, because it pro-
duces a greater result with a given amount of plant. I
have no reason to doubt the general truth of this propo-
sition, provided only that it is not disturbed by miscon-
ceptions regarding the supposed antagonism between
Siemens--Iron and Steel Inst.-1877. 2817
labour and the capital and skill directing it, which
misconceptions have exercised a baneful influence upon
the industries of this and other countries in recent
times. Both employer and employed have reason to
reflect seriously upon the experience gained during the
late period of high prices. Whilst employers added
largely to their producing plant, and required addi-
tional colliery and mining property in order to increase
their output, and so took advantage, unwisely, I think,
of the temporary inflation, it can hardly be considered
a matter for surprise that the working classes caught
up the feverish excitement, and endeavoured to obtain
their share of the golden fruits that were supposed to
accrue to their employers. Scarcity of labour was nat-
urally suggestive of combination, and high rates of
wages supplied the means of imposing onerous condi-
tions upon the employer, whereby the development of
economical processes was effectually retarded.
The commercial crisis which ensued has rendered the
depression more general and more sweeping than could
have been reasonably expected, and now that we find
ourselves at what we hope may be regarded as the ex-
treme ebb of the ever-fluctuating tide of prosperity, it
behooves us to consider carefully how a recurrence of
the same causes of mischief may in the future be ren-
dered less dangerous in their results.
One of the most effectual methods of attaining this
important result would consist in establishing the rela-
tions between employers and employed upon the basis
of mutual interest. I hold that capital has its duties
to perform as well as its rights to maintain, and that
whilst the minimum of wages is that which enables the
workman to live with reasonable comfort, both parties
would be materially benefited by so arranging wages as
to make them payable in great measure upon results,
both as regards quality and quantity of work produced,
whilst, by the establishment of mechanics' institutes,
reading rooms, and mutual benefit associations, in con-
nection with individual works, the feeling of community
of interest would be further strengthened, and a recur-
2818 Siemens-Iron and Steel Inst.-1877.
rence of antagonistic action, so destructive to commer-
cial results, might be avoided,
Fuel.-Next in importance to cheap, or rather to
efficacious, labour in the production of iron and steel
comes cheap fuel,—a matter to which, as you are aware,
I have devoted considerable attention, and I would
therefore treat it, with your permission, rather more
fully than other subjects of perhaps equal importance.
Fuel, in the widest acceptation of the word, may be
said to comprise all potential force which we may call
into requisition for effecting our purposes of heating
and working the materials with which we have to deal,
although in a more restricted sense it comprises only
those carbonaceous matters which, in their combustion,
yield the heat necessary for working our furnaces, and
for raising steam in our boilers. It may be safely
asserted that the great supply of energy available for
our purposes has been, or is being, derived from that
great orb which vivifies all nature-the sun. In the
case of coal, it has been shown that its existence is
attributable to the rays of the sun, which in former ages
broke up or dissociated carbonic acid and water in the
leaves of plants, and rendered the carbon and hydrogen,
thus separated from the oxygen, available for recom-
bustion. The same action still continues in the forma-
tion of wood, peat, and indeed all vegetable matter.´
The solar ray produces, however, other forms of en-
ergy through the evaporation of sea water, and the
resulting rainfall upon elevated lands, and through
currents set up in the atmosphere and in the sea, which
give rise to available sources of power of vast aggregate
amount, and which may also be regarded in the light
of fuel in the wider sense.
The
form of fuel, however, which possesses
the greatest interest for us, the iron smelters of the 19th
century, is without doubt the accumulation of the solar
energy of former ages, which is embodied in the form
of coal, and it behooves us to inquire what are the stores
of this most convenient form of fuel.
Recent inquiry into the distribution of coal in this
Siemens--Iron and Steel Inst.--1877.
2819
and other countries has proved that the stores of these
invaluable deposits are greater than had at one time
been supposed.
I have compiled a table of the coal areas and produc-
tion of the globe, the figures in which are collected from
various sources. It is far from being complete, but will
serve us for purposes of comparison.
THE COAL AREAS AND ANNUAL COAL PRODUCTION OF THE
GLOBE.
Area in
Production
Square Miles. in 1874.
Great Britain.
Germany.
--
United States-
France...
Belgium
Austria
Russia
-
1
!
1
I
i
1
1
1
I
1
1
1
Nova Scotia, and adjoining
Provinces.
Spain.
Other Countries__
1
1
1
Tons.
11,900
125,070,000
1,800
46,658,000
192,000
50,000,000
1,800
17,060,000
900
14,670,000
1,800
12,280,000
11,000.
1,392,000
18,000
1,052,000
3,000
580,000
28,000
5,000,000
270,200
274,262,000
This table shows roughly that the total area of the
discovered coal fields of the world amount to 270,000
square miles.
It also appears that the total coal deposits of Great
Britain compare favorably with those of other Euro-
pean countries, but that both in the United States and
in British North America, there exist deposits of ex-
traordinary magnitude, which seem to promise a great
future for the New World.
According to the report of the Coal Commissioners,
published in 1871, there were then 90,207 million tons
of coal available in Great Britain, at depths not greater
than 4,000 feet, and in seams not less than 1 foot thick,
2820 Siemens--Iron and Steel Inst.--1877.
besides a quantity of concealed coal estimated at 56,273
millions of tons, making a total of 146,480 millions.
Since that period, there have been raised 600 millions
of tons up to the close of 1875, leaving 145,880 millions
of tons, which, at the present rate of consumption of
nearly 132 millions of tons annually, would last 1,100
years. Statistics show that during the last 20 years
there has been a mean annual increase in the output of
about 3 millions of tons, and a calculation made at
this rate would give 250 years as the life of our coal-
fields.
In comparing, however, the above-named rate of in-
crease with that of population and manufactures, it will
be found that the additional coal consumption has not
nearly kept pace with the increased demand for the
effects of heat, the difference being ascribable to the·
introduction of economical processes in the application
of fuel. In the case of the production of power, the
economy effected in our best engines within the last
20 years exceeds 50 per cent., and an equally important
saving has probably been realized in the production of
iron and steel within the same period, as may be gath-
ered from the fact that a ton of steel rails can now be
produced from the ore with an expenditure not exceed-
ing 55 cwt. of raw coal, whereas a ton of iron rails
20 years ago involved an expenditure of exceeding 100
cwt. According to Dr. Percy, one large works con-
sumed, in 1859, from 5 to 6 tons of coal per ton of rails.
Statistics are, unfortunately, wanting to guide us re-
specting these important questions.
Considering the large margin for further improve-
ment in almost every application of fuel, which can be
shown upon theoretical grounds to exist, it seems not
unreasonable to conclude that the ratio of increase of
population and of output of manufactured goods will be
nearly balanced, for many years to come, by the further
introduction of economical processess, and that our
annual production of coal will remain substantially the
same within that period, which under those circum-
Siemens-Iron and Steel Inst.---1877. 2821
stances will probably be a period of comparatively
cheap coal.
The above-mentioned speculation leads to the further
conclusion that our coal supply at a workable depth
will last for a period far exceeding the shorter esti-
mated period of 250 years, especially if we take into
account the probability of fresh discoveries, of which
we have had recent instances, particularly in North
Staffordshire, where a large area of coal and blackband
ironstone is being opened up, under the auspices of His
Grace the Duke of Sutherland, by one of our members,
Mr. Homer.
Wherever coal flelds are found in Great Britain, they
exist, generally speaking, under favorable circumstances.
The deposits are for the most part met with at reason-
able depths, the quality of the coal is unsurpassed by
that of other countries, and although the coal and iron-
stone do not occur together in all the iron-producing dis-
tricts, the distance from the coal to the iron is small, com-
pared with that met with in other countries, and the
insular position of Great Britain renders water carriage,
both for internal communication and for the purpose
of export, more readily available than elsewhere. These
advantages ought to decide the present contest for sup-
plying the markets of the world with iron and steel, at
the lowest rates, in favor of this country.
Coal assumes, in many instances, the form of anthra-
cite, and although the South Wales district contains
large deposits of this mineral fuel, comparatively little
use has been hitherto made of it for smelting purposes.
When raw anthracite is used in the blast furnaces mixed
with coke it has been found that the amount so used
should be limited to from 10 to 15 per cent., or the fur-
nace is apt to become choked by an accumulation of de-
crepitated anthracite. At Creusot, in France, this diffi-
culty was overcome many years ago, by crushing the au-
thracite coal, mixing it intimately with crushed binding
coal and coking, a mixture of about equal proportions, in
Appold's vertical coke ovens. The result is a some-
what unsightly, but exceedingly hard and efficacious
2822 Siemens--Iron and Steel Inst.--1877.
coke. A similar method has been followed for some
time in South Wales, where coke is now produced, con-
taining as much as 60 per cent. of anthracite, bound to-
gether by 35 per cent. of binding coal, and a further
admixture of 5 per cent. of pitch or bitumen, the whole
of the material being broken up and intimately mixed
in a Carr's disintegrator prior to being coked in the
usual manner. Coke of this description possesses great
power of endurance in the furnace and is worthy the
attention of iron smelters.
In the United States of America, anthracite plays a
most important part, being in fact the only mineral
fuel in the Northern States, east of the Alleghany
mountains. Its universal application for blast furnaces,
for heating purposes and for domestic use, imparts to
the eastern cities of the United States a peculiar air of
brightness, owing to the entire absence of smoke, which
must impress every visitor most agreeably, and the
difference of effect produced by the general use of this
fuel, as contrasted with that of bituminous coal, is most
strikingly exemplified in a short day's journey from
Philadelphia, the capital of the anthracite region, to
Pittsburg, the centre of application of bituminous
coal.
In visiting lately the deposits
deposits of anthracite
coal of the Schuylkill district, I was much struck with
their vastness and with the manner and appliances
adopted for working them. The American anthracite
is less decrepitating than ours, but its successful appli-
cation to its various purposes is the result chiefly of
the judicious manner in which it is prepared for the
market. The raw anthracite as it comes from the mine
is raised to the top of a wooden structure some 60 to
70 feet high, in descending through which it is sub-
jected to a series of operations of crushing, dressing,
sieving, and separating of slaty admixtures, and is then
delivered through separate channels into railway
wagons, as large-coal, egg-coal, walnut-coal, and pea-
coal, each kind being nicely rounded and uniform in
size. The dust-coal, which amounts to nearly one-half
Siemens-Iron and Steel Inst.--1877. 2823
of the total quantity raised, is at present allowed to
accumulate near the mine, but experiments are now
being carried out to utilize this also for steam-boiler
purposes.
Next in importance to mineral fuel, properly speak-
ing, come lignite and peat, of which vast deposits are
met with in most countries. These may be looked upon
as coal still in course of formation, and the chief draw-
back to their use, as compared with that of real coal,
consists in the large percentage of water which they
contain, rendering them inapplicable, in their crude
condition, to the attainment of high degrees of heat.
These difficulties may be overcome by subjecting the
wet material to processes of compression, dessication
and coking, whereby excellent fuel and products of dis-
tillation are obtained; but the cost of their production
has hitherto exceeded their market value. Crude air-
dried peat has, however, been rendered applicable for
obtaining high degrees of heat such as are required for
metallurgical operations, by means of the regenerative
gas furnace, and it is important to observe that the
calorific value of a ton of air-dried peat or lignite, if
used in this manner, is equal to that of a ton of good
coal, if in both cases deduction is made of the per-
centage of moisture and earthy matter. The carbo-
naceous constituents of peat yield indeed a very rich
gas suitable for melting steel or for re-heating iron, the
only precaution necessary being to pass the gas from
the producer over a sufficient amount of cooling sur-
face to condense the aqueous vapor it contains, before
its arrival at the furnace. This precaution is not
necessary, however, in dealing with some of the older
lignites, such as occur abundantly in Austria and
Hungary, and which may be ranked as almost equal in
value with real coal, except for blast furnace purposes.
Fuel also occurs naturally in the gaseous condition,
a fact but too well known to every practical coal miner.
Occasionally, however, it is found separated from the
coal with which it may have been primarily associated,
and in those cases it has been made practically avail-
2824 Siemens--Iron and Steel Inst.--1877.
able as fuel. At Bakoo, on the Caspian Sea, natural
gas has issued spontaneously from the ground for cen-
turies past, and the column of perpetual fire thus pro-
duced has served the purpose of giving the Parsees a
holy shrine at which to worship their deity. In the dis-
trict of Pennsylvania a more substantial application has
been made of the gas issuing from many of the borings,
which serves as fuel for working pumping machinery
and as illuminating gas for the district. The quantity
of gas issuing from some of these wells may be judged
from the fact that one of them, after discharging for
three years as much gas as could escape into the at-
mosphere under a pressure estimated at not less than
200 lbs. on the square inch, has lately been connected
by means of a 5-inch pipe with Pittsburg (a distance
of 18 miles), where 70 puddling and re-heating furnaces
are worked entirely by the fuel so supplied. But even
this result furnishes only an imperfect idea of the
calorific power represented by this single issue of
natural gas, inasmuch as the combustion is carried on
in these furnaces on the most wasteful plan, the gas
being mixed imperfectly with cold air, and converted to
a large extent into dense masses of smoke. An analysis.
of this gas gives :
Hydrogen.
Marsh gas.
Ethylene.
Carbonic acid.
1
13.50
80.11
5.72
0.66
The use of natural gas is not likely to assume very
large proportions owing to its rare occurrence, but its
application at Pittsburg has forcibly reminded me of a
project I had occasion to put forward a good many
years ago, namely, to erect gas producers at the bottom
of coal mines, and by the conversion of solid into
gaseous fuel to save entirely the labour of raising and
carrying the latter to its destination. The gaseous fuel,
in ascending from the bottom of the mine to the
bank, would (owing to its temperature and low
Siemens--Iron and Steel Inst.--1877.
2825
specific gravity) acquire in its ascent an
onward pressure sufficient to propel it through pipes or
culverts to a considerable distance, and in this way it
would be possible to supply townships with heating
gas, not only for use in factories, but, to a great extent,
for domestic purposes also. In 1869 a company in
which I took a leading interest was formed at Birming-
ham, under the sanction of the Town Council, to sup-
ply the Town of Birmingham with heating gas at the
rate of 6d. per 1,000 cubic feet, but the object was de-
feated by the existing Gas Companies, who opposed
their bill in Parliament, upon the ground that it would
interfere with vested interests. I am still satisfied,
however, that such a plan could be carried out with
great advantage to the public; and although I am no
longer specifically interested in the matter, I would
gladly lend my aid to those who might be willing to
realise the same.
Fuel also occurs in the liquid state, and if mineral
oils could be obtained in quantities at all comparable
to those of solid fuel, liquid fuel would possess the ad-
vantage of great purity and high calorific value; but,
considering its rare occurence and comparatively high
price, even in the oil districts of Pennsylvania and Can-
ada, its use for smelting purposes need not be here
considered.
According to the general definition of fuel given
above we have to include the evaporative effect of the
sun's rays, by which sea water is raised to elevated
mountain levels, whence it descends towards the sea,
and in so doing is capable of imparting motion to ma-
chinery.
This form of fuel, which takes the place of the coal
otherwise expended in raising steam, has been resorted
to in all countries, since the dawn of civilization, and it
is owing to this circumstance that the industries
of the world were formerly very much scattered
over the valleys and gorges of mountainous dis-
tricts, where the mountain stream gave motion to the
2826 Siemens--Iron and Steel Inst.--1877.
saw mill or flower mill, to the trompe of the iron smelt-
er, and to the helve of the iron and steel manufacturer.
The introduction of the steam engine, towards the
end of last century, changed the industrial aspect of the
world in causing manufactories to be massed together
in great centres, and this tendency has been still further
augmented in consequence of the construction
of canals and railways, which enable us to bring
together the raw material, and to disperse the manufac-
tured product at a comparatively low cost. It is not
unreasonable, however, to expect that a certain reac-
tion in this process of centralization will gradually take
place, because, of consequence of ever-increasing com-
petition, the advantage of utilizing natural forces, which
we could afford to neglect during a period of general
prosperity, becomes again an essential element in de-
termining the very lowest price at which our produce
may be sent into the market.
The advantage of using water power applies, however,
chiefly to Continental countries, with large elevated
plateaus, such as Sweden and the United States of
America, and it is interesting to contemplate the mag-
nitude of power which is now for the most part lost,
but which may be, sooner or later, called into requisi-
tion.
Take the Falls of Niagara as a familiar example.
The amount of water passing over this fall has been es-
timated at 100 millions of tons per hour, and its per-
pendicular descent may be taken at 150 feet, without
counting the rapids, which represent a further fall of
150 feet, making a total of 300 feet between lake and
lake. But the force represented by the principal fall
alone amounts to 16,800,000 horse-power, an amount
which, if it has to be produced by steam, would neces-
sitate an expenditure of not less than 266,000,000 tons
of coal per annum, taking the consumption of coal at
4 lbs. per horse-power per hour. In other words, all
the coal raised throughout the world, would barely suf-
fice to produce the amount of power that continually
runs to waste at this one great fall. It would not be
Siemens--Iron and Steel Inst--1877.
2827
difficult, indeed, to realize a large proportion of the power
so wasted, by means of turbines and water-wheels erected
on the shores of the deep river below the falls, supply-
ing them from races cut along the edges. But it would
be impossible to utilize the power on the spot, the dis-
trict being devoid of mineral wealth, or other natural
inducements for the establishment of factories. In or-
der to render available the force of falling water at this,
and hundreds of other places similarly situated, we
must devise a practicable means of transporting the
power. Sir William Armstrong has taught us how to
carry and utilize water-power at a distance, if conveyed
through high pressure mains, and compressed air
has been employed for the same purpose at
Schaffhausen, in Switzerland, as well as at some other
places on the Continent, where power is conveyed by
means of quick-working steel ropes passing over
large pulleys; by these means, it may be carried to a
distance of one or two miles without difficulty. Time
will probably reveal to us effectual means of carrying
power to great distances, but I cannot refrain from al-
luding to one which is, in my opinion, worthy of con-
sideration, namely, the electrical conductor. Suppose
water-power to be employed to give motion to a dyna-
mo-electrical machine, a very powerful electrical cur-
rent will be the result, which may be carried a great
distance through a large metallic conductor, and then
be made to impart motion to electro-magnetic engines,
to ignite the carbon points of electric lamps, or to effect
the separation of metals from their combinations. A
copper rod 3 in. in diameter would be capable of trans-
mitting 1,000 horse-power a distance of say 30 miles,
an amount sufficient to supply one-quarter of a million
candle-power, which would suffice to illuminate a
moderately sized town.
The use of electrical power has sometimes been sug-
gested as a substitute for steam-power, but it should be
borne in mind that so long as the electric power de-
pends upon a galvanic battery, it must be more costly
than steam-power, inasmuch as the combustible con
2828 Siemens--Iron and Steel Inst.--1877.
sumed in the battery is zinc, a substance necessarily
much more expensive than coal; but this question as-
sumed a totally different aspect if in the production of
the electric current a natural force is used which could
not otherwise be rendered available.
The force of the wind is another source of natural
power representing fuel according to the general defini-
tion above given, which, though large in its aggregate
amount, is seldom used, except in navigation, owing to
its proverbial uncertainty. On this account we may
dismiss it from serious consideration until our stores of
mineral wealth are well nigh exhausted, by which time
our descendants may have discovered means of storing
and utilizing it in a manner entirely beyond our present
conceptions.
Processes.—Having thus dwelt-too long, I fear, for
your patience-upon the subject of fuel, I now ap-
proach the question as to the processes by which we
can best accomplish our purpose of converting the crude
iron ore into such materials as leave our smelting works.
and forges.
The subject of blast furnace economy has already
been so fully discussed by you, during the term of office
of your past President, Mr. I. Lowthian Bell, M. P.,
F. R. S., who has done so much himself to throw light
upon the complicated chemical reactions which occur
in the blast furnace, that I may be permitted, on the
present occasion, to pass over this question, and to call
your attention more particularly to those processes, by
which iron is made to attain its highest qualities, both
as regards power of resistance and ductility.
Iron and Steel were known to the ancients, and are
referred to in their writings, but we have no account
of the processes employed in the manufacture of these
metals until comparatively recent times. Aristotle de-
scribes steel as purified iron, and says that it is obtained
by remelting iron several times, and treating it with
various fluxes; we are hence led to suppose that in
Aristotle's time steel was made by careful selection and
Siemens-Iron and Steel Inst.--1877. 2829
treatment of steely iron, which latter was produced by
something analogous to the Catalan process.
A method referred to by ancient authors is to bury
iron in damp ground for some time, and then to heat
and hammer it. Another process first described in
Biringuccio's "Pyrotechnology," one of the earliest
works on Metallurgy, and later in Agricola's "De Re
Metallica," both published in the 16th century, is to re-
tain malleable iron for some hours in a bath of fused
cast iron, when it becomes converted into steel. Réau-
mur, in 1722, produced steel by melting three parts of
cast iron with one part of wrought iron (probably in
a small crucible) in a common forge, but he failed to
produce steel in this manner upon a working scale.
A similar method of producing steel to that proposed
by Réaumur has been employed in India for ages, the
celebrated Wootz steel being the result of partial or
entire fusion of steely iron and carbonaceous matter, in
small crucibles arranged in a primitive air furnace, fol-
lowed by a lengthy exposure of the ingots to heated air
in order to effect a partial decarbonization.
In 1750, Hasenfratz refers, in his "Siderotechnic,"
to three processes for producing steel; melting broken
fragments of steel with suitable fluxes, fusing malleable
iron with carbonaceous matter, and so treating cast
iron (probably with oxides) as to obtain cast steel
directly from it.
The credit of producing cast steel upon a working
scale is due to Huntsman, who was the first to accom-
plish its entire fusion in crucibles, placed amongst the
coke of an air furnace, which fluid metal he poured into
metallic moulds. This process is still carried on largely
at Sheffield for the production of special qualities of
steel, such as tool steel, tyre steel, castings and forg-
ings, and a ton of cast steel in ingots is produced with
the expenditure of from 2 to 3 tons of Durham coke,
according to the degree of mildness of the metal de-
sired.
At Pittsburg, where pot-melting is employed on a
considerable scale, plumbago pots having nearly double
2830 Siemens--Iron and Steel Inst.--1877.
the capacity of the Sheffield clay pots are invariably
used; 18 or 24 of these pots, each containing about a
hundred weight of metal, are placed in a gas furnace,
and each pot lasts twenty-four hours, yielding five
charges during that interval. The fuel consumed
amounts to one ton of small slack per ton of steel
melted, which is delivered to the works at the surpris-
ingly low price of 30 cents per ton. With these im-
portant advantages in his favour, the American steel
melter should be able, one would think, to meet with-
out protection his Sheffield competitor in the open
market.
With regard to Bessemer steel, great advances have
been made in recent times in cheapening its production.
At Creusot and other Continental works, a system of
direct working, or of transferring the pig metal in the
molten condition from the blast furnace to the Bessemer
converter, has been introduced, and the same method
has been recently adopted at several of the leading
English works. By this method of working, the fuel
usually employed in remelting the pig metal in the
cupola (say 24 cwt. per ton) is clearly saved, and other
advantages are realized, but, on the other hand, the
Bessemer converter is made dependent upon the work-
ing of the blast furnace, both as regards time and the
quality of the resulting metal. At Barrow and other
large works where a number of blast furnaces supply
several Bessemer converters in addition to pig metal
for the open market, this mode of working appears to be
practically free from the objection above stated, and a
hot ladle with its engine may be kept steadily at work
transferring the pig metal from one blast furnace or
another to the converters. But it still remains to be
seen whether any practical advantage can be
realized by this method of working at smaller
works, where a change in the working of the blast fur-
nace from Bessemer to forge pigs would cause a serious
interruption in the working of the Bessemer plant.
In America, the efforts of the iron master have been
directed-chiefly under the guidance of Mr. A. L.
Siemens-Iron and Steel Inst.-1877. 2831
Holley towards a saving of labour, by increasing to an
almost incredible extent the number of blows per diem.
from each converter. Thus I was informed that at the
north Chicago Steel Works, as many as 73 blows has
been obtained in one pit in 24 hours, although I have
reason to doubt whether this rate of working could be
maintained for any length of time. The Americans
have not adopted, so far as I could ascertain, the direct
process of working, but are content to re-melt their
pig metal in large cupolas in immediate proximity to
the converters. The capacity of the converters has lat-
terly been much increased, and the degree of heat en-
gendered by a blast of increased power, has been aug-
mented to such an extent that a considerable amount
of scrap metal can be re-melted within the fluid bath
before discharging the same into the ingot moulds.
Whilst the Bessemer process has been making rapid
strides, another process has gradually grown up by its side
which I cannot pass over without remark. I allude to
the open hearth steel process with which my name and
the joint names of Siemens and Martin are associated.
The conception of this process is really as old as that
of cast-steel itself. The ancient Indian steel, the
Wootz, was the result of a fusion of a mixture of mal-
leable iron and carbon. Réaumur, as already stated,
proposed to melt wrought iron and pig metal together
for the production of steel as early as 1722; and J. M.
Heath-to whom we owe the important discovery that
by the addition of manganese to cast steel its mallea-
bility is greatly increased-endeavored to realize the
conception of producing steel in large masses upon the
open hearth of the furnace in the year 1839, and he
again has been followed in these endeavors by Gentle,
Brown, Richards and others in the same direction.
When, in 1856, I first seriously gave my attention,
in conjunction with my brother (Frederick Siemens),
to the construction of a regenerative gas furnace, I
perceived that this furnace would be admirably adapted
to the production of steel upon the
hearth, and I remember proposing it for such a purpose
open.
2832 Siemens-Iron and Steel Inst.-1877.
to Mr. Abraham Darby, of Ebbw Vale, in 1861. Ever
since that time I have been engaged in the realization
of this idea, which has been retarded, however, by those
untoward circumstances which ever intervene between
a mere conception and its practical realization. Al-
though two of my earlier licensees, Mr. Chas. Attwood,
of Tow Law, and the Fourchambault Company, in
France, (with whom was my esteemed friend, the late
M. Lechatelier, Inspecteur General des Mines), suc-
ceeded in 1865 and 1866, in producing steel upon the
open hearth, they did not persevere sufficiently to attain
commercial results; and it was not until after I had
established experimental steel works at Birmingham,
that I was enabled to combat in detail the various diffi-
culties which at one time looked well-nigh insuper-
able.
Whilst thus engaged, Messrs. Pierre and Emile Mar-
tin, of Sireuil, who had obtained licenses for furnaces
to melt steel both in pots and on the open hearth, suc-
ceeded, after a short period of experimenting, in intro-
ducing into the market open-hearth steel of excellent
quality.
Messrs. Martin gave their attention to the production
of steel by the dissolution of wrought iron and steel
scrap in a bath of pig metal, whilst my own efforts.
were more especially directed to the production of steel
by the use of pig metal and iron ores, either in the raw
state, or in a more or less reduced condition, which lat-
ter process is the one mostly employed in this country.
One of the advantages that may be claimed for the
open-hearth process consists in its not being dependent
upon a limited time for its results. The heat of the
furnace is such that the fluid bath of metal, after being
reduced to the lowest point of carbonization, may be
maintained in that condition for any reasonable length
of time during which samples can be taken and tested,
and additions either of pig metal, of wrought scrap,
spongy metal, or ore, may be made to it so as to adjust
the metal to the desired temper. The requisite propor-
tion of spiegeleisen, or ferro-manganese, is then added
Siemens-Iron and Steel Inst.-1877. 2833
in the solid condition, and the result is a bath
of metal, the precise chemical condition of which
is known, and which has the advantage, if prop-
erly managed,
managed, of being what is technically
called "dead melted." This circumstance renders it
applicable for certain purposes for which pot steel has
hitherto been mostly employed.
The purpose to which the open-hearth process is
more especially applicable is for the conversion of
scrap steel and iron of every description into steel or
ingot metal, and it is now used, indeed, to a large ex-
tent for the conversion into steel of old iron rails.
The wearing qualities of these converted rails have
been under test since 1867, when the Great Western
Railway Company had some old Dowlais iron rails
converted into steel at my Experimental Steel Works
at Birmingham, which was rolled into rails by Sir John
Brown & Co.; these have been down ever since that
time at Paddington, subjected to great wear and tear.
The manufacture of steel, both by the Bessemer
and the open-hearth processes, is much facilitated by the
use of ferro-manganese. This material was introduced
into the market in 1868, by Mr. Henderson, of Glas-
gow. It was produced successfully by charging car-
bonate or oxide of manganese, and manganiferous iron
ore intimately mixed with carbonaceous matter upon
the open-hearth of a Siemens furnace with a carbo-
naceous lining; but the demand for this material was
not sufficient to render the manufacture profitable at
that time, and it was not until the year 1875 that it
was re-introduced into the market by the Terre-Noire
Company.
Manganese, when added in a proportion of .5 per
cent., or more, to steel or ingot metal, containing from
.15 to .20 per cent. of carbon, has the effect of re-
moving red-shortness, and of making it extremely
malleable both in the heated and cold conditions.
using spiegeleisen containing only from 10 to 15 per
cent. of metallic manganese, it is possible to supply the
amount necessary to produce this malleability without
2834 Siemens-Iron and Steel Inst.--1877.
adding, at the same time, such a percentage of carbon
as would produce a hard metal. The use of ferro-
manganese enables us to overcome this difficulty, and
greatly faciliates the production of a metal so malleable
and with so little carbon as to remain practically un-
affected in its temper when plunged red-hot into water.
Another result produced by the use of manganese
without carbon upon mild steel or ingot metal, is to
neutralize the objectionable effect of phosphorus, so
long as the latter does not exceed the limit of .25 per
cent. This metal, in which phosphorus may be said to
take the place of carbon, presents a large specular
fracture, and is, contrary to what might have been ex-
pected, extremely ductile when cold.
Iron when in the fluid condition can be alloyed with
other metals, and some of the compounds thus formed
are known to possess very remarkable properties.
Thus, iron, combined with 3 per cent. of tungsten and
8 per cent. of carbon, yields a metal which can be
worked like ordinary steel, but which when hardened,
retains magnetism to a very remarkable degree, a prop-
erty which was discovered by Dr. Werner Siemens in
1853. A further addition of tungsten produces an
exceedingly hard metal (introduced into the market by
Mr. Mushet in 1868) which cannot be forged, but
which when cast into bars and ground so as to form a
sharp edge, produces cutting tools of capable of great
endurance.
An admixture of chromium has for many years past.
been known to produce steel of great hardness and
strength, but it is only quite recently that it has been
brought into practical use in America by Mr. Julius
Baur, and has been taken up in this country by Sir John
Brown and Co., of Sheffield, who claim for it very re-
markable properties as regards strength, malleability,
and freedom from corrosion.
The formation of compounds such as these is a mat-
ter of great interest in connection with the future de-
velopment of the applications of steel, and is one of
those subjects which I venture to suggest might be
1
Siemens-Iron and Steel Inst.-1877. 2835
much advanced by an organized research, under the
auspices of a committee of the Iron and Steel Institute.
The value of the material known as mild steel or
ingot metal consists in its extreme ductility under all
possible conditions. Its ultimate strength is much in-
ferior to that of ordinary steel, and rarely exceeds 28
tons per square inch; the limit of elasticity of a harder
steel may reach from 25 to 30 tons per square inch,
and that of hard drawn steel wire from 45 to 50 tons.
But in estimating the relative value of these different
materials by the amount of work that has to
be expended in causing rupture, it will be found
that the mild steel has the advantage over its com-
petitors. When subjected to blows or sudden strains,
such as are produced by the explosion of gun cotton
or dynamite, extra mild steel differs in its behaviour
from that of B B iron and ordinary steel, by yielding
to an extraordinary extent without fracturing and it is
in consequence of this non-liability to rupture that it
may be loaded to a point much nearer to its limit of
elasticity than would be safe with any other material.
Attention has been recently directed in various
quarters to remedy defects appertaining to steel, viz.,
piping and showing honey-combed appearance in the
ingot. It is well known that if such steel is hammered
and rolled, the open spaces contained in it are elon-
gated and seemingly closed up, but in reality continue
to form severances within the metallic mass, to the
prejudice of the uniform strength of the finished
forging.
•
In casting steel containing more than 5 per cent. of
carbon the defect of honey-combing can easily be
avoided if care is taken to have the metal "dead
melted before pouring it into the mould, and that of
piping by continuing the inflow of fluid metal for a
sufficient length of time while it is setting. But in
dealing with mild steel containing only 2 per cent. of
carbon, the difficulty of making a sound casting is
greatly increased. Much may be done, however, by care-
ful manipulation of the fluid metal and by the judicious
2836 Siemens-Iron and Steel Inst.--1877.
addition to it of manganese or other oxidizable metals,
such as silicon or lead, by which occluded oxygen is
removed.
Sir Joseph Whitworth, who, as you well know, has
given much attention to this subject, has overcome the
evil mechanically by subjecting the steel, while setting
in the mould, to great hydraulic compression. He has
thus succeeded in producing, in large masses, mild
steel of extremely uniform strength and the only doubt
which could possibly be raised against the advisability
of producing fluid steel for ordinary applications by
this method is founded on considerations of cost.
The subject of producing sound steel castings is one
which we shall have an opportunity to discuss in refer-
ence to a paper which will be presented by Mr.
Gautier.
Application of Steel. The employment of steel for
general engineering purposes, dates only from the
year
1851, when Krupp, of Essen, astonished the world by
his exhibits of a steel ingot weighing 2500 lbs., and of
his first steel gun, and introduced a comparatively mild
description of pot steel for steel tyres, axles and crank
shafts. For the production of these he constructed his
celebrated monster hammer, with a falling weight of 45
tons, which, at that time, far surpassed in magnitude
and power our boldest conception, and is now only
being exceeded by a still more powerful hammer in
course of erection at the Essen Works. Krupp's steel
was, however, not cheap steel, and it is to our past
president, Mr. Henry Bessemer, and to the important
addition made to his process by Mr. Mushet, that we
are indebted for the production of steel at such a re-
duced cost as to make it available for railway bars and
structural purposes in substitution for iron, since which
event the application of this superior material shows a
most extraordinary rate of increase. Not only do we
travel upon steel tyres, running over steel rails, but at
least one of our leading railway companies, the London
and Northwestern, has, under the able management of
Mr. F. W. Webb, constructed as many as 748 locomotive
Siemens--Iron and Steel Inst.--1877. 2837
engines, including boiler, frame, and working parts,
entirely of that material, excepting only the fire-boxes
which are still made of copper. In France, also, much
attention has been given to the introduction of steel for
machinery purposes, and there, as well as in the United
States, Germany and Holland, that material is used
largely in the construction of bridges and other engineer-
ing works.
In this country the application of steel for structural
purposes has occupied the attention of some of our
leading engineers for many years, and Sir John Hawk-
shaw, when called upon to construct a railway bridge
at Charing Cross in 1859, proposed the use of steel in
order to lighten the structure. He was prevented, how-
ever, from carrying this idea into effect by the rules of
the Board of Trade, which provide that wrought ma-
terial of any kind shall not be weighted either in com-
pression or extension to more than five tons per square
inch. Repeated efforts have been made since that time
to induce the Board of Trade to adopt a new rule, in
which the superior strength of steel should be recognized,
and in order to facilitate their action a committee was
formed, consisting of Mr. William Henry Barlow, Capt.
Galton and others, who carried out-with the pecuniary
aid of leading steel manufacturers-a series of valuable
experiments, showing the limit of elasticity and ulti-
mate strength of various steels. The results obtained
are published separately in "Experiments on the Me-
chanical and other Properties of Steel by a Committee
of Civil Engineers."
A
At the instance of Mr. Barlow, the British Associa-
tion appointed a further Committee to promote the
object of obtaining for steel its proper recognition, and
this had led finally to the appointment under the sanc-
tion of the Board of Trade of three gentlemen, viz.,
Sir John Hawkshaw, F. R. S., and Mr. William Henry
Barlow, F. R. S., (who were nominated by the Council
of the Institution of Civil Engineers), and of Colonel
Yolland, F. R. S., of the Board of Trade, who have
agreed upon a report recommending the use of steel as
2838 Siemens--Iron and Steel Inst.--1877.
a building material, subject to a limit of strength
greatly in excess of the limit assigned to wrought iron.
It is to be hoped that the Board of Trade, by adopting
that report, will remove the serious drawback which
has too long stood in the way of the application of
steel for structural purposes, and which has rendered
the construction of large works, such as the pro-
jected bridge over the Firth of Forth practically impos-
sible.
As regards the construction of ships of extra mild
steel, the English Admiralty, following the example set
by France, has under the advice of Mr. Barnaby, the
Chief Constructor, taken the lead of the commercial
navy of the country, and several corvettes have recently
been constructed entirely of that material at the Gov-
ernment Yard at Pembroke and
Pembroke and upon the Clyde.
The constructors of merchant shipping have hitherto
been restricted by rules laid down by Lloyd's Registry,
which make no distinction between common iron and
steel in determining the classification of a vessel. It
is to be hoped that the important engineering and ship-
building interests of the country will soon be released
from regulations which may have been well adapted to
the use of an inferior material such as common iron, but
fail entirely to meet the requirements of the present
day.
In shipbuilding, the use of a material superior in
toughness and in strength produces the double ad-
vantage of greater safety to life and property, and
of an increase of carrying capacity to the full amount
of weight saved in the construction of the ship.
It should be borne in mind that this additional weight
of merchandise is carried without increasing the work-
ing expenses of the ship and power required in its pro-
pulsion, and may just suffice to strike the balance
between working a vessel designed for long voyages at
a fair profit or at a loss. In constructing the masts and
yards of vessels of the stronger material, the weight
saved is a matter of still greater importance, and I am
Siemens--Iron and Steel Inst.--1877. 2839
glad to say that this question now engages earnest
attention.
In the United States a committee, composed of both
military and civil engineers, have been engaged for
some time upon the subject of determining experiment-
ally the structural value of iron and steel. This Com-
mittee have the advantage of substantial support from
the United States Government, who, after a first grant
of 75,000 dollars, have, I observe, voted a further sum
of 40,000 dollars in aid of the experimental inquiries
which have been instituted.
·
The council of the Iron and Steel Institute are not
unmindful of the importance of this subject, and have
invited those gentlemen of this and other countries
who have given most attention to the production and
application of steel to aid us in our forthcoming dis-
cussion with the results of their experience.
In the course of this discussion the distinctive limits
between steel and iron will necessarily engage your
attention. Considering the extraordinary change of
physical condition which iron undergoes when alloyed
with small percentages of carbon, manganese, phos-
phorus, tungsten, chromium and other substances, and
considering, further, that it is never quite free from
some admixture, the question of nomenclature is one
naturally surrounded with difficulty; but it is becom-
ing one of considerable practical importance when rules
are to be laid down regulating the permissible strength
of different grades of these materials.
Dr. Percy has, in his "Metallurgy of Iron and Steel,”
defined steel as iron containing a small percentage of
carbon, the alloy having the property of taking a tem-
per, and this definition is substantially equivalent
to those found in the works of Karsten, Wedding,
Grüner, and Tunner; on the other hand, Messrs. Jordan,
Greiner, Gautier, Phillipart, Holley, and others, define
as steel all alloys of iron which have been cast and are
malleable, whilst Sir Joseph Whitworth considers that
steel should be defined mechanically by a co-efficient
representing the sum of its strength and ductility.
2840 Siemens--Iron and Steel Inst.--1877.
With the object of settling this question of nomen-
clature, an International Committee was appointed at
Philadelphia, by the American Institute of Mining
Engineers. The Committee consisted of the following
gentlemen: Mr. I. Lowthian Bell, M. P.; Dr. Her-
mann Wedding, Professor Tunner, Professor Oker-
mann, M. Grüner, Mr. A. L. Holley, and Mr. T.
Egleston, and they resolved upon the following recom-
mendation:
I. That all malleable compounds of iron, with its ordinary ingre-
dients, which are aggregated from pasty masses, or from piles, or
from any form of iron not in a fluid state, and which will not
sensibly harden and temper, and which generally resemble what is
called wrought iron, shall be called weld-iron (German, Schweiss-
cisen, French, Fer-soudé).
II. That such compounds when they will from any cause
harden and temper, and which resemble what is now called "pud-
dled steel," shall be called weld-steel (German, Schweiss-stahl,
French, Acier-soudé).
III. That all compounds of iron, with its ordinary ingredients,
which have been cast from a fluid into malleable masses, and which
will not sensibly harden by being quenched in water while at a
red heat, shall be called Ingot iron (German, Fluss-eisen, French,
Fer-fondu).
IV. That all such compounds, when they shall from any cause
so harden, shall be called Ingot steel (German, Fluss-stahl, French,
Acier-fondu).
The nomenclature here proposed is entitled to care-
ful consideration from the eminence, for both theoreti-
cal and practical knowledge, of the gentlemen com-
posing the committee, but I apprehend that for common
use, the distinctions desired to be drawn are too
manifold. Moreover, the lines of demarcation
•
laid down run through materials very similar,
if not identical in their application, where
a distinction in name would be extremely difficult to
maintain, and awkward to draw. Take, for instance,
railway bars from ingot-metal, which are usually speci-
fied to bear a given dead load without deflecting beyond
certain limits, and to resist a certain impact without
rupture. The materials answering to these require-
ments contain from 2 to 6 per cent. of carbon, depend-
Siemens-- Iron and Steel Inst.-1877. 2841
ing in a great measure upon the mode of production,
and upon the amount of admixture of phosphorus, sul-
phur, silicon and manganese. But inasmuch as the
quality of tempering is chiefly due to carbon, part of
the rails delivered under such specification might have
to be classified as ingot-iron, and part as ingot steel.
The Committee omits to define the degree of hardening
which it considers necessary to bring a material within
the denomination of ingot-steel; it is well known, how-
ever, that the temper depends upon the exact tempera-
ture to which the metal is heated before being plunged
into the refrigerating medium, and also upon the tem-
perature and conductivity of the latter, and that ingot
metal with only 2 per cent of carbon, when plunged hot
into cold water, takes a certain amount of temper. The
question of the amount of import duties payable in for-
eign countries upon metal occupying a position near
the proposed boundary line would also lead to consid-
erable inconvenience.
Difficulties such as these have hitherto prevented
the adoption of any of the proposed nomenclatures, and
have decided engineers and manufacturers in the
meantime, to include, under the general denominations
of cast steel, all compounds consisting chiefly of iron,
which have been produced through fusion, and are mal-
leable. Such a general definition does not exclude from
the denomination of steel materials that may not have
been produced by fusion, and which may be capable of
tempering, such as sheer steel, blister steel, and pud-
dled steel, nor does it interfere with distinctions be-
tween cast steels produced by different methods, such
as pot steel, Bessemer steel, or steel by fusion on the
open-hearth. The forthcoming discussion will, I hope,
lead to some general agreement regarding this question
of nomenclature.
Wrought Iron.-While steel is gradually supplanting
wrought iron in many of its applications, efforts are being
made to maintain for the latter material an independ-
ent position, for cheapness and facility of manipulation,
by improving the puddling process.
2842 Siemens--Iron and Steel Inst.--1877.
Mechanical puddling, like many other important in-
ventions, has taken a long time for its development,
and has engaged the attention of many minds, but I
will only here mention the names of Tooth, Yates and
Mr. Menelaus, our past president, who have pioneered
the road; and of Danks, Spencer, Crompton and others,
who have followed more recently in the same direction.
It is chiefly owing, however, to the persevering endeav-
ors of Mr. Heath and of Messrs. Hopkins, Gilkes & Co.,
that the mechanical puddling of pig metal has been
accomplished with a considerable amount of succes.
All the efforts have had reference to puddling in a
chamber rotating upon a horizontal axis, but numerous
attempts have also been made to accomplish mechani-
cal puddling by the introduction into stationary cham-
bers of rabbles moved by mechanical power, and by the
use of chambers rotating upon an inclined axis, in con-
nection with which latter the names of Maudsley, Sir
John Alleyne and Pernet should be mentioned. The
principal difficulty connected with the rotary puddling
furnace consists in providing a lining of sufficient power
to resist the corrosive action produced by silicious
slags, and it is important, therefore, that the pig metal
introduced into the rotative puddler should be as free
from silica as possible. By charging fluid metal into
the furnace the silica adhering to the pigs in the form
of sand is got rid of, but efforts have latterly been made,
with satisfactory results, I believe, to subject the pig
iron itself to a simple finery process on its way from
the blast furnace to the rotative puddler, with a view
of removing the silicon chemically combined with the
pig. M. Hamoir, of Belgium, has been engaged upon
this subject for some years, as you will have seen
from the "Report on the Progress of the Iron and
Steel Industries in Foreign Countries" in our journal,
while in this country, Mr. I. Lowthian Bell has called
the Bessemer converter into requisition for effecting
the desired effect.
We are informed that not only does the
lining of the furnace stand better in using this semi-
Siemens--Iron and Steel Inst.--1877. 2843
refined metal, but that the yield per furnace per diem,
as well as the quality of the metal obtained, are much
improved.
It is intended to roll the metal thus produced into
railway bars, without any intermediate process of re-
heating, and to subject the rails to a process of case-
hardening similar to what was practiced some years.
ago by D. Dodds, in South Wales. The case-hardened
iron rails are expected to rival steel rails in quality,
but it remains to be seen whether their wearing prop-
erties will not be obtained at the cost of brittleness,
and whether rails manufactured by this method will be
able to compete in price with steel rails.
Three years ago, I had the honour of bringing be-
fore the Institute a plan of producing wrought iron
directly from the ore, in a rotative furnace of special
construction, and heated by gas. This process was at
that time only carried on upon a small scale, at Tow-
cester, and in Canada, and although the results hith-
erto obtained cannot yet be considered entirely satis-
factory from a commercial point of view, I see no rea-
son to feel discouraged as regards the ultimate result
of this method of treating iron ore. By it, iron
of almost entire freedom from sulphur and phosphorus
is obtained from ores containing a considerable per-
centage of these impurities. If steel is to be pro-
duced, the raw balls as they leave the rotating furnace,
are either immediately transferred to the bath of the
open-hearth furnace, or are previously subjected to the
processes of squeezing and hammering for the removal of
scoria, which otherwise carries some of the impurities
contained in the ore into the metalic bath, and pre-
vents the attainment of steel of a high quality.
One of the drawbacks to the use of iron and steel
for structural purposes is found in their liability to
rust when exposed to air and moisture. The ordinary
means of protection against rust consists in covering
the exposed surfaces with paint, and if this is renewed
from time to time, iron or steel may be indefinitely
preserved from corrosive action. Another mode of
2844
Siemens--Iron and Steel Inst.--1877.
protection consists in dipping articles of iron and steel
while hot into a bath of oil, when some of the oil
penetrates to a slight depth into the pores of the
metal, while other portions become decom-
posed, and form a very tenacious resinuous
coating. For the protection of iron and
steel, when in the form of thin sheets or
wire, galvanizing, as is well known, is largely resorted
to.
The protection in this case depends upon the fact
that zinc, although more oxidizable than iron, forms
with oxygen an oxide of a very permanent nature which
continues to adhere closely to the metal, and thus pre-
vents further access of oxygen to the same. This mode
of protection presents the further advantage that so
long as any metallic zinc remains in contact with the
iron in presence of moisture, the latter metal forms
with the zinc the negative element of an electrolytic
couple, and is thus rendered incapable of combining
with oxygen.
Galvanizing is not applicable in those cases in which
structures of iron and steel are put together by the aid
of heat, or are brought into contact with sea water,
which would soon dissolve the protecting zinc covering.
But even in these cases the metal may be effectually
protected against corrosion by attaching to it pieces of
zinc, which latter are found to dissolve in lieu of the
iron, and must, therefore, be renewed from time to
time.
Captain Aynsley, of the Admiralty, has lately made a
series of valuable experiments, showing the relative ten-
dency toward corrosion of both iron and steel when in
contact with sea water, and of the efficacy of pieces of
zinc in preventing this corrosion. These experiments
further show that mild steel is-contrary to the results.
obtained by M. Gautier-more liable to corrosion than
wrought iron in its unprotected condition, but that zinc
acts most efficaciously in protecting it.
Quite recently another mode of protecting iron and
steel plates from corrosion has been suggested by Pro-
Siemens--Iron and Steel Inst.--1877. 2845
fessor Barff. This consists in exposing the metallic
surfaces, while heated to redness, to the action of super-
heated steam, thus producing upon their surface the
magnetic oxide of iron, which, unlike common rust, pos-
sesses the characteristic of permanency, and adheres
closely to the metallic surface below. In this respect
it is analogous to zinc, oxide adhering to and protecting
metallic zinc, with this further advantage in its favor,
that the magnetic oxide is practically insoluble in sea
water and other weak saline solutions. Time will show
to what extent this ingenious method of protecting iron
and steel can be made practically available.
Before concluding this address, I wish to call
your attention to a matter which will require your early
consideration. The Iron and Steel Institute has now
attained an influential position, and is likely to increase
from year to year in its beneficial action upon the
further development of a trade which may justly be
claimed to be the most important in this country. In
order to give additional weight to its action, it seems
necessary that its position should be recognized in
official quarters, and that it should be possessed of a
habitation in a central locality, which should comprise
office accommodation, a library, a model room, a
lecture room and laboratory. Such a building, if
especially erected for the Iron and Steel Institute,
would exceed the means at their disposal for such a
purpose, but the moment has arrived when other insti-
tutions devoted to the cultivation of different branches
of applied science feel the necessity for similar accom-
modation. Would it not be possible for our Institute
to join efforts with those kindred institutions, for the
erection of a joint building, representing applied science
as completely as Burlington House represents pure
science. Such a project could not be realized without
the concurrence of the parent institution of applied
science, "The Institution of Civil Engineers," whose
building, though large, is by no means sufficient for its
actual requirements. The new building might, there-
fore, accommodate the Institution of Civil Engineers, the
2846 Siemens---Iron and Steel Inst.--1877.
Institution of Mechanical Engineers, the Institution of
Naval Architects, the Society of Telegraph Engineers,
the Iron and Steel Institute, and possibly other societies
which hold their ordinary meetings on different days of
the week, and some of them at considerable intervals
of time; it would not, therefore, he necessary to provide
more than one, or perhaps two, general meeting rooms,
and one library, but each society would require separate
office accommodation and council chambers, the whole
being so arranged as to be able to be thrown open for
the holding of conversaziones.
The common interests of the societies might be
placed under the supervision of a joint House and
Library Committee, presided over by the President of
the Institution of Civil Engineers, and comprising
amongst its members one or two members of councils
and the secretaries of the different societies.
The Government would probably not be unwilling to
further the realization of an object of such great use-
fulness by granting a site in a central portion of the
metropolis. Each society might be called upon to
furnish a portion of the capital required, either out of
its accumulated funds, or by voluntary contributions of
its members, and the remainder could probably be
raised upon debentures, and thus become chargeable
upon the ordinary subscriptions of future years.
The details of such a scheme would, of course, require
most careful consideration; but I believe that the
present moment would be favourable for its realization
if you, as well as the other scientific bodies concerned,
consider the matter worthy your attention.
The great variety and importance of subjects of in-
terest to our Institute are my apology for having
detained you longer than I intended to do in reading
this address.
Preece--"Nature "--1879.
2847
Complainant's Exhibit, Editorial by W.
H. Preece.
"GAS VERSUS ELECTRICITY."
"NATURE," JANUARY 23, 1879, VOL. 19, P. 261.
The gas companies are at last awakening to the pe-
culiarity of their position, and gas-shareholders are re-
covering their confidence in the stability of their
property. It is interesting to observe how steadily the
shares in all the great gas companies have during the
last few weeks been rising, and unless any untoward
event occurs there is no reason why in a short time
they should not recover the position they so singularly
lost in August of last year. Looking dispassionately
upon the events that have occurred, it is difficult to
understand how such a panic and scare could have
arisen. Nothing of any sort or kind has been discov-
ered either in the laws of electricity or in their applica-
tion to electric lighting to account for it. We know no
more of the electric light now than we did in 1862,
when as great a display was made in our Exhibition
of that year as was made in the French Exhibition of
last year. There is no doubt, however, that the enter-
prise of our neighbours on the other side of the Chan-
nel in lighting up so brilliantly one of their grand new
streets produced a sensation that will not easily be for-
gotten. Engishmen never like to be beaten. We are
accustomed to be startled by inventions from the other
side of the Atlantic, but we are not accustomed to be
beaten either in commercial enterprise or in inventive
skill by our neighbours on this side of the Atlantic.
Hence, all of those, whose name is legion, who visited
Paris last year came back with exaggerated ideas of the
effect of the electric light in the Avenue d l' Opéra, and
spread through England a profound opinion of the
value of electricity as a means of illumination.
