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PUB

HARTLEY

PUBLIC WORKS m THE UNITED STATES
AND IN CANADA.

3 J* J

^1 n I iiu ijipi

««PMi«l

1S"?5

NOTES

PUBLIC WORKS IN THE UNITED STATES

AND IN CANADA,

INCLUDING A DE8CUIPTI0N OP

THE ST. LAWRENCE AND THE MISSISSIPPI RIVERS
AND THEIR MAIN TRIBUTARIES.

Sm CHARLES A. HARTLEY, M. Inst. C.E., F.R.S.E.

- • By permission of the Council.

Excerpt Minutes of Proceedings of The Institution of Civil Engineers,
Vol. xl. Session 1874-75. — Part ii.

Edited by James Forrest, Secretary.

LONDON : PRINTED BY WILLIAM CLOWES AND SONS,

STAMFORD STREET AND CHARING CROSS.

1875.

[^The right of rublication and of Tramlation U rtterved.]

,-j. ..; ;,. ;■ 'i

ADVERTISEMENT.

' I

The Institution is not, as a body, responsible for the facts and
opinions advanced in the following pages.

b
b

THE INSTITUTION OF CIVIL ENGINEERS.

Sect. II.— OTHER SELECTED PAPEES.

No. 1,413. — " Notes on Public Works in the United States and in
Canada, including a description of tlie St. La-wrence and the
Mississippi Rivers and their main Tributaries." By Sir Chables
A. Hartley, M. Inst. C.E., F.R.S.E.

Having visited the United States and Canada in the autumn of
1873, the accompanying notes on certain engineering works of mag-
nitude are submitted, in the hope that they may prove interesting
to the members.

I,— EAILROADS AND BRIDGES.

Philadelphia and Reading Railroad.^ (Visited ISth November,
1873.) — Through the kindness of Mr. Gowen, the President
of this Company, and Mr. NicoUs, the second Vice-President,
the Author had an opportunity of visiting the principal -works
on this railroad, which, in point of finish and substantial work,
is equal to any line that he has travelled on in Europe. Mr. Nicolls
has kindly enabled the Author to correct his notes up to the 31st
of November, 1874.

The total length of single and double tracks and sidings is
1,452 miles, thus distributed : —

Single
Track.

Double
Track.

Length

Sidings

Total Length

of Tracks

and Sidings.

of ^^- LatTr^ls.

Eoads owned . .
Boads leased . .
Roads contracted

Aggregate . .

Miles.
171-9

279-4

42-9

Miles.
155-1

76-0

Miles.
327-0

355-4

42-9

Miles.
283-6

196-5

15-3

Wiles.
765-7

627-9

58-2

494-2

231-1

725-3

495-4

1,451-8

' For complete statistical iuformation respecting the railways of America re-
ference may be made to the " Manual of the Railroads of the United States,"'
by Henry V. Poor, and to the " American Raibroad Manual," by Edward Vernon,
both of which are published annually in New York,

B 2

4 OTHER SELECTED PAPERS.

The workshops and rolling mills of tho Company aro at Eeading.
a flourishing town of forty tliousand inhabitants, 58 miles from
Philadelphia. Both locomotive and marine engines are fitted up
at these shops, where tho cranes aro all worked by hydraulic
power. The mills are connected with four puddling and ten
heating furnaces, and the hot blast evolved from the furnaces is
employed as at Phoenixville. In 1874; 20,000 tons of iron rails
were rolled, the rails being 24 feet long and weighing 08 lbs. per
yard. The two holes for tho fish-plates at each end of the rails
were punched cold simultaneously. Steel rails of the same pattern
as the 08-lbs. iron rails weigh 70 lbs. per yard. Up to the 30th
of November, 1874, 1,588 tons of steel rails had been rolled in tho
Company's rolling mill, and an aggregate length of 92 miles had
been laicl with these rails, with the best results, in the most
exposed places on the line.^

The Company possess and work four hundred and five loco-
motive engines. These cost K45G,245 for repairs in 1874.

The traffic of the railroad principally consists of anthracite and
bituminous coal, iron ore, lime and limestone, grain, petroleum, pig
iron, lumber, and manufactures of ail kinds. The aggregate
amount of traffic transported over the railroads of the Company
in 1874 was as follows : — . , ,

iTumber of passengers carried 6,964,869

„ tons of coal, of 2,240 lbs 6,348,812

„ „ merchandise, of 2,000 lbs 3,098,831

„ „ Company's materials 493,591

Total tonnage of the Company in tons of 2,000 lbs., includ-'k

ing weight of passengers and Company's materials . . / ' '

The Company's line penetrates into the heart of the anthracite
basin of Pennsylvania ; but owing to the difficulties of the country,
the coal is hauled up steep inclines by stationary engines. From
C"ie coal field, the anthracite is sent to market by three separate

' According to the last report of the American Iron and Steel Association,
the iron trade in the United States was more depressed at tjie close of 1874 than
at any time since the panic began in September 1873. Pig iron, which in April
1873 had been sold at $42 to $47, had declined to $23 and $25 per ton ; bar iron,
then 4 J cents per lb. at Pittsburg, had fallen to 2 J cents ; iron rails, quoted at $82
in 1873, could be bought for $48 per ton in New York or in Philadelphia. Only
1,900,000 tons of pig iron were produced in 1874 — a falling-off of one-third from
the production of 1873. The manufacture of Bessemer steel rails was about the
same in 1874 as in 1873 — 130,000 tons. The total manufacture of rails of all
kinds was 450,000 tons, while 100,000 tons were imported. In 1872 there were
1,000,00^* tone made, besides a large importation.

PHILADELPHIA AND READING RAILIIOAD.

routes ; on two of which are three inclined phines of 2,410 feet,
4,650 feet, and 4,755 feet respectively, overcoming elevations of
354 feet, 318 feet, and 404 feet ; and by a tunnel 3,400 feet long,
through a mountain forming the southern boundary of the coal
field. On all these planes the rope is 2^ inches diameter ; on
the first and steepest of steel, on the two last named of iron. On
the first plane the cost of hatiling the coal in 1874 was 2yVV cents
(l^d.) per ton of 2,240 lbs., including all expenses of fuel, wages,
repairs, &c.

The Philadelphia and Reading Coal and Iron Company owns
one-third of the anthracite coal basin of Pennsylvania.*

The running cost of trains hauling coal in 1874, per round trip
of 190 miles from the coal region to tidewater and back with
empty cars, transporting average loads of 647 tons, and average
through loads of 522 tons of coal of 2,240 lbs. each, was 30.^ cents
per ton carried through 95 miles, or at the rate of ^ of a cent
(-^ of a penny) per ton per mile. The total cost of trains moving
coal, including cost of roadway, superintendence, telegraph, police,
and all expenses of working the road, proportional to coal, was
f of a cent (| of a penny) per ton per mile.

The Reading Railroad Company owns a fleet of fourteen iron
steamers, equipped with the best known means of unloading cargo,
weighing anchor, &c. The largest are of 540 HP., carrying 1,700
tons (of 2,240 lbs.) of coal on a draught of 15 feet, and make nearly
9 knots per hour so loaded. They are used for carrying coal from the
Richmond terminus of the railway on tidewater in the Delaware
river (where the Company's wharves have a frontage of Ih mile)
to New York, Boston, Portland, Washington, and other ports
accessible by sea.

The Schuylkill canal now belongs to this Company. It is
worked in conjunction with the railroad. The hamlet of Schuylkill
Haven is at the head of the canalised river of Schuylkill, which
communicates with the Delaware at Philadelphia. The Susque-
hanna canal is also worked by the Company.

The gross receipts of the railway for the year ending the 30th of
November, 1874, were ^14,452,121 ; the expenses, ^8,731,916; and

' The produce from the eastern extremity of the great Schuylkill anthracite
basin — which has its outlet at Mauch Chunk (Blue Mountain), said to be the
most picturesque town in America — is conveyed to tidewater along the Lehigh
and Susquehanna railway division of the Central railroad of New Jersey. In
1870 the quantity of coal sent eastward from Mauch Chunk averaged 200,000
tons per week. The total production of the anthracite basin of Peimsylvania
was 19,585,178 tons in 1873, and 18,700,000 tons (estimated) in 1874.

\ i

OTHER SELECTED PAPERS.

the net profits, H5,720,205. The expenses, including renewal fund,
rents of lateral roads, taxes, &c., were thus 60 j^ per cent, of the
gross receipts. The not loss in 1874 in the business of the canals
and of the steam colliers and barges was ^420,059. The following
balance sheet — abridged from a statement in the last Koport of the
President and managers of the Railway Company — shows the re-
sources and financial condition of the Company on the 30th of
November, 1874: —

Dr.

BailrnadB and Icpots
Locomotives and cars .
Beal estate ....
Steam colliers
Schuylkill canal and ]

barges J

Ship-yard at Port Rich-1

moud J

Philadelphia & Reading
Coal and Iron Co.'s
bond and mortgage .

Ditto stock . . .

Railroad and telegraph^
stock J

Assets in cash —
Stocks and bonds, ma-
terials, &c., less lia-
bilities

2!), (330, 192
8,787,571
7,459,868
2,542,149

1,607,439
308,977

50,336,196

30,000,000

1,000,000
1,405,902

82,742,098

12,173,168

94,915,266

Or.

Stock, $32,722,775 .

Preferred stock,]
$1,551,800 . . .

Mortgages and deben-
tures at from 5 to 7 1
per cent. .

Loan of Schuy'kill Na-j
vigation Co. . . . /

Loan of East Pennsyl-I
vania Railroad Co. . j

Sinking Fund Bonds

Reserved Fund, less Di-"t
vidond Fund . . ./

34,274,575

55,080,988

2,578,250

495,900

614,800

1,870,753

94,915,266

The Company has paid 10 per cent, dividend on its stock for
some years past.

Phcenixville Bridge Works, belonging to Clarke, Eeeves and
Company. (Visited 26th November, 1873.) — These works are situated
between Philadelphia and Eeading. The Author was accompanied
by Mr. S. Reeves, the President of the Company, who supplied the
principal part of the following information.

From 1869 to 1873 the Company built seventy bridges, having
an aggregate length of 35,000 feet, or 6^ miles of single track,
comprising in all one hundred and seventy-six spans. With the
present facilities they can turn out 100 feet of finished bridge for
each working day in the year.

Everything is done on the premises; beginning with the

BRIDGE WORKS IN THE UNITED STATES. /

manufacture of the iron from the ore ; next rolling it into the
shapes required ; and, finally, applying the machine labour which
completes the structure ready for erection. About fifteen hundred
men are employed on the works. Two 300-HP. engines drive the
blasts for the furnaces day and night, the air being heated by the
consumption of the gases evolved.

The Phoenix columns or tubes are made of from four to eight
sections, rolled in the usual way up to 24 feet in length, and
riveted together at the flanges. When necessary, they are joined
together by cast-iron joint blocks with circular tenons, which fit
into the hollows of each tube.

The ends of all the links, to resist tensile strains, undergo a
procp"" called die-forging, by which the head is shaped and the
hole struck by hydraulic pressure at one operation. The threads
of the screws are so formed that rupture, when under pressure,
always occurs in the unscrewed part of the bar. The iron is
required to be of such elasticity that, after being subjected to a
tensile strain of 30,000 lbs. per square inch, it will return to the
original dimensions ; while it should be so tough that bars, 2 inches
in diameter, bent back from 90° to 180\ when cold, should show
no sign of fracture.

Mr. Keoves particularly directed attention to the fact that,
as a rule, iron trussed bridges in America have all their principal
parts formed by machinery. They are of imiform dimensions in
similar spans, and hence are perfectly interchangeable. Thus
machinery can be applied in their manufacture, and the cost at the
works be reduced to a minimum. They are sj made, in fact, that
nearly all the work is done at the shops, and they can be erected
with the least possible amount of unskilled labour. • ' ,'.

Keystone Buidge Company, Pittsburg. (Visited 15th November,
1873.) — Through the kindness of Messrs. McCandlish and Carnegie,
the Author was shown over these works by Mr. Nicholls, the
second engineer of the Company.

The Company has built numerous bridges throughout the United
States. Of these, the Author has seen the Steubenville bridge,
which has three spans of 210 feet, four of 255 feet, and one
channel span of 320 feet; the Newport and Cincinnati bridge,
which has fourteen spans of 150 feet and one channel span of
420 feet ; and the Keokuk and Hamilton bridge, which has ten
spans of 180. feet and one channel span of 387 feet.

The Company has a capital of Kl, 500,000, and can turnout more
than ^3,000,000 worth of work annually. It gives employment
to six hundred and fifty men. Its business is to construct general

OTHER SELECTED PAPERS.

machine work, and the substructuro and suporstrticturo of build-
ings, bridges, &c,, in any part of the United States and Canada.

Special pride is taken in obtaining lightness, strength, and
economy, by employing wrought iron in tubular forms for com-
pressiye strains, and weldless links in tension members. The esta-
blishment is now almost exclusively occupied in completing the
chrome-steel tubes for the great St. Louis bridge.^ The ultimate
tensile strength of this steel is 100,000 lbs. per square inch; but
the Author saw one 1-inch bolt which only yielded to 120,000 lbs.
The ironwork for the bridge is required to bear an ultimate
tensile strain of 60,000 lbs. per square inch. The steel staves com-
posing the tubes are submitted to a tensile strain of 40,000 lbs.,
and to a compressive strain of 60,000 lbs., without permanent set.
The ^-inch plate-steel for enveloping the staves is tested to
40,000 lbs. for compression and tension. There are six staves in
each cylinder, and, after five have been placed, the sixth is driven
home by a force of 20 tons.

Railroad Bridgk across the Mississirri at Eock Island. (Visited
Ist November, 1873.) — This bridge, which has often been termed,
and apparently with justice, " the strongest and most perfectly
finished bridge in America," was opened in the summer of 1872.

The superstructure was designed by Mr. C. Shalor Smith, the
President of the Baltimore Bridge Company, to whom the contract
for the ironwork was awarded, in September 1870, for the sum
of ^459,784. The workmanship, which was ;3uperintended by
Major Benyaurd, under the direction of Colonel Macomb of the
U.S. Corps of Engineers, is admirable in every particular. The
abutments and piers, the construction of which had been in the
charge of Major Sticknoy, were founded on the rock by means of
ordinary coffeidams, at a depth which d'A not exceed 20 feet below
low water. The masonry is uncommonly well built.

There are two spai^s of 260 feet, three of 220 feet, one draw-
bridge 368 feet long, covering two openings of 160 feet each, and
two land spans of 196 feet and 100 feet. The total length is there-
fore 1,844 feet.

The trusses of the main bridge are ' double-system Whipple,'^

' Chrome steel can be welded as well as the best wrought iron. The quantity
of chromium required in the steel is so small that the cost of the alloy is not
greater than that of carbon steel. In a pure and orystallised state it is a grey,
very hard metal, not oxidizable by any acid, nor reducible in a furnace.

'•' The late Mr. Zernh Colburn's Paper on " American Iron Bridges," in the
Minutes of Proceedings Inst. C.E., vol. xxii., p. .540, will he found to contain an
account of the best known systems.

BRIDGE WORKS IN THE UNITED STATES. 9

in which everything but the washers, &c,, is of wrought iron.
They are 33 feet high and 19 feet apart. T1\ero are two floors;
the upper, for a single rail track, placed a little below the centre
of the trusses, and the lower, for horses and carriages, on the
bottom chords. The footpaths are on each side of the lower plat-
form.

The draw-span has a weight of 683 tons, of which four-fifths are
placed on the thirty -six bearing wheels of the cast-iron turntable,
30 feet in diameter, and one-fifth on the centre pin. The
swing is turned by hydraulic power in two and a half minutes,
when there is no wind. It is opened about twelve times a day for
the passage of vessels.

The total weight of the superstructure of the bridge is 2,080
tons, distributed thus: 1,910 tons, ironwork; 90 tons, turntable;
90 tons, tramway and spikes ; and 890 tons, oak and pine lumber.
The total cost of the bridge was K 1,000,000 (£200,000).' The
diflferenco between ordinary high and low water at the lower end
of Rock Island, whence the bridge crosses the main branch of the
river to the city of IJavenport, is 16 feet, except when the ice
packs momentarily and dams the water back to a height some-
times of 24 feet above low water.

Iron Trussed Railroad Bridge over the River Ohio at Cin-
cinnati. (Visited 12th November, 1873.) — This bridge carries a
single ' track ' and two wide footpaths over twenty -five ' deck '
or undergrade openings, varying from 60 feet to 245 feet, and two
overgrade openings, one of 370 feet and the other of 400 feet.
On the left or Kentucky bank a drawbridge, worked by two
men, gives the river and canal craft two openings of 125 feet
each, when they cannot pass freely under the overgrade openings.
The ' draws ' are spanned by the ' Warren ' truss, the two mid-
channel spaces by ' Fink ' triangular trusses, and all the others by
' Fink ' trussed girders. The line of roadway bearers of the Indiana
Channel span is 96^ feet above low water and 45^ feet above
highest water, the maximum oscillation being 51 feet. The total
cost of the bridge from abutment to abutment was K 1,6 15, 200
(£323,000, or £61 per lineal foot for 6,294 feet). The piers and
abutments are all founded on rock, which is almost bare at extreme
low water. The contract price for the masonry was Kl5 (£3) per
cubic yard, but much of it cost from K18 to K20, although tlio
limestone of which the masonry is composed came from quarries
in the immediate neighbourhood. The bridge is level for

In these notes the dollar is assumed to be worth four sliilliuga.

OTHER SELECTED PAPERS.

!;ii

ii;>

2,242 feet, with a fall at each end of 79 feet per mile (1 in (37).
Pilot engines assist heavy trains over these approaches. The speed
over the bridge is restricted to 12 miles per hour nominally ; but
the Superintendent said that a speed of 30 miles per hour is often
run by risiiy drivers. The engines on which the Author traversed
the bridge weighed 56 tons. Four of them at rest, weighing
200 tons and covering as many feet, only gave a deflection of
1|^ inch on the 400-feet span. The deflection, with the same load,
on one of the 245-feet undergrade spans was 1^ inch. The weight
of the 400-feet span complete, with stringers, cross-ties, track, foot-
walk, railings, and pier bearings, is 4,162 lbs. (say 1^ ton) per
lineal foot. All the wrought iron has been tested to a strain of
20,000 lbs. per square inch, and its breaking or ultimate strength
has been proved at 60,000 lbs. per square inch. The maximum
strain in practice with a full load is 12,000 lbs. per square inch,
and 7,000 lbs. is the minimum strain. The Chief Engineer and de-
signer of this, in every respect, first-class bridge was Col. Albert
Fink.

St. Charles Eailroad Biudge across the Missoqei at 20 miles
FROM St. Louis. (Visited 10th November, 1873.) — This bridge, which
is remarkable on account of the difficulty of its fourdations, was
designed and constructed by Mr. C. Shalor Smith. It has
seven spans ; four ' trellis ' or • double triangular girder truss,' of
320 feet each, and three Fink 'deck' trusses of 305 feet each.
The rails are 90 feet above low water, or 51 feet above the extra-
ordinary high- water mark of 1844. The track is single, without
footways, and there are no ' draws.'

There are eight river piers, and the foundations of six of them
presented new and extraordinary difficulties of construction, owing
to the existence of a bed of boulders below a shifting sandy bottom,
to the sudden rising of the water, to the great velocity of the
current at times of flood, and to the immense fields of ice which
float down at the end of the winter season. Nos. 1 and 2 piers
were founded easily on the rock at low water. No. 3 pier was
founded in 23 feet of water at ordinary water stage. A wooden
caisson without a floor was sunk on the site, the decomposed
limestone within it was excavated by divers till solid rock was
reached, and the crater was filled with concrete and two courses
of stone laid upon it. The foundation was then ready for pumping
out the water ; but the river suddenly rose 26 feet, and crushed
the caisson. On the subsidence of the river, the foundation proving
uninjured, the pier was built on a caisson boat and sunk on the
spot. No. 5 Pier. —The rock was here 68 feet from the surface. The

BRIDGE WORKS IN THE UNITED STATES.

compressed-air system was, in sinking the foundation, combined
with Eads' sand-pump and air-lock at the bottom of the caisson,
and a peculiar ' boulder sh jft,' with a separate lock, was designed to
get rid of the boulders. Piers G, 7, and 8 are alike in the character
of their foundations. Inside a circle of piles a caisson was sunk
about 30 feet, by dredging, and stones were pitched round the piling
as the caisson sank. This was continued till stone began to appear
in the dredger buckets, which was a sign that the ' rip-rap ' had
begun to pass beneath the piles. When this took place, dredging
was stopped, and bearing piles were driven down to the rock and
cut off at the level of the bottom of the caisson. The pier was
then lowered on the top of the pile-heads, and the caisson being
filled with stones, the foundation was complete.

The superstructure was erected on three temporary piers of
piling, protected by cribwork, under each river span. On these
supports Howe truss spans, 80 feet in length, were placed; and from
this foundation sprang the ' false work ' or centering on which the
iron superstructure was put together.

The approaches of the bridge are upon forty iron tressels, and,
including these tressels, the bridge is 6,570 feet long. Its entire
cost was about K2,250,000, or double the original estimate. This
excess was due to tlie great and unforeseen difficulties encountered
in constructing the foundations.

St. Louis Bridge. (Visited November, 1873.) — The Mississippi at
St. Louis is confined to a single channel, 1,600 feet wide and 8 feet
deep at extreme low water, by an embankment or levee on the
Illinois side, which is carried up to above the level of extreme high
water, at which time the width is augmented to 2,200 feet.

Both shores are revetted below the low-water line with rubble
stones, and protected by the wharf pavements above that line. The
extreme range between high and low wat(3r is 41 feet. Owing to
the narrow gorge through which the whole volume of the Mis-
sissippi flows, the variations in the bed of the river are very great.
Captain James B. Eads, M. Inst. C.E., the distinguished Engineer
who designed the bridge and superintended its construction, in-
formed the Author that a rise of 13 feet less than high- water mark
caused a scour of 18 feet, and that in the freshet of 1870 the scour
reached a depth of 61 feet below low- water mark alongside the
east pier. These facts induced him to believe it possible, that the
scour at times of extraordinary high flood might extend even to
the rock itself He therefore determined to establish the piers and
abutments on the rock ; an* his was done by means of caissons
provided with air chambers and locks at depths, for the east pier

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and east abntment, reaching 136 feet below high- water mark, or
110 fe*^t from the surface of the water, when the foundation work
was actually performed. This feat, which was satisfactorily
executed in 1870-71, is quite unprecedented in the annals of
engineering.^

The piers and abutments are composed of coursed rubble masonry
up to low- water mark. Above this level they are faced with grey
granite from the State of Maine, which cost £10 per cubic yard
in situ. The interior of the work is of magnesian limestone. The
massive appearance of the granite rock facing, and its close joint-
ing, are very striking;.

The contract prices and the total quantities of the steel and
ironwork required for the bridge are as follows : —

2,500 tons of steel, at £60 per ton .

500 „ wrought iron fit £40 per ton .
1,000 „ roUe'l iron, at £28 per ton .

200 „ cast iron, at £16 per ton

•)

I of 2,1

000 lbs.

of 2,240 lbs.

The bridge has three spans, each formed with ribbed arches
made of cast steel — a novelty in bridge-building. The centre span
is 520 feet and the side ones 502 feet each in the clear. The rise
of the centre arch is 47^ feet, that of the side ones 46 feet each.
These are by far the largest arched spans in the world, and,
under the able direction of Colonel Flad, Captain Eads' chief
assistant, they are now being rapidly erected gradually from
each pier and abutment, without the aid of centering.^ Each span
is composed of four double ribs of steel (well braced together, at
their relative distances from each other), and the tubes forming
them are jointed butt to butt. They are clasped together by
wrought-iron couplings (which proved to be much better than
steel), furnished with parallel grooves corresponding with similar
grooves on the tubes. Steel pins, varying from 4-^ inches to 7 inches
in diameter, pass through the centre of the couplings and the ends
of the tubes at every joint. The vortical bracing between the
upper and the lower tubular ribs — which are 1 2 feet apart from
centre to centre — convert the two members into a single arch.

' Capt. Eads* Reports to tlie Illinois and St. Louis Bridge Company from
1868-71, containing a full account of tlie foundations of the bridge, are in the
library of the Institution, and the most important of them will be found in
" Engineering."

2 All details concerning the erection of the arches are given in a valuable Paper
read before the American Society of Civil Engineers by Mr. J. C. Cooper, C.E.,
and published in " Engineering " iu January 1875.

BRIDGE WORKS IN THE UNITED STATES AND IN CANADA. 13

At the time of the Author's visit two of the openings were
already spanned by the steel tiibes, which are all 18 inches in
diameter and 12 feet io 13 feet long, bnc of thicknesses varying
from 1 ^ inch to 2| inches.

I'he archcp are to carry a double railroad track, and above the
track a roadway, 54 feet wide, for earria£;e8 and foot-passengers.
Captain Eads hoped to bo able to opjn the bridge in tho summer
of the following year. As fc^urteen railroads were waiting to
make use of it, he was of opinion that the Bridge Company
would eventually secure a good di/idend on their capital, al-
though, from causes too numerous to mention, the outlay on the
bridge had already considerably exceeded the original estimate.
The extreme range of temperature at St. Louis is 160°; and it is
calculated by Captain Eads that at 140"^ the arches will rise
8 inches, and that at 20° they will fall as much below the point
at which they will be maintained at a medium temperature.

Since the above wr.s written, the Author has received a letter
from Capt. Eads, dated St, Louis, loth July, 1874, in which he
says : —

"My bridge was thoroughly tested on the 2nd with 560 tons of
engines and 140 tons of tenders. This weight of 700 tons was
run, first on one track on each span and then on the other, to pro-
duce twisting of the arches, and then it was divided into two trains
(seven engines and tenders in each), and these were advanced
abreast on to each span to produce the greatest distortion of
the curve of the arch, and finally each arch was covered with the
trains. Tho latter produced only 3i inches deflection on the
520 feet span and 3;^ inches on the other two. No lateral move-
ment could be detected by the instruments under the effect of the
side-loading or twisting strain. The deflections were almost in
exact accordance with the theoretical computations. The bridge
was opened on the 4th July with great enthusiasm, a procession
being formed of all trades and callings, which was five hours in
passing a fixed point. It was estimated to be 15 miles long, and
passed over the bridge and back." , • .

Eoebling's Kailiioad Suspension Bridge (single track) over the
Niagara River. ( Visited 10th October, 1873, with Mr. McAlpine, M. Inst.
C.E.^ — This bridge has one span of 800 feet, which weighs as many
tons. The height of the tower on the American side is 88 feet, and on
the Canadian side 78 feet. The bridge, which is 24 feet wide, and
has a road for carriages suspended 28 feet below the railway line,
is hung on four wire cables each 10 inches in diameter. Their com-
bined ultimate capacity is about 12,400 tons. To preserve them

I:'!

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from rust they are covered with a tliick coating of hydraulic
cement. The old timber-work of the load way, which is 250 foot
above the river, is now being r^rioved an''. leplaced. Trains
passing over the bridge are restrict id to a speed not exceeding
4 miles an hour. The first locomotive passed over it in March
1855. The cost of its construction wap £96,000, and the railway
companies using it pay an annual toll of £9.000 a year. The road
and passenger tolls bring in about £2,000 a year in addition. The
rise and fall at the centre of this bridge is stated by Mi", Eoebling
to be 27 inches under a change of 100° of temperature ; that is,
the roadways are 2^ feet higher at zero than at a temperature
of 100°.i

International Eailroad Bridge (single track) over the Nia-
gara, FROM Fort Erie to Buffalo. ( Visited lith October, 1873.) —
This bridge is being built by a company, of which Mr. Brydges,
Assoc. Inst. C.E., is President, and Mr. Hannaford the Engineer-
in-Chief. The chief contractors are Messrs. Gzowski and Mac-
pherson. By common consent, the chief credit in overcoming the
extraordinary difficulties which beset the building of the piers of
this bridge is due to Colonel Gzowski, upon whom all the practical
operations devolved.