It seems to be forgotten that only three years ago a
2848
Preece-"Nature"--1879.
competitive trial of gas and electricity was made in the
clock tower of the Houses of Parliament. Each of
these lights were tried for several months, the electric
light being a Serrin lamp lit by a Gramme machine;
and that, after a very careful examination, gas was suc-
cessful, was adopted, and is now used by the Office of
Works.
Again, it seems to be forgotten that the Elder
Brethren of the Trinity House have been experiment-
ing upon this question ever since 1857, and that the
results of their experiments have only led to the adop-
tion of the electric light in three of their lighthouses.
If the electric light had had the wonderful advantage
over gas or oil that its projectors profess for it, surely
the governors of such an institution as the Trinity
House would have fitted up all the lighthouses upon
our coasts with this wonderful light.
The recent experiments, however, have shown both
the strength and weakness of the position of the gas com-
panies. Their strength consists in their being in posses-
sion of the ground; their weakness consists in their pro-
ducing only a poor light-and a very poor light-when
compared with electricity. But is there any reason
why this weakness should continue? Is there any rea-
son why gas should remain such an indifferent light?
There is none but that of expense, and expense will not
deter people from having a better light if they can only
get it. The Phoenix Company has taken the question
in hand, and has shown in the Waterloo Road what can
be done with gas when the question of expense is not
considered. Indeed, it would almost seem, from the
experiments that have been made, that the quantity of
light to be produced by gas is only a question of the
quantity of gas consumed in a given space. There are
now burning in the Waterloo Road two brilliant gas
lamps, giving a light of 500 candles, and this is greater,
in point of fact, than the intensity of the light devel-
oped by any one of the electric lights that are now on
trial in the thoroughfares of London. There is, how-
ever, a defect in gas light which remains to be eradica-
Preece--" Nature ”—1879.
2849
ted, and that is the colour of the light. The one great
advantage which the electric light has over gas is that
the electric light, owing to its very high temperature,
produces rays of every degree of refrangibility, and
therefore, as an illuminating power it is equal to that
of the sun. But gas light, owing to the lowness of its
temperature, is deficient in blue rays, and is therefore
not so effective in discriminating colours as the electric
light.
A very marked advance towards perfection in this
direction in gas lighting has been made in the albo-car-
bon process, by which the gas burnt is enriched with
the vapour of naphthaline-a refuse of gas manufac-
ture. This process is being introduced by Mr. Livesey,
and, to judge by the experiments that have been shown,
it is very promising indeed. The intensity of the light
of a gas burner is improved at least five times, and in
some experiments witnessed by the writer the improve-
ment was as much as twenty times.
The tentative trials that are being made with the
electric light in London cannot be said to be very suc-
cessful. That at Billingsgate was certainly a fiasco,
that on the Embankment is very brilliant, but we have
yet to learn its cost, and there is no doubt whatever
that the efficiency of the light is very much less than
that usually ascribed to the electric light. The trial on
the Holborn viaduct is not a success. The experiment
seems to be conducted by some one who is not experi-
enced in the working of electric circuits, for occasion-
ally all the lamps are found extinguished, on other
occasions only a portion of them are burning, and fre-
quently they are very dull. It is quite difficult even at
the distance of the Post Office to distinguish the gas
from the electric lamp. The same effect is observed on
crossing Blackfriars Bridge and looking towards the
Houses of Parliament when there is the slightest mist
in the air, and it is quite evident that electric light has
no more-if as much-penetrative power than gas.
A most complete and careful inquiry into the work-
ing of the electric light has been made by Mr. Louis
2850
Preece-" Nature "-1879.
Schwendler for the East Indian Railway Company, and
his results are extremely interesting. He has recom-
mended the introduction of the light into certain rail-
way stations where no gas exists, and the system he
proposes to use is the Siemens dynamo-machine and
one Serrin lamp, and thereby save that waste which
the multiplication of the light unquestionably produces.
He proposes to distribute this single light by diffusion
on a plan originally suggested by the Duke of Suther-
land. His investigation has been conducted in a thor-
oughly scientific spirit, and when his report is published
it will be a very valuable addition to our knowledge of
the theory of the electric light. It has been shown by
the writer that the full effect of the current can only be
obtained by one lamp on a short circuit, and that when
adding to the lamps by inserting more of them on the
same circuit, or on a circuit so that the current is subdi-
vided, the light emitted by each lamp is diminished in
the one case by the square, and in the other case by the
cube of the number of lamps so inserted. Dr. Siemens
maintains also the concentration of the power on one
light, but other experimentors are endeavouring to par-
tially multiply the light. For instance, M. Rapieff, in
the Times office, very successfully distributes six lights
about the office, and Ladd and Co., with the Wallace
form of machine, also distribute six lights over the Liv-
erpool Street Station. Although there is undoubtedly
a loss of power in this distribution of the lamps, there
may be an advantage in such distribution in cases like
printing offices and railway stations. A successful ex-
periment has been made by the British Electric Compa-
ny in lighting up some of the stations of the Metropoli-
tan Railway Company, and the India Rubber and Gutta
Percha Company have been successful in lighting up
the London Bridge station of the London Brighton and
South Coast Railway Company. In all these cases we
have scarcely emerged from the sphere of experiment.
The electric light has not yet been permanently intro-
duced on any large scale. Many are trying it, many
are captivated by the brilliancy of the light, and many
in their eagerness to keep up with the spirit of the age,
Preece--" Nature 2851
""
-1 79.
are introducing it, as, for instance, the London Stereo-
scopic Company, and the Messrs. Nichols, the clothiers
in Regent Street, where, however, the light does not ap-
pear to give very great satisfaction through its fluctua-
tion.
We were led to expect very much from the experi-
ments of Mr. Werdermann, but his attempt to subdivide
the light seems to have subsided, for we have heard
nothing of it for some time past. Again, we have heard
no more of M. Arnaud's discovery, and the accounts
that reach us from America of the doings of the Sawyer-
Man light, and the supposed discoveries of Mr. Edison,
are unworthy of attention.
The present state of the electric light question may
therefore be said to be a tentative one, and the gas
companies are with much enterprise now giving their
retort courteous by showing that they are in a position
-if people choose to pay for it-to give quite as pow-
erful a light as the electric light; and, let us hope, be-
fore long that it will be quite as perfect. There can be
no doubt that the use of electricity for the production.
of light is a very wasteful as well as a costly process, for
the energy that is generated in the machine is not all
consumed in the lamp, but is proportionately distribu-
ted over the whole circuit. It is therefore not utilised
only in the place where it is wanted, as in the case of
gas. If we are using a certain amount of energy in an
electric lamp to light a street, we are wasting as much
if not more energy in the street in maintaining the
current to produce that light.
There are three points which all electric lights for
general purposes should be required to attain. The
first is a brilliancy far exceeding that of any known lamp;
the second is a durability greater than that which would
be required for night operations in England; and the
third is absolute steadiness, to enable work to be con-
ducted without affecting the eyes. There is no electric
light that has yet been introduced which supplies us
with these desiderata.
W. H. PREECE.
2852 Morton, Mayer and Thomas, Scientific Am.,
April 17, 1890.
Complainant's Exhibit, Some Electrical
Measurements of one of Mr. Edison's
Horseshoe Lamps. BY HENRY MORTON, PH.D.,
ALFRED M. MAYER, PH.D., AND B. F. THOMAS, A.M.,
AT THE STEVENS INSTITUTE OF TECHNOLOGY.
Scientific American, New York, April 17, 1880, page 241.
Much has been written and said within the last few
months on the subject of Mr. Edison's new horseshoe
lamps, and with all the writing and saying there has
been wonderfully little produced in the way of precise
and reliable statement concerning the simple primary
facts, a knowledge of which would give the means of
estimating both the scientific and commercial status of
this widely discussed invention.
It was, therefore, with great pleasure that the present
writers found themselves, through the kindness of the
“Scientific American," placed in possession of one of
these horseshoe lamps of recent construction.
To satisfy themselves as to the real facts of the case
they soon made a series of careful measurements and
determinations, and as the results of these are likely to
interest others, they now put them in print for general
benefit.
A further examination of other lamps would have
been made at the same time had opportunity offered;
but as a communication on this subject addressed to
Mr. Edison did not evoke a reply, they are obliged to
content themselves with the one lamp as a subject of
experiment.
They would, however, here remark that the behavior
of this lamp, under the tests, and the agreement of its
results with the information otherwise obtained, con-
Morton, Mayer and Thomas, Scientific Am., 2853
April 17, 1890.
vince them that it is at least a fair specimen of the
lamps of this form so far produced at Menlo Park.
The first object, on receiving the lamp, was to de-
termine roughly what amount and character of electric
current would be needed to operate it efficiently. With
this view a number of cells of a small Grove's battery
were set up, having each an active zinc surface of
twenty square inches and a platinum surface of eigh-
teen square inches.
The lamp being placed in the situation usually occu-
pied by the standard burner in a Sugg's photometer,
the battery was, cell by cell, thrown into circuit.
When ten cells had been introduced the horseshoe
showed a dull red, with fifteen cells of a bright red,
with thirty-four cells the light of 1 candle was given,
with 40 cells the light of 4 candles, and with forty-five
cells the light of 93 candles, and with forty-eight cells
16 candles.
Having thus determined what amount of electric
current would be required for experiments, arrange-
ments were made to measure accurately the resistance
of horseshoe while in actual use and emitting different
amounts of light. The resistance of this carbon thread
at the ordinary temperature had been already deter-
mined as 123 ohms in the usual way, but it was pre-
sumed, as had been shown by Matthiessen ("Phil.
Mag." xvi., 1858, pp. 220, 221), that this resistance would
diminish with rise of temperature.
To measure the resistance under these circumstances
the apparatus was arranged as follows: The current
from the battery was divided into two branches, which
traversed, in opposite directions, the two equal coils of
a differential galvanometer. One branch then traversed
the lamp, while the other passed through a set of ad-
justable resistances composed of German-silver wires
stretched in the free air of the laboratory, to avoid
heating. (Careful tests of these resistances showed
that no sensible heating occurred under the circum-
stances.)
2854 Morton, Mayer and Thomas, Scientific Am.,
April 17, 1890.
Matters being thus arranged, the resistances were
adjusted until the galvanometer showed no deflection
when the candle-power of the lamp was taken repeat-
edly in the photometer, and the amount of resistance
was noted.
These measurements were several times repeated,
shifting the coils of the galvanometer and reversing the
direction of the current.
The results so obtained were as follows:
Resistances.
123 ohms.
94
83.7
79.8
75
((
Condition of Loop.
Cold.
I
Orange light.
5
18
candle.
CC
((
The photometric measurement was in all these cases
taken with the carbon loop at right angles to the axis
of the photometer, which was, of course, much in favor
of the electric lamp. On turning the lamp round so as
to bring the carbon loop with its plane parallel with
the axis of the photometer, i. e., the edge of the loop
turned toward the photometer disk, the light was
greatly diminished, so that it was reduced to almost
one-third of what it was with the loop sideways to the
photometer disk.
Having thus determined the resistance of the lamp
when in actual use, it was next desirable to measure
the quantity of the current flowing under the same
conditions.
To do this the current from fifty cells of battery was
passed through a tangent galvanometer as a mere check
or indicator of variations, and then through a copper
voltameter, i. e., a jar containing solution of cupric sul-
phates with copper electrodes immersed, and then
through the lamp placed in the photometer.
Under these conditions it was found that during an
Morton, Mayer and Thomas, Scientific Am., 2855
April 17, 1890.
hour the light gradually varied from about 16 candles
at the beginning to about 14 candles at the end, making
an average of about 15 candles, measured with side
loop of toward disk.
The galvanometer during this time only showed a fall
of half a degree in the deflection of the needle.
Carefully drying and weighing the copper electrodes,
it was found that one had lost 1.0624 grammes.
Now, it is well known that a current of one weber
takes up 0.00326 gramme of copper per second, which
would make 1.1736 grammes in an hour; therefore the
current in the present case must have been on the
1.0624
average
weber.
1.1736
=0.905 webers, or little less than one
Having thus obtained the resistance of the lamp when
emitting a light of 15 candles, namely, 76 ohms, and the
amount of current passing under the same condition,
namely, 0·905 weber, we have all the experimental data
required for the determination of the energy trans-
formed or expended in the lamp, expressed in foot
pounds. For this we multiply together the square of
the current, the resistance, the constant 0-737335 (which
expresses the fraction of a foot pound involved in a
current of one weber traversing a resistance of one
ohm for one second), and the number of seconds in a
minute. Thus, in the present case, we have 0·905²=
0-8125, and 0.825×76×0.737335×60=2753-76 foot
pounds.
Dividing these foot pounds per minute by the num-
ber of foot pounds per minute in a horse power, that is,
33,000, we have 0.08, that is, about eight one-hundredths
or one twelfth of a horse power as the energy expended
in each lamp.
It would thus appear that with such lamps as this,
one horse power of energy in the current would operate
12 lamps of the same resistance with an average
2856 Morton, Mayer and Thomas, Scientific Am.,
April 17, 1890.
candle-power of 10 candles each,* or 120 candles in
the aggregate.
Assuming that a Siemens or Brush machine were em-
ployed to generate the electric current, such a current
would be obtained, as has been shown by numer-
ous experiments, with a loss of about 40 per cent. of
the mechanical energy applied to the driving pulley of
the machine. To operate these 12 lamps, therefore,
we should have to apply more than one horsè
power to the pulley of the machine, so that when this
loss in transformation had been encountered there
should be one horse power of electric energy produced.
This would call for 1 horse power applied to the
pulley of the dynamo-electric machine, by the steam
engine.
To produce one horse power in a steam engine of the
best construction about three pounds of coal per hour
must be burned, and therefore for 1 horse power 5 lb.
of coal must be burned.
2
3
On the other hand one pound of gas coal will produce
5 cubic feet of gas, and will leave, besides, a large part
of its weight in coke, to say nothing of other “resi-
duals," which will represent practically about the
difference in value between "steam making" and " gas
making coal," so that it will not be unfair to take 5 lb.
of gas coal as the equivalent of 5 lb. of steam coal.
These 5 lb. of gas coal will then yield 25 cubic feet of
gas, which, if burned in five gas burners of the best
construction, will give from 20 to 22 candles each, or
100 to 110 candles in the aggregate.
We have, then, the twelve Edison lamps producing
120 candles and the five gas burners producing 100 to
110 candles, with an equivalent expenditure of fuel.
If each apparatus and system could be worked with
*The candle power being 15 candles in the best position, and 5
candles at right angles to this, the average or general illuminating
power of the lamp is 10 candles.
Morton, Mayer and Thomas, Scientific Am., 2857
April 17, 1890.
equal facility and economy, this would of course show
something in favor of the electric light; but when in
fact everything in this regard is against the electric
light, which demands vastly more machinery, and that
of a more delicate kind, requires more skillful manage-
ment, shows more liability to disarrangement and waste,
and presents an utter lack of the storage capacity which
secures such a vast efficiency, convenience, and
economy in gas, then we see that this relatively trifling
economy disappears or ceases to have any controlling
importance in the practical relations of the subject.
2858
Nature Editorial-1880.
Complainant's
Exhibit
"Incandescent
Electric Lights."
"NATURE," DECEMBER 2, 1880, VOL. 23, p. 104.
The recent experiments of Mr. J. W. Swan of New-
castle-on-Tyne have gone far towards demonstrating the
practibility of a system of electric lighting based upon
the so-called principle of incandescence. As the solu-
tion of the whole question of the possible domestic ap-
plication of electric lighting depends in all probability
upon the successful application of this method, these
experiments have claimed already a considerable share
of public attention, though no panic has yet arisen like
that created two years ago by the far less formidable
experiments of Mr. Edison in the same direction.
wire'
”
The material which Mr. Swan proposes to render in-
candescent by means of an electric current is a
of prepared carbon of extraordinary density and elas-
ticity. Twenty years ago he prepared carbon filaments
for the very same purpose from calcined cardboard, in-
closing them in a glass vessel from which the air was
withdrawn as perfectly as the imperfect air-pumps of
that date permitted. In October, 1877, or one year be-
fore Mr. Edison had begun to attempt the construction
of lamps with carbonized paper, Mr. Swan had some
prepared carbons mounted in glass globes and exhaust-
ed by the Sprengel air-pump by Mr. Stearn of Birken-
head. This enabled Mr. Swan to discover that when
the carbon was properly fixed and heated during ex-
haustions so that the occluded gases might be expelled,
there was an end of the causes that hitherto had seemed
to defeat all attempts to utilize this method of procur-
ing an incandescent electric light; for when these con-
ditions were observed there was none of the disintegra-
tion of the carbon rods, nor of the blackening of the
globes that with less perfect vacua had proved the ruin
of carbon lamps. The filaments of carbon now pro-
duced by Mr. Swan indeed resemble steel wire rather
Nature Editorial--1880.
2859
than carbon, so extraordinary is their tenacity and tex-
ture. The secret of their manufacture has not yet been
made known, being the essential point of the patent
rights which Mr. Swan has just secured. Each fila-
ment is about three inches long, and not more than the
hundredth of an inch in diameter, and is so slight as
only to weigh from one-fifteenth to one-twentieth of a
grain. The durability of these filaments is remarkable.
In the course of a lecture delivered on November 25
last before the Society of Telegraph Engineers, Mr.
Swan stated that he had had lamps lighted continuously
since August 30, with an intermission of three weeks
only, and that this seemed to be far from the actual
limits of durability. When the currents employed are
not too strong, the lamps will last longer. The light
yielded by these lamps varies, according to circum-
stances, from thirty to fifty standard candles. On the
occasion of Mr. Swan's lecture thirty-six of these tiny
lamps were exhibited working by the current of a dynamo-
electric machine requiring four horse-power to drive
it. In the debate which followed Mr. Swan's communi-
cation, the remarks made by Prof. Tyndall, Dr. Hop-
kinson, Mr. Alexander Siemens and others, showed the
real value of the advance made by Mr. Swan.
question however of the economy of the system remains
yet to be decided by the practical test of durability.
At a previous lecture at Newcastle-on-Tyne Mr. Swan
exhibited twenty lamps fed by a current generated by
a gas-engine consuming 160 cubic feet of gas per hour.
The light obtained exceeded that of the seventy gas-
jets which usually supplied the same room, and which
consumed 280 feet per hour. Mr. Swan proposes to
connect these lamps in series of fifty or a hundred in
one circuit, using automatic circuit-closers to close the
circuit in the rare case of the failure of a lamp. He
considers his method of arranging the system to be
superior to that proposed by Mr. Edison, whose method
of placing the separate lamps in single branches of a
divided circuit would involve the use of very heavy and
costly conducting-wires without any counterbalancing
The
2860
Nature Editorial--1880.
advantage. With this important difference Mr. Swan's
further proposal to erect central stations from which to
supply currents of electricity over large areas resembles
that suggested by Mr. Edison. Should the anticipa-
tions of the inventor and the present promise of the
new lamps be fulfilled, domestic electric lights will cer-
tainly become a fact at no distant date.
Meantime Mr. Edison has not been idle. It is stated
that he is at present laying down a service of about
seven miles in length upon which to test the success or
failure of his system upon a large scale. He has de-
veloped several ideas since his last appearance before
public notice. He now makes his dynamo-electric gen-
erators of a much larger pattern than any heretofore
attempted. He has abandoned charred cardboard in
favor of a filament of carbon prepared from a cultivated
variety of the Japanese bamboo. We shall hear before
long whether his indomitable perseverance has been
rewarded by final success. In spite of being in point
of date behind Mr. Swan, he has the enormous advan-
tage of a unique workshop and laboratory under his
own direction, of a wealthy company at his back, and
of the extraordinary prestige won by his previous in-
ventions. If Mr. Swan appears to be nearer to a genuine
success, Mr. Edison has a popular reputation that of
itself will win a hearing for the most trivial of his inven-
tions. Whichever of the rival systems succeeds
science and mankind are the gainers. But up to the
present point it seems to us that beyond question Mr.
Swan is nearer the goal of practical results than his
famous rival.
It may interest our readers to know that Mr. Edison's
first carbon lamp is now on view along with his original
phonograph and its earliest tasimeter in the Patent
Museum at South Kensington.
Thomson--British Association--1881. 2861.
Complainant's Exhibit Sir William
Thomson's Address.
REPORT OF THE 51ST MEETING
51ST MEETING OF THE
BRITISH ASSOCIATION FOR THE AD-
VANCEMENT OF SCIENCE.
HELD AT YORK IN AUGUST AND SEPTEMBER, 1881 (PP. 513–518)
TRANSACTIONS OF THE SECTIONS.
SEOTION A.-MATHEMATICAL AND PHYSICAL SCIENCE
PRESIDENT OF THE SECTION—
Professor SIR WILLIAM THOMSON, M.A., LL.D., D.C.L.
F.R.S.L. and E.
THURSDAY, SEPTEMBER, 1.
The PRESIDENT delivered the following address:-
On the Sources of Energy in Nature available to Man
for the Production of Mechanical Effect.
During the fifty years' life of the British Association,
the Advancement of Science for which it has lived and
worked so well has not been more marked in any de-
partment than in one which belongs very decidedly to
the Mathematical and Physical Section-the science of
Energy. The very name energy, though first used in
its present sense by Dr. Thomas Young about the be-
ginning of this century, has only come into use practi-
cally after the doctrine which defines it had, during the
first half of the British Association's life, been raised
from a mere formula of mathematical dynamics to the
2862 Thomson-British Association-1881.
position it now holds of a principle prevading all
nature and guiding the investigator in every field of
science.
A little article communicated to the Royal Society
of Edinburgh a short time before the commencement
of the epoch of energy, under the title 'On the Sources
Available to Man for the Production of Mechanical
Effect,'¹ contained the following:
Men can obtain mechanical effect for their own
purposes by working mechanically themselves, and di-
recting other animals to work for them, or by using
natural heat, the gravitation of descending solid masses,
the natural motions of water and air, and the heat, or
galvanic currents, or other mechanical effects produced
by chemical combination, but in no other way at pres-
ent known. Hence the stores from which mechanical
effect may be drawn by man belong to one or other of
the following classes :—
'I. The food of animals.
'II. Natural heat.
'III. Solid matter found in elevated positions.
'IV. The natural motions of water and air.
V. Natural combustibles (as wood, coal, coal-gas,
oils, marsh-gas, diamond, native sulphur, native metals,
metoric iron).
'VI. Artificial combustibles (as smelted or electric-
ally-deposited metals, hydrogen, phosphorus).
'In the present communication, known facts in
natural history and physical science, with reference to
the sources from which these stores have derived their
mechanical energies, are adduced to establish the
following general conclusions:
1. Heat radiated from the sun (sunlight being in
cluded in this term) is the principal source of mechani-
cal effect available to man. 2 From it is derived the
1 Read at the Royal Society of Edinburgh on February 2, 1852
(Proceedings of that date).
* A general conclusion equivalent to this was published by Sir
John Herschelin 1833. See his Astronomy, edit. 1849, (§ 399).
Thomson-British Association-1881. 2863
whole mechanical effect obtained by means of animals
working, water-wheels worked by rivers, steam-engines,
galvanic engines, windmills, and the sails of ships.
2. The motions of the earth, moon and sun, and
their mutual attractions, constitute an important source
of available mechanical effect. From them all, but
chiefly no doubt from the earth's motion of rotation, is
derived the mechanical effect of water-wheels driven by
the tides.
'3. The other known sources of mechanical effect avail-
able to man are either terrestrial—that is, belonging to
the earth, and available without the influence of any
external body, or meteoric—that is, belonging to bodies
deposited on the earth from external space. Terres-
trial sources, including mountain quarries and mines,
the heat of hot springs, and the combustion of native
sulphur, perhaps also the combustion of inorganic
native combustibles, are actually used; but the me-
chanical effect obtained from them is very inconsider-
able, compared with that which is obtained from
sources belonging to the two classes mentioned above.
Meteoric sources, including only the heat of newly-
fallen meteoric bodies, and the combustion of meteoric
iron, need not be reckoned among those available to
man for practical purposes.'
Thus we may summarise the natural sources of
energy as Tides, Food, Fuel, Wind and Rain.
Among the practical sources of energy thus exhaust-
ively enumerated, there is only one not derived from
sun heat-that is the tides. Consider it first. I have
called it practical, because tide-mills exist. But the
places where they can work usefully are very rare, and
the whole amount of work actually done by them is a
drop to the ocean of work done by other motors. A
tide of two meters' rise and fall, if we imagine it utilised
to the utmost by means of ideal water-wheels doing
with perfect economy the whole work of filling and
emptying a dock-basin in infinitely short times at the
moments of high and low water, would give just one
metre-ton per square metre of area. This work done
2864 Thomson-British Association--1881.
four times in the twenty-four hours amounts to
1-1620th of the work of a horse-power. Parenthically,
in explanation, I may say that the French metrical
equivalent (to which all scientific and practical measure-
ments we are irresistibly drawn, notwithstanding a
dense barrier of insular prejudice most detrimental to
the islanders), the French metrical equivalent of James
Watt's' horse-power' of 550 foot-pounds per second
or 33,000 foot-pounds per minute, or nearly two million
foot-pounds per hour, is 75 meter-kilogrammes per
second, or 4 meter-tons per minute, or 270 metre-tons
per hour. The French ton of 1,000 kilogrammes used
in this reckoning is 0.984 of the British ton.
Returning to the question of utilising tidal energy,
we find a dock area of 162,000 square metres (which is
little more than 400 metres square) required for 100
horse-power. This, considering the vast costliness of
dock construction, is obviously prohibitory of every
scheme for economising tidal energy by means of arti-
ficial dock-basins, however near to the ideal perfection.
might be the realised tide-mill, and however convenient
and non-wasteful the accumulator-whether Faure's
electric accumulator, or other accumulators of energy
hitherto invented or to be invented--which might be
used to store up the energy yielded by the tide-mill
during its short harvests about the times of high and
low water, and to give it out when wanted at other
times of six hours. There may, however, be a dozen
places possible in the world where it could be advan-
tageous to build a sea-wall across the mouth of a
natural basin or estuary, and to utilize the tidal energy
of filling it and emptying in by means of sluices and
water-wheels. But if so much could be done, it would
in many cases take only a little more to keep the water
out altogether, and make fertile land of the whole
basin. Thus we are led up to the interesting econom-
ical question, whether is forty acres (the British agri-
cultural measure for the area of 162,000 square metres)
or 100 horse-power more valuable. The annual cost of
100 horse-power night and day, for 365 days of the
Thomson-British Association-1881. 2865
year, obtained through steam from coals, may be about
ten times the rental of forty acres at 21. or 31. per acre.
But the value of land is essentially much more than its
rental, and the rental of land is apt to be much more
than 27. or 37. per acre in places where 100 horse-
power could be taken with advantage from coal through
steam. Thus the question remains unsolved, with the
possibility that in one place the answer may be one
hundred horse-power, and in another forty acres.
indeed, the question is hardly worth answering, con-
sidering the rarity of the cases, if they exist at all,
where embankments for the utilisation of tidal energy
are practicable.
But,
Turning now to sources of energy derived from sun
heat, let us take the wind first. When we look at the
register of British shipping and see 40,000 vessels, of
which about 10,000 are steamers and 30,000 sailing
ships, and when we think how vast an absolute amount
of horse-power is developed by the engines of those
steamers, and how considerable a proportion it forms
of the whole horse-power taken from coal annually in
in the whole world at the present time, and when we
consider the sailing ships of other nations, which must
be reckoned in the account, and throw in the little item
of windmills, we find that, even in the present days of
steam ascendency, old-fashioned Wind still supplies a
large part of all the energy used by man. But however
much we may regret the time when Hood's young lady,
visiting the feus of Lincolnshire at Christmas, and
writing to her dearest friend in London (both sixty
years old now if they are alive), describes the delight
of sitting in a bower and looking over the wintry
plain, not desolate, because 'windmills lend revolving
animation to the scene,' we cannot shut our eyes to
the fact of a lamentable decadence of wind-power.
Is this decadence permanent, or may we hope that
it is only temporary? The subterranean coal stores
of the world are becoming exhausted surely, and
not slowly, and the price of coal is upward
bound-upward bound on the whole, though no
2866 Thomson-British Association-1881.
doubt it will have its ups and downs in the future
as it has had in the past, and as must be the case in
respect to every marketable commodity. When the
coal is all burned, or long before it is all burned, when
there is so little of it left and the coal-mines from
which that little is to be excavated are so distant and
deep and hot that its price to the consumer is greatly
higher than at present, it is most probable that wind-
mills or wind-motors in some form will again be in the
ascendant, and that wind will do man's mechanical
work on land at least in proportion comparable to its
present doing of work at sea.
Even now it is not utterly chimerical to think .of
wind superseding coal in some places for a very im-
portant part of its present duty-that of giving light.
Indeed, now that we have dynamos and Faure's accu-
mulator, the little want to let the thing be done is
cheap windmills. A Faure cell containing 20 kilo-
grammes of lead and minimum charged and employed
to excite incandescent vacuum-lamps has a light-giving
capacity of 60-candle hours (I have found considerably
more in experiments made by myself; but I take 60 as
a safe estimate). The charging may be done uninjuri-
ously, and with good dynamical economy, in any time
from six hours to twelve or more. The drawing off of
the charge for use may be done safely, but somewhat
wastefully, in two hours, and very economically in any
time of from five hours to a week or more. Calms do
last often longer than three or four days at a time.
Suppose, then, that a five days' storage capacity suffices
(there may be a little steam engine ready to set to work
at any time after a four days' calm, or the user of the
light may have a few candles or oil lamps in reserve,
and be satisfied with them when the wind fails for
inore than five days). One of the twenty kilogramme
cells charged when the windmill works for five or six
hours at any time, and left with its 60-candle hours'
capacity to be used six hours a day for five days, gives
a 2-candle light. Thus thirty-two such accumulator
cells so used would give as much light as four burners
Thomson-British Association-1881. 2867
of London 16-candle gas. The probable cost of
dynamo and accumulator does not seem fatal to the
plan, if the windmill could be had for something com-
parable with the prime cost of a steam engine capable
of working at the same horse-power as the windmill
when in good action. But windmills as hitherto made
are very costly machines; and it does not seem prob-
able that, without inventions not yet made, wind can
be economically used to give light in any considerable
class of cases, or to put energy into store for work of
other kinds.
Consider, lastly, rain-power. When it is to be had
in places where power is wanted for mills and factories
of any kind, water-power is thoroughly appreciated.
From time immemorial, water-motors have been made
in large variety for utilising rain-power in the various
conditions in which it is presented, whether in rapidly-
flowing rivers, in natural waterfalls, or stored at heights
in natural lakes or artificial reservoirs. Improvements.
and fresh inventions of machines of this class still go
on; and some of the finest principles of mathematical
hydrodynamics have, in the lifetime of the British As-
sociation, and, to a considerable degree, with its assist-
ance, been put in requisition for perfecting the theory of
hydraulic mechanism and extending its practical appli-
cations.
A first question occurs: Are we necessarily limited
to such natural sources of water-power as are supplied
by rain falling on hill-country, or may we look to the
collection of rain water in tanks placed artificially at
sufficient heights over flat country to supply motive
power economically by driving water-wheels? To
answer it: Suppose a height of 100 metres, which is
very large for any practicable building or for columns
erected to support tanks, and suppose the annual rain-
fall to be three-quarters of a metre (30 inches). The
annual yield of energy would be 75 metre-tons per
square metre of the tank. Now, one horse-power for
365 times 24 hours is 236,500 foot tons; and, there-
fore (dividing this by 75), we find 3,153 square metres
2868 Thomson-British Association-1881.
as the area of our supposed tank required for a con-
tinuous supply of one horse-power. The prime cost of
any such structure, not to speak of the value of the
land which it would cover, is utterly prohibitory of any
such plan for utilising the motive power of rain. We
may or may not look forward hopefully to the time
when windmills will again 'lend revolving animation'
to a dull, flat country; but we certainly need not be
afraid that the scene will be marred by forests of iron
columns taking the place of natural trees, and gigantic
tanks overshadowing the fields and blackening the
horizon.
To use rain-power economically on any considerable
scale we must look to the natural drainage of hill
country, and take the water where we find it, either
actually falling or stored up and ready to fall when a
short artificial channel or pipe can be provided for
it at moderate cost. The expense of aqueducts, or of
underground water-pipes, to carry water to any great
distance-any distance of more than a few miles or a
few hundred yards-is much too great for economy
when the yield to be provided for is power; and such
works can only be undertaken when the water itself is
what is wanted. Incidently, in connection with the
water supply of towns, some part of the energy due to
the head at which it is supplied may be used for power.
There are, however, but few cases (I know of none ex-
cept Greenock) in which the energy to spare over and
above that devoted to bringing the water to where it
is wanted, and causing it to flow fast enough for con-
venience at every open tap in every house or factory, is
enough to make it worth while to make arrangements
for letting the water-power be used without wasting
the water-substance. The cases in which water-power
is taken from a town supply are generally very small,
such as working the bellows of an organ, or ‘hair-
brushing by machinery,' and involve simply throwing
away the used water. The cost of energy thus obtained
must be something enormous in proportion to the
actual quantity of the energy, and it is only the small-
Thomson-British Association-1881. 2869
ness of the quantity that allows the convenience of
having it when wanted at any moment, to be so dearly
bought.
For anything of great work by rain-power, the water-
wheels must be in the place where the water supply
with natural fall is found. Such places are generally
far from great towns, and the time is not yet come
when great towns grow by natural selection beside
waterfalls, for power; as they grow beside navigable
rivers, for shipping. Thus, hitherto the use of water-
power has been confined chiefly to isolated factories,
which can be conveniently placed and economically
worked in the neighborhood of natural waterfalls. But
the splendid suggestion made about three years ago by
Mr. Siemens, in his presidential address to the Institu-
tion of Mechanical Engineers, that the power of Niagara
might be utilised by transmitting it electrically to great
distances, has given quite a fresh departure for design
in respect to economy of rain-power. From the time
of Joule's experimental electro-magnetic engines devel-
oping 90 per cent. of the energy of a Voltaic battery in
the form of weights raised, and the theory of the electro-
magnetic transmission of energy completed thirty years
ago on the foundation afforded by the train of experi-
mental and theoretical investigations by which he
established his dynamical equivalent of heat in me-
chanical, electric, electro-chemical, chemical, electro-
magnetic, and thermoclastic phenomena, it had been
known that potential energy from auy available source
can be transmitted electro-magnetically by means of an
electric current through a wire, and directed to raise
weights at a distance, with unlimited perfect economy.
The first large-scale practical application of electro-
magnetic machines was proposed by Holmes, in 1854,
to produce the electric light for lighthouses, and perse-
vered in by him till he proved the availability of his
machine to the satisfaction of the Trinity House and
the delight of Faraday, in trials at Blackwall, in April,
1857, and it was applied to light the South Foreland
lighthouse on December 8, 1858. This gave the im-
2870 Thomson--British Association—1881.
pulse to invention; by which the electro-magnetic ma-
chine has been brought from the physical laboratory
into the province of engineering, and has sent back to
the realm of pure science a beautiful discovery--that of
the fundamental principle of the dynamo, made triply
and independently, and as near as may be simultane-
ously, in 1867, by Dr. Werner Siemens, Mr. S. A. Varley
and Sir Charles Wheatstone; a discovery which consti-
tutes an electro-magnetic analogue to the fundamental
electrostatic principle of Nicholson's revolving doubler,
resuscitated by Mr. C. F. Varley in his instrument 'for
generating electricity,' patented in 1860; and by Holtz
in his celebrated electric machine; and by myself in
my 'replenisher' for multiplying and maintaining
charges in Leyden jars for heterostatic electrometers,
and in the electrifier for the siphon of my recorder for
submarine cables.
The dynamos of Gramme and Siemens, invented and
made in the course of these fourteen years since the
discovery of the fundamental principle, give now a
ready means of realising economically on a large scale,
for many important practical applications, the old
thermo-dynamics of Joule in electro-magnetism; and,
what particularly concerns us now in connection with
my present subject, they make it possible to transmit
electro-magnetically the work of waterfalls through
long insulated conducting wires, and use it at distances.
of fifties or hundreds of miles from the source, with ex-
cellent economy-better economy, indeed, in respect to
proportion of energy used to energy dissipated than
almost anything known in ordinary mechanics and hy-
draulics for distances of hundreds of yards instead of
hundreds of miles.
In answer to questions put to me in May, 1879,1 by
the Parliamentary Committee on Electric Lighting, I
gave a formula for calculating the amount of energy
¹ Printed in the Parliamentary Blue Book Report of the Com-
mittee on Electric Lighting, 1879.
Thomson--British Association--1881. 2871
transmitted, and the amount dissipated by being con-
verted into heat on the way, through an insulated cop-
per conductor of any length, with any given electro-
motive force applied to produce the current. Taking
Niagara as example, and with the idea of bringing its
energy usefully to Montreal, Boston, Ne York, and
Philadelphia, I calculated the formula for a distance of
300 British statute miles (which is greater than the
distance of any of those four cities from Niagara, and
is a radius of a circle covering a large and very import-
ant part of the United States and British North
America), and found almost to my surprise that, even with
so great a distance to be provided for, the conditions.
are thoroughly practicable with good economy, all
aspects of the case carefully considered. The formula
itself will be the subject of a technical communication
to Section A in the course of the Meeting which we
are now entering. I therefore at present restrict myself
to a slight statement of results.
1. Apply dynamos driven by Niagara to produce a
difference of potential of 80,000 volts between a good
earth connection and the near end of a solid copper
wire of half an inch (1.27 centimetre) diameter, and
300 statute miles (483 kilometres) length.
2. Let resistance by driven dynamos doing work, or
by electric lights, or, as I can now say, by a Faure
battery taking in a charge, be applied to keep the re-
mote end at a potential differing by 64,000 volts from a
good earth-plate there.
3. The result will be a current of 240 webers through
the wire taking energy from Niagara end at the rate of
26,250 horse-power, losing 5,250 (or 20 per cent.) of
this by the generation and dissipation of heat through
the conductor and 21,000 horse-power (or 80 per cent.
of the whole) on the recipients at the far end.
4. The elevation of temperature above the surround-
ing atmosphere, to allow the heat generated in it to
escape by radiation and be carried away by convection
is only about 20° Centigrade; the wire being hung
2872 Thomson--British Association--1881.
freely exposed to air like an ordinary telegraph wire
supported on posts.
(
5. The striking distance between flat metallic sur-
faces with difference of potentials of 80,000 volts (or
75,000 Daniell's) is (Thomson's Electrostatics and
Magnetism,' § 340) only 18 millimetres, and therefore
there is no difficulty about the insulation.
6. The cost of the copper wire, reckoned at 8d. per lb.,
is 37,000.; the interest on which, at 5 per cent., is
1,9007. a year. If 5,250 horse-power at the Niagara
end costs more than 1,9007. a year, it would be better
economy to put more copper into the conductor; if
less, less. I say no more on this point at present, as
the economy of copper for electric conduction will be
the subject of a special communication to the Sec-
tion.
I shall only say, in conclusion, that one great diffi-
culty in the way of economising the electrical trans-
mitting power to great distances (or even to moderate
distances of a few kilometres) is now overcome by
Faure's splendid invention. High potential--as Sie-
mens, I believe, first pointed out is the essential for
good dynamical economy in the electric transmission
of power. But what are we to do with 80,000 volts
when we have them at the civilised end of the wire ?
Imagine a domestic servant going to dust an electric
lamp with 80,000 volts on one of its metals! Nothing
above 200 volts ought on any account ever to be ad-
mitted into a house or ship or other place where safe-
guards against accident cannot be made absolutely and
for ever trustworthy against all possibility of accident.
In an electric workshop 80,000 volts is no more dangerous
than a circular saw. Till I learned Faure's invention
I could but think of step-down dynamos, at a main re-
ceiving station, to take energy direct from the electric
main with its 80,000 volts, and supply it by secondary
200-volt dynamos or 100-volt dynamos, through proper
distributing wires, to the houses and factories and
shops where it is to be used for electric lighting, and
sewing-machines and lathes and lifts, or whatever other
Thomson-British Association-1881. 2873
mechanism wants driving power. Now the thing is to
be done much more economically, I hope, and certainly
with much greater simplicity and regularity, by keeping
a Faure battery of 40,000 cells always being charged
direct from the electric main, and applying a methodi-
cal system of removing sets of 50, and placing them on
the town supply circuits, while other sets of 50 are being
regularly introduced into the great battery that is be-
ing charged, so as to keep its number always within 50
of the proper number, which would be about 40,000 if
the potential at the emitting end of the main is 80,000
volts.
2874
Du Moncel & Geraldy-1883.
Complainant's Exhibit "Electricity as a
Motive Power." By Count Du Moncel and F.
Geraldy; translated by C. J. Wharton; London,
1883, pp. 269–291.
CHAPTER IX.
THE DISTRIBUTION OF ELECTRICITY.
It will have been seen from the preceding chapter how
useful it is to be able to transport a power, and how
this property has already received and will yet receive
numerous applications. The question appears most
promising, for in this way we shall be able to bring to
the work to be executed the very great natural powers,
such as those of waterfalls, hitherto useless. But the
problem is not thus completely solved. Suppose in
fact and the case will certainly happen-that a force
of 1,000 horse-power has been reclaimed and trans-
ported; advantage must be taken of it. But there are
comparatively few establishments which have need of
such an amount of motive power, and it must be
divided among several factories; this is possible, with-
in certain limits, by mechanical means, but the distance
is very restricted, and it can only be done at great
expense and with great loss of power. The true solution
is evidently to divide the electricity itself, and only to
transform it into mechanical energy after it has been
distributed among the consumers. The distribution
may in this manner be more easily managed, electricity
being easily divided and distributed by means of simple
conducting wires. A much larger subdivision may
therefore at once be imagined, almost unlimited not
only will a greater power be distributed among several
manufactories, but in each one the motive power will
be again sub-divided to supply each individual machine
or tool; further, the total current will be sub-divided
into numberless separate currents, each supplying
separate places, whether factories, works, or private
Du Moncel & Geraldy-1883.
2875
houses, thus distributing everywhere the numerous
advantages of electricity.
All that is, no doubt, possible, but on the condition
that this sub-division of the current is carried out with
regularity and certainty. It is necessary that every
individual apparatus and consumer shall receive the
allotted portion without influencing the others; in a
word, electricity must be distributed in the same way as
water.
The problem is not without difficulties, for although
it is easy to sub-divide electricity by simply presenting
to it an open passage, it is not so easy to do so in a
precise manner.
First let us recall Ohm's fundamental law. We know
that if we call I the intensity of the current, E the
electromotive force of the generator, and R the resist-
ance of the circuit, the proportion between these two
E
quantities is expressed by the equation I = Sup-
Ꭱ
R®
pose then that we dispose of a source of electricity and
distribute the current equally among several machines
(which may be lamps, depositing baths, motors, etc.),
which for simplification we will suppose all similar.
We connect the first apparatus, and a certain order of
things is the result; a current of intensity I resulting
from the electromotive source E and the resistance Ris
established, and the installation is adjusted: we have
now to put on a second apparatus; how is this to be
done? We will first put it following the other, and on
the same circuit, but then its resistance will be added
to that already existing and the intensity cannot be the
same-it will be diminished; consequently, if the in-
stallation was before properly adjusted, such can no
longer be the case, and both the first and second
machines will be insufficiently supplied. To re-estab-
lish the previous state of things and maintain the
original intensity of current, we must, in proportion as
we introduce in the circuit any apparatus increasing
2876
Du Moncel & Geraldy-1883.
the resistance, increase the electromotive force of the
generator, i. e., give it a suitable regulation.
Before adopting this means, let us try another way.
In the first case, having one machine in the circuit, we
put the second in the same circuit; instead of doing
this, we might make another circuit for the second
apparatus, thus affording the current another path.
Let us see the result: with the first apparatus the
E
current had an intensity, I
R'
and everything went
well; we introduce a second apparatus on a second
circuit, the current thus finds two paths open instead
of one, the resistance is therefore half as great as at
first; R is diminished by half, and becomes equal to
R
2
; it follows, then, that the intensity I will be
doubled: thus doubled it will divide itself between the
two similar paths open to it; the first apparatus will
maintain its intensity I, and the new one will receive
another similar intensity. From this it would seem
that the problem was solved; but unfortunately the
reasoning that we have given is not exact, and we have
neglected a necessary element. We have admitted that
in offering to the current two circuits instead of one,
the resistance which it would have to overcome would
be halved, which is not correct; in fact, the resistance
through which the current has to flow does not consist
solely of the two circuits on which are the machines, it
includes also the individual resistance of the generator.
Whether this be a machine, a battery, or whatever we
may suppose, the current must always traverse it, and
it always meets with a resistance therein; it follows
therefrom that by doubling the exterior circuit pre-
sented to the current we have halved the exterior
resistance, but we have not touched the resistance
of the generator, which is called the interior resistance.
The total resistance has therefore been diminished, but
not by half; therefore, although the intensity has been
Du Moncel & Geraldy--1883.
2877
increased, it has not been doubled, as we supposed just
now, and our installation is still defective: it could
only be exact by doing away with the resistance of the
generator, which is impossible. In default of this
means, we must vary the electromotive force of the
generator, or in other words, effect a regulation.
In whatever way we may work, we are therefore
obliged to regulate the electric generator according to
the demand of energy caused by introducing other ap-
paratus successively into its circuit.
In looking a little more closely into the question, we
see that to be satisfactory this regulation must comply
with three conditions:
1st. The several apparatus placed under distribution
must be separately supplied; that is to say, each must
receive its necessary share of electricity at any moment
and in any place, without affecting the others placed in
the same circuit.
2nd. The generator must therefore continuonsly fur-
nish all the force required, but not more, or there will
be loss.
3rd. The movement of electricity being very rapid, it
is of importance that the regulation necessary to fulfil
these conditions should be automatic.
Such are the necessary exterior conditions for any
distribution to be complete.
Before enumerating the attempts made in this
direction, we will glance at the conditions which they
ought to fulfil.
As we have said, there are two ways of supplying
several electric apparatus from the same source. The
first consists in putting them one after the other in the
same circuit, or in series; the second is when each has
a separate circuit, or rather a separate branch off the
the main circuit. This arrangement is variously called
in parallel, in multiple arc, or in derivation.
In both cases, if it is required that the various
machines should receive their proper supply of current
continuously, and that the addition of one should not
2878
Du Morcel & Geraldy--1883.
affect the others, a regulation of the electromotive force
or the current must be effected, the nature of such
regulation depending on the system adopted, whether
the series or parallel.
For example, suppose we wish to utilize a waterfall
which, we will say, is of great height but of small
volume, and we arrange a set of water-wheels one under
the other, so that each receives the whole of the water
escaping from the one above it. Each wheel then
utilizes the whole of the volume of the fall, but only a
portion of the head. If with this arrangement we wish
to add another wheel, we must put it above the others,
and consequently the height and not the volume of the
fall must be altered.
If, on the other hand, we have a broad fall but of
moderate height, we may take off a certain number of
channels of suitable width, and in each place a wheel.
Then each wheel will utilize the whole of the height of
the fall, but only a portion of the volume. If we want
to add another, we must take off another channel for
the current, when the total volume of water must be
be increased, the height of the fall remaining un-
changed.
The two above-mentioned arrangements for electric
machines are somewhat similar; if they are placed one
after the other in the same circuit, when one is added
we have only to increase the tension which corresponds
to the height of the waterfall without increasing the
amount of the current. If, however, they are in
parallel, and the number is altered, the current must
be modified, the tension remaining the same.
We have thus two modes of regulation. The series
arrangement has many defects, for in the first place
each machine is dependent on all the rest.
If one of
them meets with an accident, all the others are at once
stopped; and further, very great variation in the
electromotive force is pre-supposed, and extremely high
tensions would often be necessary. This arrangement
is theoretically possible, but it is doubtful if it could be
Du Moncel & Geraldy--1883.
2879
practically employed. The parallel system appears
more possible and certain in its action, and is the only
one which has been at all used hitherto.
The problem is, therefore, to maintain a constant
pressure or tension, whatever may be the number of
machines, etc., in the parallels; and it will be seen that
the tension which it is required to maintain constant is
that at the terminals of the generating machine; it is
from these points that the derived circuits feeding the
various motors, etc., are supposed to take their origin,
and it is the tension at these points which determines
the exterior current; this tension, then (scientifically
termed, difference of potential), must be so regulated
that at any moment it may be constant, whatever may
be the exterior circuit, or whatever variations it may
undergo.
The solution of this question has recently become of
such urgent importance that a considerable number of
plans have been put forward from different quarters,
all of which have more or less helped to solve the
difficulty.
We will therefore refer to some of these, but we must
at once state that the period in which they have all
been brought out is really so short, that it is next to
impossible to give them in chronological order, or to
award the various priorities of conception. The legal
points of the question, based on authenticated dates,
are of course easily solved, but, as a matter of science,
to decide the priority of invention is difficult, owing to
the number of claims put forward. Besides, now-a-
days scientific researches are, so to speak, democracised.
Formerly, inventors were a small and select aristocracy,
but now the results seem to arise from a number of
small individual researches, rendering them neither less.
brilliant nor less useful, but somewhat hiding the origin
in mystery. We will therefore, instead of following the
chronological order, go through them in such a way as
to see the successive development of the means
employed.
2880
Du Moncel & Geraldy--1883.
One of the earliest was that of Edison, in which he
sought to obtain regularity by modifying the production
of the current. There are, of course, three ways of
varying the current produced by a machine: the first is
to vary the speed, which is extremely difficult mechanic-
ally, and not very practical; the second way is to vary
the action of the field magnets by moving them further
away from the armature, and it will be seen that this is
out of the question; the third way is to vary the
current through the field magnets; this is evidently the
most convenient method, and the one which has been
most generally adopted.
For this there is an essential condition, namely, that
the inagnets are not excited solely by the useful current
of the machine; in fact, it would then be impossible to
vary the excitat.on of the magnets without equally vary-
ing the exterior circuit. In the Edison system the field
magnets are excited by a shunt from the main circuit.
In this accessory circuit is placed a box, and by means
of a handle worked by an attendant variable resistances
may be be thrown in, as may be shown necessary by an
indicator, thus always maintaining the proper current
according to the demand.
The necessary presence of this attendant is the weak
point in this arrangement; it is not automatic, and for
an extended service, supplying various and unforeseen
wants, this kind of regulation would be insufficient.
Mr. Edison has, however, applied his system to a large
lighting installation in New York, which is said to work
well; but in any case it must be observed that this de-
scription of distribution is one of the simplest, includ-
ing only apparatus all identical, namely, lamps, and has
only to supply wants which may in a great measure be
foretold.
At the Exhibition was also shown Mr. Maxim's regu-
lator, represented in Fig. 109. This is a mechanical
regulator, and consists essentially of a lever continually
worked by the machine. This lever, having two cams

Du Moncel & Geraldy -1883.
2881
FIG. 109.
DIC
EMORIEU.Sc.
on it, is suspended between two cog-wheels; if it rises, it
touches the upper one, and by means of the cam turns
one tooth at each oscillation; if it falls, the lower wheel
is turned. The lever is fixed to the armature of an
electro-magnet, through the coils of which passes the
current to be regulated; it follows that if the current is
too great the armature is attracted and falls, carrying
the lever, which then acts on the lower wheel; if the
current is too weak the armature, acted on by a spring,
is drawn up, thus putting in motion the upper wheel;
but for a normal current there is no movement. The
cogged wheels thus put in play are not employed to put
in resistances as in the Edison arrangement, but they
act on the brushes of the machine and alter their
position. It will be remembered that in dynamo-
electric machines the current is collected by two springs
2882
Du Moncel & Geraldy--1883.
or brushes rubbing on the revolving cylindrical commu-
tator. According to the pesition of these brushes the
current may be collected either at the maximum point
or at any other, when there will be less; it will thus be
seen that by varying the position of the brushes the
current may be varied.
This arrangement is very defective, as will be easily
understood. From what has been said about dynamo-
electric machines, it will have been understood that the
position of the brushes was determined; but if these
brushes must be capable of being shifted either way, it
follows that their mean position which they occupy
normally is not their most advantageous position, and
it will be understood how grave a fault this is.
This system has also the great disadvantage of slow-
ness: theoretically, it ought to act; practically, it did
not do so at the Exhibition, and it is very doubtful if it
has ever really been used. For a large distribution it
it would be quite insufficient.