The river Niagara at Fort Erie is about 1,900 f^et wide, and
its depth ranges from 16 feet to 48 feet. The vatiation in the
level of the river does not exceed 2 feet when uninfluenced by the
wind. Its bed 'ionsists partly of rock, and partly of clay and
large boulders. The normal current is 5J miles an hour, but
during south-west gales it sometimes attains 12 miles an hour
— when the water has risen 4 feet in a few hours. With such
unusually strong currents, and with ice floes often 3 feet thick to
contend against in the winter months, the founding of the piers
was no ordinary task. Five of them on the Canadian side are
built on the rock, whilst the three on the United States side rest
on bearing-piles. The masonry was got in by means of outer and
inner caissons. The anchoring of the former, while being sunk
in place, was a most difficult operation, and quite unique in ci *-
racter as an engineering feat. • , *

The main bridge has nine spans, varying from 180 feet to
250 feet, and is 1,968 feet long, including the abutments; but

' For a detailed descriptiou of the state of this bridge at the time of the
Author's visit see letter at page 157, vol xviii. of " Engineering," addressed by
Mr. Thos. Curtis Clarke, M. Inst. O.E., Philadelphia, to the Minjster of Public
Works, Caur.da.

RIVERS AND CANAL, IN THE UNITED STATES AND IN CANADA. 15

including the length of the bridge across Black Rock Harbour,
or the Erie Canal (600 feet), and the embankment joining
the two bridges, the total length of the work is 3,650 feet. The
iron superstructure, all from the Phoeuixvillo Works, is known
as the ' Pratt ' or quadrangular truss. Its great strength is due
to its depth, which in the centre of the 240-feet spans is 26 feet,
and in the centre of t^e 'draw' 35 feet. It only weighs 1^ ton
per lineal foot, and was put in place by mooring watertight
caissons between the spans, and then building a platform on them
to the required height. By means of hydrants in the caissons they
can be sunk to any level and be easily removed. The draw or
swing is 362 feet long, and can be worked either by hand or by
steam ; by the latter it can be swung in about a minute.

Since the above was penned, Colonel Gzowski has published a
most valuable description of the International Bridge,^ in which
he states that it was opened on the 3rd of November, 1873, and
that the cost was about £300,000, including extras and interest on
the outlay during construction.

It was intended by the Author that the foregoing Notes should
be oflfered as a contribution to tl a discussion on Messrs. C. D. and
F. Fox's (MM. Inst. C.E.) Paper on ' The Pennsylvania h'ailroad "; '^
and if they are still regarded in that light, as he would desire, the
scantiness of his remarks on the important subject of railway
construction in North America will be explained.

II.— RIVER AND CANAL WORKS. (Plate 6.)
The St. Lawrence and its Tributahies.

The St. Lawrence
He to Fond-du-lac,
2,384 statute miles.
2,383 miles. From
Superior, there are
of open navigation,
the distance is 1,942

navigation extends from the Straits of Belle-

at the head of Lake Superior, a distance of

The distance from Belle-Ile to Chicago is

the Straits of Belle- He to the head of Lake

71f miles of artificial navigation, and 2,312^

From the Straits of Belle-He to Liverpool,

geographical, or 2,234 statute, miles.

' This work is in the library of the Institution.

* Vide Minutes of Proceedings Inst. C.E., vol. xxxix., p. 62.

16 OTHER SELECTED PAPEK8.

Table of Distances, Compilkd from Canadian Blue-Kooks. ,

Sections of Navigation.

Statute Miles.

From

Inter-
mediate.

Total

from
SiralU of
Belle-Uo.

Streits of Belle-Ile

Quebec ....

1 River and Gulf of
\ St, Lawrence
(River St. Lawrence

826

Quebec ....

Three llivers . .

] to Three Rivers
(highest tidal flow)
Head of tidal flow

900

Three Rivers . .

Montreal .

1 to head of ocean
I navigation .

986

Montreal .

Prescott

Canal section .

119

1,105

Prescott

Kingston .

rHead of River St.j
Lawrence . ./

1,164

Kingston .

Port Dalhousie

Lake Ontario .

170

1,334

Port Dulhousie

Port Colborne .

Welland Canal. .

1,361

Port Colborne . .

Amherstburgh .

Lake Erie .

232

1,593

Amherstburgh.

Whulsor

Detroit River .

1,611

Windsor

St. Mary's Island .

Lake St. Claire .

1,636

St. Mary's If<liind .

Sarnia ....

St. Claire River .

1,669

Bamia ....

St. Joseph's Island

Lake Huron .

270

1.939

St. Joseph's Island

Sault St". Mario .

St. Mary's River .

1,986

Sault St*. Marie .

Ditto ditto

/Sault St^ Marie\
\ Canal . . ./

1
1

1,987

Ditto ditto

Pointe aux Pins .

St. Mary's River .

1,994

Pointe aux Pii

Fond-du-Lac . .

Lake Superior .

390

2,384

It will "be seen that the length of the St. Lawrence is 1,334 miles.
Its drainage area is estimated at 297,000 square miles (or about
the same as the Danube), of which one-third is covered by the
largest chain of fresh- water lakes in the world.

1. Lake Superior is 390 miles long, 114 miles broad, and has an
area of 32,000 square miles ; its depth is 900 feet ; and the surface
of its waters is 628 feet above the sea level.

2. Lake Huron is 270 miles long, and has an area of 20,000
square miles, a depth of 1,000 feet, and an altitude of 574 feet.

3. Lake Michigan is 320 miles long, 100 miles broad, 1,000 feet
deep, and 628 feet above the sea. It is connected with Lake Huron
by a narrow but deep channel on the north.

4. Lake Erie is 232 miles long, 50 miles broad, and has an area
of 9,600 square miles. It is less than 100 feet deep, and has an
elevation of 565 feet.

5. Lake Ontario is 170 miles long, 50 miles broad, 500 feet deep,
and has an elevation of 232 feet.

The difference between the elevation of the two last-named
lakes (333 feet) causes the great Falls of Niagara. These are

fal

tol

Miles.

Total

from
SI raits of
BeHc-llc.

826
900

986

1,105

1,164

1,334
1,361
1,593
1,611
1,636
1,669
1.939
1,986

1,987

1,994
2,384

J4 miles.
)r about
i by the

d ^as an
B surface

20,000
feet.
,000 feet
ce Huron

B an area
i has an

feet deep,

,st-nained
These are

THE RIVETl ST. LAWRENCE AND ITS TRIED TORIES.

divided by Goat Jslaiid. The Canadian or Horseshoe Fall is 1,800
feet wide, aud 158 feut high. The American Fall is 600 feet wide,
and 163 feet hign. It is estimated that tlie Niagara Falls dis-
charge 400,000 cubic feet of water per second, a volume equal to
the flow of the Danube at Isaktcha at times of ordinary high
floods.

Ocean vessels ascend the St. Lawrence as fjir as the city of
Montreal, where ocean navigation terminates, and inland naviga-
tion begins. Prior to 1851, no vessel drawing more than 11 feet
could pass through Lake St. Peter — a wide expanse of the St.
liawrcnce between the mouth of the Three Rivers and Montreal ;
but since then a cutting, 300 feet wide and 9 feet deep, has been
dredged througli the lake, so that vessels of 20 feet draught can
now reach Montreal at low water. This important work cost
£257,250, of which the Government paid two-thirds, and tlie
Harbour of Montreal the remainder. A further deepening of the
channel through Lake St. Peter has been determined upon, so as
to give a depth up to Montreal of 24 feet at low water.

The Canadian canals ^ are the Lachino, the Beauharnois, the
Cornwall, the Farran's Point, the Kapid Plat, the GaloT)s, and the
Welland. They were constructed at the expense of tLe Canadian
Government. Their united length is 70^ miles, and the total
lockage is 536^ feet, through fifty- four locks.

The St. Lawrescp: Cavals are all situated between Montreal
and Prescott. As shown by the Table (page 18), they have an
aggregate length of 43^ miles, and a rise of lockage of 206^ feet.
The cost of construction of these six canals, to the 30th June,
1867, was £1,555,200.

It is nov ' in contemplation to enlarge them, and to increase the
size of the locks to 240 feet by 45 feet by 12 feet, a work estimated
to cost about £2,000,000, including the deepening of the main
channel of the reaches between the canals where necessary, so as
to admit of the passage of vessels drawing 12 feet of water.

The eastern extremity of Lake Erie overlaps the western end of
Lake Ontario in such a manner as to leave only a narrow peninsula
between them. The Niagara river forming the eastern side of this
peninsula falls, as has been already observed, 333 feet from the
upper to the lower lake in a distance of 31 miles. The navigable

' Exclusive of the Richelieu and Champlain canals, which will be referred to
farther on, and of the Rideau canal, which joins the city of Ottawa with
Kingston, and whi(;h need not here be referred to in detail, ns it is only a feeder
to the main line.

[1874-75. N.sj . .0.

I s

OTHER SELECTED PAPERS.
The St. LAwnExoE Canals.

Dat(!

Name of Canal.

Length

in
Miles.

Dimensions of

liOC'ICH.

Wiilili (

jfCmiul.

No. of
LocltH.

of
Comple-
tion.

Length.

wiatii.

Deptli

on
Sill.

Bottom.

Surface

of
Water.

Lift.

Fcft.

Foot.

Feet.

1848

'Lachino .

200

120

1845

Beaulmrnois ,

llj

200

120

82i

1848

Cornwall. .

llj

200

100

150

1846

Farran's Point

200

and

Rapid riat .

200

llj

1847

Galops .

43}

200

15f

••

20GJ

' Tlic Lacliine cunai was lx;gun in I«21, anil completed for the navigatidti of vessels drawing
4* feet In 18'24, nt an e.xpenso of ±"109,601. It was widened and deepened in 1843-48 to the
dimensions shown in the Table.

channel of communication between the two lakes, and by means of
which the Falls of Niagara are flanked, is by

The Welland Canal, which is 27 miles in length. It has
twenty-seven lift locks, which are, for the most part, 150 feet long
by 20 j^ feet wide by 10^ feet deep, and has a total rise of lockage
of 330 feet. It was first opened in 1833, for the navigation of
small vessels; but it only attained its present dimensions in 1867,
when vessels of 400 tons burthen could pass through the locks.
Up to that date the cost of its construction and maintenance
amounted to £1,557,360. The downward movement of freight of
all kinds through the Welland canal, in 1871, was 962,565 tons;
but the Author has seen no statement of the distribution of this
tonnage by the three routes which lead from Lake Ontario to the
sea — viz., by the Gulf of St. Lawrence, by Oswego and the Erie
canal to New York, and by the Richelieu and Champlain canals
to New York. The total exports of grain in 1872 from the ports
of New York and Montreal, as stated in the " Returns " of the
Montreal Chamber of Commerce, were : —

•df- 1

New York.

Montreal.

Maize or Indian corn .
Wheat and flour . .
Peas, oats, barley, and rye.

Total ....

Quarters.
1,750,000
3,200,000
85,000

Quarters.
1,001,000
944,000
225,000

5,035,000

2,170,000

RIVERS AND CANALS IN THE UNITED STATES AND IN CANADA.

Works for tlio straightening and furthor widening and deepening
of the Welland canal were begun lust year, and will probably bo
completed in 1878, at a further exponso of £2,000,000. The locks
will then bo 270 feet long by 46 feet wide, and have 12 feet of water
on their sills.

Lakk Navigation. — I.ako Hiiron is connected with Lake Erie by
the Kiver St. Claire, T>ako St. Claire, and the Detroit river. The
navigation is eaisy throughout, except on Lake St. Claire, where
there are extensive sandbanks, covered with a depth of water vary-
ing from G to 10 feet. Previous to 18r)8 niucli inconvenience was
experienced in navigating the lake from the insufficient depth of
water; but at the end of that year the Governments of the I'nited
States and of Canada dredged the navigable channel to a minimum
depth of 12 feet, and to a minimum width of 300 feet. In con-
sequence of the improvements alieady ellccted, vessels carrying
300 tons of cargo can now pass from Lakes Superior and Michigan
to Montreal without breaking bulk; and it is confidently antici-
pated that in less than five years the additional works of improve-
ment which have been referred to, as being either already in
progress or in contemplation, will be completed, and thus enable
vessels of 1,200 tons burthen to navigate freely between the same
points. By far the best and cheapest, as well as the shortest,
water route for the transit and exportation of the produce of the
north-west of America will then be by the improved Welland and
St. Lawrence canals to Montreal, and thence directly to Europe by
ocean steamers of tho largest class.

It has been aptly stated by Mr. John Young, M.P., of ]\Iontrcal,
that a vessel from sea in the port of IMontrcal is 120 miles nearer
to ports on the lakes than are any of the seaports in North
America; while tho distances from Chicago, or from any other
lake port, to Liverpool, is 480 miles less by Montreal than via tho
port of New York.

The Sault St. Marie Canal, 1 mile in length, and 18 feet
lockage, avoiding the Sault St Marie, and uniting Lake Huron
and Lake Superior, was constructed by a company with tho aid
of the United States Congress.

The Erie Canal. — Tho downward movement of freight of all
ki^.ds by the Erie caaal from Buffalo and Oswego to tidewater,
in 1873, was 2,466,022 tons. This canal was constructed in 1825,
by the State of Now York,^ for tho passage of vessels of 60 tons ;

' The total cost, including maintenance and mana^^ement to the Bame date of
all the New York State Canals, which have a combined length of 907 miles, was

c 2

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but by tho year 1HG2 it was snfficiontly enlarged to allow of the
passage of vchhoIs of 240 tons. The trunk lino of canal, as it may
bo called, oxtondH from Buffalo on Lake Erie, from Oswego on
Lake Ontario, and from Lake Chan)j)lain to Al])any on the Iliulson
river, a combined length of 45.5 miles. Tho distance from Albany
to >.'ew York by the Hudson river is 145 miles.

D1MKN8ION8 and Capacity of tho Eiiik Canal and of its Two

PlUNCIPAL FeEDEUS.

Linglh

III
Miles.

Size of Canal.

No. and Size of Locks.

Rise

Locality.

Width

on
Surfoce.

Width

on
Bottom.

Depth

of
Water.

No. of
Lucks.

Length. Width.

of
Lockage.

Buflfalo to Albany .

Oswego to Syracuse

Lake Chauiplain to"l
Albany . . ./

351
SB

Feet.
70

70
50

Fret.

56
56

Feet.
7

7
5

72
18

Feet.
110

110
100

Feet.

Feet.
655

155
180

455

Tho cost of construction, maintenance, and management of this length of
455 mile.^ up to tho 30th of September, 1873, amounted to $87,21)9,924, or
£17,460,000,

EicnELiF<:u River and the St. Ours and Chambly Canals. — This
route of navigation extends from Sorel, at the confluence of the
St. Lawrence and Richelieu rivers, 46 miles below Montreal, to
the oiitlet of Lake Cham plain, a distance of 81 miles. Thence
the line of navigation is by Lake Champlain and the Champlain
and Erie canal (alieady noticed) to Albany and New York. The
Richelieu ottnal has ten locks, with a total rise of lockage of 79 feet;
and vessels of 300 tons, 116 feet long, 23 feet beam, and drawing
7 feet, can be passed through the canal from end to end, a distance
of 44 miles. The cost of the Richelieu canal works to the 30th
of June, 1867, was .8756,249.

$107,906,763, or £21,600.000, and the total receipt from tolh $97,025,066, The
total freight service on all these canals for the year 1872-3 was 6,673,370 tons,
including timber, vegetables, food, machinery, manufactures, and merchandise of
every description, the value being estimated at $220,913,321, and the tolls
collected amounted to $3,072,411. In tho same year, and included in the
tonnage, 2,200,000 quarters of wheat and 453,370 barrels of flour (= 3,964,836
barrels in all) were transported from the United States and Canada to tidewater
by the Erie canal. ,

*•>

THE niVER ST. LAWRENCE AND ITS TRIBUTARIES. 21

Tlio total length of navigation between Montreal and New York
by this route is 456 miles, divided thus : —

Mllen.
Montreal to flrHt lock on the Richeliou, at St. Ours ... CO

Ht. OurH lock 32

Chiunl)ly ciuiiil 12

— 41
Chambly cuniil to frontior at north end of Lake Champlain . 23

Montreal to frontior 127

Frontior to New York 329

Total ... 456

After this brief description of the principal channels of com-
munication, from the great fresh-water lakes of North America to
the eastern seaboard, it may bo useful to refer to the relative
traffic expenses of the most important of these routes as compared
with each other, and with the route by rail between the same
points, as well as to quote the following paragraphs touching on
this subject from a lieport, dated 29th April, 1872, on the pro-
posed enlargement of the Welland canal, by Mr. John Page, the
Chief Engineer of Public Works, Canada.

" Between the head of Lake Michigan and the eastern end of
Lake Erie, the distance by water is about 1,000 miles; by land
it is only about 500 miles; but even this advantage has not
enabled the land routes to compete successfully with that hy water
for the carriage of those heavy articles which constitute the main
items of export.

" It is nevertheless true that flour, animal food, and such other
kinds of freight, as either require to be conveyed speedily to
market, or the value of which will bear higher transport rates,
are now frequently carried by rail.

" During the season when navigation is closed, the movement
by the land routes lightens the pressure on the water lines in the
open season. Still, the producing powers of the West are increas-
ing so fast as to threaten to outstrip all the existing means of
getting the surplus to market.

" The keen competition which exists for this vast carrying
trade, has induced the State of iS'ew York to reduce the tolls on
her canals, 60 per cent., with a view of regaining the large
business w^hich has deserted them.

"This was done in the early part of 1870; but although the
eastward movement of the Erie canal has increased considerably
since that time, it is quite probable that a large portion of this

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I :

is duo to the fact that the crop for exportation in 1871, was much
larger than that for 1870.

" Strenuous efforts are now being made to introduce steam power
on this route, with a view of diminishing the time necessary to
pass through it, and thus lessen the contrast in this respect,
between it and the railways. A very largo premium has lately
been oiferod by the State authorities, for any design that can be
judiciously brought into use for this purpose.^

" The great length and limited capacity of this canal, has enabled
the railways to take from it a portion of heavy freights, the
carriage of which it formerly monopolized, so that it is ques-
tionable whether oven the entire abolition of tolls, and the suc-
cessful application of steam power, would do more than partly
restore the traffic which it has lost.

" In this connection it may be ob^rved that all the leading
lines of commimication in the United States, oast of the Mississippi
river, from the producing regions of the West to the Atlantic
seaboard, cross the Alleghany range at some point, with the
exception of the Erie canal and the New York Central railway,
which are carried through a break in the chain, forming the valley
of the Mohawk river.

" This being the best possible route for a canal in that direction,
gives it an advantage, for the western trade, over all other water
oh inels in the United States ; still it does not present a continuous
downward lockage towards tidewater ; the long level at Rome
being higher than those to the east .and west of it — and although
its draught of water is comparatively small, the supply is main-
tained with great difficulty during dry seasons.

" There cannot bo a doubt but that there will always continue
to be a considerable competition, between railways and canals, for
the , carrjdng trade eastward from the foot of Lake Erie ; but
from the westward to that point the water route, although
twice the length of that by land, will in all probability keep the
load.

" This may safely be inferred from the known characteristics
of the navigation, and the large class of vessels employed on it.

' It has since been afflrmod on good aiitliority that the most economical mode
of employing steam on the Erie Canal is in vessels carrying their own macliinery
and 200 tons of cargo. The greatest obstacle to the development of steam power
on the Erie and WoUand canals is the smallness of tlicir locks. The lust report
of the Nov*- York State Engineer states that the progress made in the use of
steam for towing warrants the belief that it will supersede all other kinds of
motive power on the Erie canal. . . •

RIVERS AND CANALS TN THE UNITED STATES AND IN CANADA. 23

tho

some of which draw about 12 feet of water, and are capable of
carrying from 40,000 to 50,000 bushels of wheat.

" TL 1, together with tho rapidity with which vessels can bo
unloaded, and allowed to proceed on their return voyage, and tho
attractions of tho commercial port of Now York, must, to tho
extent of these advantages, have a tendency to throw tho stream
of trade towards Buffalo.

" To the westward of this point the route to the heads of Lakes
Michigan and Superior, is common to all ; so that the rivalry
between tho New York State canals and those on the St. Lawrence
for the carrying trade to tho seaboard, may very properly be said
to commence at the foot of Lake Erie.

" If vessels of the capacity above mentioned could proceed down-
wards withoiit breaking bulk, until alongside the ocean-bound ship,
a great object would bo achieved, and a route established which
might reasonably be expected to defy successful competition for
the cheap and rapid transport of the heavy and bulky articles of
agricultural produce."

In comparing the distances, and in calculating the relative cost
of tho transport of grain by water and land carriage to the sea-
board, tho Author has selected the famous port of Chicago — tho
largest grain emporium in the world — as being the best point of

CoMPAnisoN of Distances and Transit Charges from Chicago to tho
SiiA'soAui) by Water and Land Carriage.

To Montreal, by the lakes, the Welland and tho St. Law-j

rence /

To New York, by Buffalo, the Erie Canal, and the Hudson I

river )

To New York, by the lakes, tho Welland, Oswego, and Eriej

Canals, and the Hudson /

To New York, by the lakes, tho Welland, tho St. Lawrence,^

llifhelii'u, Cliamplaln, and Eric Canals and tho Hudson ./

To New York, by railroad

Winter souson

Summer season

DiBtance

iD
Miles.

Expense

per
Quarter.

1,278

1,418

1,412

1,632
960

g. d.

4 7

5 7
5 1
5

Cost of Transport in 1872.

^'cZdingToUs ^'^ ^^''. ^^'\ ^^. '''°''\'''';^ "''"■; ^;} ft cent per ton per mile
Ditto by canal and river, without tolls \ cent „ „ '

' Tho charge for transport by steam power against the stream on the Rhone ,
from Aries to Lyons, a distance of 200 miles, is 1 cent (i<i.) per ton per mile.
Ditto with the stream on the Danube, between Galatz and Sulina, a distance of
lOG miles, is J cent (Jd.) per ton per mile.

;.'if

24 OTHER SELECTED PAPERS.

departure eastward, both on account of its pre-eminence as a lake
city, also because it is situated at the head of Lake Jlichigan,
and, therefore, as far from the Atlantic as the " Fond du Lac " in
Lake Superior.

The exports of grain alone, from Chicago, for home and foreign
consumption, reached 10,375,000 quarters in 1872, or nearly two-
thirds of the total receipts of grain from all the laki ports together,
which, in the same year, amounted to 17,500,000 quarters.^

The average rate of freight on wheat by canal and river from

Buifalo to New York was —

For 1872 10-9 cents per bushel.

„ 18G4 18-9 „

., 1863 17-7 „

„ 18G2 15-8 „

When the rate by railways from Buffalo to Now York is reduced
to 1 cent (hd.) per ton per mile, the expense will be reduced to
13*5 cents per bushel.

The average charge per ton per mile on all freight, carried on

the Lake Shore and Michigan Southern railway,

was 1*5 cent in 1870
and 1-39 „ in 1871.

The Author is indebted to Mr. AV. J. McAlpine, M. Inst. C.E.,
for the above information relative to the transport charges by
water, and to some of the most influential merchants in Chicago
for the account of the charges by rail.

The water communication between the lakes and the sea is
practically closed for navigation for five months in the year, viz.,
from December to April inclusive Grain can then only be trans-
ported by rail, and, on this account, the freight by rail is some-
times increased 50 per cent., obviously in the absence of a healthy
competition. Notwithstanding the disadvantages that the water
transit experiences in this respect, as compared with the transit,
by rail, in 1872, out of 11,5UO,000 quarters of grain brought to
Buffalo from the west, 7,750,000 quarters arrived by water, and
only 3,750,000 quarters by rail. In connection with the enormous
shipment of grain, it should be mentioned that it is loaded and
unloaded by steam elevators in a very expeditious and practical
manner, and at a comparatively small cost. At Chicago, on the
31st of December, 1872, fifteen elevator warehouses, with a total
capacity of 1,(300,000 quarters, were already built, and by the end
of 1875 it is calculated that there will be warehouse accommoda-

' The total yield in the United States in 1872 of maize or Indian corn (" corn ")
was 138,000,000 quarters, and of wheat 30,000,000 quarters.

THE MISSISSIPPI AND ITS TRIBUTARIES.

tion for 2,000,000 quarters. The rates for the storage of grain in
these warehouses is about 2 cents per bushel (8d. per quarter) for
the first thirty days or parts thereof, and }^ cent per bushel (2d. per
(juarter) for each fifteen days additional. Elevator warehouses on
a largo scale are also provided at Bulfalo and at Montreal. At the
latter port, as well as at Kingston, and many of the ports on
the Atlantic seaboard, floating steam elevators are extensively
employed for transhipping grain from one vessel into another. In
this way from 400 to 500 quarters of grain per hour can easily be
transferred, or say, a ship of from 1,000 to 1,200 tons can readily
be loaded in one da3\ The charge for this operation at Kingston
and at Montreal is ^ cent per bushel (2d. per quarter), of which
one-half (J cent) is paid by the vessel discharging and one-half bj'
the vessel receiving. Magazine elevators are of great service
where grain is brought to a port by rail, as at Chicago for
instance, and floating elevators answer best where lighterage is
required, as at Kingston, or where the inland navigation ends and
ocean navigation begins, as at Montreal. No doubt similar
facilities for the storage and handling of grain might be introduced
with great advantage at many of the great corn-exporting ports
of the Baltic and Black Sea, where the most primitive modes of
loading grain by hand labour are still in vogue.

The Mississippi and its Tributaries.

The Mississippi drains the greater part of the United States
lying between the Alleghany and the Kocky Mountains, and its
basin surpasses in area the whole continent of Europe, exclusive
of Russia, Norway, and Sweden.^ To compare its rank as a river
with that of the Danube, it may be stated —

1. That the Mississippi drains ai area of 1,244,000 square miles,
the Danube an area of 300,000 square miles.

2. That the mean discharge of the Mississippi is 018,000 cubic
feet per second, or 676,000 cubic feet including the three outlet
bayous, and that of the Danube is 207,000 cubic feet per second.

;3. That the length of the Mississippi, reckoning from its mouth
to the source of the Missouri, is 4,194 miles; and that of tho
Danube, 1,700 miles.

It may therefore be said that the chief river of North America
is more than three times greater than the chief river of Europe.

' The topogruphical description of tho Mis8i8aipi)i and its brunches is princi-
pally derived from Generals Humphreys and Abbot's great work on tLe " rhysios
aud Hydraulics of the Mississippi lliver."

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I,' '

The true Mississippi begins at the confluence of the Missouri
and the Upper Mississippi. Its five principal tributaries, in the
order of the magnitude of their basins, are, the Missouri, Ohio,
Arkansas, Upper Mississippi, and Red River.

The area of the basin of the Missouri is 518,000 square miles,
and its mean discharge is 120,000 cubic feet per second, or about
one-fifth that of the Mississippi at New Orleans. Unlike the other
tributaries of the Mississippi, a large portion of the Missouri basin
consists of lofty mountain chains. Comparatively little rain falls
upon the mountains and the plains, and hence the size of the main
river is disproportionately small when the drainage area alone is
considered. The annual discharge of the Missouri is only three-
fourths that of the Ohio, although its basin is nearly two and a half
times as large. Ascending the river, the Missouri divides, at Fort
Union (1,894 miles from the Missouri mouth), into two branches
of about equal size, the Yellowstone and the Upper Missouri. The
source of the Upper Missouri branch, which has an elevation of
6,800 feet above the sea, is 2,908 miles above the mouth of the
Missouri ; and that of the Yellowstone branch, 2,489 miles. The
range of the Missouri, between high and low water, is about 35 feet
at the mouth. The navigation of this river depends upon the
temporary floods ; and barges are loaded and their time of starting
is regulated accordingly'. Vessels drawing from 3 to 4 feet carry
from 150 to 250 tons of cargo to the Yellowstone branch, and
make the passage up in from twenty-two to thirty-five days.
At seasons of low water there is only a depth of 1 foot on many
of the bars of the Missouri, and at such times the navigation is
practically closed. No efforts have yet been made to deepen these
bars ; and operations for clearing the river of impediments have
hitherto been confined to the removal of 'snags,' which abound
in the lower part of the Missouri, and render the navigation of
vessels by night extremely dangerous.

The distinguishing character of the Upper Mississippi is the
entire absence of mountains in the basin which it drains. Near
the source of the river the country is only about 1,680 feet above
the level of the sea. The area of its basin is 109,000 square miles.

Distances.