The Lane Fox regulator somewhat resembled the
foregoing. Like it, it relied on the action of an electro-
magnet, but instead of acting on the brushes as in the
Maxim system, it served to introduce or take out arti-
ficial resistances in the exciting circuit. These modifi-
cations being occasioned by the attraction of a magnet,
take place very slowly, and altogether it is not likely to
be much used, on account of its being so very slow
working.
The Brush system of lighting was very much noticed
at the Exhibition, and for some things very rightly so.
Without being actually more perfect than others as re-
gards the lamp and the results obtaiued, it must share
with the Jamin candles the honor of having first
employed high tensions in the application of electricity
to lighting. It has been already stated that M.
Gramme had made machines reaching tensions of 300
volts; those of Mr. Brush reached 1,000 and even 2,000
volts. We have remarked that M. Marcel Deprez, in
his experiments on the transmission of force, has also
attained and surpassed these tensions. It is interesting
Du Moncel & Geraldy-1883.
2883
to note that an inventor who has not, like Jamin and
Deprez, guided by well-thought-out theory, should also
have so well understood the necessity for high tensions
as to adopt them with boldness.
Our readers will excuse this digression. This was
not the only point of notice in the Brush system, which
included also a regulating arrangement, which was,
however, very elementary. To vary the exciting
current, a shunt was arranged which was opened more
or less according to the energy required. It will be
seen that by this arrangement any excess was lost, the
production remaining uniform. The system also con-
sists of a double regulating arrangement, the one
automatic, the other worked by hand, both of which
may be criticised from several points. Similarly with
those already mentioned, it has not acted well, and
is not capable of being extensively used.
Interesting theoretical studies were being at the same
time carried on, and to M. Hospitalier is due a com-
plete projected system, apparently satisfying the
required conditions. To M. G. Cabanella is also
due a special system of distribution. Instead of
arranging all the apparatus in parallel as others had
done, he put them in series: this has, as we have
stated, the objection of necessitating the use of very
high tensions, which we think can never be really
applied.
One of the most elementary systems of regnlation is
that of M. Gravier. He reduces the problem to its
most simple terms. We have said that the difficulty
consisted in the fact of the generating machines having
an internal resistance, and that the problem would dis-
appear if this resistance could be done away with. This
not being possible, M. Gravier set himself to reduce it.
For this he took a number of machines, and joined them
up for quantity, so that they offered the least resistance
possible to the current. To reduce it still further, he
took care to excite the field magnets separately. This
done, he places the machines in circuits as equal as
possible, in which he employs very thick leads. It
2884
Du Moncel & Geraldy--1883.
therefore happens that if one circuit is taken out,
the remainder, being equal, continue to be supplied as
before, and the interior resistance being also very
slight, the electric production remains approximately
proportional to the exterior resistance. M. Gravier had
at the Electric Exhibition an installation on this sys-
tem; he fed lamps and machines on six different
circuits, his generating apparatus being five machines
coupled together.
This, however, is not a solution-it is an arrange-
ment which may be useful, a good application of a
known principle; but it will be seen that the difficulty
is not got over, it is only lessened. It also possesses a
great disadvantage, namely, that machines with slight
internal resistance necessarily produce electricity of
very low tension, and it will therefore be seen that they
would in consequence not be adapted to the transport
of electricity to a distance. But to distribute usefully,
transmission is necessary; this system is then only use-
ful within certain very narrow limits.
We now come to the solution proposed by M. Marcel
Deprez, which is certainly the most important of those
which we have yet enumerated, and it has this advan-
tage, that it has been tried. This took place at the
Palais de l'Industrie during the Electrical Exhibition of
1881. The circuit from the generator almost made the
round of the building, forming a total lead of about two
kilometres; at various points chosen without distinc-
tion, and only taking into consideration the require-
ments, parallels were taken off each, feeding various
kinds of apparatus working machines for sewing, fold-
ing, cutting out, sawing, turning, &c. At one point a
number were placed together and formed a small work-
shop, a branch being taken off for the production of
light as well. At the end of the circuit was installed a
printing-press, driven by a motor also supplied by a
branch off the main circuit. All these were started or
stopped at will, and each one quite independently
of any other, thus forming an example of distribu-
tion.

Du Moncel & Geraldy--1883.
2885
The system merely consisted of two generating
machines, one large and one small, working together,
and presenting the appearance shown in Fig. 110. That
was all; in fact, its great simplicity was its great advan-
tage. No mechanical apparatus was necessary; it was
solely dependent on the action of physical forces. M.
Deprez discovered that the required result could be
arrived at by combining two exciting circuits on the
field magnets. For this purpose, on the magnets of the
large machine he winds two separate wires; the one
being traversed by the current from the small machine,
thus giving to the generator a constant magnetisation
entirely unconnected with the exterior circuit, and the
second wire, being in the main exterior circuit, is
traversed by a variable current, thus adding to the con-
stant magnetisation one varying with the requirements
of the exterior circuit. He showed that by proper ad-
justment this variable magnetisation would be just
sufficient to give the necessary increase of electromotive
FIG. 110.
force as the demand increased. He thus obtained an
2886
Du Moncel & Geraldy-1883.
automatic regulation without the intervention of any
exterior apparatus, and satisfying in the most complete
manner the required conditions. The Palais de
l'Industrie experiment was on a small scale; prudence
demands that, before giving a final opinion, a larger or
more practical realization should be waited for; how-
ever, it must be acknowledged that we have here the
greatest guarantee for ultimate success.
Closely connected with the above system of com-
pound winding of the field magnets is the Crompton-
Kapp principle. These inventors only use one machine,
the Bürgin, and on the field magnets they wind two
wires, the one being included in the main circuit as in
an ordinary series dynamo, and the other being a shunt
off that circuit; by this means, with a varying resistance
in the exterior circuit, very perfect automatic regulation
is obtained. This arrangement was designed for light-
ing incandescent lamps in multiple are, and is very
largely and successfully used for this purpose; but at
Messrs. Crompton's works, at Chelmsford, this machine
is also used for the distribution of electric energy of
every description. Wires are laid throughout the
building having a convenient number of terminals,
switches, and safety fuses, placed in the different shops,
offices, and the laboratory. To some of these terminals
are attached branch circuits (all in parallel arc), which
feed Swan lamps for lighting the different parts of the
works; other terminals have no permanent connection
with branch circuits, but can at any time be coupled up
to such branches for the purpose of using the current
for some special experimental work. The main circuit
is kept charged to a difference of potential of 80 volts
by one of these compound wound machines, the combi-
nation of main and shunt wires being so chosen that,
no matter what current is taken out of the machine,
that current is always delivered at a predetermined and
fixed difference of potential. In the present instance,
the current taken from the machine varies largely
throughout the day, because from the main circuit the
following operations are carried on independently of
Du Moncel & Geraldy-1883.
2887
each other, viz. lighting by means of Swan lamps in
parallel, testing arc lamps, testing and classifying Swan
lamps, charging secondary battery, and transmission of
motive power.
This last is done in the following
manner: each dynamo, after it is finished, and before
being sent out, is carefully tested. But before driving
it by steam power it is found convenient to run it for
some time as a motor, but doing no work, so as to get
the journals and the brushes to a proper bearing. The
current is also used for polarizing dynamos, for the pur-
pose of making sure that the different coils on the field
magnets are properly connected up; calibrating volt-
and am-meters, testing the fusing point of safety fuses,
testing the magnetic properties of different mixtures of
cast iron, and a number of other laboratory experi-
ments, which of necessity are constantly going on in a
large electric light works. As most of these operations
are carried on independently of each other, it often
happens that current is required at the same time for
many different purposes. Yet there is no difficulty
whatever in this, the machine always proving equal to
the demand.
Another system of distribution is that proposed by
Professors Ayrton and Perry, who advocate the use of
accumulators in the town or centre where the electricity
is required, the charging current being supplied from a
distance wherever the motive power may be available.
They propose the use of electricity of very high tension
but of low intensity; by this means, as we have
already shown, increasing the economy of working, and
not necessitating the use of heavy and expensive con-
ductors. To transform this current into useful propor-
tions, it is to be used to charge a great number of
accumulators in series; these are then to be broken up
by commutator switches into a number of batteries,
each giving a proportionately large current of moderate
tension, such as can be made use of for arc or incande-
scent lamps, motors, etc. This system has never been
worked on a large scale, but it has, in common with so
many others, the objection of necessitating the use of
2888
!
Du Moncel & Geraldy-1883.
currents of extremely high tension, which, although
necessary for the economical transmission of power to a
distance, would in this case be more than usually
dangerous to life, as the circuit through the accumu-
lators would of necessity be exposed; and any two
persons standing on the ground and simultaneously
touching the two extreme accumulators during the
charging would be instantaneously killed, owing to the
immense difference of potential, which might often
amount to many thousands of volts. Of course, when
broken up into batteries for use this danger would not
exist, as the only current then would be that from
the battery itself, being perhaps only 100 to 200
volts.
Another solution of the problem is that put forward
recently by Messrs. Goulard and Gibbs. They have
shown a small installation on their system at the West-
minster Royal Aquarium Electrical Exhibition, where
the results obtained certainly appear very satisfactory.
The principal employed is that of the induction coil,
and consists of a cardboard or wooden cylinder about
50 centimetres high, on which is wound in parallel
spirals, and in rows one above the other, a cable, com-
posed of a central copper wire of 4 millimetres diameter,
highly insulated. Parallel to this, and completely sur-
rounding it, are six strands of twelve small wires each,
individually insulated. The large wire forming the in-
ductor is traversed by the current from an alternating
current machine, and the six strands of twelve wires.
each in which the induced currents are generated have
their ends attached to a commutator, so that they may
be joined up at will in quantity or in tension. Inside
this hollow column is placed a soft-iron cylinder, which
can be raised or lowered, by which the current induced
in the small wires may be regulated. The instruments
shown at the Aquarium consist each of four of these
colums arranged in a square, and the ends of all the
wires are brought up to the commutator in the middle,
so that the whole of the wires may be grouped in
tension or in quantity, or some in quantity and some in
tension. The practicability of this is shown: one of
Du Moncel & Geraldy--1883.
2889
the instruments has all its wires grouped for quantity,
and the current lights twenty-six incandescent lamps.
The other generator has two columns grouped in
tension, and lights a Jablochkoff candle, and at the
same time one of the remaining columns lights five
Swan lamps in multiple arc, and the other drives a
small motor. The intensity of the current induced is
proportional to that of the primary current, and the
tension may be varied according to the way in whic
the induced wires are coupled up. The inducing wire
forms a closed circuit, and of course may traverse any
number of these instruments, provided the electro-
motive force is sufficient to overcome the resistance of
the circuit and of the electromotive force generated by
the secondary current. The inventors therefore pro-
pose to use for the transmission and distribution of
power, alternating currents of very high tension,
traversing as many of these secondary generators as
may be required, they being all arranged in series.
From this arrangement they say there can be no
danger, since the primary current only traverses a
closed metallic circuit, and contact with the body at
any part of the circuit would offer too great a resistance
to allow the slightest derivation of the current. This
system has at present only been shown on this small
scale, and therefore it is impossible to speak with
certainty as to its action in a practical shape, but the
objection to it appears to be in the necessary use of
alternating currents of high tension; whether such
currents can advantageously be employed on long
circuits, where the effects of static charge and induction
will have to be taken into account, yet remains to be
seen.
This, then, is the present position of the all-important
question of the day-the transport and distribution of
power by means of electricity. Much, very much has
been done, but much yet remains to be accomplished
before that almost Utopian state of things arrives,
when all the vast powers of nature at present wasted
shall be reclaimed and made subservient to human will
by being transported through a wire to the centres of
2890
Du Moncel & Geraldy-1883.
civilization, and there distributed to every one accord-
ing to each individual requirement. But in the im-
mediate future we may safely prophesy that great
progress will be made, and that before many years have
elapsed electricity will be almost universally distributed.
That will, then, certainly be one of the greatest events
of our century, and will constitute a veritable social
revolution.
This progress may be summed up in one word: to
bring electricity to the home. And electricity is at the
same time light, chemical work, and motive power; and
that in the smallest quantities that may be desired at
the disposal of the consumer, by the simple turning of
a key. What advancements may we not look for, then,
when many who have now no opportunity of making
the experiments necessary to useful discoveries have
this wonderful power readily obtainable, when every
one has in his own hands, power in its most varied
forms, and that at his own home, at his own time, and
without being compelled to go to a stuffy workshop for
it. The workshop! This word opens to our view
other points, for if the distribution of electricity has for
men an immense advantage, it has much more for
women. It is for them that the workshop is in the
highest degree baneful: all know the dangers of this
life in common, so profoundly destructive to health and
morals. We have already mentioned that the first
practical application of the transmission of power was
to a factory of sewing machines, thus saving women
from a hurtful labor. How much greater will be the
advantage when the woman can work her machine, no
longer in the workshop, but at home by the hearth of
her husband, by the cradle of her infant! It is thus
that will be found the true equality of the sexes; it is
thus that must be sought the solution of this burning
question, the support and the independence of woman.
This distribution will prove an efficient remedy for
these social difficulties, and if we do not now actually
possess it, we may consider it as certain that we soon
shall do so.
Fleming--Letter to Electrician--1884. 2891
Complainant's Exhibit "The Electric
Lighting Act of 1882."
THE ELECTRICIAN (LONDON), JULY 5, 1884, PAGE 177
TO THE EDITOR OF THE ELECTRICIAN.
SIR: In your last issue you enter at some length into
the vexed question of the cost of electric lighting, and
hazard the conjecture whether any one will be bold
enough to say that the cost of a central electric light
station is more than the cost of a central gas station.
Twenty-two months ago the Legislature of this country,
after careful scientific examination of the then state of
the art of distribution of large currents for lighting
purposes, arrived at the conclusion that it was in such
a complete and advanced condition that the time had
arrived for "facilitating and regulating" it according
to the title of the Act-that is to say, for laying down
stringent conditions under which the novel experiment
of distributing electrical energy on a large scale should
first be tried. The question of cost and maintenance
will therefore to a very large extent be influenced by
the legal conditions under which it has to be under-
taken. If these conditions are wise and elastic enough
to accommodate the uncertain direction of development
of the youngest of the arts, your question may not be
long in receiving a practical reply. But if these con-
ditions have been based upon a complete misconcep-
tion of the differentice which separate the distribution
by pipes of a material substance from the first attempts
at distribution of energy in the form of electric current
by subterranean copper mains, then the interesting
question whether the best and cheapest light in every
way is obtainable from the combustion of a hydro-
carbon or the incandescence of a carbon filament by
distributed electricity may, in England at least, be
indefinitely delayed. Which of these prevails is easily
ascertainable by an examination of the main special
2892
Fleming--Letter to Electrician--1884.
provisions of the Act in the light of past and present
experience. The general conception of the Act is that
of permitting the laying down of a network of conduc-
tors under these general conditions. The undertakers
have to specify beforehand—in the absence of guarantee
as to demand—the area they will cover at first, and the
direction in which they will undertake to extend the
mains. They are to bind themselves as to price with-
out any limitations per contra as to the cost of the
ground, for central site, facility of or compulsory pur-
chase for extension, right of way, or security against in-
junction for nuisance. They are debarred from any selec-
tion of customers, on the ground apparently (although
a mistaken one) that as electricity is sold by measure
customers are all proportionately profitable. They
are expressly interdicted from interference with the
most important section of the electrical loop, viz., the
lamp, and finally they are given 21 years or less within
which to achieve practical success and the return of
invested capital. To any one who has had practical
experience of even small electrical distributions it is
only too apparent in every line of this Act that the
conditions of commercial success were not understood
by those who framed it to "facilitate" the supply of
electricity for lighting purposes, and they allowed
themselves to be misled by the analogy of the electric
main to a gas pipe. But the supply of electric current
is not similar to the carriage of stored-up gas. In the
one case a form of energy has to be transformed as
wanted, and when once the plant has been set up for a
given supply the cost of maintenance will not be pro-
portionately affected by variation in actual consump-
tion. In the other case, a material substance is pre-
pared and stored, and if the consumption is less to-day
there is more left over for to-morrow without additional
cost. Hence the paramount condition of success at the
outset is liberty to select customers, so that the hours
of burning may be a maximum, and the mains and
machinery kept as little idle as possible. Again, in the
case of electric supply, the commercial commodity re-
Fleming-Letter to Electrician--1884. 2893
f
tailed is light, and the apparatus of conversion—viz.,
the carbon filament-is only a portion of the endless
loop of lead and return in which the dissipation of
energy in the form of light is made a maximum. Privi-
lege to select for the consumers that form of lamp
which is best adapted to the distribution of potential,
and is electrically and commercially most economical is
an obvious necessity.
Briefly, what is required for any sort of prospect of
success is this,
1. Abolition of areas compulsory and permissive,
specified streets, &c. The network of conductors must
extend as required round the most favourable site pre-
viously selected.
2. Free option to pick and choose customers, and to
favour long burning hours clients whilst the station is
small.
3. Complete control over the lamps used, the under-
takers to sell light or power in standard candle hours
or horse-power, and the customer to have no perplexity
about units of any kind as compared with gas.
4. Freedom from obligation to transfer the property
or to do anything at the end of any period which will
compel the revenue to be so taxed as to prevent invest-
ors from reaping such profits as may be reasonably
looked for in pioneer enterprises of this description.
5. Conditions of safety, insulation and regulation of
pressure to be maintained of course by suitable regula-
tions.
As it stands at present, the Electric Lighting Act of
1882, so far from facilitating electric supply affords the
most complete barrier to its introduction, and will con-
tinue to do so until repealed. The notion that there
was a danger of the upgrowth of a great monopoly is
an instance of the danger of premature legislation in
advance for difficulties which have not arisen.
Whilst such important questions as those of triple or
multiple conductor systems, central station dynamos,
meter measurement, and methods of laying mains and
feeders are admitted to have scarcely reached their
2894 Fleming-Letter to Electrician-1884.
final solution, is it not too much to expect that wise
commercial men shall plunge into a new undertaking
under conditions which do not give them the very
freest scope to feel their way gradually and modify
their methods of charge and supply, in proportion as
industrial invention supplies the means for cheapening
the cost and widening the area of practicable distribu-
tion. The problem of distributing small electric cur-
rents by conductors for the purposes of commercial
telegraphy was not solved without much experience;
but if the more difficult one of distributing currents a
thousand or ten thousand times as strong is to be
attempted under the trammels of legislative restrictions,
we are not likely to have the opportunity of comparing
in England, under equally favourable circumstances,
the cost of electric and gas supply.
Yours, &c.,
20 Coleman-street, E. C.
J. A. FLEMING.
2909
52
L_
DIAGRAM OF ILLUSTRATIVE MODEL OF FEEDER SYSTEM.
OS
C
C3
2½ % Loss.
C4
E
430 430 43 L3
CA
2½ % Loss.
4,6
40 40 40 40 420
420 420 420 420
KANDUSSELDIT@ITRAILLEMZIE JE
GE
М2
NA
N5
M₁
N₁
N₂
C6 O
SHUNT-WOUND
DYNAMO.
FEEDER "A" 10% Loss.
የቀ
DYNAMO
REGULATOR
`6.— €-
EQUALIZER
OR
ARTIFICIAL
FEEDER
D2
D2
Sy
S7
شرق
SK
H₂
=
REFERENCES.
C1 C2 C3 C4 C5 C6 C7 POINTS AT WHICH TO CONNECT THE PRESSURE INDICATORS.
04 D₂ = POINTS AT WHICH TO CONNECT AMPERÉ METERS.
E, E₂ = DOUBLE POLE SWITCHES.
F = SWITCH TO THROW OUT FEEDER "B" & THROW IN THE ARTIFICIAL FEEDER.
G
= MAIN LINE CUT OUT
H₁ H₂- POINTS HALF WAY DOWN FEEDERS "A" & "B" AT WHICH PRESSURE WIRES
Ly Ly Ly™ LAMPS ON THE TWO CONSUMPTION CIRCUITS
M, M₂ = AMPERÉ METERS
=
N₁ N2 N3 N4 Ns = PRESSURE INDICATORS
NA
Sj S ₂ S z S 4 S 5 S & S
-
=
ARE CONNECTED.
16 C.P. LAMPS, 100 VOLTS, ON FEEDERS "A" &¨B¨
54 55 56 57 CONTROLLED BY SWINCHES OR KEY SOCKETS.
S.C. SHORT CIRCUITING DEVICE, CUTTING OUT THE EQUALIZER.
55
FEEDER "B" 10% Loss.
56
U.S.C.C. Dist of New Jersey
Edison E. L. Co
apst
Westinghouse. C.K. Co
Competo Ex "Diagram of
illustrative model of feeder system
produced and described by M Jenks
ni answer
to up.
"
ли
J & R
Sp Ex
Preece--Telegraphic Journal--1879.
2911
Complainant's
Exhibit, Extract
from
THE
Lecture, by W. H. Preece.
"TELEGRAPHIC JOURNAL AND ELECTRICAL
REVIEW" (LONDON) VOL. VII., NO. 145,
FEB. 15, 1879. PP. 59-60.
•
THE CRITERIA OF THE ELECTRIC LIGHT.
We extract the following passages from a very in-
structive lecture to the Royal United States Service
Institution, by Mr. W. H. Preece:
Heat and light are identical in character, though dif-
ferent in degree; and whenever solid matter has im-
parted to it motion of a very high intensity-in other
words, when solid matter is raised to a very high tem-
perature-it becomes luminous. The amount of light
is dependent upon the height of this temperature, and
it is a very remarkable fact that all solid bodies become
self-luminous at the same temperature.
This was determined by Daniell to be 980°, by
Wedgewood, 917°, by Draper, 977°; so that we may
approximately assume the temperature at which bodies
begin to show a dull light to be 1,000°. The intensity
of light, however, increases in a greater ratio than the
temperature. For instance, platinum at 2,600° emits
forty times more light than at 1,900. Bodies when
raised to incandescence pass through all stages of the
spectrum; as the temperature increases so does the
refrangibility of the rays of light. Thus, when a body
is at a temperature of
Temperature
250° it may be called warm.
500°
hot.
66
1,000° we have the red rays.
1,200°
CC
(C
orange rays.
1,300°
(6
(6
yellow rays.
1,500°
<<
blue rays.
1,700°
CC
CC
indigo rays.
2,000°
(C
violet rays.
2912
Preece--Telegraphic Journal--1879.
So that any body raised to a temperature above 2,000
will give us all the rays of the sun. Inversely the
spectroscope may thus be enabled to tell us the tem-
perature of the different lights; and it is, perhaps, be-
cause some lights do not exceed 1,300° that we lose all
those rays beyond the yellow.
* * *
Dr. Tyndall has shown that the visible rays of an in-
candescent wire bear to the invisiblo rays a much
smaller proportion than in the arc, and it is generally
assumed that for the same current the arc will give at
least 2 times greater light than an incandescent wire;
Dr. Tyndall's figures are as follows:
Gas..
Incandescent wire.
The arc
1
1
I
1
Visible Rays. Invisible Rays.
1 to
1
1
24
23
9
The requirements of a good electric lamp are: first,
intense brilliancy; secondly, great steadiness; thirdly,
duration. The Serrin lamp has the first kind of
excellence; all those lamps based on incandes-
cence excel in the second respect; the Wallace-Farmer
light is the only one that attains the third point. The
Rapieff is perhaps that form which up to the present
most nearly combines the three requisites, but in reality
no lamp has yet been introduced which fulfills all
three requirements.
The objections to the use of the electric light are:
1. The deep shadow it throws.
2. The indifferent carbon that has hitherto been
manufactured for the purpose, which leads to unpleas-
ant sounds, to great variation in the intensity of the
light and to waste.
3. The difficulty in distributing the light itself. It
is so intense, and confined to so small a space, that it
does not lend itself to distribution like the gas flame,
which occupies a considerable space.
4. The unsteadidess of the light due to variations
in the speed of the engine employed in driving the
dynamo machine. There is another cause of variation
Preece--Telegraphic Journal--1879. 2913
in the electric arc, and that is, the variation in the re-
resistance of the arc itself, for it has been clearly de-
monstrated by experiments both in America and in Eng-
land that the resistance of the arc varies as the resist-
ances in circuit vary; The following table will show
this:
Current in Webers.
Light Candles.
Resistance of
Arc Ohms.
10
440
2.77
16.5
705
1.25
21.5
900
1.67
30.12
1230
.54
The light in the arc varies directly as the current,
and not as the square of the current, as is generally
assumed.
:
Now, in the case of light raised by incandescence,
the light will increase as the square of the current. It
follows that if in the one case, viz. the arc, the light
increases as the current only, and in the other case,
viz. incandescence, it increases as the square of the
current, a point is reached when the light produced by
incandescence will equal that produced by the arc.
The difficulty in reaching that point is the difficulty in
obtaining a conductor with a sufficiently high point of
fusion to resist the effect of powerful currents. Iridium
is the only metal that is known to do this, and iridium
is too scarce and too dear to be used for the purpose.
The multiplication of the light by Gramme's machine.
upon the Thames Embankment must not be taken as
the solution of the problem of the subdivision of the
light. Theory shows unmistakably that to produce
the greatest effect we must have only one machine to
produce only one light. We know from absolute meas-
urements that such a machine can be used to produce a
light of 14,880 candles, and it is possible to produce 1,254
2914 Preece--Telegraphic Jouurnal--1879.
""
candles per horse-power. But the moment that we at-
tempt to multiply the number of lights in circuit, this
power diminishes, so that we have on the Embankment
lamps giving us a light of scarcely more than 100 can-
dles. The light of the Rapieff lamp in the "Times
office appears to be about 600 candle-power, and the
Wallace light is equal to 800 candle-power. In these
two instances six lights are used in one circuit, but
we have not here the subdivision of the light; we have,
on the contrary, the multiplication of the light, pro-
duced by the increased speed of the engine, due to the
insertion of additional lamps. It is, however, easily
shown that in a circuit where the electro-motive force
is constant, and we insert additional lamps, that when
these lamps are joined up in one circuit, i. e., in series,
the light varies inversely as the square of the number
of lamps in circuit, and when joined up, as in multiple
arc, the light diminishes as the cube of the number in-
serted. Hence the subdivision of the light is an abso-
lute ignis fatuus. In the first place no machine has yet
been produced which is competent or capable of light-
ing over 20 lamps; secondly, no conductor is known
but copper competent to convey the current required
to light these lamps, and copper is an expensive ma-
terial. Thirdly, no electric light has yet been pro-
duced which combines all the criteria needed for a
good light.
2915
Complainant's Exhibit, Siemens' Presidential Address.
THE ELECTRICIAN, NOVEMBER 18, 1882.
"
•
belongs, and shall have the same weight in the country they may be
appealed to as if they emanated from the competent authorities of that
country."
For the proof of the infractions, the clause refers to the laws of the
country wherein they are tried, that is the common law.
The right of reporting was adopted by analogy by the Hague Fishery
Convention.(Clause 28).
The second paragraph is a reiteration of Clause XXXI., Paragraph I., of
the same Convention.
Clause II. "The procedure and the judgment of the contraventions of
the provisions of this Convention shall always be carried out as summarily
as. the laws and regulations in force permit.
This clause is only a reiteration of Clause 37 of the Hague Fishery Con-
vention.
Articlo XII. "The high contracting parties hereto undertako to adopt,
or to propose to their respective Legislatures, the measures requisite for
carrying out this Convention, and notably for punishing either with im-
prisonment or fine, or both, all contraventions of the provisions of Clauses
2, 5, and 6.”
Clause XIII. "The high contracting parties hereto shall communicate
the laws which may already have been passed, or may subsequently be
passed, in their respectivo States relative to the object of this Convention."
Clause XIV. "This Convention shall be ratified. The ratification shall
bo interchanged in Paris within the shortest delay possible.'
Clause XV. "This Convention shall be in force from the day the high
contracting parties shall agree on.
"It shall remain in force years from said date, and in the event
of any of the high contracting parties failing to notify twelve months
before the expiration of said term of years its intention of with-
drawing from this Convention, it shall continue in force another year, and
so on from year to year.
"
In the event of any of the high contracting parties renouncing this
Convention, such renunciation would affect only the high contracting
party thus renouncing."
·
SOCIETY OF ARTS.
On Wednesday, Nov. 15, the President, Dr. C. W. Siemens, F.R.S., gave
his inaugural address, which referred principally to electric lighting. Dr.
Siemens said: Having received the honour of being elected Chairman of
the Council of the Society of Arts for the ensuing year, the duty devolves
upon me of opening the coming session with some introductory remarks.
17
ciples, but when, five years ago, I ventured to predict for the
dynamo-electric current a great practical future, as a means of trans-
mitting power to a distance, those views were still looked upon as
more or less chimerical. A few striking examples of what could be prac-
tically effected by the dynamo-electric current, such as the illumination of
the Place de l'Opera, Paris, the occasional exhibition of powerful arc
lights, and their adoption for military and lighthouse purposes, but espo
cially the gradual accomplishment of the much desired lamp by incandes-
cence in vacuum, gave rise to a somewhat sudden reversion of public feel-
ing; and you may remember the scare at the Stock Exchange, affecting
the value of gas shares, which ensued in 1878, when the accomplishment of
the sub-division of the electric light by incandescent wire was first an-
nounced, somewhat prematurely, through the Atlantic cable.
1
-1
From this time forward electrio lighting has been attracting more and
more public attention, until the brilliant displays at the exhibition of Paris,
and at the Crystal Palace last year, served to excite public interest to an
extraordinary degree. New companies for the purpose of introducing elec-
tric light and power have been announced almost daily whose claims to
public attention as investments were based in some cases upon only very
slight modifications of well-known forms of dynamo-machines, of aro regu-
lators, or of incandescent carbon lights, the merits of which rested
rather upon anticipations than upon any scientific or practical proof.
These arrangements were supposed to be of such superlative merit that
gas and other illuminants must soon be matters simply of history, and
hence arose great speculative excitement. It should be borne in mind,
however, that any great technical advance is necessarily the work of time
and serious labour, and that when accomplished, it is generally found that
so far from injuring existing industries, it calls additional ones into exis
tence, to supply new demands, and thus gives rise to an increase in the
sum total of our resources. It is, therefore, reasonable to expect that side..
by side with the introduction of the new illuminant, gas lighting will go on
improving and extending, although the advantages of electric light for many
applications, such as the lighting of public halls and warehouses, of our
drawing rooms and dining rooms, our passenger steamers, our docks and
harbours, are so evident, that its advent may be looked upon as a mutter of
certainty. Our legislature has not been slow in recognising the import-
ance of the new illuminant. In 1879 a Select Committee of the House of
Commons instituted a careful inquiry into its nature and probable cost,
with a view to legislation, and the conclusions at which they arrived were,
I consider, the best that could have been laid down. They advised that
applications should be encouraged tentatively by the granting of permis-
sive Bills, and this policy has given rise to the Electric Lighting Bill, 1882,
promoted by Mr. Chamberlain, the President of the Board of Trade, re
garding which much controversy has arisen. It could, indeed, hardly be
expected that any act of legislation upon this subject could give universal
satisfaction, because while there are many believers in gas who would
gladly oppose any measure likely to favour the progress of the rival illumi-
Amongst the practical questions that now chiefly occupy public atten- nant, and others who wish to see it monopolised, either by local authori-
tion are those of electric lighting, and of the transmission of force by elec- ties or by large financial corporations, there are others again who would
tricity. These together form a subject which has occupied my attention throw the doors open so as to enable almost all comers to interfere with the
and that of my brothers for a great number of years, and upon which I public thoroughfares, for the establishment of conducting wires, without
may consequently be expected to dwell on the present occasion, consider- public let or hindrance. The law as now established takes, I consider, a
ing that at Southampton I could deal only with some purely scientific con- medium course between these diverging opinions, and, if properly inter-
siderations involved in this important subject. I need hardly remind you preted, will protect, I believe, all legitimate interests, without impeding
that electric lighting, viewed as a physical experiment, has been known the healthy growth of establishments for the distribution of electric energy
to us since the early part of the present century, and that many attempts for lighting and for the transmission of power. Any firm or lighting com-
have from time to time been made to promote its application. Two prin- pany may, by application to the local authorities, obtain leave to place
cipal difficulties have stood in the way of its practical introduction, viz., electric conductors below public thoroughfares, subject to such conditions
the great cost of producing an electric current so long as chemical means
as may be mutually agreed upon, the term of such license being limited to
had to be resorted to, and the mechanical difficulty of constructing electric seven years; or an application may be made to the Board of Trade for a
lamps capable of sustaining with steadiness prolonged effects. The provisional order to the same effect, which, when sanctioned by Parlia-
dynamo-machine, which enables us to convert mechanical into electrical force, ment, secures a right of occupation for twenty-one years. The license
purely and simply, has very effectually disposed of the former difficulty, offers the advantage of cheapness, and may be regarded as a purely tenta-
inasmuch as a properly conceived and well constructed machine of this tive measure, to enable the firm or company to prove the value of their
character converts more than 90 per cent. of the mechanical force imparted plant. If this is fairly established, the license would in all probability be
to it into electricity, 90 per cent. again of which may be re-converted into affirmed, either by an engagement for its prolongation from time to time,
mechanical force at a moderato distance. The margin of loss, therefore,
or by a provisional order which would, in that case, be obtained by joint
does not exceed 20 per cent., excluding purely mechanical losses, and this application of the contractor and the local authority. At the time of ex-
is quite capable of being further reduced to some extent by improved modes piration of the provisional order, pre-emption of purchase is accorded to
of construction; but it results from these figures that no great step in the local authority, against which it has been objected with much force by
advance can be looked for in this direction. The dynamo-machine presents
so competent an authority as Sir Frederick Bramwell that the conditions
the great advantage of simplicity over steam or other power-transmitting of purchase laid down are not such as fairly to remunerate the contracting
engines; it has but one working part, namely, a shaft which, revolving companies for their expenditure and risk, and that the power of purchase
in a pair of bearings, carries a coil or coils of wire admitting of perfect would inevitably induce the parochial bodies to become more trading asso-
balancing. Frictional resistance is thus reduced to an absoluto minimum, ciations. But while admitting the undesirability of such a consummation,
and no allowance has to be made for loss by condensation, or badly fitting I cannot help thinking that it was necessary to put some term to contracts
pistons, stuffing boxes, or valves, or for the jerking action due to oscil- entered into with speculative bodies at a time when the true value of elec-
lating weights. The materials composing the machine, namely, soft iron tric energy, and the best conditions under which it should be applied, are still
and copper wire, undergo no deterioration or change by continuous work very imperfectly understood. The supply of electric energy, particularly in
ing, and the depreciation of value is therefore a minimum, except where its application to transmission of power, is, a matter simply of commercial
currents of exceptionally high potential are used, which appear to render demand and supply, which need not partake of the character of a large
the copper wire brittle. The essential points to be attended to in the con- monopoly similar to gas and water supply, and which may therefore bo
ception of the dynamo-machiuo are tho prevention of induced currents in safely left in the hands of individuals, or of local associations, subject to a
the iron, and the placing of the wire in such position as to make the whole certain control for the protection of public interests. At the termination
of it effective for the production of outward current. These principies, of the period of the provisional order, the contract may be renewed upon
which have been clearly established by the labours of comparatively fow such terms and conditions as may at that time appear just and reasonable
workers in applied science, admit of being carried out in an almost infinite to Parliament, under whose authority the Board of Trade will be en-
variety of constructive forms, for each of which may be claimed some real powered to effect such renewal. Complaints appear almost daily in the
or imaginary merits regarding questions of convenience or cost of publio paners to the effect that townships refuse their assent to applica-
production. For many years after the principles involved in the construc-
tions by electric light companies for provisional orders; but it may bo
tion of dynamo-machinos had been made known, little goueral interest was surmised that many of these applications are of a more or less speculativo
manifested in their favour, and few were the forms of construction offered character, the object being to secure monopolies for eventual use or sale,
for public use. The essential features involved in the dynamo-machino, under which circumstances the authorities are clearly justified in
the Siemens armature (1856), the Pacinotti ring (1861), and the self-exciting withholding their assent, and no licenses or provisional orders should,
principle (1867), wore published by their authors for the pure scientific indeed, bo granted, I consider, unless the applicants can give assur-
interest attached to them, without being made subject matter of letters
ance of being able and willing to carry out the work within a reasonable
patent, which circumstance appears to have had the contrary effect of time. But there are technical questions involved, which are not yet suffi-
what might have been expected, in that it has retarded the introduction of ciently well understood to admit of immediate operations upon a largo
this class of electrical machine, because no person or firm had a sufficient scale. Attention has been very properly called to the great divergence in
commercial interest to undertake the largo expenditure which, must neces- the opinions expressed by scientific mon regarding the area that each.
sarily be incurred in reducing a first conception into a practical shape. lighting district should comprise, the capital required to light such an area,
Great credit is due to Monsieur Grammo for taking the initiative in the and the amount of electric tension that should be allowed in the conduc-
practical introduction
introduction of dynamo-machines
of dynamo-machines embodying those prin- tors. In the case of gas supply the works are necessarily situated in the
:
1
18.
2916.
THE ELECTRICIAN, NOVEMBER 18, 1882.
outskirts of the town, on account of the nuisance this manufacture occa-
sions to the immediate neighbourhood; and, therefore, gas supply must
range over a large area. It would be possible, no doubt, to deal with elec.
tricity on a similar basis, to establish clectrical mains in the shape of
copper rods of great thickness, with branches diverging from them in all direc-
tions; but the question to be considered is, whether such an imitative
course is desirable on account either of relative expense or of facility of
working. My own opinion, based upon considerable practical experience
and thought devoted to the subject, is decidedly adverse to such a plan.
In my evidence before the Parliamentary Committee I limited the desirablo
area of an electrio district in densely populated towns to a quarter of a
square mile, and estimated the cost of the necessary establishment of
engines, dynamio machines, and conductors at £100,000, while other wit-
nesses held that areas from one to four square, miles could be worked ad-
vantageously from one centre, and at a cost not exceeding materially the
figure I had given. These discrepancies do not necessarily imply wide
differences in the estimated cost of each machine or electric light, inasmuch
as such estimates are necessarily based upon various assumptions regard-
ing the number of houses and of public buildings comprised in such a
district, and the amount of light to be apportioned to each, but I still main-
tain my preference for small districts. By way of illustration, let us take
the parish of St. James's, near at hand, a district not more densely popu-
lated than other equal areas within the metropolis, although comprising,
perhaps, a greater number of public buildings. Its population, according
to the preliminary report of the census taken on the 4th April, 1881, was
29,865, it contains 3,018 inhabited houses, and its area is 784,000 square
yards, or slightly above a quarter of a square mile. To light a comfortable
house of moderato dimensions in all its parts, to the exclusion of gas, oil,
or candles, would require about 100 incandescent lights of from 15 to 18
candle-power each, that being, for instance, the number of Swan lights
employed by Sir William Thomson in lighting his house at Glasgow Uni-
versity. Eleven horse-power would be required to excite this number of
incandescence lights, and at this rate the parish of St. James's would require
3,018 × 11 = 33,200 horse-power to work it. It may be fairly objected,
however, that there are many houses in the parish much below the standard
here referred to, but, on the other hand, there are 600 of them with shops
on the ground floor, involving larger requirements. Nor does this estimate
provide for the large consumption of electric energy that would take place
in lighting the 11 churches, 18 club houses, 9 concert halls, 3 theatres,
besides numerons hotels, restaurants, and lecture halls. A theatre of
moderate dimensions, such as the Savoy Theatre, has been proved by expe-
rience to require 1,200 incandescence lights, representing an expenditure of
133 horse-power; and about one-half that power would have to be set
aside for each of the other public buildings here mentioned, constituting
an agregate of 2,926 horse-power; nor does this general estimate comprise
street lighting, and to light the six and -half miles of principal streets of
the parish with electric light would require, per mile, 35 arc lights of 350
candle-power cach, or a total of 227 lights. This, takon at the rate of 0-8
horse-power per light, represents a further requirement of 182 horse power,
making a total of 3,108 horse-power, for purposes independent of house
lighting, being equivalent to one horso-power per inhabited house, and
bringing the total requirements up to 109 lights 12 horse-power per
house. I do not, however, agree with those who expect that gas lighting
will be entirely superseded, but have, on the contrary, always maintained
that the electric light, while possessing great and peculiar advantages for
lighting our principal rooms, halls, warehouses, &c., owing to its brilliancy,
and more particularly to its non-interforence with the healthful condition
of the atmosphere, will leave ample room for the development of the former,
which is susceptible of great improvement, and is likely to hold its own for
the ordinary lighting up of our streets and dwellings. Assuming, there
fore, that the bulk of domestic lighting remains to the gas companies, and
that the electric light is introduced into private houses, only at the rate
of, say, 12 incandescence lights per house, the parish of St. James's would
have to be provided with electric energy sufficient to work (9+12) 3,018=
63,378 lights 7,042 horse-power effective; this is equal to about one-
fourth the total lighting power required, taking into account that the total
number of lights that have to be provided for a house are not all used at
one and the same time. No allowance is made in this estimate for the
transmission of power, which, in course of time, will form a very large
application of electric energy; but considering that power will be required
mostly in the day timo, when light is not needed, a material increase in
plant will not be necessary for that purpose.
In order to minimise the length and thickness of the electric conductor,
it would be important to establish the source of power, as nearly as may be,
in the centre of the parish, and the position that suggests itself to my
mind is that of Golden-square. If the unoccupied area of this square,
representing 2,500 square yards, was excavated to a depth of 25 feet, and
then arched over so as to re-establish the present ground level, a suitable
covered space would be provided for the boilers, engines, and dynamo
machines, without causing obstruction or public annoyance, the only erection
above the surface would be the chimney, which, if made monumental in form,
might be placed in the centre of the square, and be combined with shafts
for ventilating the subterranean chamber, care being taken of course to
avoid smoke by insuring perfect combustion of the fuel used. The cost of
such a chamber, of engine power, and of dynamo-machines, capable of con-
verting that power into electric energy, I estimate at £140,000. To this
expense would have to be added that of providing and 'aying the con-
ductors, together with tho switches, current regulators, and arrangements
for testing the insulation of the wire. The cost and dimensions of the con-
ductors would depend upon their length, and the electromotive force to be
allowed. The lattor would no doubt bo limited by the authorities to the
point at which contact of the two conductors with the human frame would
not produce injurious effects, or say to 200 voits.except for street lighting,
for which purposo a higher tension is admissible In considering the proper
size of conductor to be used in any given installation, two principal factors
have to be taken into account; first, the charge for interest aud deprocia-
tion on the original cost of a unit length of the couductor; and, secondly,
the cost of the electrical onergy lost through the resistance of a unit of
length. The sum of these two, which may be regarded as the cost of con-
voyance of electricity, is clearly least, as Sir William Thomson pointed out,
some time ago, when the two components are equal. This, then, is the
principle on which the size of a conductor should be determined. From
the experience of large installations, I corsider that electricity can roughly
speaking, be produced in London at a cost of about one shilling por 10,000
ampere volts or watts (746 watts being equal to 1 horse-power) for an
hour. Hence, assuming that each set of four incandescence lamps in
series (such as Swan's, but for which may be substituted a smaller number
of higher resistance and higher luminosity) requires 200 yolts electromo
tive force, and 60 watts for their efficient working, the total current
required for 64,000 such lights is 19,200 amperes, and the cost of the electric
energy lost by this current in passing through 1-100th of an ohm resist-
ance la 16 per hour. The resistance of a copper bar que quarter of a
mile in length, and one square inch in section, is very nearly 1-100th of an
ohm, and the weight is about 2 ton. Assuming, then, the price of insu
lated copper conductor at £90 per ton; and the rate of interest and depre-
ciation at 7 per cent., the charge per hour of the above conductor, when
used eight hours per day, is 1d. Hence, following the principle I have
stated above the proper size of conductor to use for an installation of the
magnitude I have supposed would be one 48′29 inches section, or a round
rod eight inches diameter.
If the mean distance of the lamps from the station be assumed as 350
yards, the weight of copper used in the complete system of conductors
would be nearly 168 tons, and its cost £15,120. To this must be added the
cost of iron pipes, for carrying the conductors underground, and of testing
boxes, and labour in placing them. Four pipes, of 10in. diameter each,
would have to proceed in different directions from the central station, each
containing sixteen separate conductors of lin. diameter, and separately.
insulated, each of them supplying a sub-district of 1,000 lights. The
total cost of establishing these conductors may be taken at £37,000, which
brings up the total expenditure for central station and leads to £177,000.
I assume the conductors to be placed underground, as I consider it quite
inadmissible, boch as regards permanency and public safety and conveni-
ence, to place them above ground, within the precincts of towns. With
this expenditure, the parish of St. James's could be supplied with tho
electric light to the extent of 25 per cent. of the total illuminating power
required. To provide a larger percentage of electric energy would increaso
the cost of establishment proportionately, and that of conductors, nearly
in the square ratio of the increase of the distriot, unless the loss of energy
by resistance is allowed to augment instead. It may surprise uninitiated
persons to bo told that to supply a single parish with electric energy neces-
sitates copper conductors of a collective area equal to a rod of 8in, in
diameter; and how, it may be asked, will it be possible under such condı.
tions to transmit the energy of waterfalls to distances of twenty or thirty
miles, as has been suggested. It must, indeed, be admitted that the trans-
mission of electric energy of such potential (200 volts) as is admissible in
private dwellings would involve conductors of impracticable dimensions,
and, in order to transmit electrical energy to such distances, it is necessary
to resort, in the first place, to an electric current of high tension. By increas
ing the tension from 200 to 1,200 volts the conductors may be reduced to one-
sixth their area, and if we are content to lose a larger proportion of tho
energy obtained cheaply from a wateriall, wo may effect a still
greater roduction. A current of such high potential could not
bo introduced into houses for lighting purposes, but it could
be passed through tho coils of રી secondary dynamo-machine,
to give motion to another primary machine, producing currents
of low potential to be distributed for general consumption. Or
secondary batteries may be used to offect the conversion of curronts of
high into those of low potential, whichever means may be found the
cheaper in first cost, in maintenance, and most economical of energy. I
may be advisable to have several suck. relays of energy for great distances,,
the result of which would be a reduction of the size and cost of conductor
at the expense of final effect, and the poifey of the electrical engineer will,
in such cases, have to be governed by the relativo cost of the conductor,
and of the power at its original source. If secondary batteries should be-
come more permanent in their action than they are at the present time,
they may be largely resorted to by consumers, to receive a charge of elec-
trical energy during the day time, or the small hours of the night, when the
central engine would otherwise to unemployed, and the advantage of re
sorting to these means will depend upon the relative first cost, and cost
of working the secondary battery and the engine respectively.
These questions are, however, outside the range of our present
consideration. The large aggregate of dwellings comprising the metropolis
of London covers about seventy square miles, thirty of which may bo taken
to consist of parks, squares, and sparsely inhabited areas, which are not to
be considered for our present purpose. The remaining forty square miles
could be divided into, say, 140 districts, slightly exceeding a quarter of a
square mile on the average, but containing each. fully 3,000 houses, and a
population similar to that of St. James's. Assuming twenty of these dis-
tricts to rank with the parish of St. James's (after deducting the 600 shops
which I did not include in my estimate) as central districts, sixty to bo
residential districts, and sixty to be comparatively poor neighbourhoods,
and estimating the illuminating power requirod for these three classes in
the proportion of 1 to 3 to, we should find that the total capital expendi-
ture for supplying the metropolis with electric energy to the extent of 25
per cent. of the total lighting requirements would he :-
177,000
20
60
60
X X X
X 177,000
X 177,000
£3,540,000
= £7,080,000
£3,540,000
£14,160,000
or say £14,000,000, without including lamps and internal fittings, and making
system over the towns of Great Britain and Ireland would absorb a capital
an average capital expenditure of £100,000 per district. To extend the samo
exceeding certainly £64,000,000, to which must be added £16,000,000 for
lamps and internal fittings, making a total capital expenditure of £80,000,000.
Some of us may live to see this realised, but to find such an amount of
capital, and, what is more important, to find the manufacturing appliances
to produce work representing this value of machinery and wire, must, neces-
sarily be the result of inany years of technical development. If, therefore,
tric energy, not only for every town throughout the country, but also for
we see that electric companies apply for provisional orders to supply elec-
colonies, and for foreign parts, we are forced to the conclusion that their
ambition is somewhat in excess of their power of perinmance; and that
being executed within a reasonable time, as without such a provision the
no provisional order should be granted except conditionally on the work
powers granted may have the effect of retarding instead of advancing electric
2917
•
THE ELECTRICIAN, NOVEMBER 18, 1882.
lighting, and of providing an undue encouragement to purely speculative
operations. The extension of a district beyond the quarter of a square
mile limit would necessitate an establishment of unwieldy. dimensions,
and the total cost of electric conductors per unit area would be materially
increased; but independently of the consideration of cost, great public
inconvenience would arise in consequence of the number and dimensions
of the electric conductors, which could no longer be accommodated in
narrow channels placed below the kerb stones, but would necessitato the
construction of costly subways-veritable cava electrica. The amount of
the working charges of an establishment comprising the parish of St.
James's would depend on the number of working hours in the day, and on
the price of fuel per ton. Assuming the 64,000 lights to incandesce for six
hours a day, the price of coal to be 20s. a ton, and the consumption 21b. per
effective horse-power per hour, the annual charge under this head, taking
eight hours' firing, would amount. to about £18,300, to which would have
to be added for wages, repairs, and sundries, about £6,000, for interest
with depreciation at 7 por cent. £13,300, and for general management
say £3,400, making a total annual charge of £41,000, or at the rate of
128.,91d. per incandescence lamp per annum. To this has to be added the
cost of renewal of lamps, which may be taken at 5s. per lamp of 16 candles,
lasting 1,200 hours, or to 9s. per annum, making a total of 21s. 91d. per
lamp for a year. In comparing these results with the cost of gas lighting,
we shall find that it takes five cubic feet of gas, iu a good argand burner,
to produce the same luminous effect as one incandescence light of 16 candle-
power. In lighting such a burner every day, for six hours on the average,
we obtain an annual gas consumption of 10,950 cubic feet, the value of
which, taken at the rate of 28. 8d. per 1,000, represents an annual charge
of 298., showing that electric light by incandescence, when carried out on
a large scale, is decidedly cheaper than gas lighting at present prices, and
with the ordinary gas burners.
•
On the other hand, the cost of establishing gas works and mains of a
capacity equal to 64,000 argand burners would involve an expenditure not
exceeding £80,000 as compared with £177,000 in the case of elecuricity;
and it is thus shown that, although it is more costly to establish a given
supply of illuminating power by electricity than gas, the former has the
advantage as regards current cost of production.
It would not be safe, however, for the advocates of electric lighting to
rely upon these figures as representing a permanent state of things. In
calculating the cost of electric light, I have only allowed for depreciation
and 5 per cent. interest upon capital expenditure, whereas gas companies
are in the habit of dividing large dividends, and can afford to supply gas
at a cheaper rate, by taking advantage of recent improvements in manu-
facturing operations, and of the ever-increasing value of their by-products,
including tar, coke, and ammoniacal liquor. Burners, have, moreover, been
recently devised by which the luminous effect for a given expenditure of
gas can be nearly doubled by purely mechanical arrangements, and the
brilliancy of the light can be greatly improved.
On the other hand, electric lighting also may certainly be cheapened by
rosorting, to a greater extent than has been assumed, to arc lighting, which,
though less agreeable than the incandescence light for domestic purposes
can be produced at less than half the cost, and deserves on that account
the preference for street lighting, and for large halls, in combination with
incandescence lights. Lamps by incandescence may be produced hereafter
at a lower cost, and of a more enduring character.
The latter portion of the address referred principally to the question
of heating by ges, Dr. Siemens stating that probably electricity would
provide light, and gas would provide heat.
stroot.
THE SOCIETY OF TELEGRAPH ENGINEERS.
The first meeting after the summor recess was held on Thursday, Novem-
ber 9, in the theatre of the Institution of Civil Engineers, Great George-
After the formal business of the meeting, a contribution by Colonel F.
Bolton was announced. This gentleman bas cortinued his list of electric
light patents to a very recent date, and it will be seen that the introduction
to this new list paid a well-deserved tribute to the management of the
Society's library, in the hands of Mr. A. J. Frost. The introduction to
Colonel Bolton's list was as follows:-
19
lieved I could not fail to render some slight service to electrical engineers
by undertaking this task.