Miles Miles from

' from Mouth of

Source. Missouri.

Source 1,330

St. Paul (Falls of ^'t. Anthony) .... 672 658

■•• Rock Island Rapids (head) 1,020 310

Des Moines River 1 , 165 165

Illinois River 1,306 24

RIVERS AND CANALS IN THE UNITED STATES AND IN CANADA. 27

Falls of St. Anthony. — These falls, which are a complete
l)arrier to the navigation of the Upper Mississippi, are caused by
the damming up of the waters by a layer of limestone rock (which
is 11 feet thick at the crest of the falls, and 3 feet thick at its
upper end, about 1,000 feet above the crest), overlying a mass of
sand rock about 100 feet in thickness. The total fall is 50 feet.
The crest of the falls is continually receding, and in 1872 it was
from 300 to 600 feet above its position in 1857. This retrogression
is caused by the falling water undermining the sandstone which
sustains the limestone, so that the latter becoming unsupported
breaks off by its own. .veight. In order to preserve the falls from
further erosion, and consequently to perpetuate the utility of the
water-power caused by them, which involves large interests, v»^orks
are now in progress to prevent the wearing away of the sandstone
at the foot of the falls, and to stop the upper current from passing
through the soft sandstone rock under the limestone ledge. The
sum of K 200,000 (£40,000) will be necessary to fix the position of
the falls permanently. The range between high and low water at
St. Paul is 20 feet.

Rock Island Arsenal. — This establishment, which is now in
course of construction under the able direction of Colonel Flagler,
of the Ordnance department, is apparently destined to be the
most important arsenal in the United States, for the manufacture
and storage of arms and all other military equipments, whether for
land or river service. Eock Island has an area of 1,000 acres,
elevated from 30 to 35 feet above the river, and is joined at its
lower end to the city of Rock Island, in Illinois, and the city of
Davenport, in Iowa, by a road and railway bridge. Its upper
end is connected with the city of Moline, on the Illinois, or loft
bank, by a Government wagon bridge. The island is about 3
miles long; and as the river falls 9 feet in this distance, im-
portant, substantial, and well-designed works have been con-
structed, to utilise this fall as much as possible, by the use of
turbines in the Illinois channel, not only for working the machinery
of the arsenal, but for the large paper and iron mills in Moline
city. The water-power is estimated at 2,(300 horses, of which the
Government is bound to make over one-fourth to the mills in per-
petuity. Colonel Flagler is in favour of transmitting the water-
power to tho arsenal by the wire-rope system, as practised at
Schaffhau?en and Moline, which he considers to be more econo-
mical than tho system of compressed air, as adopted at many
similar localities. Each of the ten buildings forming the arsenal
and armoury will cover an area of 1 acre ; and as each will have

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'I'ii

' i!i;

four floors, tho total floor area will bo 40 acres. At the time of
the Author's visit, only three of the buildings were completed.
They are solidly built, and are all fireproof — the walls being
of Joliet stone, tho girders of malleable iron from the Phoenixville
works, tho arching between the girders of brick, the floors of
concrete, covered where necessary with planking, the framework
of the roofing of iron, and tho root I'-self of slate.

Rock Island Rapids. — These raj ids are 348 miles below the
Falls of St. Anthony, and extend i rom St. Claire to Davenport, a
distance of 14 miles, with a total fall of 21 J feet. The mean width
of the Mississippi in this distance is 2,500 feet ; tho velocity varies
from 1^ mile to 3^ miles an hour. The bed of Rock Island Rapids
consists of chains of hard magnesian limestone, which dip to the
south more rapidly than the surface of the water. They are
seven in number, and, before the improvements, either overlapped
each other, leaving only a narrow, tortuous channel between them,
or extended entirely across the river. Between the chains, through-
out almost the entire distance, there is a wide and navigable
channel, and at such places the velocity of the current is much
less. These pools have an aggregate length of 11 miles, so that
the obstructed portion of the river to be improved has only a
length of 3 miles. The ordinary range between high and low
water at Rock Island is 16 feet. The maximum range, observed
by Lieutenant Warren (now Brevet-Major-General, U.S.A.) in 1851,
was 23 feet at Davenport, and 13 feet at the head of the rapids.
On account of the hydrographic features of the lapids, it was
deemed advisable to cut simple channels through the reefs, rather
than to avoid them altogether by adopting the more expensive
plan of constructing a lateral canal, furnished with locks, as at
the Des Moines and Ohio Rapids. It was therefore decided, in
December, 18GG, to enlarge by excavation the old steamboat chan-
nel of the Rock Island Chains to a width of 200 feet, and to a
depth of 4 feet at the time of low water, which is somewhat
greater than the ruling depth in the river north and south of
the rapids during that season. Tho estimated quantity of excava-
tion for this work was 57,451 cubic yards, and the estimated cost
g813,602 (£162,000). Tho Author was told by Major Hoffmann,
the inventor of an ingenious and accurate mode of sounding a
rocky bottom, that the cost of excavating by contract 60,000 cubic
yards of rock over large areas, by means of low-water cofferdams,
had varied from KlO to ^13 per cubic yard during the last six
years ; whilst, in tho same period, the breaking up of half that
quantity by of Osgood and Whitney's steel chisels (weighing

THE MISSISSIPPI AND ITS TRIBUTARIES.

8,000 lbs. each, and worked by macliinery similar to that used for
pile-driving) had varied from Kl3 to K18 per cubic yard, in-
cluding the dredging of the pulverised material. The improve-
ments were begun in 1867, and were nearly completed at the
time of the Author's visit in November, 1873, when he was in-
formed by Colonel Macomb of the Corps of Engineers, U.S.A.,
who has charge of the works, that there is now no difficulty
in passing by the new channel, except during unfavourable winds ;
and that, so far as has yet been observed, no lowering in the level
of the pools between the chains, or in the river above the rapids,
at low water, has been caused by the cutting above described,

Dks Moines Rapids. — Tliese rapids are situated immediately
above the Des Moines river, at 145 miles below Rock Island.
They extend from Montrose, where the width of the channel is
5,000 feet, to Keokuk, where it narrows to 2,500 feet. During
the low- water season, they interpose a serious, and at times an
impassable barrier, to steamboat navigation. The river bottom,
which, for the most part, consists of carboniferous or mountain
limestone, is a broad, smooth rock, seamed by a crooked channel
50 feet wide and 3 feet deep, and the rapids, therefore, are not
broken and noisy, but, the descent being gradual the water flows
over its bed in a smooth, unbroken sheet, with a varying velocity
of from 1.^ mile to 3.^ miles an hour.

After long discussions as to the best mode of overcoming the
difficulties of the rapids, the execution of the project of General
Wilson, U.S.A., to construct a lateral canal on the right or Iowa
bank, was decided upon in 18(37. The works were begun in the
following year, and by the end of 1873 more than two-thirds had
been completed. The Author is indebted to Major Stickney, of
the Corps of Engineers, U.S.A., for the greater part of the follow-
ing particulars concerning the canal works, for which ho is the
Resident Engineer under Colonel Macomb.

The canal skirts the Iowa or right bank, and is 8 miles long,
200 feet wide in cuttings and 300 feet where embanked. It is
furnished with two lift-locks, the lower one of which has a lift of
11 feet, and the upper one — 2 miles above the lower one — a lift of
8 feet. At 8 miles above the lowest lock is a guard lock, by
means of which, when the water is 3 foet above extreme low water,
a depth of 8 feet can bo maintained in the canal, which, as well
as the lift-locks, will only have a depth of 5 feet at low water.
All the locks are 350 feet long by 50 feet wide, and are ad-
mirably constructed of solid masonry. The lift-locks are fed and
emptied, through the walls of the lock-chambers, by culverts

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at nearly equal distances apart along the whole length of
the chambers. The puddled embankment wall of the canal is
mostly founded in the bed of the river, and is carried up to a
height of 2 feet above the level of high water. It is 10 foot wide
at the top, has slopes of 1^ to 1, and is protected on both sides with
" rip-rap " (rubble stones). The range between high and low water
is 22 feet at Keokuk, and 12 feet at Montrose. The excavation of
rock amounts to 400,000 cubic yards, and of loam to 800,000 cubic
yards. The estimated cost of the canal, including ^259,000
(37,000 cubic yards at S7) for the excavation of a channel
through a chain of rocks at Nauvoo, at the head of the rapids,
opposite Montrose, is K3,200,000 (£640,000)— a sum nearly one-
third in excess of the original estimate. The cost of the rock
excavation, exclusive of cofferdams and pumping (which treldes
the expense), has varied from H2"20 to H^'SO per cubic yard,
and the earth excavation from 30 cents to 65 cents. The interior
of the embankment (derived from the excavation) cost 70 cents
per cubic yard. The cost of the cut stone masonry, from quarries
in the neighbourhood, was KlO per cubic yard, and of the concrete
masonry K4. Major Stickney deprecates the system of executing
hydraulic works by contract, and is of opinion that the canal
could have been executed at more than 25 per cent, less if, from
the first, and as is now the case, the work had been carried on
under the immediate orders of the Engineer.

The Illinois Eiver. — At 145 miles below the Des Moines rapids,
and 24 miles above the Missouri mouth, the Illinois river joins the
Mississippi after a course of 450 miles through the rich and fertile
State of Illinois. A description of the lower part of the river, and
of the plan proposed to render it navigable for large steamers, in
connection with the improvement of the Illinois and Michigan
canal, is referred to in the following extracts from the Eeport of
General Humphreys, the Chief of Engineers of the U.S.A., dated
13th May, 1867 :—' , .

" The distance from Grafton, at the mouth of the Illinois to
the outlet of the Illinois and Michigan canal at La Salle, is
224 miles. The difference of level between the two points in the
plane of low water is 29 feet. The river varies in width from
500 feet to 1,400 feet. -« .. ^. -v

" In ordinary and high-water stages it affords good navigation
for the largest class of steamboats used on the Mississippi ; while at

' Vide Annual Reports of the Chief of Engineer:;, .vhich may be consulted in
the library of the Institution.

i::il I

RIVERS AND CANAI,8 IN THE UNITED STATES AND IN CANADA. 31

low water it can only be used by the smallest class of flat-
bottomed boats. The whole distance, from the mouth of the
Illinois river to Bridgeport, near Chicago, by river and canal, is
about ;520 miles, and the lockage between the two points (ordinary
water level of Lake Michigan and low water of the Mississippi)
is about 170 feet, which, by making a through cut from Chicago
river to Lock port, on the Des Plaines river, would be all a
descending lockage, with the lake as a summit.

" General Wilson recommends the improvement of the Illindis
river by a system of locks and dams, and that the navigation
be extended from Lockport to Chicago by the enlargement of part
of the Illinois and Michigan canal, giving a depth of 7 feet,
both in the river and canal, with locks 350 feet long and 75 feet
wide.

" The distance from La Salle to Chicago is 07 miles. It is pro-
posed to cut down the present summit to low- water level of the
lake. With the exception of two short canals, it is deemed ad-
visable to abandon the old location, and to improve the natural
channel of the river by locks and dams, they being less expensive
than the enlargement of the original canal.

" Estimated cost of canal frcm Bridgeport
(4 J miles from Oliicago) to Lockport,
29 mile.i loug, 160 feet wide, and 7 feet
deep

Improvement from Lockport to La Salle .

River improvement from La Sallo to

Grafton

Total ....
Being about $68,000 a mile."

10,098,000

8,118,200
3,123,796

$21,3;?9,996 (£4,207,999)

Since the above report was written, the canalisation of the
river below La Salle has been begun, and the first slack-water
pool has been created over a length of 28 miles by the con-
struction of a lock and dam at Henry — a work which was suc-
cessfully completed at an expense of ^400,000 (£80,000). The
lock at Henry is 350 feet long by 70 feet wide ; the side walls
are 30 feet high, although the lift of the lock is only 6 feet.
A sJTuilar lock has been commenced at Copperas, 61 miles below
Ft^nrj; and when this and three other shave been completed, at
intervals apart of 61^ miles, 29i miles, and 41 miles respectively
from Copperas, thus converting the lower half of the Illinois into
a series of five pools, each with a lift of 6 feet, vessels drawing
6 feet of water, and carrying from 1,000 tons to 1,200 tons, will be

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iiiip

al)lo to navigate at all soasonK between the lllinoiH mouth and La
Salle, Until, however, the improvements recommended by General
"Wilson, between La Salle and Chicago, have been carried out, the
dimensions of vessels on that part of the route must be restricted
to the size of the locks of the Illinois and Michigan canal, which
are only 110 feet long by 18 feet wide. Hitherto, the only executed
portion of the proposed improvement, between La Salle and Cliicago,
has been the cutting through the summit level of 26 miles which
divides the valleys of the St. Lawrence and the Mississippi. This
work was performed at the expense of the city of Chicago, as it was
considered the best means of getting rid of the sewage matter of
the city, and was completed at an expense of >}3,301,000 (£G<30,000)
in 1871.

TiiK IMiciiioAN Canal. — By moans of this cut, the bottom of
which is 8 feet below the level of Lake Michigan, the Chicago
river, with most of its impurities, and a clear stream from Lake
Michigan itself, now flow into the Michigan canal, and thus help
to feed the Illinois river. The real importance of the improvement
of the Michigan canal and the Illinois river can only be properly
estimated by regarding it as completing a system of water com-
munication between the east and the west.

The Mississippi mouth has ceased, it is alleged, to be the great
outlet for the trade of the Upper Mississippi and Missouri. The
present course of trade from these vast regions indicates that it is
gradually being diverted to the east, and abandoning its natural
course by New Orleans and the mouth of the Mississippi, which is
inaccessible to the large ocean steamers now trading to Boston, New
York, Baltimore, and Philadelphia.

The improvements up to this time, excepting those already
mentioned at Eock Island and Des Moines, have been confined to
the dredging and scraping of bars, the removal of snags, and the
cutting of trees to prevent them from forming new snags. ^

Dredging and scraping are mere palliatives, and if carried
on by fifty dredgers, instead of by the solitary machine now
employed, but little impression would be made on the shifting
sandy bars which stretch across these mighty rivers in innumer-
able places, and, at times of low water, make the river impassable

' From June, 1869, to June, 1870, four snag boats, wiiich are very ingeniously
contrived, removed 3,031 sungs, weighing 60,000 tons, and cut down 33,.')00 trees
in ttie Upper Mississippi, Missouri, and Arkansas rivers. The annual expense of
working these four snag boats, the cost of which was 100,000 dollars each, is
$340,000, and of the dredger $60,000, or $400,000 (i;80,000) in all.