Although in 1879. electric lighting was beginning to create considerable
interest in the public mind, it had not assumed the vast importance it now
possesses, The enormous amount of capital that has lately been embarked
in various electrical undertakings, and the great number of persons not
electricians who are connected with the subject, render it more than ever
necessary that some system of classification should be attempted. It night
well be thought that such a work should properly be performed by tho
Commissioners of Patents, who have the funds and all the material at thoir
disposal for the purpose. Apparently its desirability, not to say necessity,
has failed to strike them. It is true that an abstract of specifications on
electric lighting has been issued by the Patent Office, but, although a
revent publication, it only goes up to 1876. It will, probably, be admitted,
therefore, that its usefulness is very much impaired, and, however thankful
we ought to be for small mercies, we have not here much to be thankful
for.
The limited time that I have been able to devote to the matter, and tho¨
great difficulty that exists in making a satisfactory classification of the
immense number of patents produced during the last few years, have ren
dered the work one of great labour and considerable difficulty. I can only
offer the paper as supplementary to the previous one, in the hopo that the
mere fact of bringing the various systems under one heading, with a few
necessary subdivisions of all the published specifications to September 30,
1882, may prove of value to those who, in large and daily-inoreasing num
bers, aro devoting their attention to the subject of eleotrio lighting.
I would here refer to the greet assistance I have derived from the valu
able collection of electrical patents presented to the Society by H.M.
Commissioners of Patents. have thereby been enabled to have laid
before me week by week the whole of the published specifications on
electricity and magnetism as soon as they were issued to the public, a fact
which, I-think. speaks weli for the management of our library.
I would, however, suggest that, if the specifications were classed under
their various headings, and bound up, or a classified index of them made,
the labour of searching for any particular patent would be considerably
lessened.
•
MR. W. H. PREECE, F.R.S., ON THE MUNICH EXHIBITION.
We do not intend to follow Mr. Preece seriatim in his paper, because we
and admire Mr. Preece's ability to interest his hearers, and can say that
are already dealing with the exhibition in our other columns. We all know
this description of his visit to Munich was given in his best-style. The
paper, though long, did not weary, inasmuch as it was lightened by many
We canie in for our share
asides and sly allusions to controversial points.
joke" the Saturday
of criticism, inasmuch as we had the temerity to
Review for its ignorance of Mussrs. Buston, Procter, and Co. Wo havo
wondered whom the Saturday Review writer might be-aud whoever he is
that the firm mentioned was not particularly well known to him. The
we can only say he sinnod in good company-for Mr. Preece acknowledged
that the firm mentioned was not particularly well known to him. The
Munich Exhibition, although termed international, was so only in name-
nor, indeed, was it really national, when such firms as Siemers and Halske,
Feltea and Guilleaume, &c., were unrepresented. It was, indeed, South
German-Bavarian-intensely so. There was little new to chronicle, and
that little of no very great importance. Great praise was given to Messrs.
Crompton as having an excellent exhibit, and being the only English ropre-
sentatives at the oxbition. The Edison installation was noticed, as was
that of Schuckers, whose machine was well spoken of. A. secondary battery
of an old type with a new name, and giving off in process of making a
nauseous smell was mentioned, as was the new-old incandescent lamp with
filaments like those of Swan only shaped and interwoven spirally. That,
with the hollow carbor, and other exhibits have already been mentioned in
our columnus. The lead-covered cables of Berthould and Borel were spoken
of also as a new-old arrangement.
The archeological exhibits of the instruments of Sommering, Steinheil,
Reis, &c., were mentioned, and so on. Reference was made to the phos-
phor bronzo wires exhibited by M. Weiller, an exhibit which we have not
yet mentioned. Mr. Preece seemed to think yery favourably of this wire,
and stated that a wire, 14) B.W.G., was exhibited which would stand a
strain equal to a similar wire of steel, and had a resistance similar to that
of copper.
Mr. Preece insisted upon the fact that the Munich Exhibition would be
known more on account of the tests carried out than for the appuratus ox-
hibited. He justly spoke of the able men who undertook the work of test-
ing as admirably fitted for their self-imposed task, as energetic, and greatly
interested in the work. The testing instruments were all arranged pre-
tests could be taken at the same time The results are not yet ready, but
will, no doubt, be shortly.
A hearty vote of thanks was given to Mr. Preece, subsequent to a short
discussion, and the President announced thefat the next meeting he should
give a description of the experiences of the telegraphic work during the
late campaign in Egypt.
SOME FURTHER HISTORICAL NOTES ON THE ELECTRIC LIGHT, BRING-viously to the opening of the exhibition, and so arranged that the crucial
ING THE SUBJECT UP TO THE 30TH SEPTEMBER, 1882.
The paper on
"Electric Lighting" which I had the honour to read
before the Society in May, 1879, met with so favourable a reception, while,
as I am assured, it has not been without value to those interested in the
subject, that I have been encouraged and induced to continue the work,
with a view to bringing it down as far as possible to the present time. In
1879 the conditions were different from what they are now. Then the sub-
ject of electric lighting was comparatively a new one, and the number of
specifications to be examined, although extending over a number of years,
was considerably less than the number issued between 1879 and the present THE ORIENTAL TELEPHONE COMPANY (LIMITED)).
year of grace. From an historical point of view my former paper neces-
sarily possessed far greater interest for the student than the present one
can possibly do, as it embraces so brief a period.
I have unavoidably been led to deviate in some respects from the plan
formerly adopted, and to make this paper of a somewhat more practical
character, in the desire to assist the student in his investigation of that
particular system of electric lighting which may happen to be the subject
of his search.
The abstracts of specifications given under each heading do not pretend
to be even a précis of the whole of each patont. Indeed, such a compila-
tion would be entirely beyond the scope of this paper or the limits allowed
by the Society's Journal. The number of patents which have been taken
out since the date of my last paper has been so great, exceeding 550, as to
almost cause me, when 1 found the muss of work to be done, to hesitate
before continuing it; nor should I have done so had I not known the great
difficulty there is in obtaining even a more list of the numbers, dates, and
tities of the various patents on any particular subject, and therefore be
An extraordinary general meeting of the members of this Company wILD
held at the City Terminus Hotel, Cannon-street, on the 13th November.
1882, under the presidency of John Pender, Esq., M.P.
The SECRETARY (Mr. W. G. Hall) read the notice convoning the meet-
ing, and subsequently the minutes of the last meeting, held on the 19th
April, 1882, which were approved by the present meeting and signed by the
chairman.
The CHAIRMAN then said: Gentlemen, the objects of calling you together
to-day are, first, to ask you to confirm a salo of our rights to a company
formed in Bombay, and secondly, to take powers to make similar sales
elsewhere without the necessity of a special meeting. When I last bed the
pleasure of addressing you, I find, on referring to the speech I made on
that occasion, that I made the following remarks:
"We have not yet
attempted any sales of privileges which we hold in India, but I expect
before long (having established these important exchanges in the important
Scale: 3" = 1 foot.
2918
Complainant's Exhibit, TREE SYSTEM, Diagram Nº1.
James For Kaggler
Special Examiner
Dilobes 13.1841
1
1
t
3.979"
← 2.297-
k.1297 >
.406″
7.959"
9.474*
2 297*.
3.979*
<- 2.297" →
•
TREE SYSTEM.
ONE QUARTER THE AREA SUPPLIED FROM STATION IN CENTRE OF A
DISTRICT OF 36 CITY BLOCKS WHERE GREATEST ECONOMY IS ATTAINABLE
BY TOTAL DROP OF 18 VOLTS.
EACH BLOCK,400 FEET SQUARE, SEPARATED BY STREETS 100 FEET WIDE
EACH BLOCK FACE, 16 HOUSES.
EACH HOUSE, 15 LAMPS. TOTAL 8,640 LAMPS.
EACH LAMP 1/2 AMPERE, 100 VOLTS.
TOTAL DROP IN TENSION, 3 VOLTS.
EACH CONDUCTOR (THAT IS,+OR-) IS
19
99
99
99
9.75 INCHES IN DIAMETER AT STATION.
0.406
FARTHEST HOUSE.
ONLY ONE POLARITY SHOWN.
TOTAL COPPER IN BOTH CONDUCTORS 803, 250 POUNDS.
TOTAL COST OF COPPER @.25¢ Per tb.- $200, 812.50
COST OF COPPER Per LAMP-$23.25
ENTIRE SYSTEM USED AS MAINS (CONSUMPTION CIRCUITS)
SOLID PORTION OF CONDUCTOR SHOWS COPPER REQUIRED FOR
TRANSMISSION TO POINTS BEYOND.
SHADED TAPERED PORTION SHOWS ADDITIONAL COPPER REQUIRED
FOR DISTRIBUTING TO HOUSES ON EACH BLOCK.
Complainants Shitet
- Th
11.5"
ότι
Free Sistemin
Deagram N2.
James For Kugle
Spenal Examiner
October 13.1891
か
​101
11.0"
11.15-
-12.75-——.
ThLtib-
58-
1
I
2.2895
kada
ایی
2.297
Scare: 1½ 1 for
-Hortilib-
ध्
This Cube représente Tooth. of the Mase
of
Copper Conduitors
this system for
required by be this store,
City
Containning
the 9
8 Lamp of 160.0.
Lauape
8641
-29.29*
Tree Sypter Model
Diagram
No. 2.
29.29
-29.29
•
21.091-
This Cube represente 100 the of |
the Maes of Copper Conductors pe-
quired for the of city Blocke
shown above, containing 8,
640
- 21.09"
-21.09"-
Lamps of 16 Candle Power,
but.
The
Three Wire Free Dystem
of Distribution.
C
2919
Scale: 3"= 1 foot.
*2920
Complainant's Exhibit. FEEDER SYSTEM Diagram Nº 3.
Fames Fr Ringgles
Spesia Excamins,
59
!
•
1.326
1.453
k 839
1.028
1.453>
Diam.
Diam
Dışın
Dian
Diam
1.326
Diam
October 13. 1891
-----
FEEDER SYSTEM.
ONE QUARTER THE AREA SUPPLIED FROM STATION IN CENTRE OF A DISTRICT OF 36 CITY
BLOCKS, WHERE GREATEST ECONOMY IS ATTAINABLE BY TOTAL DROP OF 18 VOLTS.
EACH BLOCK, 400 FEET SQUARE, SEPARATED BY STREETS 100 FEET WIDE.
EACH BLOCK FACE 16 HOUSES
EACH HOUSE, 15 LAMPS. TOTAL 8640 LAMPS.
EACH LAMP½ AMPERÉ, 100 VOLTS.
DROP IN TENSION IN FEEDERS, 15 VOLTS.
99
"9
99
MAINS, 3
ONLY ONE POLARITY SHOWN.
"
TOTAL COPPER IN BOTH CONDUCTORS:
MAINS.
25, 584 POUNDS.
FEEDERS 103, 155
THE SYSTEM 128, 739
TOTAL COST OF COPPER $32, 185.00
$32,185.00
COST OF COPPER Per LAMP $3.72
99
ONLY TAPERED CONDUCTORS USED AS MAINS (CONSUMPTION CIRCUITS)
Complamants Exhibit
4930)
3
+
S
Feeder System
Diagram N 4
worp
James & Ruggles
Special Examiner
59195
October 13.1891
wwwbys
Seale & 1/1 foot
15
1.453" du.
1.326" di.
•
1.028
.234
do.
"
aly
.839
do.
1.326" die vr
1.1-59
N
alu.
15.8"
This Cube represents 100 the of.
the man of copper conductore, re
quired by this systern for the 91
City blocks shown, containing
8,640 Lauaps of 16 candla Fower
15.5.
-15.8".
-11.46=>
1145".
This Cuve represents thi
of
100
The Mass of Copper Com-
ductore required for the 9
City Blocks above shown.
Contamung 8,640 Lacups
of 16 Candle Prover, bur
the Three Wire Freder
Distribution.
System of
Feeder Systein Model.
Владиат
No.4.
2921
2922
(No Model.)
T. A. EDISON.
ELECTRIC DISTRIBUTION SYSTEM.
No. 266,793.
PP
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P
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Patented Oct. 31; 1882.
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WITNESSES:
D. 19 Mott
M.J. blagets.
n
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Fig. 3.
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I
I
* JE KORRIS PETERS CO, PHOTO-LITHO
VASHINGTON D C
BY
INVENTOR:
J. A Edison
agens Milber.
ATTORNEYS.
2923
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
ELECTRIC DISTRIBUTION SYSTEM.
SPECIFICATION forming part of Letters Patent No. 266,793, dated October 31, 1882.
Application filed December 9, 1881. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 usefulImprovement in Electrical Distribution
Systems, (Case No. 361;) and I do hereby de-
clare that the following is a full and exact de-
scription of the same, reference being had to
the accompanying drawings, and to the let-
10 tors of reference marked thereon.
In a system of electric lighting in which a
town or village or a portion thereof is sup-
plied from one central station it may some-
times occur that the district supplied is irreg-
15 ular in shape, and that in some parts of the
district more lights may be used, and conse-
quently more electricity required, than in
others.
The object of this invention is to so arrange
20 the system of conductors supplying the dis-
trict that the supply in the various localities
of the district will be proportioned to the de-
mand.
In a prior application I have set forth the
25 manner in which I usually prefer to arrange
my conductors in cases where about the same
supply is required all over the district, viz:
Along each face of each block in the district |
are laid two conductors-one "positive," the
30 other "negative"-and at every street-corner
where the conductors intersect each other all
the positive conductors are connected together
and all the negative-that is, wherever two
conductors of the same name cross each other
35 they are connected together-and feeding-
conductors connect with these street-mains
at certain definite and regularly-arranged
points, so that a constant amount of electric-
ity is supplied in all parts of the district. in
40 a uniform manner; but where, as explained
above, the district is irregular in shape and
some parts of it require more current than
others this arrangement is modified as fol-
lows: By estimating the number of lamps or
45 other translating devices used in the entire
district and the proportion used in various
parts thereof, I am enabled to discover what
may be termed the "centers of consump-
tion "—that is, the points in the neighbor-
50 hood of which or around which a certain
amount of electricity is consumed.
In parts of the district which are thickly set-
tled and contain a good many consumers of
electricity the center of consumption would
be the center of a very small space, while in 55
sparsely-inhabited localities, where few lamps
are used, the space surrounding the center of
consumption would be larger.. The district
might thus be considered as divided into ir-
regularly-shaped sub-districts, each contain- 60
ing about the same number of lamps, and
each consuming approximately the same
amount of energy. To each of these centers
of consumption is run from the central sta-
tion a "feeding-circuit," consisting of a posi- 65
tive and a negative conductor, each of which
is connected at the proper point to a similar
conductor of the main system. As stated
above, all the positive and all the negative
main conductors are connected together 70
wherever they intersect. I sometimes find
it desirable to connect them also at other
points by running cross-connections across
the street at various places along the faces of
the blocks.
75
The feeding-conductors are preferably of
the form set forth in my prior application,
(Serial No. 31,825,) with the exception that
small additional wires are laid in the tubes,
which form additional circuits, each of which 80
runs from a center of consumption back to
the central station, where it passes through
an electro-dynamometer or other suitable de-
vice for indicating electric pressure, and
thence returns again to the center of con- 85
sumption, so that the amount of energy used
in each feeding-circuit or the electrical poten-
tial at center of consumption is indicated,
and adjustable resistances are placed in each
feeding-circuit, so that according to the indi- 90
cations of the electro-dynamometer more or
less current may be supplied to the circuit.
The main conductors of the consumption-cir-
cuit are made of such size that the drop in
electro-motive force upon them will not be 95
sufficient to vary practically the candle-power
of the lamps, while upon the feeding-conduct-
ors any drop may be provided for without
affecting the relative candle-power of the
lamps of the consumption-circuit, such feed- 100
ing-conductors having no translating devices
connected therewith. The loss upon the feed-
2924
2.
266,793
ing-conductors is preferably greater than that
upon the main conductors of the consump-
tion-circuit, but will be varied in different lo-
calities according to the relative cost of cop-
5 per for conducting purposes and horse-power
for generation. The electro-dynamometer
used is preferably that of Weber, a large re-
sistance say 10,000 ohms-being placed in
circuit with the instrument, as is well under-
ro stood, so that the instrument will vary with
the variations in tension, and will practically
indicate the electro-motive force of the cur-
rent.
In the accompanying drawings, Figure 1
15 is a diagram of a district, showing the system
of mains and feeding-circuits; Fig. 2, a dia-
gram showing a part of the district, with a
portion of the apparatus used at the central
station; and Fig. 3 is a cross-section of one of
zo the underground tubes containing the con-
ductors of a feeding-circuit.
A, Fig. 1, represents a central station; N
and P, respectively the negative and positive
poles of batteries of electric generators situ-
25 ated in the station. BB' B" are blocks which
compose the district or part of it. The blocks
B'B' may be taken as types of all the others.
In each of the streets surrounding these blocks
are laid the main conductors p n, p represent-
30 ing positive and n negative conductors.
Wherever conductors of the same name
cross each other they are run into a junction-
box and connected, and additional connec-
tions may also be made between them by
35 cross-conductors n'p', placed across the street
at various points along the faces of the blocks.
The centers of consumption are, as before
explained, various irregularly-located points
at different distances from the source of sup-
40 ply, A, such as the points CDEF. To these
points are run the feeding-circuits, each con-
sisting of a positive conductor, p', and a nega: |
tive conductor, n". The conductors p" all
run from positive poles P of the generators
45 and the conductors n' from negative poles
N. By these feeding-circuits electricity is
supplied to the different groups of lamps, each
of which surrounds a center of consumption.
In Fig. 3, n" p' are the feeding-conductors,
50 surrounded by insulating - washer G, which
separates them from an inclosing metal tube,
H. c care small wires, which also pass
through the tube H.
55
Fig. 2 illustrates the manner in which the
conductors surrounding any block B of the
district are arranged.
II represent a battery of electric generators,
NP being respectively its negative and posi-
tive poles, from which run the feeding-con-
60 ductors n' p' to the centers of consumption
of the block, where they are connected to the
street-conductors n p by means of the junc-
tion-boxes described in a prior application.
For convenience in the drawings, the wires
65 cc', which are inclosed in the same tube with
the conductors n' p", are shown separated
from these conductors in Fig. 2. These wires
cc' form an auxiliary circuit to each feeding-
circuit, passing through electro-dynamome-
ters b b or other suitable devices for indicat- 70
ing electric pressure at the central station,
which by this means indicate the electrical
potential at the centers of consumption..
dd are adjustable resistances, placed in the
feeding-circuits, by means of which more or
less current may be made to pass through
such circuits, according to the indications of
the electro-dynamometers.
What I claim as my invention is—
75/
1. In a system of electrical distribution, the 80
intersecting and connected positive conduct-
ors and the intersecting and connected nega-
tive conductors, forming the main conductors
of the consumption-circuit, upon which the
drop in electro-motive force is not sufficient to 85
vary practically the candle-power of the lamps,
in combination with a central station and
feeding-conductors having no translating de-
vices connected therewith, and extending from
the source of electrical energy at the central 90
station to the main conductors of the consump-
tion-circuit, said feeding-conductors being
connected with such main conductors of the
consumption-circuit at or near centers of coa-
sumption, substantially as set forth.
95
2. The combination, with a feeding-circuit
of an electrical distribution system, of an aux-
iliary circuit composed of smaller conductors
connected at its terminals with the terminals
of the feeding-circuit, and containing a suit- 100
able device for indicating electric tension, so
that the electro-motive force of the current in
the main circuit is indicated, substantially as.
set forth.
3. The combination of the conductors forin- ros
ing a circuit of an electrical distribution sys-
tem, placed in an inclosing tube, of smaller
conductors in the same tube, having their ter-
minals connected with those of the main con-
ductors, and forming a circuit in which is 110
placed a suitable device for indicating electric
tension, substantially as and for the purpose
set forth.
4. In a system of electrical distribution, the
combination of the intersecting and connected 115
positive conductors and the intersecting and
connected negative conductors, forming the
main conductors of the consumption-circuit,
with cross-connections connecting the con-
ductors of the same polarity together between 120
the points of intersection, a central station,
and feeding-conductors having no translating
devices connected therewith, and extending
from the source of electrical energy at the cen-
tral station to the main conductors of the con- 125
sumption-circuit at or near.centers of con-
sumption, substantially as set forth.
5. In a system of electrical distribution, the
intersecting and connected positive conduct-
ors and the intersecting and connected nega- 130
tive conductors, forming the main conductors
of the consumption-circuit, in combination
with a central station, feeding-conductors ex-
tending from the central station to the con-
2925
266,793
sumption-circuit, and having no translating | sumption-circuit, and having no translating
devices connected therewith, and means lo-
cated in each feeding-circuit for regulating
the tension of the current supplied thereby
5 to the consumption-circuit, substantially as
set forth.
6. In a system of electrical distribution, the
intersecting and connected positive conduct-
ors and the intersecting and connected nega-
10 tive conductors, forming the main conductors
of the consumption-circuit, in combination
with a central station, feeding conductors ex-
tending from the central station to the con-
devices connected therewith, an auxiliary cir- 15
cuit extending to the outer end of each feed-
ing-circuit and containing a device for indi-
cating electro-motive force, and an adjustable
resistance in each feeding-circuit, substan-
tially as set forth.
This specification signed and witnessed this
25th day of October, 1881.
THOS. A. EDISON.
Witnesses:
H. W. SEELY,
RICHD. N, DYER.
20
1
2926
(No Model.)
No. 274,290.
T. A. EDISON.
3 Sheets-Sheet 1.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Mar. 20, 1883.
5
5
От
a
6
6
6
16
Fig. 1.
Oã
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5
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Fig. 3.
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Fig. 2.
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7
8
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Fig. 4.
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ATTEST
E. C. Rowland.
Kusuly
Ј
THE NORRIS PR.TERS CO., PHOTO-LITHO., WASHINGTON, D. C.
INVENTOR:
Thomas A. Edison,
By Rich? A. Dyer,
Ady.
2927
(No Model.)
T. A. EDISON.
8 Sheets-Sheet 2.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Mar. 20, 1883.
No. 274,290.
R
P
A
a
a
N
Flig 5.
О
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N
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teebelee
WITNESSES:
&. C. Rowlands
Wevdaly
स
Fig.6.
a
P
D
D
popo
R
INVENTOR:
Thomas A. Edison,
By Rich. A Dyer,
Aby.
THE NORRIS PETERS CO, PHOTO-LITHO, WASHINGTON, DC.
2928
(No Model.)
T. A. EDISON.
3 Sheets-Sheet 3.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Mar. 20, 1883.
No. 274,290.
N
Оа
a
WITNESSES:
E.C.Rowland.
Seely
Fig. 7.
A
انيا
E
a'
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ليا
لبا
A
}
P
INVENTOR:
Thomas A. Dire
а
By Rich. St. Dyer,
Alter.
THE NORRIS PETERS CO., PHOTO-LITHO, WASHINGTON, D. C.
2929
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 274,290, dated March 20, 1883.
Application filled November 27, 1882. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Systems of Electrical
Distribution, (Case No. 520,) of which the fol-
lowing is a specification,
In multiple-arc systems of lighting by elec-
trical incandescence in which complete or
10 round metallic circuits are used it may some-
times be desired to employ electric currents
of unusually high electro-motive force, so
that the size of the conductors which convey
said current may be diminished, thus econo-
15 mizing in metal, and allowing the conductors
to be placed overhead instead of laid under
ground in places where the former arrange-
ment is more convenient. It is also generally
desirable in such systems that the incandesc-
20 ing electric lamps or other translating devices
should be independent of each other—that is,
that such devices shall be independently con-
trollable, so that each lamp can be lighted
and extinguished separately and without af-
25 fecting any others.
the earth might be used for the purpose, if it
is so desired.
In carrying out my invention the central sta- 55
tion or source of electrical supply for the sys-
tem may contain one, two, or any desired num-
ber of generators, according to the number of
translating devices to be supplied with cur-
rent, such generators developing a high elec- 60
tro-motive force. Such generators are prefer-
ably dynamo or magneto electric machines;
but secondary batteries may be employed, if
desired, and the generators may be connected
in any desired manner. If two generators, 65
placed in series, are employed, the compensat-
ing-conductor is connected between the two
to the wire connecting their armatures, such
compensating-conductor extending out be-
tween the two main conductors leading from 70
the generators. The multiple - arc circuits
which contain the lamps or other translating
devices extend across from each main con-
ductor to the compensating-conductor. When
equal numbers of lamps are in circuit on op- 75
posite sides of the compensating-conductor, no
current will traverse such compensating-con-
ductor, the whole amount. generated passing
out through the positive main conductor across
both sets of multiple-arc circuits containing 80
lamps, and back by the negative main con-
ductor, as will be more fully hereinafter ex-
plained. Thus the same effect is produced as
though two lamps were in series in each mul-
tiple-arc circuit, as the current must pass 85
through two lamps to get from the positive to
the negative conductor. At the same time,
however, such two lamps are independently
controllable.
To provide a system in which currents of
high tension can be used, while at the saine
time each lamp is entirely independent of all
the others, the lamps being also each of the
30 standard or usual resistance, is the object of
my invention; and I accomplish this by em-
ploying a source of energy of high electro-mo-
tive force, arranging the translating devices
in multiple series, dividing said source into as
35 many parts as there are translating devices in
series in any circuit, and correspondingly di-
viding each series of lamps, such division be-
ing made by means of a central compensating In case lamps are removed from one side of 90
conductor or conductors connected between the compensating-conductor, so that the num-
40 the divisions of the source of energy, and also bers on opposite sides become unequal, a por-
between the translating devices, so that when tion of current varying in amount according
all the devices in any multiple-arc circuit are to the degree of inequality will pass through
in use current will pass through all such de- the compensating-conductor, the direction of 95
vices, the current passing across from the such current varying according to whether the
45 positive to the negative main conductor; but positive or the negative side contains the
if one or more translating devices are removed greater number of devices. The system should
from any series circuit the excess of current be so arranged by properly locating the lamps
which would otherwise affect the other lamps and conductors that at no time can there be a 100
in the circuit is taken by the compensating.very great inequality between the two sets of
50 central conductor, so that the other lamps lamps. Thus very little current will ever trav-
remain unchanged. The compensating-con-erse the compensating-conductor, almost the
ductor is preferably a metallic wire, though whole passing out through the positive and re-
2930
274,290
turning by means of the negative main con- the other by a'. When, as shown, the number
ductor. The compensating-conductor can of lamps a is equal to that of lamps a', any
therefore be of very small mass, it never being current which may tend to return through con- 70
required to convey much current. An adjust-ductor 4 will be neutralized by the current
5 able resistance is preferably placed in each which will meet it from wire 3, so that no cur-
main conductor, so that in case the drop in rent will pass in either direction in said con-
electro-motive force is greater on one main con- ductor 4; but if a lamp, a', is removed from
ductor than on the other the resistance may circuit, so that less current will pass from con- 75
be adjusted to compensate for such inequality. ductor P to conductor 4, the tendency from
Io In systems of general distribution such resist-wire 3 to wire 4 will be correspondingly great-
ances would be placed in the conductors of
the feeding-circuit.
It is evident that two or more generators
may be placed on each side of the central con-
15 ductor in series or in multiple arc, if desired.
If currents are to be employed of such high |
tension that three or more lamps must be
placed in each cross-circuit between the posi-
tive and negative sides of the main circuit,
20 three or more generators or series of generators
may be placed in series, with two or more com-
pensating-conductors extending between the
main conductors, such compensating-conduct-
ors being connected between the generators or
25 series of generators, the source of energy being
thus divided into as many parts as there are
lamps in series.
By the use of my invention lamps in differ-
ent districts connected with separate central
30 stations may be connected in series with each
other, the generators of the two stations being
connected by a conductor, and compensating-
conductors running from convenient parts of
the district.
35 If desired, one generator only might be
placed at the central station, having its comma-
tator provided with an extra brush or brushes,
placed between the main brushes, from which
the compensating conductor or conductors
40 run, such conductors being connected with the
multiple-arc circuits between the lamps.
My invention is illustrated in the annexed
drawings, in which Figure 1 is a diagram show-
ing an arrangement of two generators in series.
45 Fig. 2 represents a similar arrangement of gen-
erators, but a different one of the translating
devices. Fig. 3 shows the arrangement of
three generators in series. Fig. 4 shows an ar-
rangement whereby lamps in different dis-
50 tricts, supplied from separate stations, may be
placed in series. Fig. 5 shows the arrange-
ment where one generator is used. Fig. 6
illustrates the use of secondary batteries, and
Fig. 7 shows the use of the earth as a com-
55 pensating-conductor.
In Fig. 1, A A represent dynamo or mag-
neto electric machines connected in series by
conductor 3, and having positive and negative
main conductors PN extending from them.
60 Midway between the generators the compen-
sating-conductor 4 is attached to conductor 3.
Multiple-arc circuits 5 6 extend from the com-
pensating-conductor to each of the main con-
ductors, and each of such multiple-are cir-
65 cuits contains a lamp or other translating de-
vice, those on one side of the compensating-
conductor being designated by a, and those on
er than the return tendency, and current due
to the inequality will flow in wire 4,which will
pass through the lamps a and return through 80
conductor N, while if a lamp or lamps, a, be
removed, so that less current will pass from 4
to N, the difference of current will return
through conductor 4. Thus the conductor 4
compensates for differences in either side; 85
and while the lamps are independently con-
trollable and any lamp can be removed from
circuit without varying the current flowing
to the lamps on the opposite side, yet it is
evident that currents may be employed of as 90
high tension as though the lamps were ar-
ranged in multiple series in the ordinary way.
The arrangement shown in Fig. 2 is similar
to that just described, except that here the
lamps a and a' are placed across multiple-arc 95
circuits 7 8, derived from the main conductor
P N. The same effect is of course produced
as just described. The adjustable resistances
R R are shown in this figure, which are used
to compensate for differences in the drop in 100
electro-motive force of the two conductors.
In Fig. 3 three generators, A A A, are shown
in series, there being two compensating-con-
ductors, 4 and 4", and three sets of lamps, a a'
a², the main portion of the current passing 105
entirely across from conductor P to conductor
N, and an amount due to differences in the
number of translating devices will return
through the central conductors.
The num-
ber of lamps a² being greater than a', a por- 110
tion of current due to the difference will re-
turn through conductor 4", the remainder
passing through lamps a' to conductor 4.
The number of lamps a being greater than a',
current will flow from the generators through 115
conductor 4 to supply lamps a, which current
will return through main conductor N.
Το 125
In Fig. 4, C and C' each represent a district
to be supplied with electric energy, a central
station or source of supply being provided 120
for each district. At one central station gen-
erators B B are placed in multiple arc, and at
the other generators B' B' are similarly ar-
ranged. It is desired to connect lamps in dis-
trict C in series with lamps in district C'
accomplish this a conductor, D, is run from
one station to the other, connecting one pole
of each battery of generators together. From
the other poles run the feeding-circuits P'N'
and P2 N2, such feeding-circuits being con- 130
nected with the main conductors of the system.
Compensating-conductors 4 are connected at
convenient points to said main conductors, all
such compensating-conductors being connect-
2931
274,290
ed at the same point to the wire D between the
stations, so that a divided source of electric
energy is formed, as in the previous cases.
Current flows through feeding-conductors P'
5 P² to main conductors p p, thence through
cross-circuits containing translating devices
to main conductors n n, by a conductor, o, to
district C', through translating devices to
main conductors p, and back to the generators
10 by feeders N' N². It is evident that each trans-
lating device in district C is in series with
one in district C', though all such devices are
independently controllable, the conductors 4
acting to compensate for the removal of any
15 device on either side. It is evident that any
desired number of districts might be con-
nected in this manner by proportionately di-
viding the source of energy, so that currents
of very high electro-motive force may be em-
20 ployed. Fig. 5 illustrates the application of
my invention to a single generator, A, of high
electro-motive force.
The main current is taken from the machine
by the commutator-brushes F F, to which are
25 connected the main conductors P N, and an |
extra brush, F', is provided between the main
brushes, from which runs the compensating-
conductor 4. Lamps a are arranged as in Fig.
1. The current taken by the extra brush neu-
30 tralizes the tendency for current to return on
the compensating-wire, so that no current
traverses that wire so long as the number of
translating devices remains the same on
each side of the same, while as the numbers
35 vary, current traverses such conductors in
one or the other direction, as previously ex-
plained.
It is evident that the generator may be still
further divided by the use of a greater number
40 of extra brushes and compensating-conduct-
ors.
In Fig. 6, D D are secondary batteries, P N
being the main conductors, and 4 the central
conductor. R R are the adjustable resist-
45 ances, for the purpose before described. It
is evident that with either of the forms de-
scribed the adjustable resistances R R may
or may not be used, as found necessary.
Fig. 7 illustrates the use of the earth as a
50 compensating-conductor, which arrangement
may be convenient in some cases, though I
usually prefer to use a metallic conductor.
The generators A A are connected by wire
|
|
3
3 in series, and conductors P N extend from
them. Translating devices a' are connected 55
with conductor P, and also to earth E, and
translating devices a, connected to conductor
N, are also connected to earth. Between the
generators A A wire 3 is connected to earth,
as shown. It will readily be seen that current 60
will pass through the earth from P to N, and
thus through both sets of translating devices
in multiple series. An amount of current due
to the inequality between the devices a and a'
will, it is evident, pass between wire 3 and 65
the translating devices through the earth in
the same manner as explained with reference
to the metallic conductor 4 of Fig. 1.
What I claim is-
1. In a system of electrical distribution hav- 70
ing translating devices arranged in multiple
seriès, the compensating conductor or conduct-
ors connecting the translation-circuits with
the source of energy, substantially as and for
the purpose set forth.
75
2. A system of electrical distribution having
in combination the following elements, viz: a
divided source of electrical energy, main con-
ductors extending therefrom, translating de-
vices arranged in multiple series, and a com- 80
pensating conductor or conductors connecting
the translation-circuits with the source of en-
ergy at the points of division, substantially as
and for the purpose set forth.
3. In a system of electrical distribution, the 85
combination, with translating devices ar-
ranged in series across main conductors, of a
source of electric energy divided into as many
parts as there are lamps in series, and a com-
pensating conductor or conductors connected 90
between the divisions of the source of energy
and between the lamps in series, substan-
tially as set forth.
4. The combination, with a source of elec-
trical energy, of main conductors leading 95
therefrom, translating devices in circuit from
said main conductors, a compensating-con-
ductor, and an adjustable resistance in each
of said main conductors, substantially as set
forth.
This specification signed and witnessed this
20th day of November, 1882.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
EDWARD H. PYATT.
TOO
2932
(No Model.)
T. A. EDISON.
SYSTEM OF ELECTRICAL DISTRIBUTION.
3 Sheets-Sheet 1.
No. 283,983.
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THE NORAIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
2933
(No Model.)
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SYSTEM OF ELECTRICAL DISTRIBUTION.
3 Sheets-Sheet 2.
Patented Aug. 28, 1883.
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Thomas A. Edison,
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THE NORRIS PETERS CO, PHOTO-LITHO., WASHINGTON, D. C.
2934
(No Model.)
No. 283,983.
T. A. EDISON.
3 Sheets-Sheet 3.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Aug. 28, 1883.
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INVENTOR:
Thomas A. Edison
By Rich. J. Dyer,
Aby.
THE NORRIS PETERS CO, PHOTO-LITHO, WASHINGTON, DC
2935
UNITED STATES PATENT OFFICE.
5
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION,
SPECIFICATION forming part of Letters Patent No. 283,983, dated August 28, 1883.
Application filed April 17, 1823. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
useful Improvement in Systems of Electrical
Distribution, (Case No. 557,) of which the fol-
lowing is a specification.
ing devices from one part of the system to an-
other.
In the accompanying drawings is shown the 55
application of my invention to a compensat-
ing system.
Figure 1 is a diagram illustrating the pre-
ferred automatic arrangement; Fig. 2, one
showing the mode of controlling the devices 60
from the central station, and Fig. 3 illustrates
the mode of both controlling and operating
the devices from the central station.
This invention relates, mainly, to compen-
sating systems of electrical distribution such
10 as are described in my Patent No. 274,290, in
which a divided source of electrical energy is
employed to supply electric lamps or other E E are dynamo-electric machines placed
translating devices arranged in multiple se- in series and forming the divided source of en- 55
ries, and a compensating conductor or conduct-ergy, the compensating-conductor B extend-
15 ors extend from between the translating de- ing from the point of division. 1 2 are the
vices to the point or points of division of the main conductors. The circuits containing
source of energy to preserve the balance of the lamps or other translating devices, a, are ar-
system. The invention is also applicable, ranged to be thrown from one side of the sys- 70
however, to those systems in which a main tem to the other. The lamps a' are connected
20 conductor is divided into series of branches, in permanent multiple-arc circuits, each con-
such branches containing the translating de nected to a main conductor and the compen-
sating-conductor.
vices.
The object of the invention is to preserve, by
devices either operating automatically or con-
25 trolled from the central station or source of
supply, the equality of the number of trans-
lating devices in the different parts or branches
of systems of the character described. To ac-
complish this automatically I provide means
30 controlled by variations in current, which,
when the number of translating devices in one
part of the system is too great, so that the
current declines in such part, operate circuit-
controlling devices, which shift a portion of
35 the translating device from that part of the
system to another, whereby the balance is
maintained.
To control the devices from the central sta-
tion, which may be preferable to the automatic
40 operation, I may place each set in connection
with a circuit running back to said station, so
that by opening and closing such circuit the
devices may be put in condition to be oper-
ated according to the preponderance of cur-
45 rent in either part of the system; or I may
place all the electric controlling devices which
operate in the same direction and are ar-
ranged to be affected by different amounts of
current in the same circuit, and vary the cur-
50 ent in such circuit so as to throw into opera-
tion more or less of such controlling devices
and shift a greater or less number of translat-
Referring to Fig. 1, A A' are electro-mag- 75
nets. Each magnet A is connected by con-
ductor 3 and conductors 5 and 9 between the
main conductor 1 and the compensating-con-
ductor B. Each magnet A' is similarly con-
nected between main conductor 2 and con- 80
ductor B by conductors 4, 5, and 9. Thus the
magnet A is affected where there is an excess
of current in main conductor 1, and magnet
A' when such excess occurs in conductor 2, by
reason of the decrease in the number of trans- 85
lating devices on either side.
Between the magnets A A' is the pivoted
armature-lever b, which carries the two-armed
circuit-controller e d.
Arm c
To the arm'c is connected the conductor 7, 90
and to arm & the conductor 8, which form a
circuit, across which the translating devices
a a are arranged in multiple arc.
plays between contact dand contact e, the lat-
ter of which is connected with main conduct- 95
or through wire 3. Arm e' is placed between
contacts a' and e', the latter being connected
to conductor 2 through wire 4. Both con-
tacts dd' are connected to compensating-con-
ductor B by conductor 9, ƒ being a metallic 100
cylinder.
When the current in main conductor 1 is in
excess of that in main conductor 2, it is desir-
able to shift a portion of the translating de-
2936
2
283,983
vices from the latter to the former. The mag-
net A is energized by the excess of current
and draws the armature b toward it, the ball
and spring g assisting to throw the armature
5 over, the arm c making contact with e, and
the arm & with d', as shown. A circuit is thus
formed, including the lamps a, from conductor
1 to conductor B via 3, 10, 7, 8, ƒ, and 9.
When the current becomes stronger in con-
Io ductor 2, the magnet A' is more greatly ener-
gized and draws the armature b toward it,
closing circuit at e' and d, and thus placing |
the lamps a between the conductors 2 and B.
It is evident that as many sets of magnets
15 A A', with devices controlled thereby, may be
provided, as desired. Each house or building
in the district may be so provided, or only a
few arranged to preserve the balance to a suf-
ficient extent. The magnets would be ar-
20 ranged to operate with different amounts of
current, so that successive changes would be
made as desired.
It is evident, also, that the invention can be as
readily applied if the system is divided into
25 more than two parts by more than one com-
pensating-conductor.
30
and the magnets A' are similarly arranged
with relation to each other. Hence by adjust-
ing the resistance R to different extents more 70
or less of the series of magnets which is in cir-
cuit at the time can be made to act and to
throw the circuits controlled by them into con-
nection with the opposite side of the system
from before.
Suitable indicating devices are provided at
the central station, as before explained,
•
75
As shown, the magnets A' are in circuit,
but the current is insufficient to cause both to
attract their armatures. By adjusting the re- 80
sistance the other magnet may be caused to act,
and the circuit controlled by it can be con-
necfed across the other side of the circuit.
By this arrangement the devices are both
controlled and operated from the central sta- 85
tion.
It is evident that any desired number of
magnets with their accompanying apparatus
may be used.
It is evident that instead of using an adjust- 90
able resistance each magnet could be placed in
a separate circuit, means being provided at
the central station for closing the circuit of
any magnet, as desired.
The arrangement illustrated in Fig. 2 is the
same as that just described, except that the In applying this invention to a system in 95
conductors 5 of each set, instead of being con- which feeding-conductors are used it is pre-
nected directly with the compensating-con- ferred to place near the extremity of each
ductor, runs to the central station, where it is feeding-circuit, a number of the electrically.
connected with a contact-plate, h. Circuit is operated compensating arrangements indicat-
'completed by the insertion of plugs between ing circuits being provided, as usual.
the plates h and plate i, which is connected the indicators show too much or too little press-
35 by conductor 11 with the compensating-con-ure at the terminals of any circuit, one or more
ductor.
Indicating circuits and devices are provided,
as shown in my Patent 266,793, of October 31,
1882, to show the electrical condition at differ-
40 ent parts of the system.
When 100
of the magnets at that locality will be energized
and caused to change the connection of the
devices controlled by it.
In series systems wherein a main conductor
is divded into two or more series of divisions
When it is desired to throw any set of trans- or branches, each branch containing a trans-
lating devices into connection with the oppo-lating device, and the source of energy not be-
site side of the system, circuit is closed at hi
to the set of controlling-magnets A A', which
45 it is desired to operate, and that magnet will
be affected which is in connection with the side
having the preponderance of current, the ef-
fect being the same as before explained. The
electrical devices are thus controlled from the
50 station, but operated automatically.
In Fig. 3 the two magnets A are placed in
series in a circuit, 12 14, and the magnets A
are similarly arranged in a circuit, 13 14. The
switch k closes either of these circuits, as de-
55 sired. The operation of the magnets upon the
devices affected by them is similar to that de-
scribed with reference to Fig. 1.
R is an adjustable resistance in the con-
ductor which runs to the switch k. By ad-
60 justing this resistance the current in the cir-
cuit 12-14 or 13 14, as the case may be, is va-
ried.
The magnets A are so arranged, either by
difference of winding, difference in distance
65 between magnet and armature, or otherwise,
that a different amount of current is required
to cause each magnet to attract its armature,
105
ing divided, my invention may be applied to 110
change the connection of a branch from one
series to another. It is evident that this ar-
rangement is the same as that in Fig. 1, ex-
cept that the compensating-conductor B would
not be connected between the generators, one 115
generator being used alone, or two or more with
ordinary series or multiple-arc connections.
In a compensating system, if the number of
translating devices in the district becomes at
any time so small that it can be supplied by 120
one division of the source of energy, all such
translating devices can be thrown onto one
side of the district, the system becoming then
an ordinary multiple-arc system, with the un-
necessary generators out of use, and the com- 125
pensating-conductor forming one of the main
conductors of the system.
It is to be understood that all patentable
features of novelty shown or described, but not
claimed herein, are reserved for protection by 130
other patents, and have been or will be in-
cluded in other applications for patents.
What I claim is-
1. In a compensating system of electrical
2937
283,983
distribution, the combination, with a translat-
ing device or group thereof, of automatically
operated means for changing the connections
of such device or group from one part of the
5 system to another, to maintain the balance of
the system, substantially as set forth.
2. In a compensating system of electrical
distribution, the combination, with a translat-
ing device or group thereof, of electrically-op-
10 erated means for changing the connection of
such device or group from one part of the sys-
tem to another, substantially as set forth.
3. In a compensating system of electrical
distribution, the combination, with a translat-
15 ing device or group thereof, of means controlled
from the central station for changing the con-
nection of such device or group from one part
of the system to another, substantially as set
forth.
20
4. In a compensating system of electrical
distribution, the combination, with a translat-
ing device or group thereof, of means, controlled
from the central station and operated auto-
matically by the current in the system, for
25 changing the connection of such device or group
from one part of the system to another, sub-
stantially as set forth.
3
5. In a compensating system of electrical
distribution, the combination, with a translat-
ing device or group thereof, of oppositely- 30
acting electro-magnetic devices energized by
the current in the system, and circuit-con-
trolling mechanism controlled by said electro-
magnetic devices for changing the connections
of such translating device or group from one 35
part of the system to another, substantially as
set forth.
6. In a compensating system of electrical
distribution, the combination, with a translat-
ing device or group thereof, of two electro- 40
magnets, one connected with each part of the
system, and circuit-controlling devices con-
trolled by said electro-magnets, whereby when
the current in one part, is stronger than in an-
other, the connections of such translating de- 45
vice or group are changed from the weaker
side to the stronger, substantially as set forth.
This specification signed and witnessed this
5th day of April, 1883.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
EDWARD H. PYATT.
2938
E
(No Model.)
2 Sheets-Sheet 1.
T. A. EDISON & C. L. CLARKE.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
Patented Oct. 30, 1883.
No. 287,525.
H
WITNESSES:
Eward C. Rowland
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INVENTORS:
Thomas A. Edison,
Charles L. Clarke,
By Rich At Dyer.
Abby.
THE NORRIS PETERS CO PHOTO-LITHO WASHINGTON, DC
2939
(No Model.)
2 Sheets-Sheet 2.
T. A. EDISON & C. L. CLARKE.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
No. 287,525.
D'
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Fig. 3.
Patented Oct. 30, 1883.
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INVENTORS:
Thamas A. Edison,
ма
Charles L. Clarke,
By Rich. Dye Joy.
THE NORRIS PETERS CO, PHOTO-LITHO WASHINGTON, D
2940
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, AND CHARLES L.
CLARKE, OF NEW YORK, N. Y., ASSIGNORS TO THE EDISON ELECTRIC
LIGHT COMPANY, OF NEW YORK, N. Y.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 287,525, dated October 30, 1883.
Application filed October 20, 1882. (No model.) Patented in England October 14, 1882, No. 4,884, and in France October 31, 1882,
No. 151,841.
To all whom it may concern:
Be it known that we, THOMAS A. EDISON,
of Menlo Park, in the county of Middlesex
and State of New Jersey, and CHARLES L.
5 CLARKE, of the city, county, and State of New
York, have invented a certain new and useful
Improvement in Regulators for Systems of
Electrical Distribution, of which the following
is a specification.
ΙΟ
Our invention relates to a regulating appa-
ratus used in connection with a system of elec-
trical distribution in which the current is dis-
tributed from a central point to various parts of
a district where lamps, motors, and other trans-
15 lating devices are arranged in multiple arc.
In such a system the generators at the central
station are connected with feeding-circuits on
which no lamps are placed, but which are con-
nected at suitable points with the street-mains
20 on multiple-arc circuits from which the lamps
are placed. In such a system it is necessary
to preserve a constant electro-motive force or
"pressure" in the circuits where the translat-.
ing devices are placed. The electro-motive
25 force at the end of a feeding-circuit is indicated
by a suitable device placed at the central sta-
tion and connected by an auxiliary circuit with
the end of the feeding-circuit, and it is regu-
lated in accordance with such indications by
30 varying the resistance of the feeding-circuit,
all of which is fully set forth in the applica-
tion of the said Edison filed December 9, 1881,
(Serial No. 47,468.) According to our inven-
tion, this variation is accomplished by causing
35 each feeding-circuit to be broken at a conven-
ient point, and providing a number of paths
for the current across such break, each of con-
siderable resistance, means being provided
for throwing into circuit more or less of such
40 paths, as desired. Such paths or resistances,
it will be understood, are in multiple-arc rela-
tion to each other, and consequently the more
we place in circuit the less the resistance of
the feeder and the greater the amount of cur-
45 rent supplied to the lamps.
It is usually customary to vary the resist-
ance of a circuit by throwing more or less re-
sistance in series, so to speak, directly into
Such circuit. We, however, prefer the mode
just described, for here as fast as we decrease 50
the resistance, and thereby increase the cùr-
rent in the circuit, we correspondingly in-
crease the current-carrying capacity of this
portion of the circuits per unit of length, while
in the old way, when the current is increased, 55
the conductivity of the circuit remains the
same, and there may be danger of exceeding
the capacity of the conductors. The prefera-
ble form of apparatus for this purpose we
have found to be as follows: The wire or cable 60
from one pole of the generator or generators
is connected to one of two metal pipes, pref-
erably of copper, which are placed, prefer-
ably, one above the other, or in any conven-
ient position. The conductor from the other 65
pole is connected directly to the feeding-cir-
cuit, while the return-conductor of such cir-
cuit is connected with the second pipe. It is
understood that each feeding-circuit of the
district is provided with the apparatus de- 70
scribed. To the lower pipe are attached, at
short distances apart and along its entire
length in any suitable manner, the ends of
the carbon rods, the other end of each of
which is connected with the lower end of a 75
spring whose upper end approaches nearly to
but does not touch the upper pipe. Prefer-
ably a number of these carbon rods are placed
in series between the lower pipe and each
spring. Pivoted at one end to the frame which 80
supports the pipes is a "knife," consisting of a
suitable back and a handle of insulating ma-
terial, with a copper plate or blade, such
blade being preferably broad at its outer end
and narrow near the handle. Such knife is 85
so placed that the blade can be forced down
between the upper pipe and the springs and
make electrical connection between them,
more or less of the springs being in contact
with the pipe, according as the blade is pressed 90
down or drawn up.
It is evident that as more springs are con-
nected with the pipe more of the carbon rods
will be placed in multiple arc between the pipes,
2941
2
287,525
|
and consequently the greater will be the con- portion of both, so that a double clamp is
ductivity of the feeding-circuit of which such formed for holding two carbons. Metal pieces
pipes form a part. Therefore, when more trans- e are attached at one end to the side of pipe
lating devices are placed in the consumption- B, and to the other end of each a piece, f, is at-
5 circuit in the vicinity of the point of connection tached, which enters the clamp c, whose other 70
between the feeder and such circuit, the blade is half holds a carbon rod. Four of these rods
pushed down and more of the rods thrown into are shown in Fig. 2 as connected in series, the
circuit, and when such devices are removed end of the last carbon being attached to the
from circuit the blade is raised. At one end the piece g, to which is fastened the spring h,
10 pipes are connected by a rubber or other tube; which approaches nearly but does not touch 75
and one pipe is connected at its other end to the pipe A. All the pieces g are secured to
a source of water-supply, so that a circulation | the strip i, which is of wood or other insulat-
of water is kept up and the pipes are kept ing material. F is a copper blade, of the form
cool. A weight is attached to the knife as a shown in Fig. 1, attached to a suitable back,
15 counter-balance to hold it in the position in G, and having a handle, H. The knife thus 80
which it is placed; or a spring or suitable fric-formed is pivoted at I. Such knife, it will be
tion devices may be used for this purpose. seen, can be forced down between the springs
Each dynamo or magneto electric machine of h and the tube A to any desired distance and
the battery of such machines supplying the again withdrawn, thus connecting the pipes
20 feeding-circuits is regulated for the total num- through more or less of the carbon rods a a, 85
ber of translating devices in circuit in any and increasing or diminishing the conductiv-
suitable way, preferably by throwing resist- ity of the feeding-circuit 3 4. The conductors
ance into and out of its field-circuit, while the are fastened to the pipes in any suitable man-
adjustable resistances in the feeder - circuits ner. J is a counterbalance - weight used to
25 are used to regulate for the unequal distribu- hold the knife in the position in which it is 90
tion throughout the system (the variations in placed. By means of rubber tube K water is
location of translating devices) without refer- introduced into pipe A, which flows off through
ence to the total number of translating de- tube L.
vices in circuit.
30
Instead of the form of variable resistance
above described, the calorimeter barrels
shown in the application of Edison above re-
ferred to may be used, the knife above de-
scribed being employed to place a greater or
35 less number of the wire coils in circuit.
Our invention may be better understood by
reference to the annexed drawings, in which
Figure 1 is a front elevation of the regulat-
ing apparatus; Fig. 2, a transverse vertical
40 section of the same; Fig. 3, a diagram illus-
trating the circuit-connections, and Fig. 4 a
top view of the clamp which holds the car-
bon rods.
A and B are the two pipes, filled with wa-
45 ter and connected together by rubber tube C.
Referring to Fig. 3, a main conductor, 1,
from the generator or generators represented
at D is connected to the pipe A, while main
conductor 2 is connected to the conductor 3 of
50 the feeding-circuit 3 4. Such feeding-cir-
cuit runs to a point where the circuits b b',
which supply the translating devices of the
system, are connected to it in multiple arc.
The conductor 4 of the feeding-circuit is con-
55 nected to the pipe B. D'is the adjustable
resistance in the field-circuit of the genera-
tor D.
Referring to Figs. 1 and 2, E is a suitable
frame, which supports the pipes A and B. a
60 a are carbon rods having their ends held in
clamps c, such clamps being preferably of the
form shown in Fig. 4-viz., being made in two
parts, each part consisting of two curves
joined together by a straight piece, and a
65 screw, d, being passed through the straight
It is to be understood that all patentable
features of invention shown or described but 95
not claimed herein are reserved for protec-
tion in other patents, and have been or will be
embodied in other applications for patents.
What we claim is-
1. The combination, with an opened elec- 100
trical circuit, of a series of resistances con-
nected in multiple arc with the circuit on one
side of the break, separate spring-terminals
to such resistances, a conductor connected
with the circuit on the other side of the break 105
and crossing said spring-terminals in close
proximity thereto, and an intermediate cir-
cuit-controlling device making a sliding or
rubbing contact between said conductor and
more or less of the resistance-terminals, sub- 110
stantially as set forth.
2. The combination, with the parallel con-
ductors, of the carbon resistances attached to
one conductor, the springs attached to such
resistances, and the copper blade for electri- 115
cally connecting more or less of such springs
with the other conductor, substantially as set
forth.
3. The combination, with an electrical cir-
cuit, of a resistance, an adjusting device for 120
throwing the resistance into and out of cir-
cuit, and a water-pipe for conducting off the
heat, the circuits of the resistance being made
and broken upon such water-pipe, substan-
tially as set forth.
125
4. The combination, with an electrical cir-
cuit, of a series of exposed carbon rods serv-
ing as resistances, means for throwing such
rods into and out of circuit, and a water-pipe
for conducting off the heat, the circuits of the 130
<
2942
287,525
carbon rods being made and broken upon
such water-pipe, substantially as set forth.
5. The combination, with an opened elec-
trical circuit, of metallic water-pipes form-
5 ing the terminals of the circuit, resistances in
multiple arc between such water-pipes, and
means for throwing the resistances into and
out of circuit, substantially as set forth.
3.
This specification signed and witnessed this
4th day of October, 1882.
Witnesses:
H. W. SEELY,
E. H. PYATT.
THOS. A. EDISON.
CHAS. L. CLARKE.
2943
ATTEST
&C. Rowlands
July
Menny W. Seely
2
THE NORRIS PETENY CO, PHOTO-LITHÔ, WASHINGTON, D c.
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James A Edison
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T. A. EDISON.
SYSTEM OF ELECTRICAL DISTRIBUTION.
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2944
UNITED STATES PATENT OFFICE.
•
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE
EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 280,727, dated July 3, 1883.
Application filed March 16, 1883. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Systems of Electrical
Distribution, (Case No. 544,) of which the fol-
lowing is a specification.
In my system of electrical distribution I
employ at a central station several dynamo-
10 electric machines for generating current,
which is then conveyed by feeding-conductors
to the circuits which contain the translating
devices of the district.
My invention relates to the arrangement of
15 the various devices and apparatus at such
central stations, having for its object, princi-
pally, the maintaining of a constant electro-
înotive force throughout the system, and also
to promote the general efficiency and economy
20 of the system.
in order to prevent such a sudden accession of
current in the district as cannot be readily com-
pensated for by the field-resistances. This is
accomplished as follows: When the generator
is to be connected, instead of connecting its 55
armature at once to the main conductors, it
is connected with other conductors,from which
multiple - arc connections are made to the
lamps within the station, which are commonly
termed "testing-lamps." These lamps are di- 60
vided into groups, and a switch-board is pro-
vided by which more or less of these groups
may be placed in circuit. As many lamps are
first included as are being supplied in the dis-
trict by each of the machines already in cir- 65
cuit. The armature-circuit to the main con-
|
ductors is then also closed, which makes
the testing - lamps a part of the circuit sup-
plied by all the generators. The throwing in
of the additional generator,therefore, produces 70
In carrying out my invention I connect the no material effect on the current in the trans-
two or more generators employed in multiple lating devices without the station, and any
arc from the same main conductors, each ar- slight change in electro-motive force is com-
mature and each field-magnet being in its pensated for by adjusting the field-circuit re-
25 own separate multiple-are circuit. In con- sistance. The testing-lamps are then grad- 75
nection with each machine I preferably em- ually plugged out at the switch-board, the reg-
ploy a single circuit-controller of such formulating-resistances being constantly adjusted
that it will break both the field and the ar- to maintain a constant electro-motive force.
mature circuit by the same movement, and The testing-lamps can, however, be used also
30 the latter somewhat in advance of the former, for testing the efficiency of the generators. 8c
for if the field-circuit were broken before the To accomplish this the field and armature cir-
armature-circuit, the main conductors would cuits of each generator can be disconnected
be short-circuited and the armature burned from the main conductors of the system and
out. Separate circuit-controllers might, how- connected to the main testing-circuit. By
35 ever, be employed, care being taken to always means of the switch-board a greater or less 85
break the armature-circuit before the field. number of the testing-lamps may be placed
In each field-circuit is placed an adjustable in circuit. The armature-circuit of each ma-
resistance of suitable construction. The feed- chine contains a safety-catch of the proper
ing-conductors, which convey the current to size to prevent injury to the armature. Each
40 the incandescent electric lamps or other trans- feeding-conductor also contains such a safety- 90
lating devices of the system, are connected catch, and around each safety-catch is a shunt,
in multiple arc to the main conductors. Each which may be closed by the insertion of a plug,
feeding-circuit contains an adjustable resist- if the safety-catch is destroyed, to maintain
ance, and may be provided with a suitable cir- circuit while such safety-catch is replaced.
45 cuit-controller. Within the station are pro- Around each armature and field-circuit con- 95
vided, also, al arge number of electric lamps, troller is placed a similar shunt, which is
which are thrown into circuit whenever an ad- closed by a plug after the circuit is closed, to
ditional generator is connected to the main prevent heating at the contacts of the circuit-
conductors to compensate for such addition controller.
50 in the translating devices without the station,
My invention is illustrated in the accompa- 10C
2945
2
280,727
nying drawing, which is a diagram of the cir-
cuits and apparatus at a central station.
|
side are attached a number of carbon rods k,
and the metal blade l is in sliding contact with
A A are dynamo-electric machines. Pref- the other side. When such blade is pressed 70
erably each of said machines is driven by a down, it places more or less of the carbon rods
5 steam-engine, the armature being revolved di- in multiple arc across the break, and so de-
rectly by the shaft of the engine without the creases or increases the resistance of the cir-
use of belts or other gearing, and the engine cuit. These resistances are to regulate the
and generator being both mounted on the same current in the feeders for variations in the 75
bed-plate. From the commutator-brushes of number of translating devices in the part of
to each machine a circuit, 3 4, leads, which is the district contiguous to the terminals of each
connected to the main conductors 1 2. A feeder. A guard-plug shunt, 13, is formed
conductor, 5, connected to armature-circuit around each resistance, so that circuit may be
conductor 3, includes the field-magnet coils of completed if it is desired to dispense with such 80
the machine, and thence extends to the ad- resistances. Each feeding-circuit is provided
15 justable resistance B. This resistance is pref- with a plug, t, for opening and closing the cir-
erably of the form shown in my application cuit. This, however, may be dispensed with,
No. 540, (Serial No. 82,565.) The end of arm and the circuits made and broken by inserting
a rests on a circle of contact-plates, b, (only a and removing the safety-catches and guard- 85
portion of which are shown,) which are con- plugs. Each feeding-circuit leaves the sta-
20 nected to resistance-coils c c, and the revolution inclosed in a tube, F. In each feeding-
tion of said arm, throws such coils in or out
of circuit. Such arm bears constantly on a
metal ring, d, from which the conductor 5 runs
to a conductor, 6. A single conductor, 7, runs
25 from wire 6 to main conductor 2, forming a
common return for the field-circuits of both
or all the generators.
Preferably means are provided whereby all
the resistances B may be simultaneously ad-
30 justed, as set forth in my application last re-
ferred to. The resistances are to regulate the
electro-motive force of the machines according
to the whole number of translating devices in
circuit in the system.
35
In each armature-circuit is placed a circuit-
controller, C, and 'in each field-circuit a cir-
cuit-controller, D, the circuits being opened
and closed by the withdrawal or entrance of
contacts e between contacts f. Preferably the
40 circuit-controllers C and D of a machine are
operated by the same movement, circuit being
broken somewhat sooner and closed somewhat
later at C than at D, the moving contacts of
both being attached to the same pivoted arm,
45 as set forth in my application No. 543, (Serial
No. 88,355.) Around each circuit-controller
is a shunt, 8, broken at contacts gg. These
shunts are to be closed by the insertion of
guard-plugs when the circuits are closed at C
50 D, to prevent heating of the latter contacts.
Each armature-circuit contains, also, a safety-
catch, h, to prevent injury to the armature by
an excessive reduction of resistance of the ex-
ternal circuit, and around each safety-catch is
55 a guard-plug shunt, 9, by which the circuit
may be completed while the safety-catch is re-
placed.
To the main conductors 1 2 are connected
feeding-conductors 11 12, by which current is
60 conveyed to the different parts of the district
supplied from the station. A conductor, 11,
of each feeding-circuit includes an adjustable
resistance, E. This resistance is preferably
like that shown in the joint application of
65 Charles L. Clarke and myself, (Serial No.
74,778.) The conductor 11 is broken, and the
two parts lie parallel with each other. On one
conductor is a safety-catch, m, and around
each safety-catch is a guard-plug shunt, 14,
for the purpose above explained.
90
The testing-lamps are represented by p p.
15 16 are the main testing-conductors. To con-
nect the armature of a generator to this cir-
cuit, the circuit-controller C and shunt 8 are
opened, and shunt 17 is closed by inserting a 95
plug at o. This connects conductor 4 to 16,
instead of to 2, and, as conductor 15 is already
connected to conductor 1 by conductor 18, the
armature-circuit is thus connected to the main
testing-circuit. To connect the field of a gen- 100
erator, conductor 5 is broken at rand conduct-
or 19 closed at s, making connection to con-
ductor 20, from which conductor 21 runs to
main testing-conductor 16. The lamps p are
divided into groups, each of a suitable num- 105
ber. Two of such groups, G and G', are shown.
From conductor 15 a wire, 22, runs to a switch-
board, II, and from the opposite terminals of
the switch-board wires 23 run, one to a con-
ductor of each group of lamps. The opposite 110
conductor of each group is connected through
conductor 21 to conductor 16. Each group of
lamps is connected in circuit by the insertion
of a plug between the proper terminals of the
switch-board. Thus any desired load may be 11
put upon a generator, whereby its capacity and
efficiency may be tested. The main object of
the testing-lamps-that is, to compensate in
the translating devices of the system without
the station.when an additional generator is 120
placed in circuit to prevent a sudden increase
in electro-motive force by such addition-is,
however, accomplished as follows: When such
an increase of lamps is expected in the dis-
trict as will require the addition of a gen- 125
erator to those already in circuit, as many
groups of lamps p are connected by means
of the switch-board II to the main testing-
circuit 15 16 as are supplied by each of the
already connected generators.
circuit of the generator is closed by the in-
sertion of a plug in the shunt 8 around the
circuit-controller D, the plugs being also in-
serted at rand s. The shunt 17 is then closed
115/
The field- 130
2946
:
280,727
at o, which connects the generator with all the
testing-lamps connected at the switch-board.
The circuit-controller C is then closed, which
connects both the lamps and the generator to
5 the main circuit. The proportion of genera-
tors and lamps throughout the entire system
thus remains the same or nearly the same, any
slight difference being adjusted by regulating
the resistances B B. The groups G of test-
1ɔ ing-lamps are then cut out of circuit at the
switch-board, one after another, and the field-
resistances are adjusted so that a constant
electro-motive force is maintained.
By the use of the regulating means de-
15 scribed-first, means situated within the sta-
tion for compensating in the translating de-
vices without the station for the addition of a
generator to the main circuit; second, the ad-
justable resistances in the fieid-circuits for ad-
20 justing the gradual variations which occur in
the total number of lamps in circuit; and,
third, the adjustable resistances in the feed-
ing-circuits, forming regulators for variations
at the different centers of consumption-I am
25 enabled to maintain a practically - constant
electro-motive force throughout the system
under all circumstances, and, in addition, I
may, if desired, regulate the entire system by
the connection and disconnection of feeders.
It is to be understood that all patentable
features of invention described or shown, but
not claimed herein, are reserved for protec-
tion by other patents, and have been or will be
embraced in other applications for patents.
What I claim is—
30
35
1. In a system of electrical distribution,
means situated within the central station for
compensating in the translating devices with-
out the station for the increased electro-mo-
40 tive force caused by the addition of a gener-
ator to those already in circuit, substantially
as set forth.
2. In a system of electrical distribution, the
combination of two or more generators, the
45 main circuit, means for separately connecting
said generators thereto, the circuit containing
the testing or compensating lamps, and means
for separately connecting the generators to
said circuit, substantially as set forth.
50
|
3
Со
1
| each having its field and its armature in a sep-
arate multiple-arc circuit from the main con-
ductors, of means for disconnecting the arma-
ture-circuit alone or both the field and arma- 65
ture from said main conductors and connect-
ing them instead to a circuit containing test-
ing or compensating lamps, substantially as
set forth.
5. The testing or compensating lamps ar- 70
ranged in groups, in combination with means
for placing more or less of such groups in con-
nection with the generators, substantially as
set forth.
6. The combination, with the testing or 75
compensating lamps arranged to be gradually
thrown out of circuit, of the adjustable re-
sistances in the field-circuits of the generators,
for compensating for the variations in electro-
motive force, substantially as set forth.
80
7. In a system of electrical distribution, the
combination of the testing or compensating
lamps, the adjustable resistances in the field-
circuits of the generators, and the adjustable
resistances in the feeding-circuits, whereby a 85
constant electro-motive force is maintained
throughout the system, substantially as set
forth.
8. In a system of electrical distribution, the
combination of the adjustable resistances in 90
the field-circuits of the generators, and the
adjustable resistances in the feeding-circuits,
substantially as set forth.
9. The method of maintaining a constant
electro-motive force in a system of electrical 95
distribution employing two or more gener-
ators when an additional generator is placed.
in circuit, consisting in first connecting said
generator with a number of lamps not con-
nected with the rest of the system, and then 100
connecting it also with the main circuit of the
system, whereby the proportion of lamps and
generators remains the same, substantially as
set forth.
10. The method of maintaining a constant 105
electro-motive force in a system of electrical
distribution employing two or more gener-
ators when an additional generator is placed
in circuit, consisting in first connecting said
generator with a number of lamps not con- 110
3. In a system of electrical distribution, the nected with the rest of the system, then con-
combination of the two or more generators, necting it also with the main circuit of the sys-
the main circuit, means for separately con- tem, and then gradually removing said lamps,
necting said generators to said main circuit, at the same time regulating the adjustable re-
the circuit containing the testing or compen-sistances in the field-circuits of the generators, 115
55 sating lamps, means for separately connecting substantially as set forth.
the generators thereto, and means for connect-
ing the main circuit with the testing or com-
pensating lamp-circuit, substantially as set
forth.
60
4. In a system of electrical distribution, the
combination of the two or more generators,
This specification signed and witnessed this
13th day of February, 1883.
Witnesses:
THOS. A. EDISON.
H. W. SEELY,
EDWARD II. PYATT.
H.
2947
(No Model.)
T. A. EDISON.
SYSTEM OF ELECTRICAL DISTRIBUTION.
2 Sheets Sheet 1.
Patented Apr. 6, 1886.
No. 339,279.
1
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Rayland
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INVENTOR:
Tomas A. Bren
By Ried A. Dyer
Rich
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
2948
(No Model.)
T. A. EDISON.
SYSTEM OF ELECTRICAL DISTRIBUTION.
2 Sheets-Sheet 2.
Patented Apr. 6, 1886.
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INVENTOR:
Hamas A. Edison,
By Rich A Dyer
Atty.
2949
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 339,279, dated April 6, 1886.
Application filed April 5, 1884. Serial No. 126,803. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Menlo Park, in the county of Middlesex and
State of New Jersey, have invented a new and
5 useful Improvement in Systems of Electrical
Distribution, (Case No. 618,) of which the fol-
lowing is a specification.
-
My invention is illustrated in the annexed
drawings, in which Figure 1 is a diagram il-
lustrating its application to an ordinary mul- 55
tiple-arc system, while Fig. 2 shows it in con-
nection with my three-wire or compensating
system.
75
Referring first to Fig. 1, A A' are dynamo-
This invention relates to the regulation of electric machines, and 1 2 are the common con- 60
the current supplied to the translating devices ductors at the central station, from which ex-
to in a system of electrical distribution, in which tend the feeding-circuits 3 4 and 56. These, it
such devices are connected with a system of is understood, are connected at different points
intersecting and connected main conductors, to the system of intersecting and properly con-
which are joined to the source of supply by nected positive and negative main conductors, 65
feeding circuits, and is intended as an im- on which the lamps, motors, or other trans-
:5 provement upon the method of regulation set lating devices are arranged in multiple arc.
forth in the patent granted to C. S. Bradley, The generators are connected in multiple arc
No. 291,141, dated January 1, 1884. In that to the conductors through the switch-boards.
patent the several dynamo-electric machines | B B, which are so connected that each gen- 7c
or series of such machines at the central sta-erator may, by the insertion of the proper
20 tion or source of supply are connected inde- plugs connecting intersecting bars, be con-
pendently with the feeding - circuits, and so nected with either feeding - circuit or either
arranged that any machine may be thrown generator to both feeders, or both feeders to a
into connection with any feeder, or a number single generator.
of feeders may be supplied from any required
25 number of dynamo electric machines, each
machine or series being also provided with
means for regulating its electro-motive force
independently of the others, whereby current
may be supplied to each part of the district
30 according to the number of translating devices
there in circuit, and the "pressure" is main- |
tained the same at all parts of the district, all
the translating devices receiving the same cur-
rent. Thus, if the number of translating de-
35 vices in any part of the system is increased,
the electro-motive force of the generator or
generators connected to the feeder which ter-
minates nearest to such point is increased; or,
if the increase is very great, one or more ad-
40 ditional generators are attached to such feeder.
My improvement upon this system consists
in providing means whereby all the generators
in circuit can be regulated simultaneously, in
addition to their independent regulation, so
45 that the current in all the feeders, and there-
fore that supplied to all the translating devices
in the district, can be raised and lowered at
the same time. I prefer to use for this pur-
pose the apparatus set forth in my Patent No.
50 281,349, dated July 17, 1883, with an addi-
tional device which allows the regulator-arms
to be readily adjusted independently.
-
In the field-circuit of each machine is a re-
sistance, R, adjustable by means of the arm
C, in contact with plates a and metal ring b, so
that by turning the arm more or less of the
resistance-coils are thrown into circuit. From 80
each arm Ca spindle, D, (which for conven-
ience of illustration is shown partly in dotted
lines,) extends to a bevel wheel, E. These
bevel-wheels engage with corresponding bevel-
wheels, F, on the shaft G, which is provided 85
with a hand - wheel, H, for turning it. By
turning the shaft all the resistances are ad-
justed simultaneously and to the same extent.
Each resistance is also provided with means
for moving the adjusting-arm independently 90
of the common shaft. Such means consist of
the arm G', which is locked at the position to
which it is adjusted by the catch cand ratch-
et d.
The generators are respectively connected 95
to the feeders, and their electro-motive force
adjusted by separately regulating their field-
resistances until each feeder receives the right
proportion of current. Then, in order to
regulate the current to all the feeders and all ico
the translating devices in the district, the re-
|sistances are all adjusted simultaneously.
In Fig. 2 an additional compensating-con-
ductor, 1ª, is employed in each circuit.
2950
2
339,279
The generators are connected in series of
two each, A A and A'A'. A system of this
character is set forth in my Patent No.
274,290, dated March 20, 1883. The switch-
5 board connections are made for each series the
same as for the single machines of Fig. 1, one
or more series being connected to each feeder,
as desired.
To regulate the electro-motive force of one
Io series, the resistance in the field-circuit of one
machine or those of both machines of that
series are adjusted, while by adjusting both
resistances of one of the connected sets of re-
sistances, or, if necessary, of both such con-
15 nected sets, the regulation of both series is
effected.
· 20
It is evident that each series of generators
in Fig. 2 is the equivalent of a single genera-
tor of Fig. 1.
What I claim is-
1. The combination, in a system of electrical
distribution, of two or more feeding-circuits
for supplying current to the translating de-
vices, two or more independent generators,
25 means for connecting said generators sepa-
rately with said feeders, means for separately
regulating each generator, and means for si-
multaneously regulating all said generators,
substantially as set forth.
2. In a system of electrical distribution, the 30
combination of the two or more feeding-cir-
cuits supplying current to different parts of
the district, two or more independent genera-
tors, means for connecting each generator sep-
arately with the feeders, an adjustable resist- 35
ance in the field - circuit of each generator,
means for adjusting each resistance separately,
and means for adjusting all said resistances
simultaneously, substantially as set forth.
3. The combination of two or more dynamo- 10
electric machines, an adjustable resistance in
the field-circuit of each machine, means for
adjusting all said resistances simultaneously,
and means for adjusting each resistance sep-
arately, substantially as set forth.
45
This specification signed and witnessed this
8th day of February, 1884.
Witnesses:
THOS. A. EDISON.
A. W. KIDDLE,
E. C. ROWLAND.
2957
(No Model.)
T. A. EDISON.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Oct. 14, 1890.
No. 438,308.
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THE KORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
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INVENTOR:
Thomas A. Edwin
Lury
2956
4
365,978
division of the source of supply, substantially
as set forth.
which said main circuit is broken and con-
nected to suitable terminals, an additional ter-
10. In a system of electrical distribution, minal at each sub-station, a circuit composed 25
the combination of a source of supply, a main of positive, negative, and compensating con-
5 circuit extending therefrom, sub-stations at ductors extending, respectively, from said
which said main circuit is broken and con- main-circuit terminals and said additional
nected to suitable terminals, an additional ter- terminal at each sub-station, translating de-
minal at each sub-station, a circuit composed of vices in multiple series supplied from said cir- 30
positive, negative, and compensating conduct- cuits, through which the main circuit is com-
10 ors extending, respectively, from said main-cir- pleted, conductors extending from between
cuit terminals and said additional terminal at the sub-stations to points of division of the
each sub-station, translating devices in multi-source of supply, and a conductor extending
ple series supplied from said circuits, through from each of said additional terminals to a 35
which the main circuit is completed, conduct-point of subdivision of the source, each sub-
15 ors extending from between the sub-stations to division of the source being independently
points of division of the source of supply, and regulable, substantially as set forth.
à conductor extending from each of said addi- This specification signed and witnessed this
tional terminals to a point of subdivision of 22d day of November, 1886.
the source, substantially as set forth.
20
11. In a system of electrical distribution,
the combination of a source of supply, a main
circuit extending therefrom, sub-stations at
Witnesses:
WM. PELZER,
THOS, A. EDISON.
E. C. ROWland.
2955
3
365,978
including indicators d, extend to the sub-sta-
tions, as before. Indicating-circuits p³ n³ ex-
tend from the sub-stations to the main station
and are connected with indicators e, by whose
5 indications the generators are regulated to af-
fect the entire current supplied to each sub-
district or that supplied to the entire system.
The conductors T extend back from between
sub-stations to the points of division of the
Io source to balance the districts, as already ex-
plained.
What I claim is-
1. In a system of electrical distribution, the
combination of a main station or source of sup-
15 ply, a main circuit extending therefrom, sub-
stations at which the main circuit is broken,
two or more feeding circuits extending from
the main-circuit terminals at each sub-station,
and a system of connected translation-circuits
20 for each sub station, to which both or all the
feeding-circuits from that sub-station are con-
nected at different points, substantially as set
forth.
2. In a system of electrical distribution, the
25 combination of a main station or source of sup-
ply, a main circuit extending therefrom, sub-
stations, circuits extending from the main cir-
cuit at such sub-stations, translating devices
supplied with current by such sub-station cir-
30 cuits, indicating-circuits extending from the
main circuit at such sub stations to indicating
devices at the main station, and means at the
main station for regulating the main circuit,
substantially as set forth.
35 3. In a system of electrical distribution, the
combination of a main station or source of
supply, a main circuit extending therefrom,
sub-stations at which said main circuit is
broken, feeding-circuits extending from the
40 main-circuit terminals at the sub-stations to
translation-circuits, through which the main-
circuit connections are completed, means for
regulating the pressure on each feeding cir-
cuit, and means at the main station or source
45 of supply for regulating the main circuit, sub-
stantially as set forth.
|
3
70
a main circuit extending from one terminal to
the other of said source, sub-stations at which
said main circuit is broken, circuits extending
from the main-circuit terminals at said sub-
stations, translating devices supplied by said
circuits, through which the main circuit is com-
pleted, and conductors extending from the
main circuit between the sub stations to the
points of division of the source of supply, sub- 75
stantially as set forth.
6. In a system of electrical distribution, the
combination of a divided source of electricity,
a main circuit extending therefrom, sub-sta-
tions at which said main circuit is broken, cir- 80
cuits extending from the main-circuit termi-
nals at said sub-stations, translating devices
supplied by said circuits, through which the
main circuit is completed, conductors extend-
ing from the main circuit between the sub- 85
stations to the points of division of the source
of supply, and means for separately regulat-
ing each division of the source of supply, sub-
stantially as set forth.
7. In a system of electrical distribution, the 90
combination of two or more electrical gener-
ators connected in series, a main-circuit ex-
tending from the terminals of the series, sub-
stations at which said main circuit is broken,
circuits extending from the main-circuit ter- 95
minals at said sub-stations, translating devices
supplied by said circuits, through which the
main circuit is completed, conductors extend-
ing from the main circuit between the sub-sta-
tions to between the generators, and means for 100
regulating each of said generators, substan-
tially as set forth.
8. In a system of electrical distribution, the
combination of a divided source of electricity,
a main circuit extending therefrom, sub sta- 105
tions at which the main circuit is broken, feed-
ing-circuits extending from the main-circuit
terminals at the sub-stations, translation-cir-
cuits connected with said feeding - circuits,
through which the main circuit is completed, 110
indicating and regulating devices at the sub-
stations for said feeding-circuits, conductors
4. In a system of electrical distribution, the extending from the main circuit between the
combination of a main station or source of sup- sub-stations to the points of division of the
ply, a main circuit extending therefrom, sub- source of supply, and indicating and regulat- 115
50 stations at which said main circuit is broken, ing devices at the main station for each divis-
feeding-circuits extending from the main-cir-ion of the source of supply, substantially as
cuit terminals at each sub-station to transla-
tion-circuits, through which the main-circuit
connections are completed, indicating-circuits
55 extending from the outer terminals of each
feeder to its sub-station, indicating devices
connected therewith, means for regulating the
pressure at each of said feeding circuits, indi-
cating circuits extending from the main cir-
60 cuit at the sub-stations to the main station or
source of supply, indicating devices connected
therewith, and means at the main station for
regulating the main circuit, substantially as
set forth.
65
5. In a system of electrical distribution, the
combination of a divided source of electricity,
set forth.
9. In a system of electrical distribution, the
combination of a main station or source of sup- 120
ply, a main circuit extending therefrom, sub-
stations at which the main circuit is broken
and connected to suitable terminals, an addi-
tional terminal at each sub-station, a circuit
composed of positive, negative, and compen- 125
sating conductors extending, respectively, from
the main-circuit terminals and said additional
terminal at each sub-station, translating de-
vices in multiple series supplied from said
circuits, through which the main circuit is 130
completed, and a conductor extending from
each of said additional terminals to a point of
2954
2
15
365,978
ing of indicators dd, connected across the
conductors of three-wire indicating - circuits
p² n² c², one of which extends back from the
terminals of each feeding-circuit into the sub-
5 station, and which continually show the press-
ure at the points where the feeders are con-
nected. The sub-station D' is similarly ar-
ranged and equipped, the conductor 2 being
carried to the terminal point P' and the con-
10 ductor 3 from the main source to the terminal
N', and the feeders extending from terminals
P', N', and C, and supplying translating devices
a'g', and being provided with indicating and
regulating apparatus precisely as explained
with reference to the other station. It will
be seen that the conductor 2 connects the two
districts supplied from the two sub-stations in
series with each other and with the generators
at the main station. From any point on the
20 conductor 2 between the sub-stations a con-
ductor, T, extends to the middle point of the
series of generators, whereby a divided source
of electricity is produced, at whose point of
division the compensating conductor T is con-
25 nected. I have shown the conductor T as ex-
tending from the terminal point P' in sub-sta-
tion D'. The effect is evidently the same as
though it were connected anywhere along the
line 2 between the sub-stations. It will be
30 usually more convenient to make the connec-
tion in the sub-station, as shown.
2
-
|
From the terminal point C in station D a
conductor, T', extends, which is connected be-
tween the generators A' and A³-that is, at
35 the middle point of one of the divisions of the
source—and from C' in station D'a similar con-
ductor, T, extends and is connected between |
generators A and A', the two divisions of the
source being thus themselves divided, or, in
40 other words, the source being thus subdivided
into four subdivisions. Thus the two districts
form a compensating or three wire system
having a divided source and a compensating
conductor, while each district is itself a three-
45 wire system having a divided source and a
compensating conductor. The translating de-
vices of the two districts are in multiple series
with each other—that is, any two devices a a
in series in district D are in series with two
50 translating devices a' a' in district D'. There
are therefore four translating devices in se-
ries, and hence high tension currents and
small conductors are employed. At the same
time all the translating devices are independ-
55 ent. In each sub-system, when the number of
devices on the two sides becomes unequal, cur-
rent flows in one direction or the other on con-
ductors c and T'or T' to maintain the balance,
and if the number of devices in one sub-system
60 differs from that in the other the balance is
similarly preserved by the compensating con-
ductor T. As stated, the adjustable resist-
ances at the sub-stations are employed to keep
a constant pressure at all the feeder terminals,
65 thus regulating for unequal distribution or
changes in the number of translating devices
3
in circuit in different parts of the district.
Indicating circuits also extend from the sub-
stations to the main station, each of which
consists of three conductors, psn c, including 70
suitable indicators, ee, by means of which the
condition of each side of each sub-system is
continually shown, and in accordance with
which the generators are regulated together
or separately to regulate the whole current 75
supplied to the entire system, or that supplied
to each sub-system, or that supplied to each
side of each sub-system. It is evident that
there may be any desired number of sub-sta-
tions and districts supplied therefrom, the So
number of generators at the station being cor-
respondingly increased, so that there will be
one or more generators for each side of each
sub-system, and conductors being run from be-
tween the sub-stations to the points of division, 85
and from the middle terminals of the sub-sta-
tions to the points of subdivision of the source.
The generators` comprising the high-tension
source are not necessarily all placed in the
same building or at the same place; but they 9c
may be placed at two or more different points,
they being, however, always connected in se-
ries by conductors extending between the
different points.
·
In the above described system economy is 95
attained not only in conductors, but in other
ways also. In the matter of renting or pur-
chasing property for stations, for instance, for
the main station may be placed at a distance
from the thickly settled areas to be illumi- 100
nated, at a point where rents are low or prop-
erty cheap, while for each of the sub-stations
only a small room is necessary, which can be
cheaply obtained, it being necessary only to
have room enough for the indicators and ad- 105
justable resistances. A single attendant is
kept at each sub-station, whose only duty is to
observe the indicators and adjust the resist-
ances accordingly.
·
In the modified arrangement shown in Fig. 110
2 each sub district is arranged as an ordinary
two-wire multiple-arc system, although the
general system is a compensating system.
Three sub-stations, D², D", and D¹, are shown
supplied with high tension current from a 115
series of three generators, (or three connected
sets of generators,) A, A', and A. Conduct-
ors 2 and 2ª connect the sub-stations in series.
At each sub-station the circuit is broken, as
before described, at terminal points P N, and 120
from these terminals the conductors pn of any
desired number of feeding circuits extend to
lighting or translating circuits p'n', with which
the translating devices a a are connected in
multiple arc. The translating devices of the 125
three districts are in series with each other
through the conductors 2 and 2, there being,
as shown, three translating devices in series,
or as many as there are sub-stations. Each
feeding-circuit p n is provided with an adjust- 130
able resistance, b, for regulating the current
conducted by it, and indicating circuits p² n²,
·
2953
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF LLEWELLYN PARK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 365,978, dated July 5, 1887.
Application filed November 29, 1886. Serial No. 220,125. (No modol.)
To all whom it may concern:
·
Be it known that I, THOMAS A. EDISON, of
Llewellyn Park, in the county of Essex and
State of New Jersey, have invented a certain
5 new and useful Improvement in Systems of
Electrical Distribution, (Case No. 700,) of
which the following is a specification.
lighted or supplied with current from a single
source.
3
Referring, first, more especially to Fig. 1, A, 55
A', A², and A³ are dynamo-electric machines,
all connected in series and situated at a suit-
able point where the necessary power to op-
erate them can be conveniently and cheaply
procured, and which may be for that purpose 60
situated, if necessary, at a considerable dis-
tance from the places to be supplied, since the
current generated by the series of machines
has a high tension and can therefore be eco-
nomically conveyed by conductors of small 65
mass. Each generator is separately regulable,
preferably by means of the adjustable resist-
ances B B, placed in the shunted field-circuit
of each machine.
From the terminals of the series of machines 70
a circuit, 1 2 3, extends. D and D' represent
sub-stations to which this circuit extends.
The dotted rectangles indicate suitable rooms
or places into which the conductors are run,
and in which the connections are made and 75
the indicating and regulating devices are
placed. In the station D the conductor 1 is
brought to a suitable terminal point, P, and
from a similar terminal point, N, the con-
ductor 2 extends to the next sub-station. So
There is also a third terminal point, C. From
The object of my invention is to produce a
system for the distribution of electricity for
Io lighting and similar purposes, in which cur-
rents of high tension may be used, and conse-
quent economy in the metal required for con-
ductors will be attained, which system shall
be of a simple and efficient character and read-
15 ily and conveniently regulable. In accom-
plishing this object I provide a divided source
of electricity of high tension, consisting of two
or more dynamo-electric machines connected
in series placed at a suitable building at a place
20 where power may be procured conveniently
and economically. A circuit extends from
this source of power to two or more sub-sta-
tions, at each of which a feeding circuit or cir-
cuits are taken off, which extend to a district
25 to be supplied with current. All these sub-
stations are in series, and from the main cir-
cuit-conductor between the stations compen-
sating conductors extend, which are connected
with the points of division of the source of
30 supply. At each sub-station suitable indicat-the sub-station extend two feeding-circuits, p
ing and regulating devices are provided, where- n c. There are provided any desired number
by the electrical condition of the circuits ex- of such feeding-circuits, according to the ex-
tending therefrom is indicated and regulated, tent of and number of translating devices in $5
and from each sub-station a circuit extends to the district supplied. The conductors p ex-
35 the main station or source of supply, with which tend from terminal P, conductors n from ter-
circuits are connected indicating devices, in minal N, and conductors c from terminal C;
accordance with whose indications the gener- and these conductors are all connected, re-
ators are regulated according to the require- spectively, with positive, negative, and com- 90
ments of the district supplied from each sub-pensating lighting or translation circuit-con-
40 station. I prefer to connect the districts from ductors p'n' c', with which the electric lamps
the sub-stations on the three-wire or compen- or other translating devices a a are connected
sating system, but I may arrange them as two- in multiple series, as is now common in the
wire systems.
three-wire system of electrical distribution. 95
Each of the feeding-conductors p n is provided
with an adjustable resistance, b, whereby the
two sides of the sub-system are regulated to
keep the same constant pressure at all points
on the lighting - circuits, thereby regulating 100
for unequal distribution or changes in the
number of translating devices in circuit in the
different parts of the district. This regula-
tion is effected in accordance with the show-
My invention is illustrated in the accompa-
45 nying drawings, in which—
Figure 1 is a diagram of the preferred form,
in which the districts are arranged on the three-
wire system; and Fig. 2 a diagram of the modi-
fied form with each district arranged as a two-
50 wire system.
The invention is particularly applicable to
cases where there is a very large area to be
e
2952
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SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented July 5, 1887.
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SYSTEM OF ELECTRICAL DISTRIBUTION.
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Patented July 5, 1887.
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| KIBRAˇNKEE
Correction in Letters Patent No. 438,308.
It is hereby certified that in Letters Patent No. 438,308, granted October 14, 1890,
upon the application of Thomas A. Edison, of Llewellyn Park, New Jersey, for an
improvement in "Systems of Electrical Distribution," an error appears in the printed
specification requiring correction, as follows: In line 50, page 2, the word "connector"
should read converter; and that the Letters Patent should be read with this correction
therein that the same may conform to the record of the case in the Patent Office.
Signed, countersigned, and sealed this 25th day of November, A. D. 1890.
[SEAL.]
Countersigned:
C. E. MITCHELL,
CYRUS BUSSEY,
Assistant Secretary of the Interior.
Commissioner of Patents.
2958
UNITED STATES PATENT OFFICE.
THOMAS A. EDISON, OF LLEWELLYN PARK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 438,308, dated October 14, 1890.
Application filed December 6, 1886. Serial No. 220,792. (No model.)
To all whom it may concern:
Be it known that I, THOMAS A. EDISON, of
Llewellyn Park, in the county of Essex and
State of New Jersey, have invented a certain
5 new and useful Improvement in Systems of
Electrical Distribution, (Case No. 691,) of
which the following is a specification.
My invention relates to multiple-arc sys-
tems of electrical distribution, in which alter-
10 nating-current generators are used, in connec-
tion with converters, for supplying current to
lamps and other transmitting devices, and
especially to the combination, with such a
system, of a current-indicating device of the
15 character hereinafter described and claimed.
My invention is illustrated in the accom-
panying drawings, in which-
Figure 1 is a diagram of a system of elec-
trical distribution embodying said invention
20 with the converter primaries in multiple arc
on separate circuits from the same source;
Fig. 2, a diagram of the system with the con-
verters in series on the same circuit, and Figs.
3 and 4 are sectional views of the indicating
25 device which I prefer to employ.
30
A represents an alternating-currentdynamo-
electric machine generating current of high
electro-motive force, one or more of which
machines form the source of current.
up of thin plates or bundles of wire, as is
common in the armatures of dynamo-electric
machines, this construction being useful for
the prevention of Foucault currents in the
core and for giving greater efficiency in con- 55
version. Such converters are set forth in my
application, Serial No. 219,358, filed Novem
ber 19, 1886, and therefore are not illustrated
herein, the simple form of induction-coil being
shown to illustrate the principle of the inven- 60
tion.
The conductor P extends to the primary of
converter D, conductor P' extends to that of
converter D', and conductor P2 extends to
that of converter D². The opposite terminals 65
of all the primary circuits are connected with
conductor N, which therefore forms a com-
mon return for all the multiple-arc primaries.
It is evident that separate return-conductors
may be provided, if desired. The converters 70
are placed at or near the centers of consump-
tion of the district supplied. From their sec-
ondary circuits conductors² and n² extend,
which are connected with the intersecting
positive and negative main conductors p'n'. 75
Connected across the conductors p n is an in-
dicator a of pressure or electro-motive force,
and connected across each of the circuits P
N, P' N, and P² N are similar indicators a',
a², and a³. These indicators are adapted to 80
indicate electro-motive force in an alternat-
ing-current circuit, and are shown more in de-
tail in Figs. 3 and 4. Each consists of two
coils b and b', the latter suspended within the
former and both connected in the same cir- 85
cuit in series. Since upon the passage of cur-
rent the inner coil tends to set itself at right
angles to the outer one, any increase or de-
crease of current due to changes of potential
in the conductors across which the indicators 90
are connected acts to change the position of
said inner coil, and since this is provided
with a pointer c, traveling upon a scale d,
such changes of potential are constantly in-
dicated, and since the coils are in the same 95
circuit change in direction of current does
I have shown induction - coils of ordinary not affect the movements of the indicating-
form, which are efficient for the purpose of coil, for which reason these instruments are
my invention. I may, however, use induction well adapted to be used in a system employ-
50 devices having cores of ring form and builting alternating or reversed currents.
B is a continuous-current generator ener-
gizing the field - magnets of the alternating
machine and having an adjustable resistance
C in its circuit, by adjusting which the field-
magnet strength of the alternating machine
35 and the electro-motive force thereof are regu-
lated.
Referring more especially to Fig. 1, conduct-
ors p n extend from the commutator-brushes
to suitable terminal points within the gener-
40 ating-station. From the terminal of conductor
p conductors P, P', and P² extend, and from
the terminal of conductor n a conductor N
extends. The system of intersecting and con-
nected positive and negative main or lighting
45 conductors is represented by p′ n'.
D, D', and D2 are converters.
100
2959
2
438,303
The indicator a indicates the pressure or indicates the ampères of current. The regu-
electro-motive force at the source, and by ad-lation is accomplished by the resistance Cin 40
3
justing the resistance C in accordance with
these indications this pressure is kept con-
5 stant. The indicators a', a², and as show the
pressure in each of the feeding-circuits, and
such circuits are regulated to maintain the
same constant pressure at all parts of the sys-
tem by adjusting the resistances E, E', and E2,
to situated in the conductors P, P', and P2. A
circuit p³ n³ of small wires may extend back
from the district at a suitable point to the
station, where it is connected with an indi-
cator a¹ to show the general reduced pressure
15 on the system of lighting-conductors, where-
by any derangement in the action of the con-
verters may be shown.
The conductors P, P', P², and N are of small
size, being required to convey the high-ten- |
20 sion current. This current is reduced by the
converters, and the short conductors which
connect the secondary coils with the main
conductors are of larger size. The economy
in the amount of metal used for conductors
25 which results from this arrangement is evi-
dent.
In the arrangement shown in Fig. 2 a sin-
gle circuit P N extends from the high-ten-
sion source of supply, and the primaries of all
30 the induction-coils D, D', and D² are placed in
series therein, the secondary circuits thereof
being connected with the main or lighting
conductors, as before. The indicator a5, of
the character already described, is connected
35 across the line, having a resistance d in cir-
cuit with it. This indicates the volts of elec-
tro - motive force. A similar indicator a“,
shunted around a resistance d' in the line,
the field-circuit of the generator..
What I claim is-
1. In a system of electrical distribution, the
combination of a high-tension alternating-cur-
rent generator, a circuit extending therefrom, 45
a converter connected with said circuit and
supplying current to translating devices, and
an electrical indicator not affected by changes
in polarity connected with one coil or circuit
of the connector, substantially as described. 50
2. In a system of electrical distribution, the
combination of a high-tension alternating-cur-
rent generator, a circuit extending therefrom,
a tension-reducing converter connected with
said circuit and supplying a current of re- 55
duced tension to translating devices, and an
electrical indicator not affected by changes in
polarity connected with the high-tension cir-
cuit, substantially as set forth.
3. In a system of electrical distribution, the Co
combination of a high-tension alternating-cur-
rent generator, a circuit extending therefrom,
a tension-reducing converter connected with
said circuit and supplying a current of re-
duced tension to translating devices, and an 65
electrical indicator having two relatively-mov-
able coils in the same circuit connected with
said high-tension circuit, substantially as set
forth.
This specification signed and witnessed this 70
9th day of November, 1886.
Witnesses:
WM. PELZER,
E. C. ROWLAND.
THOS. A. EDISON.
2960
(No Model.)
No. 287,501.
E
f
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C. S. BRADLEY.
METHOD OF ELECTRICAL TESTING.
Patented Oct. 30, 1883.
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Nusuly
INVENTOR.
Charles S. Bradley
By Rich St. Dyer,
Koty.
प
2961
UNITED STATES PATENT OFFICE.
CHARLES S. BRADLEY, OF NEW YORK, N. Y., ASSIGNOR TO THE EDISON
ELECTRIC LIGHT COMPANY, OF SAME PLACE.
METHOD OF ELECTRICAL TESTING.
SPECIFICATION forming part of Letters Patent No. 287,501, dated October 30, 1883.
Application filed February 17, 1883. (No model.)
To all whom it may concern:
Be it known that I, CHARLES S. BRADLEY,
of the city, county, and State of New York,
have invented a new and useful Improvement
5 in Methods of Electrical Testing, of which the
following is a specification.
My invention relates to methods of discov-
ering the presence and location of leaks or
ground-connections caused by defects in the
10 insulation of electrical conductors, and espe-
cially of the conductors employed in multiple-
arc systems of electrical distribution, my ob-
jects being, first, to discover the resistance of
the insulation between each conductor of a
15 circuit and the ground, hence determining
whether any defects or leaks occur in such in-
sulation, and in which conductor such leaks
occur; and, second, to determine the location
in the system of such leaks, if any are found
20 to be present, both of these operations being
performed without withdrawing the current
from the system to any material extent.
tion the latter is readily determined. As I
know also the ratio of the resistances of this
and the other insulation, I can also easily cal-
culate the latter. If, in applying these tests
to the main circuit of an electrical-distribu- 55
tion system, it is found that the resistance of
the insulation of either side of the circuit is
unusually low, it will be known that a defect is
somewhere present in such insulation, causing
a ground-connection or leak.
60
As stated, the second object of my inven-
tion is to discover the location in the system
of such a leak. To accomplish this I connect
the galvanometer or other instrument for in-
dicating electric current at the central station 65
to the pole of the circuit in which such leak
occurs, thus forming a shunt around that por-
tion of the conductor which lies between the
galvanometer and the leak. The direction of
deflection of the galvanometer-needle will de- 70.
termine the direction in which the leak lies,
and the amount of such deflection will indi-
I accomplish the first object by so connect-cate the distance of such leak, as the amount
ing the conductors and the earth that the in- of current in the circuit depends upon the
25 sulation lying between them and the earth | electrical distance from the source of supply. 75
forms two of the sides of a Wheatstone bridge. It is also necessary to determine in or near
This may be done by connecting both conduct- which feeding-circuit leading from the central
ors to one terminal of a galvanometer, or to station to the intersecting consumption-cir-
any suitable device for indicating electric cur- cuits the leak occurs. This may be done by
30 rents through resistances, one of which should adding a number of electric lamps or other 80
be adjustable, the other terminal of the indi- translating devices to the system, successively,
cating device being connected to the earth. at points near the terminals of the different
If one insulation is of less resistance than the feeding-circuits, thus causing increase of cur-
other, the bridge will be thrown out of balance rent in each of such circuits, one after another.
35 and the indicating device will show the pas- When the circuit nearest the leak is reached, 85
sage of current. The adjustable resistance is the effect of the increase will be perceptible
then changed until said indicating device is in the increased deflection of the galvanometer.
not affected, and by the amount of adjustment The same result may be accomplished by suc-
the ratio of resistance of the two insulations cessively increasing the resistance of the feed-
40 may be determined; but to determine the posi- ing-circuits, for when the circuit nearest the 90
tive value of such resistances, either conductor leak is reached the deflection of the galvanom-
is connected to the earth through a known re- eter will be more than with the other circuits;
sistance, a shunt being thus formed around or the successive disconnection and reconnec-
the unknown resistance of the insulation of tion of the feeding-circuits produces a like
45 said conductor. I then again vary the adjust- effect.
able resistance until the indicating device is
not affected, by which I determine the effect
of the known resistance of the shunt, and by
noting the difference between this and the ef-
50 fect of the unknown resistance of the insula-
95
By successively employing the different
parts of my invention I am enabled to deter-
mine the location of a leak with great precis-
ion, first determining in which conductor the
leak exists and the extent of such leak, then 100
2962
2
287,501
defining the direction and distance of the leak,
and finally discovering its location with ref-
erence to the feeding-circuits of the system.
My invention is illustrated diagrammatically
5 in the annexed drawings, in which-
¡
|
known. If the leak were at a point between
the galvanometer and the generator-for in-
stance, at f-this would be shown by the di-
rection of deflection. It now only remains 70
to determine in what particular part of the
system the leak occurs. To do this I may
either increase or decrease the resistance of
the feeders one after another, as explained,
or successively disconnect such feeders, and 75
by noting the effect on the galvanometer-nee-
die determine which feeder approaches near-
est to the point of leakage.
While I have described my invention with
reference to systems of electrical distribution, 80
it is evident that it may readily be applied to
any round metallic circuits to measure the in-
sulation of the conductors of such circuits
and to determine the location of any defects
which may exist in such insulation. It is also 85
evident that the connections necessary for ac-
complishing my invention may be made and
the tests applied not only at the central sta-
tion, but at any part of the system.
What I claim is-
rection and distance of the leak, substantially
as set forth.
90
Figure 1 is a diagram showing the manner
of measuring the insulation of conductors; and
Fig. 2, a diagram of an electric-lighting sys-
tem, illustrating the method of determining
Io the location of leaks or ground-connections.
Referring to Fig. 1, P N represent electrical
conductors, preferably the main conductors at
the central station of an electrical-distribution
system, or points in electrical connection with
15 such main conductors. Conductor P is con-
nected to one terminal of a galvanometer, A,
through a resistance, B, which is adjustable
by means of pivoted arm a. Conductor N is
connected to the same terminal through con-
20 stant resistance B'. The other terminal of the
galvanometer is connected to earth E, as
shown. The dotted lines b b' indicate the con-
nection between the conductors and the earth
throughout the system through the insulation
25 which surrounds said conductors. If the re- 1. The method of ascertaining the location
sistances of the two insulations are equal, the of ground-connections in a round metallic cir-
galvanometer-needle will remain stationary; cuit, consisting in first measuring the resist-
but should they be unequal, current will pass ance of the insulation on each side of the cir-
through the galvanometer and deflect its nee- cuit to determine on which side a leak occurs 95
30 dle. By then adjusting the resistance B until and the extent of such leak, and then con-
the galvanometer is again balanced, the differ- necting an electrical indicating device between
ence of resistance between the two insulations the side which contains the leak and the earth,
is indicated by the amount of such adjustment, the direction and amount of the current pass-
and any improper ground-connection or leaking through said device determining the di- 100
35 in either conductor will be apparent. Dur-
ing these operations the circuit through the
known resistance D between conductor P and
the earth is open. By closing this I form a
shunt around the insulation of conductor P
40 and again deflect the galvanometer-needle. I
again adjust the resistance B, and by noting
the difference between this and the former
adjustment the relation between the resist-
ances D and b will be known, and from this
45 the positive value of the resistances of b and
b' are readily determined. Having thus dis-
covered the extent of the leak and the side of
the circuit in which it occurs, I connect the
galvanometer to this side of the circuit, which
50 may be the negative side N, as indicated in 3. The method of electrical testing for as-
Fig. 2. In this figure F represents a gener- sisting in determining the resistance of the
ator or battery of generators feeding into the insulation of each side of a round metallic
main conductors PN. From these main con- circuit, consisting in connecting both conduct-
ductors feeding-circuits p n, p'n', and p² n² run ors to the earth, one through a constant re- 120
55 to the system of intersecting and connected sistance and an electrical indicating device,
positive conductors P' and negative conductors the other through an adjustable_resistance
N', on which lamps and other translating de- and the same indicating device, and adjusting
vices, e c, are arranged in multiple arc. The said adjustable resistance until said indicating
dotted lines d indicate a leak between a con- device is not affected, thus determining the 125
60 ductor, N', and the earth. It is evident that ratio of the two resistances, then connecting
when the galvanometer A is connected to main one conductor to the ground through a known
conductor N by wire e, a shunt, d E e, is resistance, and again adjusting said adjustable
formed through said galvanometer, through resistance, whereby the ratio between such
which current will pass, and the distance of the known resistance and the resistance of said 130
65 leak will be determined by the amount of de-last-mentioned insulation is determined, sub-
flection, the extent of the leak being already stantially as set forth.
2 2
2. The method of ascertaining the relative
resistances of the respective insulations of the
two conductors of a round metallic circuit, 105
consisting in connecting both conductors to
the earth, one through a constant resistance
and an electrical indicating device, the other
through an adjustable resistance and the
same indicating device, and adjusting said ad- 110
justable resistance until such indicating de-
vice is not affected, the amount of such ad-
justment indicating the difference between the
resistances of the two insulations, substan-
tially as set forth.
115
2963
287,501
3
4. The method of ascertaining the location | rying or removing the current in the feeding-
of a leak or ground-connection in a multiple- circuits, successively, to determine which feed-
arc system of electrical distribution employ- ing circuit approaches nearest to the leak,
ing feeding-circuits, consisting in first com- substantially as set forth.