THE MISSISSIPPI AND ITS TRIBUTARIES.

to craft larger than a fishing boat. In respect to this discouraging
condition of tlio Upper Mississippi and Missonri, Colonel Macomb
in his ]{eport to the Chief Engineer, on the 20th of September,
1870, remarks : —

" The works of improving the western rivers belong to the class
of works which may be considered as indefinite or admitting of no
permanent completion. It is indeed in the very nature of these
great rivers, flowing through vast bottom lands, that such should
be the case ; for improve the channel as we may one season, in the
following year it will very likely be found that some of the im-
proved reaches of channel have been abandoned by the river, and
a channel chosen with dangers in it requiring a repetition of our
labours, or new improvements."

Thk Lower Mississippi. — It has been already remarked that the
true Mississippi begins at the confluence of the Missouri and the
Upper Mississippi. . •

Distances and Inclination at Hioh Wateh.

Inter-

tncdiuto

Distances.

From the
Missouri
Mouth.

From tho

MlHslsHinpl
Mouth.

RlRht or

Left Hanlc

of the

Ulver.

High

Water

above the

Gulf of

Me.xlco.

Slope per
Mile.

Mouth of the Missouri .

Miles.

• •

Miles.

MilPS.
1,286

right

Feet.

Inches.

St. l.ouia ....

1,270

right

408

• •

Mouth of the Ohio ( Cairo)

173

189

1,097

left

322

„ of the Arkansas.

405

594

692

right

149

„ of the Red river

376

970

316

right

New Orleans

211

1,181

105

left

Head of the passes ofi
the Mississippi . . /

105

1,286

••

. .

• St. Louis. — This important city of four hundred and fifty thousand
inhabitants is situated on the right bank of the river in the State
of Missouri, and is the largest inland city in the United States.^

' The celebrated Horace Greely, late Editor of the " New York Tribune," thus
describes " the future great city " in a letter to Mr. L. U. Beavis, of Missouri, on
the 4th of Feb., 1870 : — " I have twice seen St. Louis in the middle of winter.
Nature made her the focus of a region embodying a vast area of the most
fertile soil on the globe. Man will soon accomplish her destiny by rendering
her the seat of an immense industry, the home of a far-reaching, ever-expanding
commerce. Her gait is not so rapid as that of some of her Western sisters, but
she advances steadily and surely to her predestined station of the first inland city
on the globe."

[1874-76. N.S.] D

■

OTHER SELECTED PAPKU8.

It 18 16 miloH from tho MisBouri month, and is now joinotl to the
Illinois bank by tho most romarkahlo bridge of nuHlorn times.
This bridge Iuvh already been ])riofly described. Ko other bridge
spans tho Mississippi l)etwoen th'> mouth of tho IMissonri and tho
Gulf of Mexico, a distance of nearly 1,300 miles.

The Ohio River. — 'I'his river flows into tho Mississippi at
(^airo, 173 miles below St. Louis. 'J'he average width of tho
Mississippi between these cities is 4,000 feet, and the least depth
at any point is 2 feet at extreme low water. Tho total area of
tho Ohio basin is 214,000 square miles, and its annual discharge
of water is l.')0,000 cubic foot per second, or one- fourth that
of tho Mississippi. The Ohio is formed by tlie junction of tho
Alleghany and Monongahela rivers at Pittsburg.' 'J'liroughout
its whole length (967 miles) tho river flows with a gentle current
uninterrupted by rapids, except at the Falls near Louisville. At
low water the Ohio is a succession of long pools and ripples,
with a current alternately sluggish and rapid. The bars in the
upper part of tho river are mostly gravel and boulders, in tho
lower part shifting sand. The range between extreme high and
extreme low water is about 46 feet throughout the entire river.

Distnnco

Fnll

Fall per

Depth.

from

Mile in

rittsburg.

Feet.

Inches.

At Wlieeling ....

. 45 feet .

91 miles

10}

„ Louifiville, on the Falls

. 42 „ .

. 598 „

308

„ „ bolow them

. 64 „ .

. 601 „

333

100

„ Evansville.

. 40 „ .

. 783 „

384

„ Paducah ....

. 51 ., .

. 920 „

418

„ Cairo (mouth) . .

. 51 ,. .

. 967 „

427

The usual range is 25 feet. The width of the river varies from
1,200 feet to 3,000 feet. Proceeding upwards, the least low-water
depth on the bars from the mouth of the river is, to Paducah,
about 3 feet; to Louisville, 1^ foot; to Cincinnati, 2 feet to 2^
feet ; and to Wheeling, 1 foot.

The business on the river is so arranged, that, at periods of
very low water, all through steamboat traffic on the Upper Ohio
ceases. The great bulk of the river traffic is, however, carried on

" The Alleghany river, 290 miles long, is navigable for steamers for a distance
of 259 miles abovn Pittsburg. The Monongahela river was * slack watered * in
1842 and 1856 for 84 miles above Pittsburg by the construction of six dams
and eight locks Six of the latter are 190 feet long by 50 feet wide, and the
other two are 250 feet by 56 feet. The cost of the work was about $600,000
02120,000).

RIVERS AND OANALS IN THE UNITED STATES AND IN CANADA.

when tho depth o^ water is ',\ foet or more in the channels, which
is on not less tlian two hiinelrcd and sixty days in tlic year.

I'ho FallH of tho (^liio at LouiHvillo, which descend 25 feet in
3 miles, and which have been called a natural rook dam, are not
navigable at extreme low water. At very high water any craft
can pass them safely ; and at medium floods, with goml pilots,
steamers and other vessels are taken over.

In 1825, tbo Ijouisville and Portland Canal Comi.any obtained
authority to make locks (184 feet by oO feet), and a cannl on tho
Kentucky side, and tho first boat passed through in 1828. This
canal is now superseded by an improved one with now locks,
constructed in 18(30-GG by tho United States Government, under
tho direction of General G. ^Veitzcl, I .S.A., ut an expoiiKO of about
i?l,800,000 (£3(;0,()0()), after nearly the same amount had been
spent on the works by a private company.

Tho following information concerning tho Portland canal was
given to the Author by Captain Adams of the Corps of Engineers,
U.S.A., who kindly accompanied him over the work of wh ch
Captain Adams had then tho charge.

The canal is 2. J miles long, and is cut mostly in rock through a
neck of land, about 70 feet above low water, between two reaches of
the river on the Kentucky shore. By it, a level of 20 feet is sur-
mounted at low water, at which time there is a depth of G feet of
water in the canal. Of this depth 2 feet are obtained by tlio back-
water caused by a dam of cribwork (not. yet completed), wliieli crosses
the river at the upper end of the canal. Near the Indiana shore this
dam has an opening or ' chute,' 400 feet wide, for the passage of
vessels when tho locks are not required. The canal is about 80 feet
wide, and has vertical walls of masonry 12 feet high. The upper
guard lock is about | milo above tho entrance to tho canal, and
its gates being but little higher than the vertical walls will
only be useful in case of repairs, and are of no service in dam-
ming back tho water, which sometimes rises 42 feet above the
falls. When the water rises to 12 feet in tho canal,' the latter is
no longer used by vessels descending the river, as they can then
run tho rapids without difficulty or danger. The two lower locks
are 390 feet by 80 feet in tho chamber, and each has a lift of
14 feet.* The lower gates are 68 feet high to provide against high
floods, which have been known to rise 65 feet below the falls.

• AUIiougli tho looks of the Portland and Dea Moinca canals are the largest
oanal-looks in the world, some of the steamers on th(3 Mirisissippi which trade
between St. Louis, tho Ohio, and New Orleans, from their breadth of beam,

D 2

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Il I
hi I

Vessels now p:vy 50 cents (28.) per ion for passing through the
canal, but it is expected that this high rate will soon be reduced
60 per cent.

Otheu Works of Improvement on the Ohio, — These are of
slight importance, and have hitherto been confined to dredging
the more obstructive bars, and constructing here and there what
are called ' rip-rap ' dams (artificial dams of rubble stones), with
a view of concentrating tlie flow of the streanx into comparatively
narrow cliannels, to secure an additional depth of water.

Although these measures are of a very palliative kind, they
would undoubtedly improve the navigable channel of the Ohio, if
carried out systematically year by year on a commensurate scale,
throughout the entire length of the river. When it is stated,
however, that an annual grant of only Si 00,000 (£20,000) is
allowed for this work, it is not surprising that no one can say
precisely how much real improvement in the river has been
acliieved since the attempt to deepen the channel was begun.
Various plans have been suggested by American engineers during
the last half century to effect a radical and permanent improvement
of the Ohio. Of these may be noticed : —

1. Mr. C. Ellet's plan of artificial reservoirs to store up water
enough, when gradually drawn out at lov. -water seasons, to make
a perennial flow 6 feet deep in tui, ;hannels.

2. The scheme of a continuous canal 200 feet wide on one side
of the river.

3. The method of locks and dams similar to the actual navisra-
tion on the Monongahela, and to that now under executioi. on tho
Illinois river.

Difficulties and objections are inherent to erch of these expe-
dients, but of all the schemes proposed it is ^ vneraily believed
by those who have carefully studied t)ie subjv „ thid locks and
dams, with chutes so arranged that coal fleets migl'.t be ppssed from
one pool to another without division, would be tho best and most
economical means of securing the desired depth of water from
Cairo to Pittsburg, say, 6 feet, at all seasons. This is the decided

cannot pass through them. For instance, tho "City of Richmond" steamer,
which the Author inspected at St. Louis, had the following d aaensions : —

Extreme length
„ width
Load line
Light line

Iroff

340 feet. |

f 11

»>

I 4

Two 5-foet cylinders andj

l()-ft?et stroke,
Six boilers.
Paddle-wheels, 44 feet in

diameter.

Burthen, 2,500 tons.
Height, from water-line to

top of funnels, 92 feet.
Ditto, to top of pilot houae,

tiU feet.

THE MISSISSIPPI AND ITS TRIinTTARIES.

opinion of Mr. W. Milnor Roberts, the Engineer in charge of the
Ohio river improvement, who, iu a report, dated the 11th of April,
1870, to General Humphreys, on the radical improvement of the
Ohio, estimates the cost of the system as follows : —

Pittsburg to Louisvillo 598 miles.
51 seta of locks double, 370 feet by 80 feet,
and 300 feet by CO feet, with 6-fect lifts,
including dams and chutes at . . .

Loniavillo to Cairo 369 miles.
15 sets of locks, do. do., with dama and

chutes at

Extra length of dams below the falls .

334,357 = 17.052,207

334,357 =

5,015,350
1,710,105

$23,777,062

£4,700,000, or $23,550 per milo for 9G7 miles.

So far as the Author has been able to learn, no works have
3'et been iindortaken for the improvement of the navigable
channel of the Mississippi livor below Cairo, although at low
water the depth on some of the shoals between that city and tho
mouth of the lied river, a distance of 781 miles, does not exceed
5 feet. Surveys and projects are now J)eing made, however, for
tho improvement of these bars. Tho width of the Mississippi at
the Ked river landing is 3,020 feet at high water and 2,<)50 feet
at low water. The distance from the mouth of the Ohio to tide-
water by the Mississippi river is about 1,100 miles, and the average
fall is at the rate of 3 inches per mile. The moan area of cross
section at high water over this length is 105,000 square feet, and
the mean annual rainfall 30;^ inches.

The Arkansas River joins the right })ank of tho Mississippi at
405 miles below Cairo. The area of its basin, including that of tho
White river, is 189,000 square miles, and the mean annual discharge
is at the rate of 63,000 cubic feet of water per second. This river
is 1,514 miles long; the width varies from 1,500 to 5,000 feet, and
the least depth on the bars at low water is 1 foot. Tho estimate
for its improvement for tho year ending the liOth of Juno, 1874, is
^100,000 (£20,000) for tho running expenses of four snag boats,
five months each at S5,000 per month.

The Rkd River joins the right bank of the Mississippi 781 miles
below Cairo, and at 316 miles from the Mississippi mouth. It is
1,200 miles long, tho width varies from 800 to 2,000 feet, and the
least depth of water on tho bars is also 1 foot. Tho area of the
basin is 97,000 square miles, and the mean annual discharge of
water is 57,000 cubic feet per second.

OTHER SELECTED PAPERS.

1'he only expenditure made by the Government for the im-
provement of this river has been in the many attempts to
remove the obstruction known as the " Eed river raft," which
is composed of an immense accumulation of drift wood, partly
sound, partly rotten, partly sunk, and partly afloat, but always
advancing steadily up the river. Its length in the summer of
18o4r was 13 miles, and it had then advanced to a point 53 miles
above Shreveport.'

The Deli'a (Plato 7). — Just below the confluence of the Eed
river is the first of the bayous,- w^hich, fed by the Mississippi,
discharge into the Gulf of IMexico. Below this point the great
river receives no appreciable increase from tributaries. It has,
therefore, fov these reasons been generally considered the head of
the delta. On the assumption that a delta begins where it first
sends off a branch to th(! sea, at the head of the bayou Atchafalaya
in tliis instance, the delta of the Mississipppi has an area of 12,300
square miles, of which one-third is composed of soa marsh. It is
contended by some writers, however, that the origin of the delta is
3 miles below Capo Girardeau (47 miles above the mouth of the
Ohio), where the waters of the Mississippi used to escape into the
St. Francis, and thence through the Arkansas valley into the
Atchafalaya, &c.; and that, therefore, the area of the delta is really
38,706 square miles. This is stated in a recent paper by I'rofessor
C. Forshey. Between Bayou la Fourche (the last of the outlets) and
Fort St. Philip, the Mississippi flows through a tolerably uniform
channel, averaging at low water 200,000 sqiiaro feet in cross
section, 2,470 feet in width, and 12i) feet in depth at the deepest
part. In the Iot,- water stage, these measurements are 163,000
square feet, 2,250 feet, and 114 feet respectively.