5 paring the resistances of the insulations of the
two sides of the system to determine on which
side the leak occurs, connecting an electrical
indicating device between the side containing
the leak and the earth to determine the dis-
10 tance and direction of such leak and then va-
This specification signed and witnessed this 15
2d day of February, 1883.
Witnesses:
CHARLES S. BRADLEY.
H. W. SEELY,
EDWARD H. PYATT.
(No Model.)
2964
No. 353,915.
al
C. S. BRADLEY.
ELECTRICAL TESTING.
Fig1.
Patented Dec. 7, 1886.
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WITNESSES:
Bowland
F.W Kiddle.
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INVENTOR:
Charles S Bradley;
By Rich A Dyer.
Aben.
N PETERS Photo-Lithographor Washington, DC
2965
UNITED STATES PATENT OFFICE.
CHARLES S. BRADLEY, OF NEW YORK, N. Y., ASSIGNOR TO THE EDISON
ELECTRIC LIGHT COMPANY, OF SAME PLACE.
ELECTRICAL TESTING.
SPECIFICATION forming part of Letters Patent No. 353,915, dated December 7, 1886.
Application filed April 5, 1884. Serial No. 126,800. (No model.)
To all whom it may concern:
Be it known that I, CHARLES S. BRADLEY,
of New York city, in the county and State of
New York, have invented a certain new and
5 useful Improvement in Electrical Testing, of
which the following is a specification.
The object of this invention is to discover
the location of leaks on ground-connections in
multiple-arc systems of electrical distribution,
10 and is an improvement upon or continuation
of the method of testing set forth in my Pat-
ent No. 287,501.
15
The system of electrical distribution in
which my invention is especially applicable is
one in which a system of positive and nega-
tive main conductors or "mains" is employed,
such conductors extending along the faces of
the blocks of the district supplied, and inter.
secting each other at the street-corners, and
20 being all connected together, positive to posi-
tive and negative to negative, at each point
where they intersect. The translating devices
of the system are arranged in multiple arc
upon these conductors or upon house-circuits
25 derived from them. Current is supplied by a
number of separate circuits, called "feeders"
or "feeding circuits," each of which extends
from the source of supply to a different point
in the district, at which point its conductors
30 are respectively connected to the positive and
negative conductors of one of the mains.
Usually from the terminals of each feeder a
circuit of fine wire returns to the central sta-
tion, where it is connected with an electro-
35 dynamometer or other suitable electrical indi-
cating device, whereby the electrical potential
at the terminals of each feeder is indicated.
nals of whose circuit are nearest the leak will
be affected to the greatest extent. If constant
indicating devices are not used, the same indi-
cator can be successively connected to the dif- 55
ferent indicator circuits or directly across the
feeding-circuits, the system being grounded
each time and the relative indications noted.
By this first step of my method I determine
near the terminals of which feeding circuit the 60
leak occurs.
I next determine in which of the mains,
which are laid along the faces of the blocks,
the defect is present. I do this by disconnect-
ing a main which is principally supplied from 65
the feeder found by the first step at the end of
the block nearest said feeder, thereby making
its principal source of supply another feeder.
If the main has a ground, the indications of
ground are of course transferred from one 70
feeder-indicator to the other. By successively
trying the different mains in the vicinity of the
feeder I discover which one contains the
ground connection.
·
It is next desired to find the precise point 75
on the block-face at which the leak occurs.
This is accomplished by finding the propor-
tional resistance between each end of the leak-
ing main conductor and the leak. I have de-
vised two ways of determining this, which will 80
be described with relation to the drawings, as
they can thus be more clearly set forth.
In the drawings, Figures 1, 2, and 3 are dia-
grams illustrative of the different steps of my
invention.
85
Referring first to Fig. 1, A A' are common
conductors at the central station, with which
one or more electrical generators, C, are con-
In carrying out my invention I first ascer- nected. PN, P′ N', and P² N² are feeding-
tain on which side of the circuit the leak oc- circuits extending from the station to the cen- 90
40 curs and the extent of the leak, preferably in ters of consumption of the district supplied,
the manner set forth in the patent referred where they are connected with the main con-
to-that is, by determining the relative values ductors pn, which intersect each other, and
of the insulations of the two sides of the sys- are connected, positive to positive and nega-
tem. Having discovered this, I next ground tive to negative, at the corners of the blocks B. 95
45 the opposite side of the system, preferably Indicating circuits p'n' extend from the feeder-
through a resistance, so that but little current terminals to the central station, where they
will pass. It will be seen that when the two are connected with suitable indicating devices,
sides of the system are grounded the reduc- a a. It is not necessary, however, to connect
tion of resistance in the whole circuit will the indicating device with both conductors pɔɔ
50 cause the indicating devices at the central sta- n', for it may be connected with one of said
tion to be affected, and that device the termiconductors and one of the common conductors
2966
•
353,915
A A', being thus in a shunt through which | porary wires along the block-face, which is
current will pass, according to the difference inconvenient in a crowded street. By it all
of potential between the central station and the operations are performed at the corner 70
the feeder-terminal. Suppose a leak or ground-junction-box. In carrying this out I discon-
5 connection to exist at c. The side of the sys- nect one end of the main from the system, and
tem in which it occurs is determined by meas- then connect a graduated resistance, one ter-
uring the insulation. Then the opposite side minal to the conductor p and the other with
is grounded through a resistance at d, or other the conductor n. This latter connection is 75
convenient point. The ground circuit thus preferably made through another main, n,
Io formed makes a change in the difference of coming from another direction, whereby the
potential between the central station and the effect of slight changes in potential is avoided.
feeder terminals, and affects the indicating de- The galvanometer is placed between this re-
vices a a. That whose circuit terminates near- sistance and the end of the leaking main, its 80
est the leak will be most affected, and it will terminal being connected to such a point on the
15 thus be seen that the leak is near the feeder P² resistance that its needle will stand at zero
I then proceed to disconnect the mains in when the current is applied at the opposite end
that vicinity at their ends nearest the feeder of the main, a portion thereof passing through
P² N², and when the main having the leak is the galvanometer. I then ground the main p, 85
disconnected the indications of ground are this also being preferably done at a point elec-
20 transferred to P' N'. The main having the trically distant, as shown. This brings the re-
leak is thus indicated.
sistance and galvanometer into a shunt around
a conductor which includes that portion of
main n on the left (in the drawings) of the leak, 90
or, in fact, into the bridge-circuit of a Wheat-
stone bridge, and the galvanometer is deflected.
I adjust the galvanometer-terminal upon the
resistance until the needle is again at zero and
note the portion of the resistance passed over. 95
I now repeat this operation at the other end
of the main, applying the current at the pre-
viously-disconnected end. The galvanometer
and resistance are shunted when the earth-
connections are made around a circuit the 100
same as before, except that the portion of con-
stead of that on the left; hence the galvanome-
ter deflections differ according to the rela-
tive resistances of these portions, and the rela- 105
tive extent of the adjustments of the galva-
nometer-terminals upon the resistance deter-
mines these resistances.
What I claim is-
I may now use either of two methods, both of
which, however, involve the same principle-
viz., finding the proportionate resistances of
25 conductors between the two ends of the leak-
ing main and the leak. The method shown in
Fig. 2 is the more simple, though that in Fig.
3 is more conveniently carried into practice.
Referring first to Fig. 2, a leak has been
30 found to exist in conductor n of the main n p.
I connect a galvanometer. G, in a shunt be-
tween the two ends of the leaking conductor,
and then disconnect the main from the system,
say at the end on the left of the drawings, and
35 at any convenient point connect conductor pductor on the right of the leak is included, in-
to ground. It will be seen that the galva
nometer is thus placed in a shunt around that
portion of the conductor n between its con-
nected end and the leak, for the disconnected
40 portion on the left of the leak will form part
of the galvanometer-shunt, and current will
therefore pass through the galvanometer ac-
cording to the resistance of the right-hand 1. The method of determining in which main 110
portion of the conductor. The consequent de- circuit of a system, such as described, a ground-
45 flection is noted. I now reconnect the main conuection occurs, consisting in changing the
at the left hand end and disconnect it on the connection of the mains from one feeder to an-
right, grounding conductor p as before. This other, whereby the leak indications are trans-
shunts the galvanometer around only that part ferred from one of the indicators connected 15
of the conductor to the left of the leak, the part with the feeder terminals to another when the
50 on the right being thrown into the galvanom-right main is reached, substantially as set forth.
eter-shunt. The deflection is noted as before. 2. The method of determining the location
It is evident that the ratio of the two deflec- of a ground-connection in an electrical con-
tions is the ratio of the resistances of conductor ductor, consisting in connecting a galvanome- 120
on each side of the leak. This being deter-ter in a shunt around a portion of the circuit,
55 mined, the operator, knowing the respective including the conductor on one side of the
distances from each end, can at once proceed leak, and then around a portion including the
to the point at which the leak occurs. Where conductor on the other side of the leak, the
there are lamps or other translating devices different effects on the galvanometer indicat- 125
in circuit on the main, the deflection due to ing the relative distances of the leak from the
60 the difference of potential caused by them ends of the conductor, substantially as set forth.
must be taken into account and the difference
between this and the whole deflection when
the line is grounded noted.
The second method by which this last step
65 of my process may be carried out is illustrated
in Fig. 3. This method is advantageous, be-
cause it does away with the stringing of tem-
3. The method of determining the location
of a ground-connection in an electrical circuit,
consisting in connecting the conductor oppo- 130
site to that which contains the leak to ground,
and then applying current first at one end and
then at the other, and noting the deflection of
a galvanometer placed in a shunt between the
2967
5
353 915
terminals of the leaking conductor, the differ-
ent deflections of the galvanometer indicating
the relative distances of the leak from the ends
of the conductor, substantially as set forth.
4. The method of determining the location
of a leak in a main circuit of a system, such as
described, consisting in connecting the con-
ductors through a galvanometer, grounding
the conductor opposite to the ground-con-
Ia nected one, and applying the current first at
one end of the circuit and then at the other, the
different deflections of the galvanometer in-
dicating the relative distances of the leak from
the ends of the conductor, substantially as set
15 forth.
5. The method of determining the location
of a ground-connection in a system, such as de-
scribed, consisting in first determining on
which side of the system the leak occurs, then
20 grounding the opposite side of the system,
whereupon the relative effect on indicating de-
|
3
vices connected with the feeder-terminals de-
termines near which feeder is the leak, then
disconnecting mains successively from the
feeder thus determined, whereupon the trans- 25
ferring of the leak indications from one of said
indicators to another shows which of said
mains contains the leak, and then connecting
a galvanometer in a shunt first around a por-
tion of this main circuit, including the por- 30
tion on one side of the leak of the conductor
containing it, and then around a portion of
the circuit, including the portion of conductor
on the other side, the different effects on the
galvanometer indicating the relative distances 35
of the leak from the ends of the conductor.
This specification signed and witnessed this
6th day of February, 1884.
Witnesses:
CHARLES S. BRADLEY.
H. W. SEELY,
ALFRED W. KIDDLE.
2968
2 Sheets-Sheet 1.
(No Model.)
W. S. ANDREWS & T. SPENCER.
SYSTEM OF ELECTRIC LIGHTING.
No. 318,157.
R
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Patented May 19, 1885.
Firg. 1.
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INVENTORS!
Williams S. Andrews
Thomas Spencer
Золяда
By Dyer Lucy
THE NORRIS PETERS CO., PHOTO-LITHO, WASHINGTON, D. C
2969
(No Model.)
2 Sheets-Sheet 2.
W. S. ANDREWS & T. SPENCER.
SYSTEM OF ELECTRIC LIGHTING.
Patented May 19, 1885.
No. 318,157.
N
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ATTEST
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INVENTORS.
William S. Andreins
Thomas Spencer
of Dyer
Oyer Neuly
By
Attys
N PETERS. Photo-Lithographer, Washington, D C.
2970
UNITED STATES PATENT OFFICE.
5
IO
15
WILLIAM S. ANDREWS, OF NEW YORK, N. Y., AND THOMAS SPENCER, OF
SOUTH MERIDEN, CONNECTICUT.
SYSTEM OF ELECTRIC LIGHTING.
SPECIFICATION forming part of Letters Patent No. 318,157, dated May 19, 1885.
Application filed January 17, 1985. (No model.)
To all whom it may concern:
rectly from the point of division of the source 50
Be it known that we, WILLIAM S. ANDREWS, of supply, which is precisely equivalent to the
of New York, in the county and State of New central one of such lighting-wires. This sin-
York, and THOMAS SPENCER, of South Meri-gle conductor acts as the compensating-con-
den, in the county of New Haven and State of
Connecticut, have invented a certain new and
useful Improvement in Systems of Electric
Lighting, of which the following is a specifi-
cation.
ductor for all the feeders. In most systems of
this character a derived circuit extends at 55
some point from the lighting-conductors into
the central station for lighting the station. In
such case we make the center wire of this de-
compensat-rived circuit of sufficient size for the purpose
and connect it with the center omnibus wire; 60
but in case the lighting-conductors approach
very closely to the station-building we sim-
ply extend a single conductor of sufficient size
from the center lighting-conductor to the cen-
ter omnibus wire.
Our invention relates to the "
ing" or "three-wire" system of electrical dis-
tribution, and our object is to diminish the
amount of metal required for conductors in
such a system.
Our invention may be more readily under-
stood by reference to the annexed drawings,
in which
65
Figure 1 is a diagram of a system embodying
our invention, in which the center wire of the 70
station-lamp circuit is used as the feeder com-
pensating-wire. Fig. 2 represents a system in
which a single wire extends from the lighting-
conductors to the station, and Fig. 3 is a dia-
of a modified form of the invention. 75
Like letters refer to corresponding parts in
all the figures.
Heretofore the general arrangement of a sys-
tem of this character has been as follows: At
the central station are situated two electrical
generators or two series or groups of genera-
tors connected together in series. One termi-
20 nal of the series is connected with one of the
main or "omnibus" conductors at the central
station, and the other terminal with another,
while the third or central omnibus wire is con-
nected between the generators or groups there-
25 of, the source of supply being thus divided into
two parts. From the omnibus wires the feed-gram
ing-circuits extend, each consisting of three
wires, to the system of intersecting and con-
nected positive and negative and compensat-
30 ing main conductors, in connection with which
the lamps or other translating devices of the
system are arranged in multiple series, as is
now well understood. By our invention we
do away with the central wire of each feeding-
35 circuit, thus diminishing the metal required
for the feeding-circuits by one-third. This is
a very great saving in the cost of a system, the
feeding-conductors being usually of very heavy
40
wire.
In carrying our invention into effect we em-
ploy only two wires for each feeding-circuit,
extending each from one of the omnibus wires
to a positive or negative main or lighting con-
ductor, while at some convenient point, which
45 will usually be that at which the lighting-con-
ductors approach most nearly to the omnibus
wires, a wire heavy enough to carry the whole
current of the largest generator of the system
extends from the central omnibus wire or di-
A is the central-station building.
P, N, and C are respectively the positive,
negative, and compensating omnibus wires, 80
with which the terminals and central connect-
ing-wire of the series of generators or groups
thereof (not shown) are connected.
P'N' are feeding-circuits, each consisting of
a positive and a negative oonductor extend- 85
ing from the positive and negative omnibus
wires.
P2 N2 C² represent the system of lighting-
wires, which extend throughout the district,
and are connected, positive to positive, nega- 90
tive to negative, and compensating to com-
pensating at the points where they intersect.
With these lighting-wires, or with house-cir-
cuits extending therefrom, the electric lamps
or other translating devices a a are connected 95
in multiple series.
Heretofore, as above explained, each feed-
ing-circuit has comprised a third or compen-
2971
2
318,157
|
65
sating-wire extending from C to a conductor, two wires. It is evident that this will result
C²; but this is done away with in our system. in the saving of a certain amount of metal.
In Fig. 1, p n c is a derived circuit from a This modification is illustrated in Fig. 3, in 6ɔ
convenient point of P² N² C², extending into which there are six feeding-circuits, P' N' P³
5 the central station and supplying lamps a for N3 P N', &c. The circuits P' N' and P N³
lighting the building. The center wire, c, of have each a third wire or compensating-con-
this circuit is of such size as to be adapted to ductor, C' or C³, while the remaining feeding-
carry the whole current of the largest genera- circuits have no such conductors.
tor of the system, if necessary, and is connected What we claim is-
IO with conductor C, or, in other words, to the
point of division of the source of supply, and
it thus forms the compensating-wire, which
maintains the balance of the system for all the
feeders, the current flowing in one direction
15 or the other in it, according to the changes
in the number of lamps in circuit on the two
sides of the system.
1. In a compensating system of electrical
distribution, the combination, with two or
more feeding-circuits, of a single compensat-
ing-conductor for both or all of them, substan- 70
tially as set forth.
2. In a compensating system of electrical
distribution, the combination of the lighting-
circuits consisting of positive, negative, and
compensating conductors, the two or more 75
feeding-circuits, each consisting of a positive
and a negative conductor, and a single con-
ductor extending from a compensating-con-
ductor of the lighting-circuits to the point of
division of the source of supply, substantially 80
as set forth.
In practice, in the ordinary use of the sys-
tem, very little current will flow in this con-
20 ductor, the balance being usually nearly main-
tained. It is preferred, however, to make this
conductor large enough to convey the current
of the largest generator, for it may be used as
the return-conductor of the system should all
25 the generators but one become inoperative, in 3. In a compensating system of electrical
which case the positive and negative conduct-distribution, the combination of the lighting-
ors of each feeder are connected together to circuits consisting of positive, negative, and
form one conductor, while the compensating compensating conductors, the two or more 85
feeding-conductor is the other, as set forth in feeding-circuits, each consisting of a positive
30 the application of the said William S. An- and a negative conductor, and a derived cir-
drews, Serial No. 146, 894.
cuit from said lighting-conductors, consisting
of positive and negative conductors, between
which electric lamps are connected in multi- 90
ple series, and a compensating-conductor con-
nected at the point of division of the source of
supply, substantially as set forth.
In Fig. 2 a system similar to that of Fig. 1
is shown, in which a line of lighting-conduct-
ors, P2 N2 C², runs close to the central station,
P² N²
35 being represented as passing through the cu-
pola of the building. In this case all that is
required is the large conductor p', extending
from C to C, which wire then forms the sin-
gle compensating-conductor for all the feed-
40 ing-circuits.
It is evident that our invention is equally
applicable whether the conductors of the sys-
tem are run overhead or underground, and
also that the same may be readily applied to
45 systems already in operation by removing the
center wire of each feeder and providing the
single short connecting-wire without chang-
ing the balance of the system or altering ex-
isting determinations. Thus a saving of one-
50 third on the feeders is effected, the extra wire
required being so short as to be of little con-
sequence.
A portion of the advantages of our inven-
tion may be obtained by employing, in con-
55 nection with one or two or more of the feed-
ing-circuits, a compensating-conductor, while
the feeding circuits remaining consist each of
4. In a compensating system of electrical
distribution, the combination of the lighting- 95
circuits consisting of positive, negative, and
compensating conductors, the two or more
feeding-circuits, each consisting of a positive
and a negative conductor, and a conductor ex-
tending from a compensating-conductor of the Ico
lighting-circuits to the point of division of the
source of supply, said conductor being of suf-
ficient size to convey the current of the larg-
est generator of the system, substantially as set
forth.
WILLIAM S. ANDREWS.
THOMAS SPENCER.
Witnesses as to Andrews:
GEO. H. BLISS,
F. H. WHITING.
Witnesses as to Spencer:
J. C. HILL,
P. B. SHAW.
ICO
2972
(No Model.)
M. WADDELL.
2 Sheets-Sheet 1.
SYSTEM OF ELECTRIC DISTRIBUTION.
Patented Dec. 6, 1887.
No. 374,381.
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M. WADDELL.
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SYSTEM OF ELECTRIC DISTRIBUTION.
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INVENTOR
Caddell
Bar Threy
2974
:
UNITED STATES PATENT OFFICE.
5
MONTGOMERY WADDELL, OF NEW YORK, N. Y.
SYSTEM OF ELECTRIC DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 374,381, dated December 6, 1887.
Application filed July 2, 1887. Serial No. 243,219. (No model.)
To all whom it may concern:
Be it known that I, MONTGOMERY WAD-
DELL, a subject of the Queen of Great Brit-
ain, residing at New York, in the county and
State of New York, have invented a certain
new and useful Improvement in Systems of
Electrical Distribution, of which the following
is a specification.
My invention relates to the Edison system
to of electric lighting in which several dynamo-
electric machines are connected to common or
omnibus conductors at the central station, from
which feeding circuits extend to a system of
intersecting and connected main or lighting
15 conductors from which the house-circuits sup-
plying lamps in multiple arc are derived.
nected, one at a time, to determine in what
part of the system is the leak or other fault.
My invention is illustrated in the accompa· 55
nying drawings, in which-
Figure 1 is a diagram of the conductors at
a central station according to my invention,
and Fig. 2 a diagram of the same system di-
vided by the manipulation of the switches.
The full lines represent an arrangement of
conductors in a three-wire Elison central sta-
tion.
60
A, A', and A² represent each a pair or set
of dynamo-electric machines, which forms a 65
divided source having positive, negative, and
neutral terminals, as indicated, from which ex-
tend, respectively, the positive, negative, and
The invention is applicable to either the neutral or compensating dynamo- conductors
three-wire multiple - series system or a two-p, n, and c. While each dynamo has three 70
wire multiple arc system, or to any system
20 employing omnibus conductors.
In systems such as thus generally described
difficulty sometimes arises from the occurring
of leaks, crosses, or ground-connections in va-
rious conductors, which it is necessary to lo-
25 cate and repair, as otherwise they may injure
the system by blowing out the safety-catches,
or by the waste of current due to leakage to
the earth between the different sides of the
system. In order to locate and repair a leak,
30 it has been necessary to sever the connections
of conductors in that part of the system where-
by the supply of current to the translating de-
vices is interrupted.
The object of my invention is to enable such
35 faults in the system to be more readily located
and to diminish the liability of injury to the
system thereby.
To this end iny invention consists, mainly, in
providing at the central station a duplicate or
40 supplementary set of omnibus conductors and
suitable switches, whereby any one or more
feeding-circuits can be readily connected to
the supplementary set, instead of to the regu-
lar set, and any one or more of the dynamo-
45 circuits may also be so connected, whereby the
system may be divided and any part in which
a fault occurs may be run from a separate dy-
namo or section of dynamos from the rest of
the system, so that the current of the whole
50 system will not be affected and the safety-
fuses of all the conductors will not be endan-
gered, and the feeders may be readily discon-
conductors extending from it, the positive of
one and the negative of the other are not nor-
mally in use, so that the two are in series and
form together a unit of the source of supply.
·
P, N, and C are the omnibus conductors, 75 ·
which are of copper, and each of which is made
in two parts, joined by a cross-connection, in
each of which cross connections is interposed
an amperometer, a, whereby the whole cur-
rent on the omnibus wires is indicated. The 80
dynamo-conductors are arranged to be con-
nected with the omnibus wires through plug-
switches at b b, or any other suitable switches.
The positive, negative, and compensating con-
ductors p', n', and c' of the feeding-circuits ex- 85
tend from the like conductors of the omnibus
system, plug-switches & or other switches be-
ing provided for connecting and disconnecting
them.
•
The supplementary set of omnibus wires P', 90
N', and Care shown in dotted lines. They
are arranged similarly to the regular set, being
each in two parts joined by cross-conductors,
including ampère-indicators a' a'. Plugs or
other switches are provided at b'b' for the 95
dynamo-conductors, and at d' d' for the feed-
ing-conductors, whereby these may be con-
nected to the supplementary set instead of to
the regular set. By this means—that is, by
withdrawing some plugs and inserting others- 100
any feeding circuit or circuits may be fed from
any dynamo or dynamos, and thus a part of
the system in which a leak occurs may be dis-
connected from the rest of the system, and the
1
2975
2
374,381
rest of the system will therefore not be affected
by such fault.
Fig. 1 shows all the central-station circuits,
but with no connections made, or, if all the
5 plugs are supposed to be in, with the system
running normally, I may have all the plugs
of both sets in when running normally, so that
the supplementary conductors will assist the
others to carry the whole current. It is there-
IO fore unnecessary to increase the whole amount
of copper required for the omnibus wires in
order to practice my invention.
Fig. 2 shows the system divided, and if the
proper disconnections have been made in the
15 outside or lighting system there will be no
electrical connection between the two parts or
sub-systems. It can then be easily determined
in which sub-system the fault has arisen. Or
the figure may indicate a case in which it is
25 desired to run two feeders for a time independ-
ently of the rest of the system-for instance,
if there are two grounds on the system and
they have been separated one onto each sub-
system. It will be seen that the plugs are
25 so placed that generators A are supplying
feeders Nos. 1 and 4 while generators A' and
A' are supplying feeders Nos. 2, 3, and 6,
feeder No. 5 not being in use at present. This
feeder may be connected to either omnibus
30 system by the insertion of the right plugs at
dor d', and any feeder or any dynamo may be
changed from one part of the system to the
other in the same way. The amperometers
a a and a' a' show what current is being taken
35 by each sub system, and the feeder-indicators
show the current taken by each individual
feeder.
2
The system may be divided without any
change in the steadiness of the currents flow
40 ing, in the following way: If the system is run-
ning normally, and it is desired to have one
pair of dynamos supply two feeders separately,
insert the plugs d'd of those feeders and the
plugs b'b' of that dynamo pair, (if these are not |
45 already in,) and then withdraw the plugs d d
of the feeder circuits. Then increase or de-
crease the current on the positive side of the
pair of dynamos until it equals the sum of the
currents on the positive sides of the two feed-
50 ers to be supplied, and then withdraw the posi-
tive plugs b of the dynamo. Do the same with
the negative currents and draw the negative
plugs of the dynamo. Since when the plugs
were removed there was no difference of po-
55 tential thereat, there will be no variation of
current. The system may thus be separated,
throwing off one section after another until one
that is faulty is found, and this one can be run
by itself and not affect the rest of the system.
Instead of one set of supplementary con- 6ɔ
ductors I may have two or more sets, whereby
the system may be further subdivided. Ordi
narily, however, the duplication of the con-
ductors will be sufficient.
While I have shown my invention in con- 65
nection with a three-wire system, it is evi-
dently adapted as well to a two-wire multiple-
arc system.
What I claim is--
1. In a system of electrical distribution, the 70
combination of two or more generators, omni-
bus conductors to which such generators are
separately connected, feeding circuits extend-
ing from said omnibus conductors, a supple.
mentary set of omnibus conductors, and 75
switches for connecting each feeding-circuit
with either the main set or the supplementary
set of omnibus conductors, substantially as
set forth.
2. In a system of electrical distribution, the 80
combination of two or more generators, omni-
bus conductors to which such generators are
separately connected, feeding circuits extend-
ing from said omnibus conductors, a supple-
mentary set of omnibus conductors, and 85
switches for connecting each generator-circuit
with either the main set or the supplementary
set of omnibus conductors, substantially as set
forth.
3. In a system of electrical distribution, the 90
combination of two or more generators, omni-
bus conductors to which such generators are
separately connected, feeding circuits extend-
ing from said omnibus conductors, a supple-
mentary set of omnibus conductors, switches 95
for connecting each feeding-circuit with either
the main set or the supplementary set of om-
nibus conductors, and switches for connecting
each generator-circuit with either the main
set or the supplementary set of omnibus con- 100
ductors, substantially as set forth.
4. In a system of electrical distribution, the
combination of the ordinary omnibus con-
ductors and the supplementary omnibus con-
ductors, each conductor of each set being di-
vided into two parts, and such parts being
connected through ampère indicators, sub-
stantially as set forth.
·
This specification signed and witnessed this
28th day of June, 1887.
MONTGOMERY WADDELL.
Witnesses:
FRED JOHNSON,
E. E. WINTERS.
(No Model.)
No. 398,121.
B
S. BERGMANN.
EQUALIZER FOR ELECTRIC CURRENTS.
Patented Feb. 19, 1889.
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Signed Bergmanns
By his Attorneys
Gifford Mrown
2977
UNITED STATES PATENT OFFICE.
SIGMUND BERGMANN, OF NEW YORK, N. Y.
EQUALIZER FOR ELECTRIC CURRENTS.
SPECIFICATION forming part of Letters Patent No. 398,121, dated February 19, 1889.
Application filed November 10, 1888. Serial No. 290,447. (No model.)
To all whom it may concern:
Be it known that I, SIGMUND BERGMANN, of
New York, in the county and State of New
York, have invented a certain new and useful
5 Improvement in Equalizers for Electric Cur-
rents, of which the following is a specification.
In the accompanying drawings, Figure 1 is
an end view of my invention. Fig. 2 is a plan
or top view thereof, showing the coil-connec-
To tions. Fig. 3 is a detail in section showing the
transverse strips engaging the insulators. Fig.
4 shows a modification of the end castings or
plates in which the coil ends are projected
through insulators seated in openings in said
15 plate. Fig. 5 is a transverse section of the
same, and Fig. 6 is a sectional detail showing
an insulator extended through an opening in
the plate.
This invention has relation to improvements
20 in equalizers for electric-light currents; and
it consists in the construction and novel com-
bination of parts, as hereinafter set forth, and
pointed out in the appended claims.
It is found necessary in central-station work
25 to have the ends of the various feeders at the
same potential when the full load on the re-
sistance is the same and having consequently
the same drop; but when the load on the dif- |
ferent feeders rises it is necessary to throw
30 in circuit an artificial resistance to compen-
sate for the difference of resistance caused by
a varying load in the feeder. The function of
the equalizer is to dissipate the additional en-
ergy caused by the drop of potential in this
35 resistance in order to equalize the potential
in the feeder. Heretofore these equalizers
have been placed in or provided with wooden
frames, which is found objectionable, inas-
much as they are so readily ignited and burned,
40 endangering both life and property.
45
50
The object of the present invention is to
provide a metal frame or casing for the resist-
ance-coils of the equalizer, which are prefer-
ably insulated at their points of support.
In the wooden frames the degree of heat
withstood is 300° Fahrenheit, and in the metal
frame herein described the degree of heat may
be increased to any practical degree less than
that required to melt the metal.
A further object is to economize in space.
An equalizer of the ordinary construction to
carry one hundred ampères with twenty-volts
drop requires a frame twenty-four feet by
twenty-four feet in cross-section by sixty feet
in length, whereas in my improved frame the 55
same energy can be dissipated in a space of
eighteen feet by eighteen feet in cross-section
and twenty-four feet in length, thus using less
resistance-wire.
In the wooden frames the coils are usually 60
connected by means of soft solder, as the low
temperature made necessary by the use of
wood never endangers or melts the connec-
tions. However, in the present instance, where
a great degree of heat is expended, it is found 65
necessary to connect the ends of the wires by
brazing.
Referring by letter to the drawings, A des-
ignates a metal frame comprising the up-
rights B, which are preferably tubular, and 70
the top and bottom castings C, having thread-
ed openings to receive the threaded ends of
the uprights, or the said parts may be other-
wise secured together without departing from
the spirit of my invention.
75
The uprights B are preferably hollow or
tubular, as by this construction the weight of
the whole construction is greatly diminished
and the strength of said uprights is increased.
The resistance-coils D have their ends pro- 80
jected through openings in the transverse
metal strips E, and the said ends are prefer-
ably connected in their proper relations by
brazing, as the degree of heat possible would
destroy the solder connections heretofore em- 85
ployed.
The transverse strips E may have openings
near their ends to engage a projection, a, on
the insulators F, which are preferably seated
in depressions a' in the end plates, as plainly 90
shown in Fig. 3. These insulators F are pref-
erably of an incombustible material-such, for
instance, as porcelain, glass, or like material.
A disk or washer, b, of asbestus or similar
flexible non-combustible material, may be 95
placed around the projections of the insulator
beneath the lower face of the transverse strip
E, so that the said insulators will not be en-
dangered by any sudden shock received by the
frame.
In Figs. 4 and 5 I have shown the end cast-
ings as made in plate form, with the insula-
tors F seated in depressions therein, and in
Fig. 6 I have shown the insulators as having
100
2978
29
398,121
IO
diverging sides, or in the form of a cone-frus- | lators in said openings receiving the ends of
tum and extended through suitable openings the coils, substantially as specified..
in the plate. In the examples last described
the insulators are perforated at b' for the pas-
5 sage of the coil ends.
It is to be understood that the formation of
the frame may be varied to suit the require-
ments, as I only confine myself herein to an
iron or other metal frame.
Having described my invention, what I
claim is-
3. In an equalizer for electric currents, the 25
combination, with the resistance-coils and the
metal frame, of the transverse metal strips,
the insulators between said strips and the
frame, and disks of flexible material inter-
posed between the insulators and the trans- 30
verse strips, substantially as specified.
4. In an electrical equalizer, the combina-
tion, with the coils and the metal frame, of the
transverse strips having the openings, the in-
sulators between the strips and the frame hav- 35
ing the projection, and the flexible washer sur-
rounding said projection below the lower face
of the transverse strips, substantially as speci-
1. In an equalizer for electric currents, the
combination, with the coils, of the metal frame
comprising the uprights having the threaded
15 ends, the end castings or plates having thread-
ed openings engaging the uprights, and the
insulators in said end castings or plates, sub-fied.
stantially as specified.
2. In an equalizer for electric currents, the
20 combination, with the coils, of the metal up-
rights, the metal end plates secured thereto
having the openings, and the perforated insu-
Witnesses:
SIGMUND BERGMANN.
P. H. KLEIN, Jr.,
JNO. F. GEIDEL.
2979
(No Model.)
J. W. HOWELL.
2 Sheets-Sheet -1.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 16, 1886.
No. 352,691.
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John
John W. Namese
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attr
2980
(No Model.)
No. 352,691.
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J. W. HOWELL.
2 Sheets-Sheet 2.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 16, 1886.
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مثال
N. PETERS, Photo-Lithographor, Washington, D. C.
1
2981
UNITED STATES PATENT OFFICE.
JOHN W. HOWELL, OF NEW BRUNSWICK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 352,691, dated November 16, 1886,
Application filed April 15, 1886. Serial No. 198,891. (No model.)
To all whom it may concern:
In the accompanying drawings, forming a
Be it known that I, JOHN W. HOWELL, of part hereof, Figure 1 is a view in diagram illus-
New Brunswick, in the county of Middlesex trating the principle of the invention; Fig. 2,
and State of New Jersey, have invented a cer- a similar view, showing the application of the 55
5 tain new and useful Improvement in Systems invention for indication to a two-wire multi-
of Electrical Distribution, of which the follow-ple-arc system of electrical distribution; Fig.
ing is a specification.
3, a similar view, showing the invention ap-
plied for indication to a three-wire or compen-
sating system of distribution; Fig. 4, a simi- 60
lar view, showing the preferred arrangement of
the indicators in a system station; Fig. 5, a
view, partly in diagram, of a modified form of
comparative indicator; Fig. 6, a view, partly
in diagram, illustrating the invention applied 65
for automatic regulation.
My invention relates to a novel method and
apparatus for indicating or regulating the
10 pressure of electrical circuits, and especially
those in a system of electrical distribution, by
which I am enabled to use instruments of very
much simpler construction than those now in
use, and which instruments will not be liable
15 to get out of adjustment.
In explanation of the principle involved in
the invention, reference may be had to the sim-
ple illustration, Fig. 1. Consider that it is de-
s:red to maintain at the same constant the press. 70
ure in the circuits 1 2 and 3 4, and that 1 2
is provided with an absolute indicator of any
known form, which shows the difference of po-
tential between 1 and 2.
In the installation of distributing systems it
is considered essential to keep the pressure
the same at several points in the system, these
points being the ends of the feeders where they
20 join the distributing-mains. In order to keep
the pressure at these points the same, press-
ure-wires are run back from them to the sta- |
tion, and indicators are connected with these
wires, which show the pressure, and enable
To show whether or not the pressure at 3 4 75
25 the feeders to be properly adjusted to correct is the same as at 1 2, I produce an electrical
the pressure at their outer ends. The indica- comparison of the pressures of the two circuits
tors heretofore employed have been absolute by connecting the positive conductors 1 and 3 of
instruments—that is, each is connected di- the two circuits together by a bridge-wire, 5,
rectly to the two wires whose difference of po- and the negative conductors 2 and 4 by a simi- 80
30 tential is to be kept constant-and the elec- lar bridge-wire, 6. In these two bridge-wires
tromotive force of the lines is applied directly is located a comparative instrument, A. This
to the indicator, which indicates directly the is a differentially-wound .instrument, so that
pressure at that point, so that an absolute equal currents flowing in the same direction
measure of the pressure at each of these points across the bridge-wires will neutralize each 85
35 is had, and each of the indicators which meas- other, and currents flowing in opposite direc-
ures this pressure must be kept in accurate tions across the bridge wires will act together
adjustment independently of all the others. in producing movement of the instrument.
These indicators are liable to get out of adjust- This instrument A may be a high-resistance
ment at any time and cause a wrong pressure differential galvanometer, with one coil in 90
40 to be kept at one or more feeders. In the sys-bridge-wire 5 and the other coil in bridge-wire
tem invented by me these absolute indicators 6. It is shown as a differential galvanometer
are used at one point in the system only, and by conventional illustration in all the figures,
the pressure at all the other points is measured except Fig. 5. Suppose the potentials at 1 2
by comparing it electrically with the pressure to be represented by 200 on the positive con- 95
45 at this point-that is to say, electrical forces ductor 1, and by 100 on the negative conductor
derived from two points are made to have a 2, and that the difference in potential 100 is
cumulative or differential action upon an in- the pressure it is desired to maintain constant
strument whose movement is the resultant of in both circuits. If the potentials are the
such forces. The same principle can also be same at 3 4, no current flows through the gal- 100
50 applied for automatic regulation as well as in- vanometer and the needle remains at zero.
dication.
at 3 4 there are potentials represented by 202
|
If
2982
2
352,691
and 102, then in each bridge-wire and on each
coil of galvanometer there is a current caused
by a difference of potential of 2. As in each
bridge-wire this flows from circuit 3 4 to 1 2,
5 the currents neutralize each other, and there
is no deflection. This is a correct indication,
since the difference of potential at 3 4 is still
100. If at 3 4 there are potentials represented
by 202 and 101, the currents in the galvanom-
10 eter-coils will be in the same direction as be-
fore; but one being caused by 2 units and the
other by 4 units, a deflection will be produced
by the larger current, as it should be, since
the difference of potential is 98 and not 100.
If at 3 4 we have 202 and 98, one coil of gal-
vanometer will carry a current from circuit
3.4 to circuit 12, and one from 1 2 to 3 4, and
these currents will act together on the needle
and produce a deflection, as they should, show-
20 ind the difference of potential as being 104.
15
The circuit 1 2 will be regulated by reference
to its absolute indicator, while circuit 3 4, and
as many other circuits as may be connected
with 1 2 in the same manner, will be regulated
25 by reference to their respective instruments
A; or these instruments can be utilized to ef-
fect the regulation automatically, as will be
presently explained.
|
•
comparison of the potentials on the neutral
wires of the two or more feeders. This is
done by simply breaking the bridge wires con- 7c
necting positive conductors, as well as those
connecting negative conductors, leaving the
bridge-wires between neutral conductors alone
in connection with the instruments. The com-
parative indicators then act as simple gal- 75
vanometers, and show the differences in poten-
tial between the neutral conductors. Since
the flow of current on neutral conductors in-
dicates an unbalanced system, the comparative
indicators enable the fault to be located and 80
remedied.
I prefer, for a distributing system, to provide
a standard pressure by a local station-circuit
directly from the dynamos in station or the
omnibus wires 13 14, into which they feed, and 85
to compare the pressures at ends of feeders with
this standard pressure. This is shown applied
to a two-wire system in Fig. 4. The applica-
tiou to a three-wire system will take double
the number of instruments, (the same number ço
for each side or division of the circuit,) as will
be understood from Fig. 3.
With reference to Fig. 4, an incandescent
electric lamp, A', forming a fixed resistance, is
connected with omnibus wires 13 14 in station, 95
and has an adjustable resistance, R', in series
with it.
with it. An absolute indicator, E, is con-
nected in multiple arc with the lamp A', and
by adjusting R' with reference to E the lamp
can be kept at a candle power giving the dif- 100
ference in potential between the lamp termi-
nals that it is desired for outer ends of feed-
ers. The bridge-wires, with their comparative
indicators, are connected between the feeder
pressure-wires and wires 15 16, running from 105
the terminals of this lamp A'.
In Fig. 2 the application of the invention
30 for indication upon a two-wire system of dis-
tribution is shown. The street-mains are illus-
trated by 7 8. From the street - mains at
points B, C, and D, are taken feeders 9 10, sup-
plying current to the mains from the central
35 station, and corresponding with the feeders
are pressure-wires 11 12, running from points
B, C, and D on mains back to the station. The
feeders will have adjustable resistances R for
regulation. Hand-adjusted resistances for this
40 purpose are shown in Fig. 4, and an auto- This invention, it will thus be seen, reduces
matically-adjusted resistance is shown in Fig.6. the number of absolute indicators to one in a
To the pressure-wires from B is connected multiple-arc system, and to two in a three-wire
the absolute indicator E. This may be the system the pressure at all other points being 110
lamp-indicator shown in my Patent No.339,058, shown on differential galvanometers, which,
45 or any other suitable indicator. Bridge-wires arranged for this purpose, I call "comparative"
5 6 connect an extra set of pressure-wires, 17 indicators. Central stations, as at present
18, from B with those from C and D, and in erected on the Edison system, use from eight to
these bridge-wires are located the differential twelve indicators. Each of these is an abso- 115
galvanometers A. Thus indications will be lute indicator, and has to be kept in adjust-
50 had for regulating the three feeders to keep ment independently of the others. This re-
the desired pressure at the points B, C, and D. quires a great deal of attention and time, and
For a three-wire system, Fig. 3, the press- if the instruments are not kept in adjustment
ure at B, between positive and neutral and they will give wrong indications. The com- 12c
between neutral and negative, is shown upon parative indicators, however, require no ad-
55 two absolute indicators, E, while four com-justment after being once set up; and as it is
parative indicators, A, show whether or not only necessary to keep one or two absolute in-
the pressure at C and D is the same as at B. Indicators in adjustment, it or they will receive
this figure, for clearness of illustration, the
bridge-wires for comparative indicators are
60 shown as connected with the same pressure-
wires from point B, as are the absolute indica-
tors.
The comparative indicators have a particu-
lar advantage in connection with a three-wire
65 system of distribution, since they enable it to
be determined whether current is flowing over
the neutral wire of any feeder by a direct
|
more attention and the regulation will be im- 125
proved. The comparative indicators, also, can
be made for much less money than absolute
indicators, and where ten or twelve are used
this makes a large saving.
Instead of a differential galvanometer, I can 130
use a differentially-wound polarized relay, F,
Fig. 5, which will close one of two circuits
and light one of two lamps, ab, when the press-
ure is different from that at the absolute indi-
2983
352,691
cator. In these galvanometers or relays the
resistance of each coil must be, as will be well
understood, large enough, when compared with
the resistance of the pressure-wires, to bring
5 the difference of potentials to the instrument
and not have any noticeable loss on the press-
ure-wires.
The differential galvanometer or polarized
relay may be arranged to close one of two cir-
Io cuits when moved from the normal position,
and thus control and cause to operate in one
direction or the other any suitable interme-
diate mechanism, G, Fig. 6, which will throw
into and out of circuit an adjustable resistance,
15 R, and in this manner the resistance of a feeder
and the pressure at its outer end may be regu-
lated automatically.
In Fig. 6 the arm of differential galvanometer
is shown connected constantly with one mer-
20 cury-trough, c, and standing normally between
two others, de, and in this way, by the con-
nections shown, controlling two circuits to in-
termediate resistance adjusting mechanism, G,
which is a well-understood apparatus.
25
What I claim is-
1. The method of producing movement for
the indication or regulation of pressure for
two or more electrical circuits, consisting in
effecting such movement for one circuit di-
30 rectly by the pressure thereat, and effecting
such movement for the other circuits by mov-
ing instruments by the resultant of electrical
forces acting cumulatively or differentially
thereon, such forces being derived from the
35 standard circuit and from such other circuits,
substantially as set forth.
|
tribution and the feeders leading thereto, of
one or more absolute pressure-indicators con-
nected with the conductors of the system, and
one or more comparative pressure indicators,
each acted upon differentially or cumulatively 60
by electrical forces derived from two points of
the system, substantially as set forth.
5. The combination, with the connected
main conductors of a system of electrical dis-
tribution and the feeders and pressure-wires 65
thereto, of one or two absolute pressure-indi-
cators connected with the conductors of the
system, and comparative pressure-indicators
connected in bridges between feeder pressure-
wires and the circuit or circuits provided with 70
the absolute instrument, substantially as set
forth.
6. The combination, with the connected
main conductors of a system of electrical dis-
tribution and the feeder and pressure-wires 75
thereto, of a local station-circuit provided
with an absolute pressure-indicator, and regu-
lating devices and comparative pressure-indi-
cators connected in bridges between the feeder
pressure-wires and this local station-circuit, 80
substantially as set forth.
7. The combination, with the connected
main conductors of a system of electrical dis-
tribution and the feeders and pressure wires
thereto, of a local station-circuit provided 85
with a fixed and an adjustable resistance, an
absolute indicator showing pressure across ter-
minals of fixed resistance, and comparative
indicators connected by bridge-wires between
pressure-wires and the terminals of said fixed 90
resistance, substantially as set forth.
8. The combination, with a standard cir-
cuit, of two or more comparative pressure-in-
dicators connected with the same pressure-
wires from such standard circuit, substantially 95
as set forth.
2. The combination of two or more electrical
circuits, an absolute indicator of pressure con-
nected directly with one circuit, and a com-
40 parative pressure-indicator for each of the one
or more other circuits acted upon differentially
or cumulatively by electrical forces derived 9. The combination, with a standard cir-
from the first circuit and one of the other circuit, of two or more comparative pressure-in-
cuits, substantially as set forth.
dicators connected with the same pressure-
wires from such standard circuit, and sepa- 1ỏɔ
rate wires from the standard circuit including
one or more absolute pressure-indicators, sub-
stantially as set forth.
15
3. The combination, with two electrical cir-
"uits, of two bridge-wires connecting conduct-
rs of like polarity of such circuits and a dif
ferentially-wound indicating or regulating in-
strument located in such bridge-wires, for ef-
50 fecting movement for indication or regulation
by an electrical comparison between the press-
ures of the two circuits, substantially as set
forth.
4. The combination, with the connected
55 main conductors of a system of electrical dis-
This specification signed and witnessed this
8th day of April, 1886.
Witnesses:
JOHN W. HOWELL.
WM. J. LATUS,
C. A. GUNDAKER.
2984
(No Model.)
No. 342,748.
J. W. HOWELL.
SYSTEM OF ELECTRICAL DISTRIBUTION.
2 Sheets-Sheet 1.
Patented May 25, 1886.
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SYSTEM OF ELECTRICAL DISTRIBUTION.
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Patented May 25, 1886.
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Rowland
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THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
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INVENTOR
John W. Namele
By Dy
2986
UNITED STATES PATENT OFFICE.
JOHN W. HOWELL, OF NEW BRUNSWICK, NEW JERSEY.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 342,748, dated May 25, 1886.
Application filed March 12, 1886. Serial No. 194,971. (No model.)
To all whom it may concern:
Be it known that I, JOHN W. HOWELL, of
New Brunswick, in the county of Middlesex
and State of New Jersey, have invented a cer-
5 tain new and useful Improvement in Systems
of Electrical Distribution, of which the fol-
lowing is a specification.
15
•
in several strands repairs can be made with.
out removing the whole feeder from use, as each
strand can be operated upon by itself. For 55
overhead or pole lines, the wires may be either
bare or insulated, and they are preferably run
separately upon the poles. Thus the running
of the very large and heavy wires sometimes
required for feeding-conductors is done away 60
with. The small wires can be drawn much
tighter and straighter than the large ones, and
a line of better appearance is thereby pro-
duced, and the labor of putting up the small
wires is much less. In an underground sys- 65
tem of conductors the strands, first carefully
insulated, are grouped together in cables.
These cables may be made of any desired
length in one continuous, cable without a joint,
and can be laid as one piece, obviating the 70
necessity of a joint every few feet, as in the
Edison system. This saves labor and expense
in laying and prevents the trouble now expe-
rienced from leakages and grounds at the
joints. All the strands forming both conduct- 75
ors of a feeder may be placed in one cable, or
those forming the positive conductor put in
one cable, and those forming the negative con-
ductor put in a separate cable. In a three-
wire or compensating system I prefer to make 80
only the positive and negative wires in strands,
while the middle or compensating conductor,
which does not have to be regulated, is a sin-
In the Edison system of electrical distribu-
tion, as is now well known, the generators at
to the central station are all connected to com-
mon or "omnibus" wires within the station,
from which a suitable number of feeding-cir-
cnits extend to the centers of distribution of
the district supplied, where they are connected
with the main or lighting conductors, from
which the house-circuits are derived. In such
a system it is necessary to provide means for
regulating the current carried by each feeder
so as to maintain the same pressure at all the
20 centers of distribution, whereby all the lamps
throughout the system will be kept at the same
candle-power. Heretofore there has been used
for this purpose an adjustable resistance in
each feeding-circuit. Such resistances are
25 bulky and expensive, being necessarily com-
posed of a large number of coils of heavy wire.
The main object of my invention is to do
away with such resistances, and thereby gain
in space and in economy, and simplify the op-
30 eration of regulating the feeders. I accomplish
this by making each feeding-conductor consist
of a suitable number of separate strands, in-gle wire of the proper size. Where cables are
sulated from one another, the total conduct-
ing capacity being that desired for the feeder.
35 The strands are all connected at the same point
to the omnibus conductor, and at the same point
to the main or lighting conductors. A switch
or switches are provided for each conductor
at the station, whereby any desired number of
40 the strands may be placed in or out of circuit,
and the current of the feeder thereby increased
or diminished.
Another feature of my invention is the plac-
ing of a safety-catch or fusible length of wire
45 in each strand of each feeding conductor.
Preferably I place two safety-catches in each
strand, one near the junction with the omni-
bus wire, the other near the junction with the
main conductor. Thus, if a cross or short cir-
50 cuit occurs, the safety-catch of only one strand
will be burned out and the feeder therefore
will not be destroyed. By making each feeder
used, the central wire of each cable is prefer- 85
ably used as the compensating-conductor.
I usually prefer to make each conductor of
from five to ten strands, though the number
of strands will be, of course, governed by the
circumstances of each case.
90
In the annexed drawings, Figure 1 is a dia-
gram of a system embodying my invention;
Fig. 2, a view showing the preferred arrange-
ment of a feeding-conductor at the central sta-
tion; Fig. 3, a view of another arrangement 95
thereof; Fig. 4 a diagram illustrating the
manner of connecting the compensating-con-
ductor in an underground system; and Fig. 5,
a section of the cables employed in such sys-
tem.
Referring first to Figs. 1, 2, and 3, P, N,
and C are respectively the positive, negative,
and compensating omnibus wires at the cen
tral station, to which the generators (not
100
2987
2
342,748
shown) are connected. P', N', and C are main
or lighting conductors. Each positive feed-
ing-conductor is composed of several separate
strands, p p, and each negative feeding-con-
5 ductor of a number of strands, n n. c care
the compensating feeding-conductors. A is a
switch for placing the strands in and out of
circuit. One of these switches is provided for
each conductor of each feeding-circuit, so that
10 the two sides of a feeder may be kept alike.
The switch consists of a suitable number of
contact-blocks, a a, to each of which a wire, p,
(or n,) is connected, and a long block, b, from
which a wire, B, large enough to carry this
15 whole feeder-current, goes to the omnibus wire..
D is a pivoted contact-arm, whose end d is
wide enough to bridge all the blocks a and
whose other end, e, travels upon long block b.
Arm D may be provided with a hand-wheel,
20 f, (shown by dotted line,) for turning it. It
will be seen that when arm D is turned more
or less of the strands of the feeding-conductor
are connected with the omnibus wire. Suffi-
cient space is left between blocks a and block
25 b to permit the circuit to be broken by throw-
ing arm D off from all the blocks. On the
same base as the switch, or in any other con-
venient location, are placed safety-catches gg,
one for each strand of the conductor. Near
30 the junction of each strand with the main con-
ductor is placed a safety-catch, g'.
•
In Fig. 3 is shown a separate switch for each
strand. Plug-switches h h are shown; but it
is evident that any other suitable form of
35 switch may be employed.