Lkvkes and Cut-offs. — Between Cairo and Fort St. Philip 1,600
miles of levees, or embankments, have been constructed to protect
the adjacent lands from overflow ; but the system was so imperfect
in 1869 (and the same may even now be said) that General Abbot,
U.S.A., reported that an outlay of K38, 230,000 was required to
raise the existing levees in the states of Arkansas, Mississippi, and
Louisiana, (^19,0(50,000, K4,150,000, K15,020,000 resi^ectively) to
their proper height. This sum, at the estimated cost of the work,

' Since tliia was written the Autlior has been informed by General Humplircye
that the laft liaa lx;en removed, and that by annual grants from Government ita
reformation iu to be {ircvintcd.

- A bayou in liOuisiauu means a stream not so large as a river, and a crook
()roporly no called.

RIVERS AND CANALS IN THE UNITED STATES AND IN CANADA. 39

viz., 40 cents per cubic yard, represents embanking to the amount
of 95,000,000 cubic yards.^

The efficacy of ' cut-oifs ' as a means of relief from floods has been
contested by many authorities on the 'regime' of the MiKsisHip{)i.
In December 1874 General M. Jeff Tliompson, Chief State Engineer,
reported to the Governor of Louisisina that two out of the six
cut-offs, made below the mouth of the Arkansas and Tunica since
the days of steamboats, were fast elongating themselves, at the ex-
pense of the levees. With regard to these this engineer remarks that
there are none from Cairo to Memphis on the left bank, nor from
^icksburg to Baton Eouge, except a few private ones; but that
there has been a system of levees along the whole of the right
bank, from Commerce to Fort Jackson, near the mouth of the
Mississippi. He also adds that from Memphis down to the mouth
of the Tazoo, and from Baton Kouge down to Fort Philip on tho
left bank, the levees form a complete system.

An aggregate length of 107^ miles of levees — wings and main
line included — were lost from October 1866 to October 1874, in
consequence of the caving of the banks of tho river in tho State
of Louisiana. During the disastrous floods of the spring of 1874,
a crevasse of unusual magnitude occurred at Bonnet Carre, in
Louisiana, of which a detailed account (from tho Levee Commis-
sioner's report) is given in Ajipondix I.

Twenty miles below Fort St. Philip, a great change takes place.
(Plate 7.) The river widens to 8,000 feet, with a maximum depth
of about 40 feet, and a cross section of about 250,000 hquare feet.
It then separates into three principal branches, called from tho
directions they take, the South- West Pass, the South Pass, and the
North-East Pass, the latter sending off a branch called the Pass a
I'Ontro. The dimensions of these passes are shown by the Table
on the next page.

The bars at the mouths, are composed of sand and soft mud,
and are described in Humphreys' and Abbot's work as being pro-
duced by sand and silt rolled along the bed of the river, and not by
the precipitation of matter held in suspension by the outflowing
waters. The length of tho bar of the South-West Pass, or the
distance between the 18-feet contour lines, is 2^ miles.

' To the 1st of October, 1874, the Louisiana Levee Company, which was
incori)orated iu February 1871, have built levees containing 4,823,012 cubic
yards, at a cost of $2,520,G12, being at tlie rate of 58 cents (28. 4rf.) per cubic
yard. General Al)bot'8 estimate was based on the heiglit obtained by the great
flood of 18.'58, which has not been exceeded since, and an allowance was made of
about 1 foot for a possible rise above that extraordiuariiy high flood.

111'

i \r.

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Dimensions of the Main Passm of tho Misbissippi.'

Pass.

I^cngtli to

outer crest

of Bar.

Mean Width.

Mean
Depth.

Mean Area of
Cross Section

Proportion of
Discharge,
thatoftlio
MitiBissippf

being unity.

Miles.

Feet.

Square feet.

South-Weat Pass . .

1,200

70,000

•340

South Pass. . .

700

24,000

•080

Nortli-East Pass . .

2,500

92,000

•225

Pass k I'Outio . . .

1,300

47,000

•254

Remainder mi

xinly through South-West Pass

•

•101

Discharge and VELoniriEs at tho head of tho South- West Pass, which delivers
one-third of tlxe total volume of the Mississiiipi into the Gulf. The dis-
char^ro through this Pass exceeds the entire volume of tho Danube.

lUvor Stage.

Usual

Minimutn

Discharga
per Secund.

Mean

Voiocity
per Hour.

Discharge
per Second.

Mean
Velocity
per Hour.

Flood

Low water .

Cubic Feet.
340,000
102,000

Miles.
4-9
14

Cubic Feet.

272,000

75,000

Miles.
3-9
1-0

The natural depth on tho South-West Pass is only 13j feet, but
by the use of two eiteam-dredgers, or mud-scrapers, a depth varying

' Mr. G. W. R. Bayley, civil euginoer, New Orleans, an acknowledged
authority on all matters connected with the Lower Mississippi, has lately
directed attention to the fact that, while the high-water slope of tho river,
from New Orleans to tho head of the passes, is only about 1 J inch to the mile
for the whole river, tho high-water slope of the South-West Pass channel is
about 2 iuches per mile ; of the Pass a I'Outre, about 2J inches per mile, and of the
South Pass, about 2J inches per mile. It is well known, he maintaius, that the
greater the normal quantity of water flowing in a sedimentary riVer, below its
last affluent, the less will be its surface slope, and the greater its depth and
Telocity of current and sectional area of channel. The width of the Mississipin
river does not increase from the mouth of the Ohio down, but its depth does,
below each affluent; while the surface slope diminishes, gradually, as far down
as the head of the passes. See Table of Inclinations at page 33 ; also remarks
on the same subject in Mr. Alfred Tyler's highly interesting Paper, on " The
Curve of Denudation," Geological Magazine, vol. ix, pp. 392, 485.

THE MISSISSIPPI AND ITS TRIBUTARIES.

from 16 to 18 feet was maintained over a channel from 200 to
800 feet wide, for the two working seasons previous to 1873, It
is considered that by this means a channel 18 feet deep could always
be maintained, at an expense of ^200,000 (£40,000) a year, a sum
which includes the entire renewal of a steam-scraper every four
years. The cost of the scrapers is ^200,000 each. They are
arranged so as to bring up the silt, which has been agitated by the
screw of the vessel, into the upper stratum of the outgoing current.
In the channels where the machines ha/e been employed, the
velocity of the surface is generally from 2 to 3 miles per hour ; but
at 10 feet below the surface the velocity is reduced to 1 mile per hour ;
and at the bottom, not only to zero, but occasionally on a rising tide,'
and when the flow of the Mississippi is under 800,000 cubic feet per
second, which is the discharge at ordinary high-water, the current
flows in an inverse direction, or into the river. Hence the neces-
sity of having the scraper vessels so contrived as to bring the mud,
which has been stirred up by the screw, as near the surface of the
water as possible. The machines only work on the crests of the
bars over a length of less than 4,000 feet, and the current does
the rest of the deepening.

Major Howell, U.S.A. (Resident Engineer for the Lower Missis-
sippi), informed the Author that each steamer removes about 10,000
cubic yards of mud a day, and that early last year, owing to ob-
structions designedly thrown in the way of the navigation by the
Towage Steam Company, which has a monopoly of the towing at the
mouths, the scrapers were withdrawn to the Pass a 1 'Outre, where
they worked for the remainder of the year. The natural depth of
water on the bar of the Pass a I'Outre is only 1 1 feet, but the effect
of the scraping was to deepen it to nearly 18 feet, over a width of
about 200 feet, at the end of 1873, by which time the depth on the
South- West Pass was again reduced to 13 feet, although vessels
drawing 17 feet were actually then being drawn across the bar,
through 4 feet of soft mud, by the Steam Tug Company.

Fort St. Philii' Canal. — The majority of a Board of Military
E: ^rineers, who assembled at the mouths of the Mississippi, in
Kovember 1873, to consider and report upon the plan submitted by
Major Howell for a ship canal, recommended Congress to construct
a ship canal from Fort St. Philip to Breton bay ; and accordingly, on
the 9th of February, 1874, a Bill was introduced into Congress which
" provides for the construction of this canal, and its maintenance

' The tide has a mean tiec of 15 iuolies every twenty-four hours at the
Missiasippi muuths.

OTHEB SELECTED PAPERS.

as a public highway." In the Bill it is enacted, — " That a ship
canal to connect the Mississippi with the Gulf of Mexico, com-
mencing at some convenient point on the river below Fort
St. Philip, and terminating at some convenient point in Breton
bay, shall be constructed and maintained at the expense and under
the control of the Government of the United States : That the
dimensions of the canal shall not be less than 200 feet wide at
the bottom, and with not less than 26 feet in depth of water,
with the necessary guard-gates, locks, &c., which may be neces-
sary for the safe and convenient navigation of the canal." The
estimate for the above work is K 10,296,600 (£2,000,000), which
includes the cost of jetties for extending the canal into the deep
waters of the Breton bay.

Parallel Piers versus Caxal. — General Barnard, U.S.A.,
who was in the minority of the Board of Military Engineers,
of which he was the President, is of opinion " that the con-
ditions of the location and execution of a canal have received
no adequate study," and he therefore demands "new studies
ot location, and an entire revision of plans of execution." He
is also in favour of an open river mouth rather than of a canal
impeded by locks. He likewise agreed with the Author in the
opinion, that the South Pass of the Mississippi should bo selected
for a full trial of the jetty system, on the principle that it is more
advisable, in an economical point of view, to improve the mouth of
a minor branch of a river, rather than to grapple with the diflfi-
culties at the mouth of a principal branch, if that minor branch
debouches into deep water, and offers a sufficient breadth and depth
of channel for the navigation till its bar is reached. The south
branch has a width of from 600 to 800 feet, and a depth of not less
than 26 feet throughout its entire length of l:J miles, excepting
for about ^ mile at its bifurcation with the main river, where
parallel training works would be necessary to secure the depth and
width required. Although holding these views in favour of the
South Pass, the Author is by no means opposed to the opening of
the South- West Pass, by means of jetties, if it is considered that
the far greater expense of construction in the first place, and of
the maintenance of the works and channel afterwards, contingent
on the improvement of the larger mouth, would bo compensated
by the grander result to be ol)tained.

Since these notes were written. Captain J. B. Eads has formally
proposed to the United States Government to deepen the South-
West Pass to 28 feet, for the sum of S 11,000,000, by means t.f
parallel piers ; and a new commission, consisting of civil and

WATERWORKS IN THE UNITED STATES.

military engineers, has boon named to report to Congress on the
merits of all the plans of improvement yet devised for providing
the river with a deep sea entrance.

III.— WATERWORKS.

Croton Waterworks, New York.- (Visited SOth December, 187;^,
with Mr. G. M. Van Nort, Commissioner of Public Works, and Mr.
Edtvard H. Tracy, Chief Engineer.) — The Croton Aqueduct, which
supplies the city of New York with water, is a monument to the
ability and skill of Mr. John B. Jervis, C.E., the designer and
constructor of the works. The aqueduct was begun in 18:57, and
finished in July 1842, with the exception of the Migh Bridge at
Harlem, which was not completed till 1848, the water in the
meantime being conveyed across the Harlem Valley by a tem-
porary pipe.

The following sketch of the priuc^'pal features of the aqueduct
is abridged from Mr. Jervis's report of the 27th July, 1842, to
the Water Commissioners, which has not yet been published in
England.^

The Croton Aqueduct commences about 6 miles above the mouth
of the Croton river, where a dam has been constructed to elevate
the water of the river 40 feet to the level of the head of the aque-
duct, or 16G feet above mean tide. The aqueduct passes along the
valley of the Croton to near its mouth, and thence into the vf ,iley
of the Hudson. The length, from the Croton dam to Karlem
river, is 33 milefe, for which distance it is an uninterrupted con-
duit of stone and brick masonry in hydraulic cement.

Description of the Country. — The soil, earth, and rock of the
country, from the banks of the Croton to the city of New York,
are of one general character. The prevailing rock is gneiss, of
great variety in quality. The surface is generally a sandy loam.
Below it, soil, gravel, sand, boulders, or detached rock, have in
most cases been found. A largo portion of the open cutting, and
nearly the whole tunnel cutting, has been through rock, more than
400,000 cubic yards of which have been excavated. The general
formation of the country is extremely irregular, and unfavourable
for the economical construction of an aqueduct.

Aqueduct. — The bottom is an inverted arch, the chord being

' A full description of tlio Croton Aqueduct in English, Gormrin, and French,
by T. Schramke (London and Berlin, 185.^), is in tlie library of the Institution.

Ill

OTHF

ICTED PAPERS.

1 '^'

■

. sine 9 inches. The side walls rise
g of the invert. The roofing arch is

6 feet 9 inches, and th'

4 feet above the s*
semicircular, v/ith a as of 3 feet 8j inches. Thus the greatest
interior height is 8 feet 5^ inches, the greatest width 7 feet

5 inches, and the area 6;J * 34 square feet. The inverted arch is
of brick, 4 inches thick. The roofing arch is also of brick, 8 inches
thick. The abutments are of rubble stone, with a brick facing
4 inches thick. In all cases a course of concrete in hydraulic
cement was laid under the extrados of the inverted arch. The
area of a cross section of masonry in the aqueduct is 42^
square feet. The proportion of the line of aqueduct masonry on
foundati(m walls over valleys, to that in excavation, is about
1 to 8. The masonry of the aqueduct is covered with earth to a
suificient depth to protect it from frost.^ There are sixteen tunnels
on the line, varying in length from IGO feet to 1,263 feet, making
an aggregate length of 6,841 feet. The height of the ridges above
the grade level at the tunnels ranges from 25 feet to 75 feet. The
foundation walls, in crossing uneven ground and ravines, are of
dry masonry.

Culverts. — To pass the streams that intersect the line, one hun-
dred and fourteen culverts, varying in span from 1^- foot to 25 feet,
have been constructed, at depths varying from 16 feet to 83 feet
below the top covering of the aqueduct.

Ventilators. — There are thirty- three ventilators to give free
ventilation of air through the aqueduct.

Waste Weirs. — Six are constructed on the line of aqueduct, so
arranged as to allow the water to pass off when it rises to the
proper height, with gates to draw off the water when necessary.