In Figs. 4 and 5, P represents a positive ca
ble, and N a negative one. The switches,
safety-catches, and connections of the sepa-
rately-insulated wires of the cables are the
40 same as those already described. The central
wires, f, of each cable are connected together
near each end of the feeder, and connected to
the compensating omnibus wire and to the
|
·
compensating lighting conductor, the two
wires ff thus forming together the compen- 45
sating feeding-conductor.
What I claim is—
1. In a system of electrical distribution, a
feeding-conductor composed of two or more
strands or wires insulated from one another, 50
in combination with means for placing a great-
er or less number of such strands in circuit,
substantially as set forth.
2. In a system of electrical distribution, the
positive and negative conductors of a feeding- 55
circuit, each composed of two or more strands
or wires insulated from one another, in com.
bination with means in connection with each
conductor for placing a greater or less num-
ber of its strands in circuit, substantially as 60
set forth.
3. In a system of electrical distribution, a
feeding-conductor composed of two or more
separate strands insulated from one another,
in combination with one or more safety-catches 55
in each strand, substantially as set forth.
4. In a system of electrical distribution, the
combination, with a feeding-conductor com-
posed of two or more strands or wires insulated
from one another, of a switch adapted to place 70
more or less of said strands in circuit, or to
break the circuit of all said strands, substan-
tially as set forth.
5. In a compensating system of electrical
distribution, a feeding-circuit whose positive 75
and negative conductors are each a cable com-
posed of two or more insulated strands or
wires, and one or more wires of each cable be-
ing connected to form the compensating.con-
ductor, substantially as set forth.
This specification signed and witnessed this
16th day of February, 1886.
Witnesses:
JOHN W. HOWELL.
WM. J. LATUS,
CHAS. A. GUNDAKER.
80
2988
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Howland
Paul B. Dyer.
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No. 329,621.
H. M. BYLLESBY.
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SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 3, 1885.
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THE NORAIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
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Henry M. Bylleshy
By Dyer Fly
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No. 329,621.
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H. M. BYLLESBY.
2 Sheets-Sheet 2.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 3, 1885,
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오오오 ​오오오
​2990
UNITED STATES PATENT OFFICE.
HENRY M. BYLLESBY, OF NEW YORK, N. Y.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 329,621, dated November 3, 1885.
Application filed October 10, 1884. Serial No. 145,137. (No model.)
To all whom it may concern:
Be it known that I, HENRY M. BYLLESBY,
of New York, in the county of New York and
State of New York, have invented a certain
5 new and useful Improvement in Systems of
Electrical Distribution, of which the follow-
ing is a specification.
My invention relates to systems for the gen-
eral distribution of electricity for light, power,
10 and other purposes. Usually in such systems
the generators at the central station or source
of supply have all been connected to two main
conductors, from which conductors feeding
circuits extend to a system of intersecting and
15 connected positive and negative main conduct
ors. In this arrangement difficulty arises from
the mutual dependence upon one another of
all the feeding-circuits, they being connected
together at both ends through the "omnibus-
20 wires" at the central station, and through the
system of main lighting-conductors in the dis-
trict. For instance, when a cross occurs in
one part of the district, causing an excess of
current on the feeder nearest thereto, so as to
25 burn out the safety-catch in that feeder, this
current is all thrown upon the next feeder, and
so overloads it as to destroy its safety-catch,
and this will continue throughout the system
until all the feeder safety-catches are destroyed
30 and the supply of current ceases throughout
the entire system. It has been proposed, in
order to remedy this, to do away with the com-
mon main conductors at the central station,
and connect each generator separately with
35 the feeders, so that such feeders are connected
together only through the lighting-conduct-
ors, and are thereby made independent and
separately controllable; but in this system the
advantages of using the omnibus - wires are
40 lost. When such wires are used, the difference
of potential is the same at the station-termi-
nals of all the feeders, each feeder being sup-
plied by all the generators, while if they are
not used the feeders, being separately connect-
45 ed with the generators, may each be supplied
at a different electro-motive force, each gener-
ator having its own regulator. Further, by
means of the omnibus wires the whole current
supplied to the district is most readily varied,
50 as any change in the generation of current by
any machine affects the whole system, and the
generators may be readily thrown on and off,
to increase or diminish the current supplied.
-
In the system which forms my invention I
am enabled to combine the advantages of the 55
independently-controlled feeders with those of
common central - station conductors. Such
system consists of one or more generators
connected to the two main conductors at the
station, and two or more feeding circuits ex- 60
tending from said maiu conductors, each of
said feeding circuits being connected with a
separate section of the lighting conductors—
that is to say, the intersecting and connected
positive and negative conductors from which 65
the house-circuits extend, instead of being all
connected together throughout the district,
are electrically divided into sections, each sec-
tion being supplied by a separate feeding-cir-
cuit. I prefer to provide each feeding circuit 70
with a circuit making and breaking switch, a
safety-catch, and an adjustable resistance or
other suitable regulating device. Any feeder
may therefore be disconnected from the sys-
tem without affecting the current in any other 75
feeder to any material extent, the generator
being regulated to maintain a constant electro-
motive force, or the current of any feeder may
be varied without changing that of the others.
At the same time, the generators all feeding into 80
the same main conductors, there is the same
initial electro-motive force for all the feeders.
The field circuit of each generator is provided
with an adjustable resistance for regulating
its electro-motive force, whereby a constant 85
electro-motive force is maintained, or the de-
termined constant electro-motive force may
be raised or lowered, if necessary, to regulate
the current for the entire system; or these ef-
fects may in some cases be produced by con- 90
necting or disconnecting one or more genera-
tors from the common main conductors.
My invention is applicable, further, to the
three-wire or compensating system of electri-
cal distribution, as will be presently set forth. 95
I may, in addition, provide the system with
means for connecting together the sections of
lighting-conductors, if at any time it should
be desired, by reason of a cross or leak in the
feeding circuit supplying a section, or for any 100
feeding-circuit
2991
2
329,621
other reason, to supply two or more sections
from the same feeder. Normally such con-
nections are open, and they are only closed
under circumstances such as I have just men-
5 tioned.
The invention may be more readily under-
stood by reference to the accompanying draw
ings, in which-
Figure 1 is a diagramr representing a two-
10 wire system, and Fig. 2 a diagram of a three-
wire system, both embodying the said inven-
tion.
|
in the drawings between the central station
and the lighting-conductors to indicate that
there may be a considerable intervening dis- 70
tance.
-
Jo
As above stated, I may provide means for
temporarily connecting the sections at any
time. Such means preferably consist of con-
ductors rr', which I term "relief-wires," 75
each provided with a plug-switch, s, or other
suitable circuit controlling device. These
wires connect the terminals of the feeder of
each section with those of the sections con-
tiguous to it. They are normally open at s s; 80
but if a cross or ground or other defect should
arise in any feeder the circuit r', connecting
it with the next section, is closed, and the
feeder of said next section will therefore sup-
ply both sections with current. Both con- 85
ductors of the defective feeder should previ-
ously be broken at tt, these switches being
situated close to the feeder-terminals, so that
the cross or leak can not affect the system.
Circuits may be closed to several neigh- 90
boring sections, if more current is required
than one feeder can supply. It will be un-
derstood, however, that normally the circuits
rr' are all open and feeding-circuits all closed,
the sections being connected together only for 95
the relief of the system in the event of such
difficulties occurring as have been set forth.
·
A A', &c., are electrical generators. Refer-
ring first to Fig. 1, these generators are all
15 connected in multiple arc with two main con-
ductors, P and N, by wires p n. Each of said
wires pn contains a switch, a, for throwing
the machine on and off, and a fusible-wire
safety catch, b, for breaking the circuit on an
20 excess of current. The field circuit of each
machine contains an adjustable resistance, c,
for regulating the electro-motive force. While,
for convenience, these resistances are shown
as independently adjustable, it is usually pre-
25 ferred to arrange them for simultaneous ad-
justment, as in the patent of T. A. Edison, No. |
281,349, dated July 17, 1883. From the cen-
tral station main conductors P N extend the
feeding circuits composed of conductors p'n'.
30 Each feeding conductor has break - circuit
switch d and safety-catch e, and each feeding- In Fig. 2 there are three common main con-
circuit contains a regulating - resistance, f. ductors, P, N, and C, the middle one, C, be-
Each feeding-circuit extends to a certain point ing the compensating-conductor. The gen- 100
in the district supplied from the station, where erators are in series of two each, A A and A'
35 it is connected with the positive and negative A', the compensating - conductor being con-
lighting-conductors p² n². These conductors nected between the generators of each group
are connected together, positive to positive and by conductor c'. The generators are provided
negative to negative, at the street-corners, each with a regulating-resistance, c, as shown; 105
where they intersect one another, as has here- or the field-coils of each group may be in se-
40 tofore been customary; but, instead of being ries and have a common resistance. Switches
all connected throughout the district, they are and safety catches are provided for conductors
divided into sections, as illustrated, one feed-p c'n. The feeding circuits also consist each
ing circuit extending to each section. The of three conductors, p'cn', and these are 110
sections may be of any convenient area, each connected, as shown, to the lighting-conduct-
45 comprising such suitable number of translat-
ors p² c³ n². The feeding conductors have
ing devices as can be conveniently supplied switches and safety-catches, as before, and an
by a single feeding-circuit, and the divisions additional adjustable resistance, g, is placed
may be made at convenient points. Electric in the compensating-conductor, to be used if 115
lamps or other translating devices, xx, are one main conductor is thrown off, so that the
50 connected in multiple arc with the conductors compensating-conductor forms one side of the
pn. Each feeder having its own regulating circuit. The lamps or other translating de-
device f, the current in each is regulatel ac- vices are in multiple series, as shown. The
cording to the amount required in its section lighting-conductors are divided into sections, 120
at any time; and it is evident that such regu- to each of which a feeder is connected, as in
55 lation will not affect the other feeders, a con- Fig. 1, and the effect is the same. In this
stant electro-motive force being maintained, case also the system is provided with relief-
as has been already pointed out; but by means conductors r², each having a switch, s, so
of conductors P N the same initial pressure that the sections may be connected together, 125
is maintained at the station for all the feeders. if necessary, as above described.
60 If a safety catch is burned out on one feeder,
that section is cut out, but there is no increase
in current on the other feeders. At the same
time the total current supplied to the district
is readily varied by means of the field-resist-
65 ances, or by changing the number of genera-
tors in connection with the system.
The feeding-conductors are broken away
|
What I claim is-
-
-
1. A system of electrical distribution com-
prising one or more generators, main conduct-
ors to which said generators are connected, 130
a system of lighting conductors divided elec-
trically into sections, two or more feeding-
circuits extending from said main conductors,
one to each of said sections, and circuit-con-
2992
5
2992
329,621
trolling devices for each feeding circuit, sub-
stantially as set forth.
3
4. A system of electrical distribution com-
prising one or more generators, main conduct-
2. A system of electrical distribution com- ors to which such generators are connected, a
prising one or more generators, main con- system of lighting-conductors divided elec-
ductors to which said generators are connect-trically into sections, two or more feeding- 25
ed, a system of lighting-conductors divided circuits extending from said main conduct-
electrically into sections, two or more feeding- ors, one to each of said sections, two or more
circuits, one extending from said main con- relief-conductors connecting said sections to-
ductors to each of the sections of the lighting gether, a circuit making and breaking switch
Io conductors, and adjustable resistances for the for each of said relief-conductors, and a cir- 30
feeding-circuits, substantially as set forth. cuit making and breaking switch for each
conductor of each feeding - circuit, substan-
tially as set forth.
-
3. A system of electrical distribution com-
prising one or more generators, main con-
ductors to which said generators are connect-
15 ed, a system of lighting-conductors divided
electrically into sections, two or more feeding-
circuits extending from said main conductors,
one to each of said sections, and means for
temporarily connecting together any two of
20 the sections, substantially as set forth.
This specification signed and witnessed this
8th day of October, 1884.
Witnesses:
HENRY M. BYLLESBY.
WM. H. MEADOWCROFT,
THOS. G. GREENE, Jr.
រ
. 2993
(No Model.)
H. M. DOUBLEDAY.
SYSTEM OF ELECTRIC LIGHTING.
2 Sheets-Sheet 1.
Patented Jan. 26, 1886.
No. 335,060.
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H. M. DOUBLEDAY.
SYSTEM OF ELECTRIC LIGHTING.
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2995
UNITED STATES PATENT OFFICE.
HARRY M. DOUBLEDAY, OF NEW YORK, N. Y., ASSIGNOR OF THREE-FOURTHS
TO JAMES S. HUMBIRD AND FRANK S. MARR, BOTH OF HARRISBURG,
PA., AND JAMES LYMAN, OF MIDDLEFIELD, CONN.
SYSTEM OF ELECTRIC LIGHTING.
SPECIFICATION forming part of Letters Patent No. 335,060, dated January 26, 1886.
Application filed June 26, 1885. Serial No. 169,825. (No model.)
To all whom it may concern:
Be it known that I, HARRY M. DOUBLEDAY,
of New York city, in the county and State of
New York, have invented a certain new and
5 useful Improvement in Systems of Electric
Lighting, of which the following is a specifica-
tion.
My invention relates to systems of lighting
by electrical incandescence, and more partic-
10 ularly to the supplying of street-lamps from
such a system.
-
The object I have in view is to provide in a
simple and efficient manner a separate control
of the street-lamps from the central station, so
15 that such street-lamps can be turned off and
on from the station, the street lamps being
supplied with current from the same source
that supplies the domestic lamps, and the
conductors for the domestic lamps being
20 utilized in conveying current for the street
lamps.
The invention consists in the means em-
ployed for accomplishing these general ob-
jects, and also in details used in the carrying
25 out of these objects practically in connection
with a domestic system of electric lighting, to
provide for safety for the regulation of the
street-lamps independent of the domestic
lamps, and for permitting the turning on and
30 off of the street-lamps without noticeably af
fecting the domestic lamps.
The invention is especially applicable to the
Edison three-wire or compensating system, al-
though also applicable to a simple two-wire
35 system, as will be hereinafter pointed out.
In the accompanying drawings, forming a
part hereof, Figure 1 is a diagram of parts of
an electric-lighting system illustrating my in-
vention. Figs. 2 and 3 are modifications there.
40 of, and Fig. 4 is a further modification.
With reference more particularly to Fig. 1,
A represents a central station for a three-
wire or compensating system provided with
dynamos (not shown) for generating the cur-
45 rent connected with the omnibus conductors
1 2 3 in the station. From these omnibus con-
ductors extend, as usual, feeders B B', each com-
posed of three conductors, 4 5 6, to sections C
C' of the system. These sections are portions
of the domestic mains, each composed of three 50
conductors, 7 8 9, such domestic mains being
connected together by intervening domestic
mains, as shown by the crossing lines D at the
right of Fig. 1, the whole forming a connected
system of positive, negative, and neutral or 55
compensating conductors supplied by feeders
from the central station. From these domestic
mains house-circuits extend, and in these are
located domestic incandescing electric lamps
al.
The domestic system is provided with all 60
the usual appliances for regulation, control,
and safety, which it is not thought necessary
to describe herein.
For the street-lamps I provide separate and
independent single part mains 10 11, connected 65
with the station by single part feeders 12 13.
The feeder 12 is connected at station with the
positive omnibus conductor 1, while 13 is con-
nected with the negative omnibus wire 3.
Street - lamps b are connected between the 70
mains 10 11 and the neutral or compensating
conductor 8 of the domestic mains.
Throughout the domestic system, wherever
it is desired to place street-lamps, the street-
lamp mains will extend. These will be di- 75
vided into a suitable number of separate inde-
pendent sections, and as many of the single
part feeders 12 13 will be used as there are
separate divisions to the street-lamp mains,
such feeders being preferably divided between 80
the two sides of the circuit, half of these be-
ing connected with the positive omnibus con-
ductor and half with the negative omnibus
conductor.
At the central station each street lamp feed- 85
er is provided with a switch, c, for making
and breaking the circuit of the street-lamps
connected with the particular division of the
street-lamp mains supplied by the feeder, and
each of such feeders also has an adjustable re- 90
sistance, R, which may be a wire or lamp re-
sistance located in the station. This resist-
ance is employed for regulating the street-
lamps in candle-power; but its principal use
is to permit the street-lamps to be thrown into 95
and out of circuit gradually, the resistance be-
2996
-21
335,060
ing first gradually introduced into the feeder
before the switch is opened, and being gradu-
ally cut out of the feeder after the switch is
closed. The street-lamps being thrown on
5 and off one division at a time, and by the
gradual cutting out and in of the resistances,
the effect upon the domestic lamps will not be
noticeable. Each street-lamp feeder also has
a fusible safety-catch, d, proportioned to carry
To the maximum normal load of the feeder.
Where it is desired to operate street-lamps
beyond the limits of the domestic mains, which
is often the case, I extend the neutral conduct
or 8 of the domestic mains by lines 14 15, con-
15 nected together at their outer ends. Street-
lamp mains 16 17 are run parallel to such neu-
tral lines 14 15, and are connected by positive
and negative feeders 18 19 with the station,
the effect of the full electro-motive force be-
20 ing obtained by this arrangement.
As a modification of the system it is evident
that some or all of the street-lamp mains may
be connected directly with the station, as shown
in Fig. 2. This would be done with mains
25 close to the station and not themselves of great
length.
In applying the invention to a simple two-
wire domestic system, Fig. 3, the street-lamps
will be located between positive and negative
30 street-lamp mains and domestic mains of oppo-
site polarity.
A number of street-lamp mains would pref-
erably be used divided between the two sides
of the system, as before explained with refer-
35 ence to the three-wire system.
All of the street-lamp feeders from the station,
whether to mains within the limits of the do-
mestic system or beyond, as well as all direct
connections of street-lamp mains to stations,
40 will be provided with switches, adjustable re-
sistances, and safety - catches, as before ex-
plained.
-
I prefer in some cases to dispense with the
feeders to the street-lamp mains within the
45 limits of the domestic system, and to supply
such street-lamp mains from the street-lamp
mains outside the limits of the domestic sys-
tem, the two sets of mains being connected to-
gether and the feeders running to the outly-
50 ing mains only. This arrangement, which is
shown in Fig. 4, is desirable, in order to se-
cure the best distribution of the current.
What I claim is—
1. The combination, with a domestic sys-
55 tem of lighting by electrical incandescence, of
an additional conductor connected independ-
ent of the domestic system with one pole of
the source of electrical supply at the station,
and lamps connected between such additional
60 conductor and a conductor of the domestic
system, substantially as set forth.
2. The combination, with a connected sys-
tem of conductors, incandescent electric lamps
connected in multiple arc with such conduct-
55 ors, and a source of electrical energy connected
by feeding-circuits with such system of con-
ductors, the whole forming a domestic system
| of electric lighting, of one or more additional
conductors, incandescent electric lamps con-
nected in multiple arc between such addi- 70
tional conductors and conductors of the do-
mestic system, and one or more separate con-
nections from such additional conductors to
the source of supply of the domestic system,
substantially as set forth.
75
3. The combination, with a three-wire or
compensating system of electric lighting, of
an additional conductor, electric lamps con-
nected between such additional conductor and
the neutral or compensating conductor of the 80
system, and a separate connection from such
additional conductor to one side of the source
of electrical supply, substantially as set forth.
4. The combination, with a domestic system
of electric lighting, of street-lamps connected 85
between an additional conductor and a con-
ductor of the domestic system, a separate single
part connection from such additional conduct-
or to one side of the source of electrical sup-
ply, and an adjustable resistance in such con-
necting-conductor, substantially as set forth.
5. The combination, with a domestic system
of electric lighting, of street-lamps connected
between an additional conductor and a con-
ductor of the domestic system, a separate
single part connection from such additional
conductor to one side of the source of elec-
trical supply, and a circuit making and break-
ing switch in such connecting-conductor, sub-
stantially as set forth.
95
ΙΟΟ
6. The combination, with a domestic system
of electric lighting, of street-lamps connected
between an additional conductor and a con-
ductor of the domestic system, a separate single
part connection from such additional conduct- 105
or to one side of the source of electrical sup-
ply, and a fusible safety-catch in such connect-
ing-conductor, substantially as set forth.
7. The combination, with a domestic system
of electric lighting composed of connected 110
conductors supplied by feeders from a central
station, of two or more separate and independ-
ent additional conductors, lamps connected be-
tween each of such additional conductors and
the conductors of the domestic system, and a 11
separate connection from each additional con-
ductor to the source of supply at station, sub-
stantially as set forth.
8. The combination, with a domestic system
of electric lighting composed of connected con- 120
ductors supplied by feeders from a central sta-
tion, of street-lamps arranged in divisions, the
lamps of each division being connected be-
tween an additional conductor and a conductor
of the domestic system, and separate connec-
tions from such additional conductors to the
source of supply, such connections being made
some to one side or pole and some to the other
side or pole of the source of supply, substan-
tially as set forth.
9. The combination, with a three- wire or
compensating system of electric lighting, of
street-lamps arranged in divisions between in-
dependent additional conductors and the neu-
125
130
2997
335,060
tral or compensating conductor of the system,
and separate connections from such additional
conductors to the source of supply, such con-
nections being made some to one side or pole
5 and some to the other side or pole of the
source of supply, substantially as set forth.
10. The combination, with a three- wire or
compensating system of electric lighting, of
an extension of the neutral conductor beyond
to the limits of the system, an additional con-
ductor parallel with such extension of the neu-
tral conductor, street-lamps located between
such additional conductor and the extension of
the neutral conductor, and a separate connec-
15 tion from said additional conductor to the
source of supply, substantially as set forth.
3
11. The combination, with a three- wire or
compensating system of electric lighting, of
an extension of the neutral conductor beyond
the limits of the system, two or more addi- 20
tional conductors parallel with such extension,
connections from such additional conductors
to opposite sides or poles of the source of sup-
ply, and street-lamps located between such ad-
ditional conductors and said extension of the 25
neutral conductor, substantially as set forth.
This specification signed and witnessed this
9th day of June, 1885.
Witnesses:
HARRY M. DOUBLEDAY.
ROGER S. CASE,
STEWART P. KEELING.
2998
(No Model.)
No. 378,738.
##
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T. SPENCER.
2 Sheets-Sheet 1.
SYSTEM OF ELECTRIC DISTRIBUTION.
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Patented Feb. 28, 1888.
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By
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N. PETERS. Photo-Lithographer, Washington, D. C.
2999
(No Model.)
No. 378,738.
T. SPENCER.
2 Sheets-Sheet 2.
SYSTEM OF ELECTRIC DISTRIBUTION.
Patented Feb. 28, 1888.
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N. PETERS. Photo-Lithographer, Washington, D. C.
3000
UNITED STATES PATENT OFFICE.
THOMAS SPENCER, OF WESTBROOK, CONNECTICUT.
SYSTEM OF ELECTRIC DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 378,738, dated February 28, 1888.
Application filed August 13, 1887. Serial No. 246,879. (No model.)
To all whom it may concern:
Be it known that I, THOMAS SPENCER, a citi-
zen of the United States, residing at West-
brook, in the county of Middlesex and State of
5 Connecticut, have invented certain new and
useful Improvements in Systems of Electric
Distribution, of which the following is a speci-
fication.
In electric-light systems now in use, and par-
10 ticularly in those employing the Edison three-
wire system, it is the custom to connect the
light-mains at different points to a number of
conductors called "feeders," led from the cen-
tral station, for the purpose of maintaining the
15 electro-motive force constant on the main.
Such an arrangement would be effectual if the
feeders always carried the current for which
they are calculated. In systems, however,
where the " consumer" is enabled to cut in or
20 out his own lamp at will a varying number of
lamps are in circuit, and the consequent varia-
tion of resistance of the main renders it neces·
sary to use some equalizing device, so that each
feeder will carry the proper current. For this
25 purpose, ordinarily, rheostats, called in this
connection "feeder regulators" or "equal-
izers," are employed, placed in the feeders at
the station. Such equalizers, however, require
constant watching and care to perform their
30 service, and my improvement relates to a sys-
tem of distribution wherein such equalizers are
done away with.
•
My improvement consists in the combina-
tion, with such a system of mains having a
35 plurality of feeding points, of one or more wires
connecting the mains at the feeding points in-
dependent of the feeders and not employed to
tap lights from.
My invention will be described with refer-
40 ence to the accompanying drawings, in which
Figure I represents diagrammatically an
electric-light system as customarily arranged.
Fig. II is a similar view showing my improve-
ment. Fig. III is a similar view of a modified
45 form of the latter.
Referring to Fig. I, it will be seen that the
light-mains are arranged in the form of a
net-work, supplied with current by feeders y
from dynamos c at the central station. The
feeders are connected to the main at a a' a", 50
and are provided with rheostats e' e", &c., for
the purpose stated.
In Fig. II, illustrating my system, the rheo-
stats are omitted, and the feeding-points a a' a″
are connected by wires A of low resistance. 55
The form shown in Fig. III is somewhat like
that of Fig. II; but as it is not necessary for all
the feeders to run to the central station I here
show a simple set of wires, b, running from
the station and supplying all the feeders.
6c.
It will be seen that with either of the ar-
rangements shown in Figs. II and III, should
any feeder have any different electro-motive
force from the others, a current is immediately
set up in the wires A, called by me "equal- 65
izers," and the electro-motive force is at once
equalized at the feeding points.
It is plain that, although I have here shown
my invention applied to an Edison three-wire
system, it is equally applicable to higher or- 70
ders of compensating systems or to simple sys-
tems using but two wires.
Having thus described my invention, the fol-
lowing is what I claim as new therein and de-
sire to secure by Letters Patent:
75
1. In a system of electric distribution, the
combination, with mains having a plurality of
feeding-points and feeders, of low-resistance
equalizing conductors independent of the feed-
ers and connecting the mains at the feeding. 8>
points, substantially as set forth.
2. The combination of a central station, elec-
tric-light mains, a plurality of feeders connect-
ing said station with different points on said
mains, and equalizing conductors independent 85
of the feeders and connecting the mains at the
feeding points, substantially as set forth.
THOMAS SPENCER.
Witnesses:
FRANK S. MARR,
NORMAN MARSHALL.
3001
(No Model.)
2 Sheets-Sheet 1.
0. B. SHALLENBERGER.
REGULATOR FOR DYNAMO ELECTRIC MACHINES.
No. 337,628.
Patented Mar. 9, 1886.
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REGULATOR FOR DYNAMO ELECTRIC MACHINES.
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samuri S. Wolcott
J. M. Parke
Patented Mar. 9, 1886.
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THE NORRIS PETENS CO., PHOTO-LITHO., WASHINGTON, D. C.
BY
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INVENTOR,
Oliver B Shallenberger.
George H. Chrisly
ATTORNEY.
16
3003
UNITED STATES PATENT OFFICE.
OLIVER B. SHALLEN BERGER, OF ROCHESTER, PENNSYLVANIA.
REGULATOR FOR DYNAMO-ELECTRIC MACHINES.'
SPECIFICATION forming part of Letters Patent No. 337,628, dated March 9, 1886.
Application filed December 5, 1885. Serial No. 184,791. (No model.)
To all whom it may concern:
Be it known that I, OLIVER B. SHALLEN-
BERGER, residing at Rochester, in the county
of Beaver and State of Pennsylvania, a citi-work-circuit proportional to the increase in
5 zen of the United States, have invented or dis-
covered certain new and useful Improvements
in the Regulation of Dynamo Electric Gen-
erators, of which improvements the following
is a specification.
10
placed in the circuit the large quantity of
current required to supply the lamps would
cause a fall in the electro-motive force in the 55
current. This fall in electro-motive force
produces a corresponding decrease in the
incandescence of the lamps; but they may be
brought up to their normal incandescence by 60
increasing the electro-motive force of the
In the accompanying drawings, which make generator sufficiently to compensate for the
part of this specification, Figure 1 is a dia- loss in the main conductors; hence, in a sys-
grammatic view showing the manner of aptem of electrical distribution in multiple arc-
plying the auxiliary coils to a shunt dynamo-
electric machine. Fig. 2 is a similar view
15 showing a modification of the auxiliary coils.
Figs. 3, 4, 5 are similar views showing the
manner of applying my invention to different
kinds or classes of dynamo-electric machines.
The invention herein relates to certain im-
20 provements in the manner of winding the
cores of the field-magnets of dynamo-electric
machines, and has for its object the mainte-
nance of a constant difference of potential in
its work or external circuit, under variable
25 conditions of work in said external circuit.
Au approximately constant electro-motive
force can be maintained at the terminals of
shunt-wound dynamos of the usual construc-
tion by so constructing and proportioning the
30 various parts that the resistance of the arma-
ture shall be low and that of the field-coils
high relatively to the resistance in the exter-
nal or work circuit; or the same result may be
secured by the ordinary compound winding;
35 and this electro-motive force is the same
throughout the main conductors, if their re-
sistance be sufficiently low as compared with
that of the work circuit to be negligible.
If, however, this resistance be increased to a
40 considerable amount, a loss of electro-motive
force occurs at the outer extremities of the
main conductors proportional to the amount
of current passing, and hence a constant elec-
tro motive force at the terminals of the dyna-
45 mo no longer maintains a constant difference
of potential at the point of consumption with
a varying current-as, for example, if an in-
candescent lamp were placed across the ex-
tremities of the mains, it would receive a cur-
50 rent of the same electro-motive force as if
placed across the terminals of the dynamo;
but if a large number of such lamps were
|
as, for example, incandescent lighting-it is 65
necessary to employ a generator so constructed
that the electro-motive force may be increased
with each increase in consumption of current
in the work-circuit by an amount equal to the
loss due to the resistance of the conductors, 70
and conversely to lower the electro-motive
force with each corresponding decrease in the
current consumed.
current consumed. These results may be
effected either by the use of mechanical de-
vices (operated or controlled by hand or by 75
the current in the work circuit) or by so wind-
ing and proportioning the coils of the gener-
ator as to produce the desired regulation.
·
In compound wound dynamos of the ordi-
nary type, in which the main current traverses 80
coils wound upon the field magnets, it is possi-
ble to so proportion the coils as to produce a
definite variation of electro-motive force with
a definite variation of current or external re-
sistance. This variation, however, is fixed for 85
a given machine at a given electro-motive
force, and hence such a machine can only be
employed upon a circuit in which the loss in
the mains corresponds very nearly to the in-
crease in electro-motive force due to the cur- 9ɔ
rent traversing the series coils. These coils
also introduce a useless resistance into the
main circuit.
·
The object of this invention is to so con-
struct a dynamo as to make it readily adapt- 95
able to any circuit on which it may be placed
by so winding and connecting its exciting-coils
that the varying loss of electro motive force
between the extremities of the main conduct-
ors shall be automatically compensated by a co
corresponding increase in field strength, and
consequent increase in electro motive force at
the terminals of the dynamo, whatever may
be the resistance of these mains, and conse-
3004
2
337,628
quent drop of potential between the dynamo | in the main conductors. As the resistance in
and point of consumption. Its peculiar fea-
tures of advantage, therefore, are that no
special proportioning of the coils of each ma-
5 chine to the circuit upon which it is to be
used is required; and, further, the manner of
arranging the coils and their circuits avoids
the necessity of passing the entire current
through the field-coils, which is a serious de-
10 fect, owing to the resistance thus introduced
into the circuit.
| the work-circuit is further reduced by the ad-
dition of lamps, and the current consequently 70
increased, the loss of potential in the main
conductors is correspondingly increased, and
a greater amount of current will pass through
the auxiliary coils 5 and 5", which thus assist
the field coils in producing a greater excita- 75
tion in the magnetic field.
The shunt-wound dynamo A is of the usual
form and construction, and has its high-resist-
ance field coils 2 and 2ª connected in shunt to
15 the main terminals 3 and 3ª of the dynamo..
On the cores of the magnets 1 and 1ª are also
wound the auxiliary coils 5 and 5, also of
high resistance relatively to main circuit, which
may be arranged alongside of the main field
20 coils, as shown, or may be wound on top of
such coils, or underneath the same. These
coils are independent of each other, and the
outer end or terminal of the coil 5 is connected
by a wire, 9, of low resistance, to the outer
25 terminal of the main conductor 7, and the op-
posite end of said coil 5 being connected to
the positive terminal 3, to which the inner end
of the main conductor 7 is also connected.
The coil 5 is correspondingly connected to
30 the other main conductor, 8, by a wire, 10, of
low resistance, and the negative terminal 3º.
·
By properly proportioning the field and
auxiliary coils they may be made to raise the
electro-motive force at the terminals in pro-
portional amounts to the degree necessary for 80
the proper illumination of all the lamps in the
working-circuit simultaneously. By cutting
lamps out of the circuit a contrary effect is
produced, the electro-motive force being re-
duced as the flow of current in the main con- 85
ductors is reduced. Thus the regulation is
maintained automatically, whatever may be
the resistance of the main conductors or the
amount of current passing, and the electro-
motive force is always proportional to the 90
current required in the work-circuit, the main
field-coils being proportioned to give the ini-
tial field required for the least number of
lamps used or amount of work to be per-
formed, and the auxiliary coils proportioned to 95
produce the additional field strength for the
largest number of lamps and the greatest
amount of work.
The action of the auxiliary coils 5 and 5" is
as follows: Suppose the generator to be run-
ning without doing any external work, but
35 maintaining an electro-motive force of any
given amount at its terminals, produced by
the field-coils 2 and 2ª. This electro motive
force will exist equally throughout the entire
circuit as long as no current passes, and there-
40 fore no current will pass through the coils 5
and 5ª, since there will be no difference of po-
tential between the terminals 3 and 3ª and the
outer extremities of the main conductors
Now, in case a number of translating devices-iliary coils 5 and 5" may be applied for a like
45 for example, incandescent lamps-were placed
in multiple are in the work circuit, there
would be a drop in electro-motive force at the
outer extremities of the main conductors 7
and 8 by an amount equal to the current mul-
50 tiplied by the resistance, if the action of the
coils 5 and 5ª be disregarded, while the elec-
tro-motive force at the terminals 3 and 3ª re-
mains nearly constant. This drop of poten-
tial at the extremities of the main conductors
55 correspondingly affects the lamps in the cir-
cuit; but in dynamos having the auxiliary
coils 5 and 5ª the resistance in the main con-
ductors and consequent difference of poten-
tial between the terminals 3 and 3ª and the ex-
6 tremities of the line produces a corresponding
difference of potential between the terminals
of the coils 5 and 5ª, the wires 9 and 10 being
of comparatively low resistance, and the re-
sulting flow of current is in such a direction
65 and of such an amount that the field-magnets
are further energized and the electro-motive
force increased by an amount equal to the loss
A small variable resistance, 12, can be in-
troduced into the coil-circuits to adjust the Ico
field strength to the speed of the armature,
which once adjusted will require no further
change.
In lieu of arranging the coils 5 and 5ª in-
dependent of each other, as above stated, they 105
may be connected in series with each other, the
coil 5 being connected by a wire, 13, of low re-
sistance, to the outer extremity of the main con-
ductor 8, and the coil 5" being connected to
the terminal 3ª, as shown in Fig. 2. The anx- IIO
purpose and with a like result to a compound
wound dynamo, and also to a separately-ex-
cited dynamo, as shown in Figs. 3, 4, and 5,
the coils being independent of each other or 115
connected in series, as described in connection
with shunt-dynamos; or, in the case of sep-
arately-excited dynamos, the auxiliary coils
may be applied to the cores of the magnets of
the exciting-dynamo, as shown in Fig. 5. In 120
the latter case the coils 2 and 2ª of the main
dynamo are connected in the usual manner to
the terminals 14 and 14ª of the exciting-dyna-
mo 15. The auxiliary coil 5 is connected at
its ends by the low-resistance wire 16 to the 125
terminal 3 of the main dynamo and the outer
extremity of the main conductor 7, leading
from the same terminal, and the coil 5ª is simi-
larly connected by the low-resistance wire 17
to the terminal 3 and the outer extremity of 130
its main conductor 8. Any difference of po-
tential between the ends of the main conductors
7 and 8 will cause an increased amount of
current to pass through the auxiliary coils of
337,628
3
•
3005
the exciter, thereby producing an increased | combination of a field - magnet and the main
excitation of its field of force and a corre- coils thereof, auxiliary exciting coil or coils,
sponding excitation of the field of the main main conductors connecting the terminals of
dynamo. The advantage of thus automatic- the machine and the working circuit, and a 50
5 ally proportioning the electro-motive force shunt-circuit including the auxiliary coils and
to the work to be done becomes evident when electrically connected to the terminals of the
the saving in the cost of conductors is consid- dynamo and the main conductors at or near
ered.
where the same are connected with the work-
When the source of power is located at any ing-circuit, the resistances of the auxiliary 55
Io considerable distance from the point of con- coils being suitably proportioned, so that any
sumption, very large conductors are required difference of potential in the main conductors
to accomplish the necessary regulation in the between the points of generation and con-
ordinary way, or, in other words, to reduce sumption will automatically increase or de-
the drop of potential within practical lim- crease the excitation of the magnetic field, 60
15 its the weight of conductors should in- | substantially as set forth.
crease as the square of the distance; hence a
point is soon reached where the cost of such
conductors is prohibitive. If, however, a
large drop of electro-motive force is permis-
25 sible before the point of consumption is
reached, it is only necessary to employ con-
ductors of sufficient size to prevent undue
heating, which is often only a small fraction of
the former size. This large drop of potential
25 between the points of generation and con-
sumption is permissible where machines of
the character above described are employed,
the drop of potential on the line being always
counterbalanced by a corresponding rise of
30 electro-motive force at the generator through
the whole range of current taken off.
The prominent characteristic of the inven-
tion herein is the automatic proportioning of
the electro-motive force at the terminals of the
35 dynamo to the current required in the work-
circuit by the difference of potential in the
main conductors between the points of genera
tion and consumption, and thereby causing
such difference of potential in the working
40 cireuit to react through auxiliary coils in the
field-magnets, so as to restore fully or ap-
proximately the loss or drop in electro-motive
force, which would otherwise be occasioned
thereby.
45
I claim herein as my invention-
1. In a system of electric distribution, the
2. In a system of electric distribution, the
combination of a field-magnet and the excit-
ing coils thereof, and an auxiliary exciting coil
or coils suitably connected with the extrem- 65
ities of either or both of the main conduct-
ors and adapted to automatically increase
or decrease the excitation of the magnetic
field in proportion to the difference of poten-
tial between the inner and outer terminals of 70
the main conductors, substantially as set forth.
3. In a system of electric distribution, the
combination of a dynamo-electric machine,
main conductors connecting the terminals of
the dynamo and the work-circuit, and an excit- 75
ing coil or coils upon the field magnets having
its terminals connected, respectively, to a ter-
minal of the dynamo and to one of the main
conductors at or near its connection with the
working-circuit, said exciting-coil being suit- 80
ably proportioned, so as to automatically in-
crease or decrease the excitation of the mag-
netic field in proportion to the difference of
potential in the main conductors between the
points of generation and consumption, sub. 85
stantially as set forth.
In testimony whereof I have hereunto set
my hand.
OLIVER B. SHALLENBERGER.
Witnesses:
DARWIN S. WOLCOTT,
R. H. WHITTLESEY.
3006
(No Model.)
No. 380,942.
0. B. SHALLENBERGER.
ELECTRIC INDICATOR.
Patented Apr. 10, 1888.
1
D1
D2
d
+
d
E
Fig.1,
f
A
2
1
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100
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Fig. 3,
Witnesses.
Geo. W. Breck
Carrie E. Neshley
By kis Attorneys,
Inventor.
0.13. Shallenburger.
Pope Edgecomb Terry.
THE NORAIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
3007
UNITED STATES PATENT OFFICE.
OLIVER B. SHALLENBERGER, OF ROCHESTER, ASSIGNOR TO GEORGE WESTING-
HOUSE, JR., OF PITTSBURG, PENNSYLVANIA.
ELECTRIC INDICATOR.
SPECIFICATION forming part of Letters Patent No. 380,942, dated April 10, 1888.
Application filed April 23, 1887. Serial No. 235,838. (No model.)
To all whom it may concern:
·
Be it known that I, OLIVER B. SHALLEN
BERGER, a citizen of the United States, resid-
ing in Rochester, Beaver county, in the State
5 of Pennsylvania, have invented certain new
and useful Improvements in Electric Indica-
tors, of which the following is a specification.
The invention relates to the class of appara-
tus employed for indicating at any time the
Io current upon an electric circuit; and the ob-
ject is to provide convenient means for deter-
mining and regulating at a central station the
potential upon the work-circuit.
The invention consists in deriving from the
15 main circuit currents having a potential' di-
rectly dependent upon the difference of poten-
tial at the terminals of the generator and cur-
rents upon a second circuit having a potential
dependent upon or affected by the loss or drop
20 upon the lines when that loss is sufficient to
cause an appreciable effect on the work-cir-
cuit. The effects of the currents thus derived
are balanced against or caused to oppose each
other, and the resultant indicates the differ-
25 ence of potential existing upon the work-cir-
cuit.
30
The invention will be described particularly
in connection with the accompanying draw-
ings, in which—
Figure 1 is a diagram illustrating an organi-
zation of circuits for carrying out the inven-
tion in one of its simpler forms, and Figs. 2
and 3 illustrate modifications.
Referring to Fig. 1, A represents an electric
35 generator or other suitable source of electric
currents, and L' L' represent two lines leading
from the respective poles thereof to a work-
circuit, D' D', containing translating devices d
d, designed to be operated by electrical cur-
40 rents. At or near the central station a solen-
oid, b, is connected in circuit between con-
ductors L' and L2 by the conductors 1 and 2.
A second coil, c, is connected in the direct cir-
cuit of the conductor L'. The coil b is pro-
45 vided with a core, e, preferably consisting of
a bundle of soft-iron wires magnetically sepa-
rated from each other, and the coil c is pro-
vided with a similar core, f. These two cores
are suspended from opposite ends of a beam,
E, pivoted at its center and carrying an indi- 50
cator, F, applied to a scale or index-plate, F'.
The coil b is so proportioned as to maintain a
balance when no current is flowing in the coil
c and a normal difference of potential exists at
the terminals of the generator. When very 55
little current flows through the main-line cir-
cuit L' L', the difference of potential at the
generator is practically the same as at the
lamps or translating devices d d; but as the
current increases the loss in the line increases 60
proportionately, and hence to preserve the
normal difference of potential at the translat-
ing devices the difference of potential at the
generator must be increased. This would tend
to throw the indicator out of balance, carrying 65
the pointer F toward the right hand, but for the
action of coil c, which, being traversed by the
main current, tends to restore the equilibrium.
If the loss in the main-line circuit amounts to,
say, approximately ten per cent. of the useful 70
work at a full load, then the difference of po-
tential at the dynamo should be ten per cent.
higher than when the load is very small. If,
therefore, the coil c has an effect equal to one-
eleventh that of the coil b, the balance will 75
still be maintained. When operating under
half the full load, the loss is five per cent., and
the effect of the coil c is approximately five
per cent., since the current passing through it
is reduced to one-half its former value. In 80
this manner the indicator will serve to show
when the difference of potential at the trans-
lating devices is at its required value.
In Fig. 2 there is shown a modification in
which the coils b and c are applied to the same 85
core, f', a weight, e', being opposed thereto in
place of the core e. These two coils act op-
positely upon the core f'. The weight e' is
adjusted so that when no current traverses the
main circuit it will balance the pull upon the 90
core f' at the normal difference of potential.
In Fig. 3 an organization is shown adapted
for alternating currents, in which the coil c
constitutes a portion of the primary coil of a
converter, and the coil b a second portion, while 95
a coil, s, constitutes the secondary coil. The
coil b is connected between the conductors L'
and L', as before, and the coil c is connected in
3008
2
380,942
the circuit of the conductor L'. The two coils
act in opposition to each other, and the cur-
rent induced in the secondary s will be due to
the difference of the effects of the currents in
5 the two coils b and c. The effects of the coils
IO
15
b and c are such that the resultant current in
the coil b' maintains a balance at the proper
electro-motive force for the current passing, a
weight, e, being opposed to the core f'.
1
In another application filed by me Decem-
ber 9, 1887, Serial No. 257,408, claims are
made particularly upon the use of a converter
in the manner described with reference to
Fig. 3.
I do not limit myself to an indicator of the
form shown. Any suitable means of indica-
tion may be used to which the above-described
organization is applicable.
I claim as my invention-
20 1. In an indicator for electric circuits, the
combination of two opposing coils, the one
connected in a shunt-circuit with the translat-
ing devices and the second in a series there-
with at or near the source of electricity, sub-
stantially as described.
25
2. The combination, with a source of elec-
tricity, of two opposing coils, one connected
in a shunt and the other in a series with the
work-circuit, and an indicator affected by the
currents traversing the coils, substantially as 30
described.
3. An indicator for electric circuits, consist-
ing of two coils, one connected in shunt upon
and the other in series with the work-circuit,
one of said coils being adjusted to secure a pre- 35
determined per cent. greater effect per unit of
current than the other, and an index operated
by the coils.
In testimony whereof I have hereunto sub-
scribed my name this 6th day of April, A. D. 40
1887.
OLIVER B. SHALLENBERGER.
Witnesses:
W. D. UPTEGRAFF,
LEW B. STILLWELL.
3009
(No Model.)
2 Sheets-Sheet 1.
L. B. STILLWELL.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
No. 399,218.
WITNESSES:
Stubert & Mḥalluborger.
Hubut 6. Fenes
Patented Mar. 5, 1889.
I'
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INVENTOR,
Leusi. Still well.
Pipe Edgecomb + Temy.
THE NORRIS PETENS CO., PHOTO-LITKO., WASHINGTON, D. C.
Att'ys
3010
(No Model.)
2 Sheets-Sheet 2.
L. B. STILLWELL.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
No. 399,218.
Patented Mar. 5, 1889.
L'
Fig 2.
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WITNESSES:
Jinbert B.Shallow burge
Aubrik. Fenek
FR
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2
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THE NORRIS PETERS CO.,
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C₂
$2
22
PHOTO
MOTO-LITHO
22
INVENTOR,
Lewis B. Stillwell.
Pope. Edgscomb & Fany.
Att'ys
WASHINGTON, D. C.
|
·
3011
UNITED STATES PATENT OFFICE.
LEWIS B. STILLWELL, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE
WESTINGHOUSE ELECTRIC COMPANY, OF SAME PLACE.
REGULATOR FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 399,218, dated March 5, 1889.
Application filed October 26, 1888. Serial No. 289,238. (No model.)
To all whom it may concern:
Be it known that I, LEWIS B. STILLWELL, a
citizen of the United States, residing in Pitts-
burg, in the county of Allegheny and State of
5 Pennsylvania, have invented certain new and
useful Improvements in Regulators for Sys-
tems of Electrical Distribution, (Case No.
247,) of which the following is a specification.
The invention relates to those systems of
10 electrical distribution in which alternating,
intermittent, or pulsatory electric currents are
employed for operating translating devices
located at various more or less distant points.
In organizing such systems it is customary to
15 arrange the translating devices in groups de-
pendent upon their locations and to supply
the requisite currents to the different groups
from a common source through "independent"
supply circuits or feeders, as they are com-
20 monly termed. In practice it is found that
the difference of potential applied to the trans-
lating devices through these feeders is liable
to vary from time to time, even though the
difference of potential applied thereto at the
25 central station is maintained approximately
constant. The variations in the difference of
potential at the translating devices are usually
due to the different resistances of the differ-
ent supply circuits or feeders and to the vary-
30 ing work being done in the circuits. It is
evident that if conductors of a given size are
employed for each of the supply-circuits the
resistances of those circuits will vary ac-
cording to their lengths, so that if the same
35 difference of potential is applied to all
of the feeders at the source the difference
of potential at the translating devices will
be in some circuits greater than in others.
If the amount of work being done in any
40 given circuit is increased or decreased, the
current required in that circuit will be in-
creased or decreased accordingly, and there-
fore the loss of potential upon that circuit
will be greater in proportion as the work is in-
45 creased or less as the work is decreased. If
the variations in the loss upon the several
different feeders were coincident, then the
difference of potential applied to the trans-
lating devices might be maintained approxi-
50 mately constant by increasing or diminishing
the difference of potential applied at the
station; but it is evident that if the loss upon
one circuit increases while that upon another
remains constant an increased difference of
potential applied to all the circuits would re- 55
sult in an undue increase of potential applied
to the translating devices in those circuits re-
quiring no change, so that it becomes neces-
sary to provide means for varying the differ-
ence of potential applied to any given circuit 60
without sensibly changing that applied to the
others. In systems of distribution where
secondary generators or converters are con-
nected in the feeders and translating devices
are connected in their secondary circuits there 65
is a slight loss of potential in the converter
itself, dependent upon the load or work be-
ing done in the secondary circuit.
The object, therefore, of my invention is to
overcome these difficulties, and to provide 70
means for obtaining any required difference
of potential upon any given circuit and for
compensating for the loss or drop in any given
circuit, whether due to the resistance of the
conductors conveying the current from the 75
source to the translating devices or to the va-
rying work being done, or to any other cause,
and to insure that each group of translating
devices shall at all times be supplied with a
proper difference of potential.
80
Prior to my invention it has been proposed
to construct the translating devices which
are placed in the different groups so as to
require a difference of potential dependent
upon their distance from the source of sup- 85
ply or upon the loss in the feeding-circuits
leading thereto. This plan is objectionable
for the reason, among others, that it involves
different forms of translating devices for dif-
ferent feeders and does not provide for the 90
varying number of translating devices which
are being operated and the consequent varia-
tion in the drop upon the line.
My invention consists in developing a nor-
mal electro-motive force at the central sta- 95
tion sufficient to supply the requisite differ-
ence of potential to the translating devices
included in the circuits having the least loss
or drop, and in increasing the difference of
potential upon any given circuit by applying 100
3012
2
399,218
a supplemental electro-motive force to that
circuit sufficient to compensate for the loss
or drop, or to raise the difference of potential
to any required extent that may be desired
5 for other reasons. It also involves the ob-
taining of any required variations in the
amount of electro-motive force added to any
circuit. This may be accomplished in differ-
ent ways, two of which will be described in
10 connection with the accompanying drawings.
Instead of developing a difference of poten-
tial sufficient only to supply the translating
devices in the circuits having the least drop,
however, it may be sometimes desirable to
15 develop a higher electro-motive force and re-
duce the difference of potential upon certain
circuits while increasing it upon others. Such
a system is described in another application
of even date herewith filed by me.
20
In the drawings, Figure 1 represents one
organization of circuit adapted to carry out
the invention, and Fig. 2 is a modification.
2
Referring to the figures, G represents any
suitable source of alternating, intermittent,
25 or pulsatory electric currents, and L' L' a cir-
cuit derived therefrom. This circuit may be
supplied either directly or indirectly from the
generator or through an electric converter.
The regulator may be connected to the cir-
30 cuit at the central station or at a point at any
distance therefrom, as required.
From the circuit L' L2 different supply cir-
euits or feeders, 1 2 and 3 4, are derived.
These respectively supply groups of trans-
35 lating devices, as shown at d'd' and d² d².
The devices may be supplied with current
either directly from the conductors 1 2 and 3
4 or through electric converters, as shown at
C' C². The translating devices may be elec-
40 tric lamps, electric converters, electric mo-
tors, or other electrically-operated apparatus.
Only one converter is shown as connected in
the separate feeders; but any required num-
ber may be so connected. Considering now
45 that the circuit 3 4 is longer or for some other
reason has a greater drop or loss of potential
than the circuit 1 2, then, unless means are
provided to prevent it, there will be less dif-
ference of potential applied to the terminals
50 of the primary coil p of the converter C2,
C²,
and consequently the translating devices 2
will be supplied with a less difference of po-
tential. For this reason, therefore, a device,
C, is employed for adding to the difference
55 of potential upon the circuit 3 4 an addi-
tional difference of potential sufficient to
compensate for the drop or loss upon that cir-
cuit. This device consists, in the organiza-
tion shown in Fig. 1, of an electric converter
60 having its primary coil p³ connected between
the lines L'L', or across the respective poles
of the source G, and its secondary coil s³
connected in the conductor 4. The coils of
the converter are so wound and connected
65 with reference to each other that the current
induced in the secondary coil will be in the
same direction as that flowing through the
|
|
conductor 4, so that the additional electro-
motive force applied to this conductor will
assist in maintaining a required difference 70
of potential at the terminals of the primary
coil of the converter C².
For the purpose of regulating the amount
of the additional electro-motive force thus
obtained an adjustable self-inductive device 75
or reactive coil, T, is connected in the primary
circuit of the converter or regulator C³. This
has the effect of reducing to a greater or less
extent the difference of potential applied to
the primary coil p³ of the regulator, as may 80
be required, for changing the added differ-
ence of potential. The parts are so organ-
ized that when all the translating devices d²
are being operated the induced electro-motive
force thus obtained will approximately com- 85
pensate for the loss or drop upon the line, so
that an approximately-constant difference of
potential will be maintained at the terminals
of the primary coil p² of the converter C². As
translating devices are cut out of circuit or 90
the work being done is diminished, the loss
upon the line will be decreased and also the
loss in the converter.
t
By moving the core of the self-induction
device T farther into the coils the difference 95
of potential applied to the primary coils of
the regulator C may be diminished, and con-
sequently electro-motive force developed. in
the secondary coils s may be gradually re-
duced until the difference of potential at the 100
terminals of the secondary coil s² of the con-
verter C² is reduced to the normal. In this
way, by changing the reactive effect of the
device T, the translating devices will be sup-
plied with the proper difference of potential 105
at all times.
In Fig. 2 a modification is illustrated in
which the ratio of conversion of the converter
may be adjusted by varying the length of one
of the coils-the secondary, for instance-by 110
means of a switch, S, applied to switch-points
s, connected with different points in the
length of that secondary coil. The adjusta-
ble reactive coil may be employed in connec-
tion with the adjustable converter, if desired. 115
It is evident that two or more regulators, C3,
117
may be applied to any given feeder-circuit
without departing from the spirit of my in-
vention.
Where numerous different circuits of va- 120
rious lengths or losses are employed, a regu-
lator of the character described may be ap-
plied to each of the circuits for the purpose
of affording the required compensation.
In some instances it is desired to normally 125
maintain a higher difference of potential upon
one or more of the feeders than upon the oth-
ers. This may be done in precisely the man-
ner described with reference to compensating
for the drop or loss. By varying the ratio of 130
conversion the difference of potential applied
to any given feeder may be increased as de-
sired.
In another application of even date here-
3013
399,218
3
with the method of operation herein set forth multiple arc, and a variable number of trans-
is described and claimed.
I claim as my invention-
1. The combination of a source of alternat-
5 ing intermittent or pulsatory electric cur-
rents, independent electric circuits derived
therefrom, an electric converter having one
coil connected in one of the derived circuits,
and an independent circuit connected di-
10 rectly across the poles of said source and in-
cluding only the second coil of the converter,
whereby currents will be caused to traverse
said second coil in value directly dependent
upon the current traversing derived circuit,
15 said coils being wound and connected so that
the currents induced in the first-named coil
are superposed upon those traversing said de-
rived circuit, substantially as described.
lating devices connected in their respective
secondary circuits, and a device for superpos-.
ing electric currents upon the primary cir- 50
cuit of one of said converters, consisting of
an electric converter having one of its coils
connected in said primary circuit in series
with the converter included therein and its
other coil connected in multiple arc with said 55
converter.
5. The combination, with a source of alter-
nating, intermittent, or pulsatory electric cur-
rents, of two or more circuits receiving cur-
rents therefrom, a regulator for one or more 60
of said circuits, consisting of an electric con-
verter having one coil independently con-
nected in circuit with said source between
points of approximately constant difference
2. The combination, with a source of alter- of potential and its other coil delivering cur- 65
20 nating, intermittent, or pulsatory electric currents to the circuit to be regulated, the first-
rents, of circuits derived therefrom, and an ad- named coil receiving currents opposite in di-
justable converter having one coil connected rection from those traversing the last-named
in one of the said derived circuits, and a spe- coil.
cial independent circuit including the other
25 coil connected in the circuit of said source in
parallel with said derived circuit, the coils of
said converter being so wound and connected
as to superpose induced currents upon the
current traversing said derived circuit.
30
3. The combination, with a source of alter-
nating, intermittent, or pulsatory currents, of
two or more groups of translating devices re-
spectively supplied with currents therefrom,
and an electric converter having its secondary
35 coil connected in the circuit supplying one of
said groups and its primary coil connected in
the circuit of the source of current independ-
ently of any other translating or transform-
ing device, whereby an additional electro-mo-
40 tive force is applied to said circuit, and means
for varying the amount of additional electro-
motive force thus applied.
4. The combination, with a source of alter-
nating, intermittent, or pulsatory electric cur-
45 rents, of two or more converters having their
primary coils connected with said source in
6. The combination, with a source of alter- 75
nating, intermittent, or pulsatory electric cur-
rents, of two or more circuits receiving cur-
rents therefrom, a regulator for one or more
of said circuits, consisting of an electric con-
verter having its primary coil independently So
connected in circuit with said source between
points of approximately constant difference
of potential and its secondary coil delivering
currents to the circuit to be regulated, the
said primary coil receiving currents opposite 85
in direction from those traversing the sec-
ondary circuit, and an adjustable reactive
coil in series with the primary coil of said
converter.
In testimony whereof I have hereunto sub- 90
scribed my name this 23d day of October, A.
D. 1888.
Witnesses:
LEWIS B. STILLWELL.
CHARLES A. TERRY,
C. C. WOLFE.
3014
(No Model.)
L. B. STILLWELL.
2 Sheets-Sheet 1.
METHOD OF REGULATION FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
No. 399,219.
Patented Mar. 5, 1889.
Fig 1.
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WITNESSES:
Starburst- B.Schallenburger
Stubirt & Fences.
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N. PETERS. Photo-Lithographer, Washingto、 DC.
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C2
$2
22
INVENTOR,
Lewis B. Stillwell.
Bpe, Edgecomb & temy.
Att'ys
3015
(No Model.)
L. B. STILLWELL.
2 Sheets-Sheet 2.
METHOD OF REGULATION FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
No. 399,219.
L'
Fig 2.
Patented Mar. 5, 1889.
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WITNESSES:
Stubert B.Shallenberger
Abubut bopened
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N. PETERS, Photo-Lithographer, Washington, D. C.
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INVENTOR,
Lewis B. Still will
Pops. Edgecomb TTam.
Att'ys.
3016
UNITED STATES PATENT OFFICE.
LEWIS B. STILLWELL, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE
WESTINGHOUSE ELECTRIC COMPANY, OF SAME PLACE.
METHOD OF REGULATION FOR SYSTEMS OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 399,219, dated March 5, 1889.
Application filed October 26, 1888. Serial No. 289,239. (No model.)
To all whom it may concern:
Be it known that I, LEWIS B. STILLWELL, a
citizen of the United States, residing in Pitts-
burg, in the county of Allegheny and State of
5 Pennsylvania, have invented a certain new
and Improved Method of Regulating Systems
of Electrical Distribution, (Case 248,) of which
the following is a specification.
upon one circuit increases while that upon
another remains constant an increased differ-
ence of potential applied to all the circuits
would result in an undue increase of poten- 5.5
tial applied to the translating devices in those
circuits requiring no change, so that it be-
comes necessary to provide means for vary-
ing the difference of potential applied to any
given circuit without sensibly changing that 60
applied to the others.
In systems of distribution where secondary
generators or converters are connected in the
feeders, and translating devices are connected
in their secondary circuits, there is a slight loss 65
of potential in the converter itself dependent
upon the load or work being done in the sec-
ondary circuit.
The object, therefore, of my invention is to
overcome these difficulties and to provide 70
means for obtaining any required difference
of potential upon any given circuit, and for
compensating for the loss or drop in any given
circuit, whether due to the resistance of the
conductors conveying the current from the 75
source to the translating devices or to the va-
rying work being done, or to any other cause,
and to insure that each group of translating
devices shall at all times be supplied with a
proper difference of potential.
80
The invention relates to those systems of
10 electrical distribution in which alternating,
intermittent, or pulsatory electric currents
are employed for operating translating devices
located at various more or less distant points.
In organizing such systems it is customary to
15 arrange the translating devices in groups, de-
pendent upon their locations, and to supply
the requisite currents to the different groups
from a common source through independent
supply - circuits or "feeders", as they are
20 commonly termed. In practice it is found
that the difference of potential applied to the
translating devices through these feeders is
liable to vary from time to time, even though
the difference of potential applied thereto at
25 the central station is maintained approxi-
mately constant. The variations in the dif-
ference of potential at the translating devices
is usually due to the different resistances of the
different supply-circuits or feeders and to the
30 varying work being done in the circuits. It is Prior to my invention it has been proposed
evident that if conductors of a given size are to construct the translating devices which are
employed for each of the supply-circuits the placed in the different groups so as to re-
resistances of those circuits will vary accord-quire a difference of potential dependent
ing to their lengths, so that if the same differ- upon their distance from the source of sup- 85
35 ence of potential is applied to all of the feed-ply, or upon the loss in the feeding-circuits
ers at the source the difference of potential leading thereto. This plan is objectionable
at the translating devices will be in some cir- for the reason, among others, that it involves
cuits greater than in others. If the amount different forms of translating devices for dif-
of work being done in any given circuit is in- ferent feeders, and does not provide for the 90
40 creased or decreased, the current required in varying number of translating devices which
that circuit will be increased or decreased ac- are being operated and the consequent varia-
cordingly, and therefore the loss of potential tion in the drop upon the line.
upon that circuit will be greater in proportion
as the work is increased, or less as the work
45 is decreased. If the variations in the loss
upon the several different feeders were coinci-
dent, then the difference of potential applied
to the translating devices might be maintained
approximately constant by increasing or di-
50 minishing the difference of potential applied
at the station; but it is evident that if the loss
My invention consists in developing a nor-
mal electro-motive force at the central sta- 95
tion sufficient to supply the requisite differ-
ence of potential to the translating devices
included in the circuits having the least loss
or drop, and in increasing the difference of
potential upon any given circuit by apply- 100
ing a supplemental electro-motive force to
that circuit sufficient to compensate for the
3017
ΤΟ
12
399,219
loss or drop, or to raise the difference of po-
tential to any required extent that may be
desired for other reasons. It also involves
the obtaining of any required variations in
5 the amount of electro-motive force added to
any circuit. This may be accomplished in
different ways, two of which will be de-
scribed in connection with the accompanying
drawings.
Instead of developing a difference of poten-
tial sufficient only to supply the translating
devices in the circuits having the least drop,
however, it may be sometimes desirable to de-
velop a higher electro-motive force and re-
15 duce the difference of potential upon certain
circuits while increasing it upon others. Such
a system is described in another application
of even date herewith filed by me.
In the drawings, Figure 1 represents one
20 organization of circuits adapted to carry out
the invention, and Fig. 2 is a modification.
Referring to the figures, G represents any
suitable source of alternating, intermittent,
or pulsatory electric currents, and L' L' a cir-
25 cuit derived therefrom. This circuit may be
supplied either directly or indirectly from the
generator or through an electric converter.
The regulator may be connected to the cir-
cuit at the central station, or at a point at any
30 distance therefrom, as required.
-
From the circuit L' L2 different supply-cir-
cuits or feeders 1 2 and 3 4 are derived. These,
respectively, supply groups of translating de-
vices, as shown at d' d'and d² d². The devices
35 may be supplied with current either directly
from the conductors 1 2 and 3 4 or through
electric converters, as shown at CC. The
translating devices may be electric lamps,
electric converters, electric motors, or other
40 electrically operated apparatus. Only one
converter is shown as connected in the sepa-
rate feeders; but any required number may
be so connected. Considering, now, that the
circuit 3 4 is longer, or for some other reason
45 has a greater drop or loss of potential than the
circuit 1 2, then, unless means are provided to
prevent it, there will be less difference of poten-
tial applied to the terminals of the primary coil
p of the converter C2, and consequently the
50 translating devices d² will be supplied with a
less difference of potential. For this reason,
therefore, a device, C, is employed for add-
ing to the difference of potential upon the
circuit 3 4 an additional difference of poten-
55 tial sufficient to compensate for the drop or
loss upon that circuit. This device consists
in the organization shown in Fig. 1 of an elec-
tric converter having its primary coil p³ con-
nected between the lines L'L2, or across the re-
60 spective poles of the source G and its secondary
coil s², connected in the conductor 4. The coils
of the converter are so wound and connected
with reference to each other that the current
induced in the secondary coil will be in the
65 same direction as that flowing through the
conductor 4, so that the additional electro-
motive force applied to this conductor will
assist in maintaining a required difference of
potential at the terminals of the primary coil
of the converter Cs. For the purpose of regu- 70
lating the amount of the additional electro-
motive force thus obtained, an adjustable self-
inductive device or reactive coil, T, is con-
nected in the primary circuit of the converter
or regulator C. This has the effect of reduc- 75
ing to a greater or less extent the difference
of potential applied to the primary coil p³ of
the regulator, as may be required for chang-
ing the added difference of potential. The
parts are so organized that when all the trans- 80
lating devices d² are being operated the in-
duced electro-motive force thus obtained will
approximately compensate for the loss or
drop upon the line, so that an approximately
constant difference of potential will be main- 85
tained at the terminals of the primary coil p²
of the converter C. As translating devices
are cut out of circuit, or the work being done
is diminished, the loss upon the line will be
decreased, and also the loss in the converter. 90
By moving the core t of the self-induction de-
vice T farther into the coils the difference of
potential applied to the primary coils of the
regulator C³ may be diminished, and conse-
quently electro-motive force developed in the 95
secondary coils s may be gradually reduced
until the difference of potential at the termi-
nals of the secondary coil s² of the converter
C² is reduced to the normal. In this way, by
changing the reactive effect of the device T, 100
the translating devices will be supplied with
the proper difference of potential at all times.
In Fig. 2 a modification is illustrated in
which the ratio of conversion of the converter
may be adjusted by varying the length of rog
one of the coils-the secondary, for instance—
by means of a switch, S, applied to switch-
points s, connected with different points in
the length of that secondary coil. The ad-
justable reactive coil may be employed in con- 110
nection with the adjustable converter, if de-
sired. It is evident that two or more regula-
tors, C3, may applied to any given feeder-cir-
cuit without departing from the spirit of my.
invention.
Where numerous different circuits of vari-
ous lengths or losses are employed, a regu-
lator of the character described may be ap-
plied to each of the circuits for the purpose
of affording the required compensation.
In some instances it is desired to normally
maintain a higher difference of potential upon
one or more of the feeders than upon the oth-
ers.
I
I 20
This may be done in precisely the man-
ner described with reference to compensating 12
for the drop or loss. By varying the ratio of
conversion the difference of potential applied
to any given feeder may be increased as de-
sired.
In another application of even date here- 131
with the organization of apparatus herein de-
scribed is claimed.
I claim as my invention-
1. The herein before - described method of
3018
399,219
g
regulating the difference of potential upon aning the same to the respective circuits, and
electric circuit, which consists in supplying to causing the effective value of the electro-mo-
such circuit a difference of potential of a given tive force so applied to the respective circuits
value, deriving from the same source an in- to approximately compensate for the loss upon 30
5 duced electro-motive force approximately that circuit due to the resistance thereof and
equivalent in value to the loss of potential to the amount of current traversing the same.
upon said circuit, and in superposing such in- 4. The hereinbefore - described method of
duced electro-motive force upon said circuit. maintaining a normal difference of potential
2. The herein before - described method of at the terminals of the translating devices in 35
10 maintaining a required difference of poten- two or more different circuits, which consists
tial at the terminals of a variable number of in applying to the terminals of all the circuits
translating devices connected in an electric a given difference of potential, deriving a sup-
circuit, which consists in applying a prede- plemental electro-motive force for one or more
termined difference of potential to said cir- of said circuits, the value of which is depend- 40
15 cuit, deriving from the same source a varia- ent upon and variable with the loss of poten-
ble difference of potential equivalent to or tial upon said circuit, and in applying such
compensating for the variable loss of poten- supplemental electro-motive force to such cir-
tial upon such circuit, and superposing the cuit or circuits.
same upon said circuit.
20 3. The hereinbefore - described method of
maintaining a normal difference of potential
at the terminals of translating devices in two
or more different circuits, which consists in
applying to said circuits a given difference of
25 potential, deriving independent electro-mo-
tive forces from the same source and apply-
In testimony whereof I have hereunto sub- 45
scribed my name this 23d day of October, A.
D. 1888.
Witnesses:
LEWIS B. STILLWELL.
CHARLES A. TERRY,
C. C. WOLFE.
(No Model.)
2 Sheets-Sheet 1.
3019
E. THOMSON.
DISTRIBUTION OF ELECTRIC CURRENTS.
Patented Apr. 15, 1890.
No. 425,470.
T
S
호
​T
호
​WITNESSES:
J. Hurdle
J. Th. Corry
6.
W
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B'
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TO
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Fig.
1.
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INVENTOR
Eliku Thoinson
BY
H.L. Townsend
ATTORNEY.
THE NORRIS PETERB CO., PHOTO-LITHO,, WASHINGTON, D. C.
(No Model.)
2 Sheets-Sheet 2.
3020
No. 425,470.
호
​I
M
WITNESSES:
gAthurdle
My St. Courry
E. THOMSON.
DISTRIBUTION OF ELECTRIC CURRENTS.
Patented Apr. 15, 1890.
же
G'
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THE NORRIS PETERS CO, PHOTO-LITHO, WASHINGTON, DC.
H
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Fig. 2.
INVENTOR
Elihu Thomson
BY
HL. Townsend
ATTORNEY.
3021
UNITED STATES PATENT OFFICE.
ELIHU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON-
HOUSTON ELECTRIC. COMPANY, OF CONNECTICUT.
DISTRIBUTION OF ELECTRIC CURRENTS.
SPECIFICATION forming part of Letters Patent No. 425,470, dated April 15, 1890.
Application filed January 29, 1890. Serial No. 338,526. (No model.)
To all whom it may concern:
Be it known that I, ELIHU THOMSON, a citi-
zen of the United States, and a resident of
Lynn, in the county of Essex and State of
5 Massachusetts, have invented certain new
and useful Distribution of Electric Currents,
of which the following is a specification.
My invention relates to systems of distribu-
tion of electric currents wherein the prime
Io generating source furnishes energy which is
carried over mains or conductors to a con-
siderable distance therefrom. In systems of
this character there is, as is well known, a
drop of potential at distant points, owing to
15 losses due to the resistances or other causes,
and in order to obtain a potential over the
whole system as nearly uniform as possible
it becomes necessary to use main conductors
of very great size or to employ some means
20 for maintaining or supplementing the poten-
tial at the more distant points, if it be de-
sired to have a uniformity of potential
throughout the system. It is also common in
such systems to provide some means to regu-
25 late the potential over the system in accord-
ance with variations in the load or demands
made for energy upon the circuits.
One of the objects of my invention is to
compensate for or prevent drop of potential
30 which takes place at points in the system re-
mote from the generating source without re-
sorting to the use of heavy or expensive main
or feeding conductors.
A further object of my invention is to keep
35 the potential at distant points up to the re-
quired amount, despite tendency to fall
through increase of load, and, in fact, to regu-
late the potential over the system in such
way as to maintain or produce a potential of
40 any desired degree under various conditions.
A further object of my invention is to pro-
vide a system of distribution having great
flexibility and adaptability to wide variations
in working conditions.
45
My invention consists, essentially, in sus-
taining, regulating, or supplementing the po-
tential at distant points of the system by
generating currents of comparatively high po-
tential by any desired means, conveying the
50 same over independent conductors or mains to
or near the points of the main system where
the potential is to be regulated, supplemented,
or maintained, transforming such high po-
tential to reduced potential suitable for feed-
ing to such mains, and applying such reduced 55
potential or energy to the main system at the
points where its potential is to be regulated,
sustained, or supplemented.
My invention consists, further, in the com-
bination of circuits and apparatus whereby I 60
am enabled to accomplish the objects of my
invention and whereby a simple and effective
regulation for variations in load is obtained,
and whereby, further, a maintenance of a uni-
form potential over a whole system may be 65
automatically produced.
My invention is applicable either to ex-
tensive net-works of mains or conductors run-
ning at moderate potential for incandescent
lighting or for other purposes, as well as to 70
motor-lines which extend to a great distance
from a generating-station for feeding station-
ary motors or for operating the motors upon
electric railways.
My invention comprises essentially in the 75
same system of distribution the combination
of apparatus feeding currents to a set of
mains, a second set of mains or conductors
fed with currents of high potential, generated,
preferably, at the main station, intermediate 80
transformers between the two sets of mains
at one or more points, such transformers be-
ing properly constructed to transform or con-
vert the high-potential current into a lower-
potential current, and connections from the 85
low-potential side of the converter to points of
the system where the potential is to be main-
tained, regulated, or supplemented. In other
words, it comprises in the same system a set
of mains extending from a generating-station 90
to a considerable distance therefrom, and a
set of mains of higher potential carrying cur-
rent which operates transforming apparatus
that in turn supplies the proper potential to
the more distant portions of the lower-poten- 95
tial mains or conductors. Owing to the use
of the higher potential, the distance is over-
come without great losses, and the necessity
of large-sized conductors on the lower-poten-
tial mains for the purpose of preventing drop 100
of potential is avoided.
The transformers or devices for converting
3022
2
2
425,470
the high potential into low potential may be
of any desired character. They may be, for
instance, the well-known device of a motor-
generator in which the motor is an electric
5 motor driven by the high potential, and the
generator mechanically operated by such mo-
tor is provided with armature coils or con-
ductors adapted to deliver the current of lower
potential, or they may be the well-known form
Io of converter or transformer consisting of an
induction-coil in which the conversion takes
place by direct inductive action between two
coils wound in inductive relation to one an-
other on the same core.
15
In the accompanying drawings, Figure 1 is
a diagram illustrating my invention. Fig. 2
illustrates the application of the invention to
alternating-current systems of distribution.
In Fig. 1 the devices are adapted to gener-
20 ate continuous currents.
M M' are mains or conductors, which are
supplied with energy from a dynamo-machine
G, of any suitable character. The generator
G may be of any proper character adapted
25 to supply current of regulated potential, or
may be of any other proper character for
supplying current to a system of mains or
conductors. The mains M M' are the main
supply-conductors from which the energy-
30 users such as incandescent lamps L L, mo-
tors S, or railway-motors T-derive current.
At or near the points of the main system
supplied by generator G, where the potential
is to be supplemented, regulated, or re-en-
35 forced, I place transformers B B', (here shown
as combination motors and generators,) which
are properly wound or organized in such man-
ner that by the application of the high-poten-
tial current they will revolve and give out
40 low-potential currents proper for feeding the
mains M M', to which they are connected.
The motor-generators here shown have their
two sets of coils-to wit, the motor and gen-
erator coils-wound on the same armature.
45 The high-potential current which works such
motor-generators, and which is transformed,
is supplied over a main or mains HH', which
derive their high-potential current from a
generating source G', that may be a dynamo-
50 generator. This dynamo-generator might be
a compound-wound dynamo, a shunt-dynamo,
a separately-excited dynamo, or any other
form of machine; or, in place of a dynamo,
any other source of current of higher poten-
55 tial than that supplied to the mains M M'
might be used. It is well to use a potential
as high as practicable under the conditions of
use, in order that the lines II II' may be of as
small gage as possible. The transformers are
60 supplied with such high-potential energy in
any desired manner, but, preferably, are con-
nected in multiple to the high-potential lines,
and the high-potential generator is of such
character as to supply a regulated potential
65 to the lines H H', or, in other words, one of
constant or approximately constant amount.
The generator G, if a dynamo-machine,
|
might be driven by any suitable power and
in any suitable manner; but I prefer to have
the machines G G' interdependent, so that 70
they shall be operated always at the same
relative speed. By this means I secure regu-
larity and uniformity in output of the ma-
chines relatively to one another and a uni-
formity of operation under various conditions 75
of the system.
By the use of the supplemental mains of
high potential I am enabled to use mains M
M' of moderate dimensions and at the same
time to secure a uniformity of potential over 80
the whole system.
Suitable fuses may be interposed in both
the high and low potential circuits, as indi-
cated at points F F', and switches for cutting
off or disconnecting any portion of the circuit 85
may be established at any desired point or
points, as at Z.
By the use of the transformers such as in-
dicated Kaving the double-wound armatures
and by running them at high speed in strongly- 90
magnetized fields, the high potential of the
high-potential circuit will be transformed to
give current to the other circuit with a lower
potential and with extremely small loss in the
transformation. The machines or converters 95
will also respond to the call upon them for
more energy as it is required, thus giving the
effect of an automatic supply of current in
accordance with the demand of the main cir-
cuits M M'. So long as the potential of the roo
mains M M' is maintained at its regulated or
normal amount and very little call exists for
current from the transformers B B', the lat-
ter will do little or no work and the gener-
ator G can be made to deliver all the current 105
needed. If, however, at a distant point on
the mains M M', near the point of attachment
to one of the transformer-machines B B', a
sudden heavy call for current takes place,
then such machine B B' becomes at once a 110
powerful and efficient generator of low-poten-
tial current, which is fed to the mains M M'
to sustain their potential at the same time
that a considerable high-potential current
from the mains II H' flows to the converter, 115
the amount depending upon the potential of
the mains relatively to one another. At the
same time this occurs the generator G' is
called upon for additional output, while the
generator G may do little work, if any.
the call, however, for current is upon the
mains M M' near the generating-station, or
the place where the wires from G are at-
tached, then but little call will be made on
the distant transforming-machines and the 125
work will be fed directly from the station at
low potential. My system, therefore, permits.
the feeding at uniform potentials to lines ex-
tending over a very large area or at consid-
erable distances from the generating-station, 130
as is the case with railways extending several
miles therefrom.
If 120
When the load is light upon the mains M
M', as by the cutting off of the lights, &c.,
3023
1
425,470
|
3
which consists not only in the particular com-
binations of circuits and apparatus herein
described, but also, broadly, in the method of 70
maintaining the desired potential at points
in the system of distribution remote from the
supply-station by supplying such points with
electrical energy in two ways-one by a low-
potential generator and the other by the trans- 75
formation of high- potential energy into a
proper low-potential energy through devices.
fed from high-potential mains or circuits. It
will of course be understood that in the case
of main conductors M M' of great length it 80
will be necessary in case a uniform potential
is desired over the whole system to adapt
each one of the transformers B B' to its par-
ticular location, and in the case of the trans-
formers more remote from the main station 85
to wind or construct them so that the poten-
tials delivered to the mains M M' will be
greater the farther the transformer is re-
moved from the main station. In the case of
the use of alternating currents it will be un- 90
derstood that the synchronism of the phases of
the directly-supplied waves and the waves of
the current supplied by induction will be re-
quired. This can be done by the relation of
the rotating parts of the generating-machines. 95
What I claim as my invention is—
then it will seldom be necessary to maintain
the action of the transforming - machines B
B', &c., and they can readily be cut out of
circuit by the switches provided, as at Z Z,
5 &c. In fact, if no call exists on the high-po-
tential line HH' for current, it can be cut off
altogether, or the machine G' be shut down,
while G remains to supply the current; hence
the system is a very flexible one and can be
10 adapted to a variety of circumstances or needs.
In Fig. 2 the system is shown modified for
application to an alternating system for feed-
ing lights. The generator G would, as before,
feed mains M M' at low potential, and
15 branches from the latter mains exist running
as desired to lights, as described, over a dis-
trict, as at L. The high-potential mains H
H' are fed from another generator G', or from
a portion of the first generator if properly or-
20 ganized, and the potential is only limited by
the insulation of the line. Atsuitable points
transfer devices-such as induction - coils,
converters, or transformers-are established
for lowering the potential of the current feed-
25 ing the line II HI' to that needed to supply
the line M M', as before, suitable cut-off de-
vices and other similar appliances being in
all cases understood as provided. The trans-
formers in this case are simply induction-
30 coils made in the ordinary way for such pur- 1. The herein-described method of main-
poses, and the relation of the windings is taining or regulating the potential at any
such as to suit the relations between the po- point of a system of electrical distribution,
tentials of H H', or high-potential mains, and consisting in supplying energy thereto from 100
M M' as low-potential mains. The transform- two sources, one connected therewith over
35 ers B B' feed the mains at the distant points, one set of mains or conductors and the other
while the direct feeding of M M' by the gen- indirectly connected therewith through an-
erator G is to those points near the station, other set of mains or conductors of high po-
especially when the load on the whole sys-tential, from which the energy is transformed 105
tem is considerable. There is nothing to pre-
40 vent, in the extension of such a system as I
have described, the addition of a third gener-
ating-machine or a third and still higher po-
tential for distribution to the still more dis-
tant points, though this is unnecessarily com-
45 plex, for the reason that the high-potential
Îine II H' may feed potential sufficient to
reach the more distant points and still be ap-
plied to feed the points much nearer to the
generating-station.
50
The operation of the generators G G' to-
gether in Fig. 1 may be accomplished by
mounting their armatures on the same shaft
with an intermediate clutch, as shown, where-
by, in case the generator G' be not required,
55 the generator G may be alone operated. Ido
not limit myself, however, to any particular
way of driving such generators together.
While I have shown two forms of convert-
ers or transformers adapted for transforming
60 the high potential into low potential, I do not
limit myself to these special devices, as any
means adapted to convert the high-potential
currents, whether continuous or alternating,
on the one circuit into the required low po-
65 tential or supply to the other portion of cir-
cuits or part of the system may be used with-
out departing from the spirit of my invention,
•
to low potential for application to such points.
2. In a system of electrical distribution, the
herein-described method of supplementing
the diminished potential at points distant
from the main source, consisting in generat- 110
ing an independent current of higher poten-
tial, conveying the same to or near the said
distant point, and there converting it into
electrical energy of lower potential adapted
to be carried directly to the conductor whose 115
potential is to be re-enforced.
3. The herein-described method of main-
taining or producing the desired potential at
any point distant from a main generator, con-
sisting in generating electrical energy of 120
higher potential than that of the main gen-
erator, carrying the same over suitable con-
ductors independent of those connected di-
rectly to such main generator, and converting
such higher potential into a suitable lower 125
potential at or near the point where the po-
tential is to be maintained or re-enforced, and
then feeding such lower potential to the main
wire or conductor of the system.
4. The herein-described method of obtain- 130
ing a uniform potential at points of a system
of distribution located at different distances
from the main generator supplying the same,
consisting in generating a higher potential
}
3024
4
425,470
by any suitable means, conveying the same
over suitable separate conductors to or near
the distant points of the system, there con-
verting such higher potential into a lower
5 potential of a suitable amount, and supply-
ing such low potential to the points of the
main system.
5. A combined system of generation and
distribution of electric currents, comprising
IO at a central station two generating appara-
tuses of high and low potential, respectively,
two sets of mains of high and low potential,
respectively, connections from the low-poten-
tial generating apparatus directly to the low-
15 potential main, connections from the high-
potential generating apparatus to the high-
potential mains, and devices at a distance,
such as transformers, using current from the
high-potential mains and transforming it
20 suitably for the comparatively low-potential
mains.
6. In a combined system of generation and
distribution, the combination, substantially
as described, of mains M M', fed from a suit-
25 able generator, lines H H', supplied with en-
ergy of approximately constant potential,
transformers connected in multiple to such
lines H H' and adapted to convert the po-
tential of such mains into lower potential on
30 a separate circuit, and connections from the
latter to the mains M M', for feeding such
lowered potential thereto, as and for the pur-
pose described.
>
7. The combination, substantially as de-
35 scribed, of mains M M', fed from a generator
G, of any suitable description, electric lines
HH', leading from the main station and sup-
plied with currents of high potential, and
motor-generators adapted to convert such
40 high-potential current into continuous cur-
rent of lower potential, such motor-generators
being connected to the mains H H at points
distant from the main station and being con-
nected to supply continuous current to the
45 mains M M', as and for the purpose described.
8. The combination, substantially as de-
scribed, of electric supply-conductors leading
from the same generating-station to the ter-
ritory to which electric energy is to be fur-
50 nished and supplied with energy of different
potential, transformers located at points of
the system distant from the main station and
|
adapted to convert high potential into low,
and connections from such transformers to
the high and low potential mains or circuits, 55
respectively, as and for the purpose described.
9. In a combined system of electrical gen-
eration and distribution, the combination, sub-
stantially as described, of two sets of mains
M M' and H H', the generator G, supplying 6c
the mains M M', means for supplying the
mains H H' with a higher potential, and mo-
tor-generators connected to the mains H H'
in multiple and having double-wound arma-
tures, as described, the generator portion of 65
which connects to the mains M M' and is
adapted to supply thereto electric energy of
lower potential than that on the mains HH'.
10. The combination, substantially as de-
scribed, of two dynamo-generators operated 70
constantly at the same relative speed and
generating current of different potential, re-
spectively, electric conductors supplied with
energy from the lower potential generator,
conductors carrying current of the higher po- 75
tential, and transformers between the two sets
of conductors for converting the higher po-
tential current into a lower potential, as and
for the purpose described.
11. The combination, with mains supplying 80
translating devices in multiple, of supple-
mental mains carrying current of higher po-
tential, transformers connected in multiple
between the latter, and connections from the
low-potential side of said converters to the 85
lower-potential mains.
12. The combination, substantially as de-
scribed, of mains supplying translating de-
vices in multiple arc, mains of higher poten-
tial to which transformers are connected in 90
multiple, connections in multiple from the
first-named main to the low-potential side of
the converter, and dynamo-machines operated
constantly at the same relative speed and sup-
plying currents of relatively high and low po- 95
tential to said mains, respectively.
Signed at Lynn, in the county of Essex and
State of Massachusetts, this 24th day of Jan-
uary, A. D. 1890.
Witnesses:
ELIHU THOMSON.
JOHN W. GIBBONEY,
ALBERT L. ROHRER.
3025
(No Model.)
E. THOMSON.
COMPOUND WOUND DYNAMO ELECTRIC MACHINE.
No. 349,912.
P
P
R
M
Patented Sept. 28, 1886.
Fig.1.
#
Z
Z
A
M
Fig. 2.
Fig. 3.
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Fig. 6.
Fig. 5.
M
THE
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15
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W
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Fig. 8.
HA
Fig.4.
·Hami
m
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Th
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10
་་
WITNESSES:
Gabriel & W Golster
Mm. It.Capel
BY
INVENTOR
Elihu Thomson.
766. Гал
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
ATTORNEY.
3026
UNITED STATES PATENT OFFICE.
ELIHU THOMSON, OF LYNN, MASSACHUSETTS.
COMPOUND-WOUND DYNAMO-ELECTRIC MACHINE.
SPECIFICATION forming part of Letters Patent No. 349,912, dated September 28, 1886.
Application filed June 14, 1886. Serial No. 205,165. (No model.)
To all whom it may concern:
Be it known that I, ELIHU THOMSON, a citi-
zen of the United States, and a resident of
Lynn, in the county of Essex and State of Mas-
5 sachusetts, have invented certain new and use-
ful Compound-Wound Dynamos, of which the
following is a specification.
My present invention relates to compound-
wound dynamos and attachments, whereby the
10 properties of such machines may be varied to
suit varied conditions of working.
It is usual to wind compound-wound ma-
chines in such a way that as more load is
thrown on in multiple arc the volts potential
15 at the terminals rises a little so as to compeu-
sate for the drop in the mains to some degree,
and so preserve an average flow of current in
the multiple-arc branches and an average bril-
liancy of lights when incandescent lamps are
20 employed.
30
It is sometimes desirable to feed lamps at a
considerable distance from the dynamo, in
which case, to save copper, the mains can be
made so small as to involve, with full load, a
25 loss of five, ten, fifteen, or even twenty per
cent. of the energy of the current when power
is cheap. This loss necessitates an increase in
volts at the machine of five, ten, fifteen, or
twenty per cent., as the case may be; but if
in such case the load or number of lamps were
lessened, the loss would disappear and too high
potential would reach the distant points on the
mains. The case assumed is one in which the.
work is done by current supplied from a dis-
35 tributing center or centers and taken from the
mains at a considerable distance from the gen-
erating-station. The coarse wire or direct field-
wire winding of a compound-wound machine
for such uses I make of such exciting strength
4c that from light load to full load of current gives
an increasing potential at the machine termi-
nals up to, say, twenty per cent. I then provide
means, such as resistance-shunts, around the
whole or part of said winding, so that it may
45 be lowered in effect by such shunting devices
to the desired degree required for the circum-
stances of each case.
Figure 1 shows an arrangement of circuits
and apparatus embodying my invention. Fig.
50 2 is a diagram of circuits. Fig. 3 is a side view
of a form of attachment for shunting the direct
|
field; Figs. 4 and 5, other views of the same.
Figs. 6, 7, and 8 show other modifications.
In Figs. 1 and 2 S² is the derived-circuit field-
coil.
55
DD are the direct-circuit coils of a com-
pound-wound machine. Coils D are shown in
Fig. 1 as surrounding only the movable arma-
ture core, though in the cases where it is used
ou the field-cores the further attachments are 60
the same.
A is the armature.
The coils D D are in the main circuit, and
of amount of strength to give an increase of
potential on passage from light load or no lamps 65
to full load or all lamps on, which increase shall
be enough, or more than enough, for all prac-
tical requirements. Connections P P are ar-
ranged so that a shunt, S, may be used to afford
a by-pass for current around coils D D, in whole 70
or part, as desired, said connections being
suitably placed for attachment of one or an-
other of a set of shunts, S, giving definitely-
lessened effects to the coils D D, so that the
increase of potential may be less and less as 75
such shunts are of less and less resistance,
down, it may be, to a shunt giving practically
constant potential at the terminals of the ma-
chine from light load to full load. The shunt
S is made easy of attachment by clamps P P, 80
fixed to a board, R, as indicated in Fig. 3, and
may consist of a strip of German silver or cop-
per folded on itself and furnished with ears e e,
Fig. 4, for attachment in any usual way. Other
shunts are constructed with less resistances, (as 85
less folds,) Fig. 5, to be substituted for S, when
it is necessary to further lower the compound-
ing. Again, if desired, a set of shunts, as in
Fig. 6, can be arranged on a board, with plugs
g
g, to shunt one or the other of them when not go
needed; or the shunts may be combined in
multiple, as in Fig. 7, where metallic strips
W W,with clamps, are shown for the purpose,
and may be removed, or used singly or in pairs,
or all together, to obtain the desired properties. 95
Further, the shunts may be arranged as an
adjustable rheostat with an operating-handle,
as in Fig. 8. This form is especially useful for
rapid adaptations to varying potentials or
compounding.
What I claim as my invention is-
1. The combination, in a compound-wound
100
3027
2
349,912
dynamo-machine, of a direct-circuit coil of
proper power to give a considerable increase
of potential in passing from light to full load,
and shunting devices whereby the exciting
5 power of said coil may be lessened to adapt
the machine for use in conditions where a lesser
increase of potential is required, as and for the
purpose set forth.
2. The combination, with the direct-circuit
to field-coil in a compound-wound dynamo, of
shunt-connections from the same to a set of
clamping devices and a set of attachable re-
sistances of graduated amounts, each adapted
for connection to the clamping devices.
Signed at Lynn, in the county of Essex and 15
State of Massachusetts, this 10th day of June,
A. D. 1886.
Witnesses:
ELIHU THOMSON.
M. L. THOMSON,
O. S. THOMSON.
3028
(No Model.)
No. 372,330.
E. W. RICE, Jr.
2 Sheets-Sheet 1.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 1, 1887.
I
Fig. 1.
c
A
R
R
C
R
R
3′
X
3
I
WITNESSES;
Gabriel. J. W. Galster.
Masflexper
4
مخروط
P
X
-3′
S
I
P
P
BY
INVENTOR
E. Wilbur Rice, Sr.
Tensendes Mac Arthur-
THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.
3029
(No Model.)
No. 372,330.
E. W. RICE, Jr.
2 Sheets-Sheet 2.
SYSTEM OF ELECTRICAL DISTRIBUTION.
Patented Nov. 1, 1887.
H
Fig. f.
R
-I
X
2'
ď
d
2
Fig. 3.
f
R
K
ww
H
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D
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Zig. 5.
WITNESSES:
Gabriel J. W. Galster.
R
G
K
=
THE NORRIS PÉTERS CO., PHOTO-LITHO., WASHINGTON, D. C.
X
A =
2
2
V²
pu
X
I
Fig. 4
R
BY
INVENTOR
E. Wilbur Rice, Jr.
Finnsend & Machither
ATTORNEYS
3030
UNITED STATES PATENT OFFICE.
E. WILBUR RICE, JR., OF LYNN, MASSACHUSETTS.
SYSTEM OF ELECTRICAL DISTRIBUTION.
SPECIFICATION forming part of Letters Patent No. 372,330, dated November 1, 1887.
Application filed March 7, 1887. Serial No. 229,909. (No model.)
To all whom it may concern:
Be it known that I, E. WILBUR RICE, Jr.,
a citizen of the United States, and a resident
of Lynn, in the county of Essex, and State of
5 Massachusetts, have invented a certain new
and useful System of Electrical Distribution, of
which the following is a specification.
My present invention relates to an improved.
method of regulating and supplying the elec
10 tric current to a large district, where it is im-
portant to keep the potential between the ter-
minals of the lamps or other devices practi-
cally constant. It is especially adapted for
use with those systems in which an alternating
15 or reversed current is used to feed a number
of incandescent lamps or other translating de-
vices directly or indirectly through the me-
dium of induction coils or transformers.
The invention consists in laying throughout
20 the district to be supplied with electricity a
set of mains in multiple arc or multiple series
and connected, preferably, to form a net-work,
and in connecting to such net-work at differ-
ent points suitable feeders or lines carried
25 back to any suitable source of alternating cur-
rents, said feeders or feeder-lines containing
means-such as reactive coils--whereby the
self-induction or reaction of the feeders may
be varied. By varying the reactive power of
30 the coils the current supplied to the net-work
by the feeder may be changed and regulated,
and thereby compensation made for changes
in the load in different parts of the system.
The invention also consists in certain de-
35 vices whereby a certain definite potential may
be automatically maintained at the points
where the feeders enter the multiple arc net
work. Each feeder is preferably constructed
so that its resistance is inversely proportional
40 to the load it is intended to carry and is con-
nected to the mains at the proper points. The
reactive coils are adjusted to have a minimum
or practically no reactive effect when the load
is properly distributed and at its maximum over
45 the system. The potential will then be uni-
form at all places. If, now, the load be thrown
off a portion of the system, as by putting out
a number of incandescent or arc lamps, the
potential at that portion of the system will be
50 immediately increased. If, however, the self-
induction or reaction of that particular feeder
be increased by changing the reactive effect
of the reactive coil in its circuit, the current
delivered by the feeder will be diminished
and the potential can be reduced to the proper 55
amount. The same result will follow if the
load be thrown off any part of the system and
the reactive effect of the proper feeders be
varied to suit.
It has been customary hitherto whenever 60
it was desired to vary the amount of current
passing over a feeder-line to insert or remove
a resistance. Such practice, however, is ob-
jectionable and wasteful, as the resistance ab-
sorbs the current and uses up energy which 65
might otherwise be fed to the lamps. With
my present invention, however, such waste is
reduced to practically nothing, as the react-
ive coils operate by opposing a counter elec-
tro-motive force to the current and not by in- 70
serting a resistance.
Referring to the drawings, Figure 1 illus-
trates the application of the invention to a
system of electric distribution in which a net-
work of wires is employed and the alternating 75
currents are transformed into local circuit-
currents. Fig. 2 shows a device for automati-
cally varying the reactive effect of the react-
ive coils. Fig. 3 shows one form of an adjust-
able reactive coil. Fig. 4 shows a slightly 80
modified form. Fig. 5 shows still another form
of reactive coil.
85
Referring to Fig. 1, A is any source of alter-
nating currents, and 2 2 2′ 2′, 3 3 3′ 3′, 4 4 4′ 4′,
5 5 5′ 5′, and 6 6 6′ 6′ are feeder-circuits con-
nected to each other and to the source of alter-
nating currents A at one end, and connected
into a system of multiple-arc mains, X X, at
the points 2 2, 3 3′, 4 4′, 5 5′, and 6 6'. Con-
nected from side to side of the mains are in- 90
duction-coils I I I, &c. The alternating cur-
rents from the mains pass through the primary
wires of these induction coils, and the induced
currents generated in their secondaries are
used to run incandescent lamps S, or other 95
translating devices. Instead of using induc-
tion-coils, the incandescent lamps can be con-
nected directly to the multiple-arc mains. By
the use of the induction-coils, however, cur-
rents of higher potential may be used on the foo
mains and greater economy of distribution be
obtained. Connected with each of the feeder-
circuits are the reactive coils R R R R R, so
constructed that their reactive effect or self-
3031
2
372,330
85
induction can be suitably varied either by through an increase of speed of the alternate-
hand or automatically in such manner as to current generator A, or other cause, the de-
vary the amount of current supplied by each vice V2 is more greatly energized. The cop. 70
feeder, and hence the potential at the points per disk a is repelled, closing the contact t and
5 fed by each feeder in circuit. V V V are in- throwing into action the coils of the device M.
dicators of potential connected, respectively, The copper disk o, opposite the core sur-
to the points 2 2', 3 3', &c., where the feeders rounded by the coils of M, is then repelled,
enter the multiple-arc net-work, which points moving 'the lever H, to which it is attached, 75
may be termed the "distributing points," or so as to throw into action a portion of the wire
10 "distributing centers." These indicators en- on R, thus reducing the potential at a d'.
able the person in charge of the station to tell When the potential has again reached normal,
when the potential at the distributing points the contact at t will be rapidly broken and
is at the proper predetermined amount, and closed, maintaining the reaction of the coil R 80
form a convenient indicator to gage as to the at the proper amount. In case more load is
15 amount of adjustment required to be made in thrown off, the same action is further repeated.
each feeder.
In case load is thrown on again, the reverse
In Fig. 2, A is the alternate current gen-action occurs. The potential at d d' is thus
erator; 2 2 2′ 2', one of the feeder circuits; R, kept constant automatically.
an adjustable reactive coil in said feeder cir-
20 cuit; X X, multiple-arc mains fed by the
feeder; I, an induction coil, and V² is a device
responsive to changes in the potential at dd',
and consisting of a core of fine iron wire, around
which is wrapped a coil of wire whose termi-
25 nals are connected by metallic wires to d d'.
The magnetic impulses in V will therefore vary
responsively as the potential atd d'rises or falls.
The points d d' are preferably selected near
the points of connection of the feeder circuit.
30 Opposite the core of V² is a copper disk, a,
whose movement closes or opens a cut-out or
other switch at t, controlling thereby the de-
vice M, which is adapted to move the lever
H over the contacts K K and change thereby
35 the reactive effect of the coil R by varying the
number of coils in circuit.
The devices M V2, I do not specifically claim
as my invention. By these devices a continu-
ous movement of repulsion is produced simi-
lar to the movement of attraction which is
produced when a continuous current flows 90.
through the coils of an electro-magnet.
The disks a o are supposed to be of consid-
erable mass and good conductivity, so that the
magnetic induction of the core or coils of Vª M
may set up in the disks alternating currents 95
of considerable self-induction, whose tendency
to prolong themselves will cause then to en-
dure beyond the point of change of polarity
in the inducing core or coils. The resultant
effect is a continuous tendency of repulsion.
Various forms of devices embodying this
principle are described in an application of E.
Thomson, filed January 26, 1887, and patented
May 17, 1887, No. 363, 186.
ΙΟΟ
The device M may be an electro-magnet of
any suitable character; but I prefer to employ
an apparatus which shall work by the opera-
40 tion of the alternating currents in a similar
manner to the devices described in the patent
of E. Thomson, hereinafter mentioned. For
this purpose I wind the coils of the electro-
magnet on a core consisting of a bundle of
45 wires whose polar end is encircled by a ring
or annulus of copper, rather massive in char-
acter, and carried by the lever H. The re-
pulsion set up between the magnet and ring
causes the lever to move so as to change the
50 number of coils of the reactive coil R. The
coil of the device M is in a circuit from the
alternating source, as indicated, which circuit
is controlled by the switch at t in obvious
manner. When the flow of current increases
55 in the coil of V2, the closing of the contact at
t results and current is caused to flow in the
coils of M. Its action, briefly, is as follows:
The copper disk a is so adjusted by a spring
that contact t is open when normal potential
60 exists at d d', and the device M is thus unen-
ergized, and the spring S therefore holds arm Hvices and combinations of devices suitable for
on the last contact K. Coil R is therefore out
of circuit, and the minimum of reaction there-
fore exerted in the feeder 2 2. This condition
This condition
65 corresponds to that of the maximum load on
the feeder. If the potential at d d'increases
through throwing off some of the lamps or
It is apparent that either the inducing ele- 105
ment or the element in which the induced cur-
rents are set up may be the movable part of
the device.
While I have described one specific device
which may be employed for securing the ad- 110
justment of the counter-electro-motive-force
generator, I do not wish to be understood as
limiting myself in this respect, since the gist
of my invention consists in automatically regu-
lating the alternating currents by means of an 115
adjustable reactive coil or other counter-elec-
tro motive-force generator, whose adjustment
is controlled by a device of any suitable kind
that shall be responsive to changes in the al-
ternating currents.
I 20
I have described the device V2 as bringing
into action a second device upon which the
work of adjusting the reactive coil is imposed;
but it will be understood that the adjustment
might be effected directly, and also that the 125
device V2 might be employed to bring into ac
tion a motor device of any other nature.
De-
such purpose are commonly employed in regu-
lators for dynamo-electric machines, &c., and 130
many of such appliances will be found suit-
able to the purposes of my invention, pro-
vided, however, that the prime controlling de-
vice corresponding to V be one suitable for
›
3032
372,330
responding to variations in alternating cur-
rents.
Fig. 3 shows a form of reactive coil which
may be used. R is a coil of wire connected in
5 and forming a part of any of the feeders. X
is a core of iron wire attached to the lever H,
so that the core X may be inserted into or
drawn out of R to any desired extent and
firmly clamped by the nut f in the proper
10 position.
Fig. 4 shows the same form of coil with the
core X placed horizontally.
In Fig. 5 the core X consists of a bundle of
fine iron wires or bundles of sheet-iron, and
15 wrapped around the core are the coils of wire
R, wound in sections and connected to the
point K of a switch or commutator. One end
of a feeder is connected to the lever H and one
to the coil R. By moving the lever H, more
20 or less of the coils R may be inserted into the
feeder and the reactive power of the coil R be
thereby varied.
What I claim as my invention is—
1. In a system of electrical distribution, the
25 combination, with the mains traversing. the
district to be supplied, of the feeder circuits
connected to said mains at different points,
and each carrying an alternating or reversed
current, and adjustable counter-electro-motive-
30 force generators placed in said feeder circuits.
between the supply mains and the source of
alternating current, as aud for the purpose
described.
.
3
4. The combination, with mains supplying 50
one or more translating devices with alternat-
ing or reversed currents, of an adjustable
counter-electro-motive-force generator in the
circuit over which the alternating currents are
fed to said mains, and a controlling device for 55
governing the adjustment of said counter-
electro-motive-force generator, said control-
ling device being connected to the mains, as
described, so as to be responsive to changes in
the potential on said mains.
60
5. The combination, in a system of electri-
cal distribution, of a set of mains supplying
induction-coils in multiple arc, feeder circuits
carrying alternating or reverse currents, ad-
justable counter-electro-motive-force genera- 65
tors in said feeder-circuits, and controlling de-
vices for said generators responsive to changes
in the potential of the mains, as and for the
purpose described.
6. The combination, with a wire or conductor 70
carrying an alternating current, of an adjust-
able counter-electro-motive-force generator
placed in the circuit of said wire or conductor,
and a controlling device therefor, consisting,
essentially, of a conductor of low resistance 75.
and high self-induction, in which currents are
induced by the alternations of current on the
circuit, as and for the purpose described.
7. The combination, in a system of electri-
cal distribution, of mains traversing the dis- 80
trict to be supplied, feeder-wires connected
with said mains at various points and carry-
2. The combination, in an electrical distri-ing alternating currents, adjustable counter-
35 bution system, of mains traversing the dis
trict to be supplied and supplying currents
in multiple arc, a generator or source of alter-
nating currents connected with said system of
mains, feeder-wires connected to said mains at
40 different points, as described, and adjustable
counter-electro-motive-force generators in the
respective feeder-wires, as and for the purpose
described.
electro-motive-force generators in said feeder-
wires, aud controlling devices for said gener- 85
ators responsive to the changes of potential
on the mains, and connected to said mains at
or near the points where the feeder-wires are
joined to the same.
3. The combination, with an alternating-
45 current circuit, of an adjustable counter-elec-
tro-motive generator, and a controlling or ad-
justing device therefor responsive to the va-
riations in the alternating current on the cir-
cuit, as and for the purpose described.
Signed at Lynn, in the county of Essex and 90
State of Massachusetts, this 3d day of March,
A. D. 1887.
Witnesses:
E. WILBUR RICE, JR.
J. W. GIBBONEY,
ELIHU THOMSON.
ས བ 1:1:|:|:ཀུན ད ན
7
UNIVERSITY OF MICHIGAN
3 9015 07500 7032
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