Croton Dam. — The greatest height of the weir of the dam is
40 feet above the low-water level, and 55 feet above the bed of the
river. The width of the masonr}' at the low-water line of the river
is 61 feet. At 300 feet below the main dam, a second dam was
constructed of timber, stone, and gravel, to deepen the water over
the apron of the former, and form a pool to check the force of the
water as it falls. From the main dam, which raises the level of the
water of the river over a length of 5 miles, and forms a reservoir of
400 acres, the water flows into the bulkhead at the upper end of the
tunnel, from a level averaging 10 feet below the surface.

Aqueduct Bridge at Sing Sing. — The Sing Sing Kill, where it crosses
the line of aqueduct, runs in a deep and narrow gulf, the bottom
of which is 76 feet below the top covering of the aqueduct. Over

' The depth is uever lesi thau 8 feet.

WATERWORKS IN THE UNITED BTATES.

this gulf an aqueduct bridge has been constructed of stone and
bricJf masonry. Its centre arch has a span of 88 feet and a rise of
33 feet.

Harlem River Bruhje. — The width of the river, where the aque-
duct line crosses it, is t)20 feet at ordinary high-water mark, and
its greatest depth is IG feet at very low tides. The high ground that
bounds the north side of the Harlem Valley is very nearly on a
level with the aqueduct ; and the width of the valley at the aque-
duct level is about 1,450 feet, over which a bridge of the same length
has been constructed. The south bank of the valley is here a
bold, precipitous rock, rising to a height of about 220 feet above
the river. Across the river there are eight arches, each of 80-feet
span. On the south of this range of large arches there is one arch,
and on the north six arches, each of 50-feet span. The archcB
are semicircular, and their sofiSts are 100 feet above ordinary
high water. The piers are founded partly on the rock, partly
on bearing piles. All the masonry is of well-dressed granite.
The space — 21 feet— between the parapets is arranged to receive
and protect from frost two cast-iron pipes, each 4 feet in diameter,
which are to lie at the level of 108*25 feet above the level of
mean tide.^ This is 12 feet below the grade line of the aque-
duct, to which the pipes descend from the gate-chambers at the
end of the bridge. The object in using pipes was more
effectually to secure the conduit from any leakage, that might
eventually injure the masonry of the bridge, and it incidentally
allowed the bridge to be constructed of less height. To make the
capacity of the pipes for conveying the water equal to that of the
aqueduct, an extra fall of 2 feet has been given across the bridge,
and the aqueduct on the southern side of the river is constructed
2 feet lower than the regular grade to accommodate this arrange-
ment. .:.;..

It was originally contemplated, and the work put under con-
tract, to construct a low bridge with one arch for water-way ; but
a supposed value, which was attached to the future navigation of
the river, was so pressed upon the legislature as to induce them to
pass a law requi-ring that the under side of the arches should be
100 feet above ordinary high water.^

' These 4-feet pipra were never laid down, as two of 3 feet diameter were
considered to be sufficient at first ; the latter still remain, leaAy for use again in
case of need, but the water is now &:>nducted across the atiueduct by a 7J-feet
pipe of boiler-plate.

' It may bo asked, why not have raised the bridge 12 feet more, to the
grade of tho aqueduct, and thus have saved a fall of 2 feet, besides sparing the

OTHER SELECTED PAPERS.

Manhattan and Olendenning Valleys. — After croBsing nailem
Valley, the aqueduct of niasonry is resumed, and continued 2 miles,
to the termination of the high ground on the north of Man-
hattan Valley. This valley is f mile wide, iind 102 feet below
the level of the aqueduct. The conduit of masonry here gives
place to iron pipes, which descend to the bottom of the valley,
and rise again on the opposite side, from which point the masonry
conduit is again continued, and, crossing Glendenning Valley on
arches, after 2 miles reaches the receiving reservoir at York Hill.

lieceiving Reservoir. — This reservoir has an area of M acres, and
a capacity of 150,000,000 imperial gallons. It is in two divisions,
and is formed with earth banks, the interior having regular
puddled walls; the outside, protected by a stone wall, has a
slope of 1 horizontal to 3 vertical ; the face is laid in cement
raortar, and the inside is dry ; the in^ide is protected by a dry
wall, laid on the face of the embankment, which slopes li^ hori-
zontal to 1 vertical. The embankments are raised 4 feet above
the water line, and vary from 18 feet to 21 feet in width at the
top. They are of moderate height for the northern division of the
reservoir, which has a depth of about 20 feet ; but in a portion of
the southern division, whore the depth is about 30 feet, they are
38 feet high above their base.

Distributing Reservoir. — This reservoir is situated on the 5th
Avenue, between 40th and 42nd Streets, and is 3 miles from the
City Hall. It is built entirely of masonry, and covers an area
of 4 acres, divided into two equal divisions, and has a capacity of
20,000,000 imperial gallons. It has a depth of 36 feet, and when
full the level of the water is 115 feet above mean tide. Its walls
rise 4 feet above the water line, and have an average elevation
of 45^ feet above the level of the adjacent streets.

Length of the Aqueduct. — The length of the aqueduct, from the
Croton dam to the distributing reservoir, is 40^ miles. It is proper
to add to this the length of the Croton reservoir, which is 5 miles,
and extends 4 miles for the length of thfi large mains from the
distributing reservoir through the central part of the city, making
the total length of the main conduit nearly 50 miles.

Grade Line of Aqueduct. — The general declivity of the aqueduct in

expense of the two gat^-chambers ? Apropos of this question, Mr. Tracy has
written to the Author as follows : — " It is impossible in this country to construct
a conduit of masonry, of any considerable length, that will remain watertight.
The contraction and expansion of the High Bridge, from the extreme heat of
summer to the extreme cold of winter, is more than § inch by actual measure-
ment."

WATERWORKS IN THE UNITED 8TATE8.

WesteheHtor County is 0*021 fcx.t per 100 foot (TlOO foot per
niilo). The graclo from Ilarlom Kiver to Manhattan Valley is
the same as the general grade of the aqueduct in WestchcHter
County; but that from the Manhattan Valley to the receiving
reservoir, 2 J miles, is 9 inches per mile.

Coat. — Mr. Jervis concludes his Report by stating that the actual
cost of the aqueduct, fiom the Croton dam to the di.Ntributing
reservoir, inclusive, v^'as under K9,000,000 (£1,800,000), being
within 2 per cent, of the original estimate.

The following information respecting the present state of these
works was obligingly furnished to the Author by Mr. Tracy.
^ addition to a new receiving reservoir in the Central Park,*

.ich has an area of 106 acres, a depth of 3G feet, and a capacity
of 1,000,000,000 gallons, a new storage reservoir at Boyd's Corners,
in the Croton Valley, has been built to contain 3,000,000,000 gal-
lons ; so that the combined capacity of the reservoirs, including
the Croton reservoir or lake, is now 4,570,000,000 gallons.^ Ex-
perience has proved that, as long droughts prevail during the
summer and autumn, the quantity of water in the river is in-
adequate to supply the daily needs of the city, and that, there-
fore, the only way to secure a constant supply is by storage
reservoirs, to be filled during the wet season. Preparations are
accordingly being made for the construction of a third large
reservoir in the Croton Valley, with a capacity of 3,700,000,000
gallons. When this is done, the combined reservoirs will be able
to supply the city for eighty-two days at the present rate of
consumption of 100 gallons per head, irrespective of the minimum
quantity daily furnished by the Croton river in seasons of extreme
drought, viz., 27,000,000 gallons.

From 1842 to 1848, 18,000,000 gallons per day gave an abundant
supply. At that time the city had about four hundred and fifty
thousand inhabitants, and now, with a population of one million,
the quantity consumed is sometimes 100,000,000 gallons per day.
Thus, though the population of New York has little more than
doubled since 1848, the consumption of water has increased fivefold.

' There are six 4-feet mains into and out of this reservoir (which was com-
pleted in 1862), and the valves are so arranged that they can only be fully
raised in one hour.

* When the word "imperial" is not mentioned, it may be taken for granted
that the gallons indicated are United States gallons, which compared with imperial
gallons are as 5 to 6 : a United States gallon being equal to 231 cubic inches (the
capacity of the old English wine gallon), and the British imperial gallon to
277 • 274 cubic inches.

ir\

'v. ,i '

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OTHEtl RELrCTlD PAPFRS.

■I

When tho aqueduct was built, it was supposed it would only
deliver 60,000,000 imperial, or 72,000,000 I'nited States standard
gallons, every twenty-four hours. Tho discharge was computed
from formuleo based on the best-known channels at that time, but
all of which were smaller than the Croton Aqueduct. Careful
experiments on the present flow of water show that it can deliver
115,000,000 gallons every twenty-four hours, or 00 per cent, more
than its estimated capacity.'

The watershed of the Croton river is about iMO square miles,
and the annual rainfall is 49 inches. At or near the sources of
many of the tributaries there are natural lakes, varying in size
from 50 acres to 500 acres. These basins are generally of great
depth, and their waters, which are remarkably clear and pure,
are derived either from springs in the lakes themselves > in the
highlands near them.

Tho new storage reservoir at Boyd's Comers has an area of
300 acres, and has been formed by building a dam across the west
branch of the Croton river. The dam is about 700 feet long, and
high enough to lift tho water 60 feet above the surface of the
stream. The masonry wall of the dam, on its inner side, is for-
tified by a watertight bank of earth, and a canal is cut through
the rock at the northern end of the dam to allow the floods to
escape over a rock surface into the river below the dam.

The major part of the higher section of the city of New York,
north of Manhattan Valley, is supplied from a > 'v high-service
reservoir, into which water is pumped by steam from the aqueduct
near 17:ird Street (close to the Harlem Bridge), whilst the extreme
high points are supplied from a tank supported on a towor bull*
to a height of 300 feet above the sea, near the site of the reservoir.
The islands in the East and Harlem rivers are supplied with water
by pipes, varying from 2J inches to 6 inches in diameter, from
the shores of New York City. These pipes are generally about
1,000 feet long, and are laid on the beds of the rivers in depths
of from 70 feet to 100 feet of water. Until very recently, they
were either of cast iron, lead, or gutta-percha. The latter, which
are soon abraded on a rocky bottom, are now being advan-
tageously replaced by wrought-iron pipes. These are so elastic,
and are so well protected with a casing of planking, that they
can be readily laid, already put together, on the bed of the
river, at a radius of 300 feet. Shortly before the Author's visit,

' > The flow in the aqueduct, which is never full, is at the rate of about
2i miles per hour.

WATERWORKS IN TUE UNITED STATES.

it was decided to lay down a wrought-iron lap-wol 'od pipe of
6 inehes in diameter, made in the same manner as pipes for
conveying steam, coupled together with screw conplings. Tlio
operation was thus described hy Mr. Tracy : — The couplings wore
strengthened and protected by heavy cast-iron sleeves, secured by
lead joints, making the joints as rigid and stiff as any other part
of the pipe, 'i'he pijjo was then placed in a heavy oak case securely
])olted and riveted together, and the space between the pipe and
case filled with hydraulic cement. The pipe was put together
in 02nd Street. When fitted up complete in the box, and the
box thoroTighly saturated with coal-tar, it was then, by means of
a powe:ful dredge with a steam capstan of lUO III'., hauling on a
heavy chain cable fastened to the rocks on Black well's Island,
drawn across the river. The dredge was assisted by three
powerful steamboats, whieh in case of the breaking of the chain
could have held the end of the pipe in position. The pipe as fitted
up in the box was 1,;550 feet long, weighed over 200 tons, and was
put across the river in water 100 feet deep. It was laid without
any accident or injury, and it is believed to bo strong enough to
withstand the anchors of any vessel which navigates tho East
river.

Six 4-feet cast-iron pipes are now being laid in tho lOth Avenue,
between li;3th and 92nd Streets, preparatory to tho removal of
tho aqueduct work over Glendenning Valley. This tedious and
expensive work is necessitated by an Aot of tho legislature, which
directs the Waterworks Department to remove the above-named
portion of tho old viaduct, as it obstructs tho traffic from oast to
west, and to replace it by a new one, or by pipes, below the newly-
established grades of the streets and avenues, which now extend
uninterruptedly from tho Battery Point to Kingsbridgo over
Harlem river, a distance of 15 miles.

Owin^' to an alteration in tho grade of tho 5th Avenue, it be-
came necessary, about two years ago, to lower two 3-feet main
water pipes about 4 feet, in a long cutting throiigh hard gneiss,
between 68th and 72nd Streets. It was decided to lower these pipes
with the water in them, and to continue their use while the
operation was going on. Tho trench where they lay was widened
on one side to allow them to be moved laterally. They were next
placed upon saddles resting on greased skids, and moved over, one
line at a time, by screw-jacks. Then, after being protected with
timber while tho new rock trench was blasted, they were moved
back, on greased skids, supported by blocking, to their original
line, and lowered by screw-jacks into position. This delicate and

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[1874-

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OTHER SELECTED PAPERS.

hazardous operation was successfully performed without accident
to life, limb, or property.

Mr. Tracy states, in one of his last reports to the Commis-
sioners, after a personal inspection of the interior of the aqueduct,
from end to end, that the brick facing of the masonry shows no
sign of either wearing away or of disintegration, and that there
is every reason to believe the whole structure, with proper care,
will successfully perform the duties for which it was built for
centuries to come. To the latter opinion the Author would add
the remark, that all the important subsidiary works of the
aqueduct which he inspected, and which have been but lately
completed, appeared to have been as skilfully designed, and to be
as imperishable, as the famous aqueduct itself.

Chicago Waterwouks. — Hardly any one who has visited Chicago
of late years can resist the temptation, when the name is men-
tioned, of plunging into a mass of statistics, to enable those who
are not acquainted with the marvels of the place to realise the
fact of its amazingly rapid progress, from a hamlet of squatters in
1830, to a city of the first rank at the present time. The Author
may perhaps, therefore, be excused in stating a few facts relative
to the city of Chicago before referring, in some detail, to its water
supply.^

The population of Chicago in 1830 was

1840 ..

»»

1850
1860
1870

4,. 583

29,963

112,170

295,977

At the time of the Author's visit in October 1873 the number
of inhabitants was said to exceed four hundred thousand.

According to the returns of the Chicago Board of Trade, the
wholesale trade of the city in dry goods, boots and shoes, clothing,
groceries, iron, drugs, &c., for 1872, was K500,000,000. In the
same year the receipts of cattle were six hundred and eighty-four
thousand and seventy-five, and of hogs three million four hundred
and eighty-eight thousand five hundred and twenty-eight, of a
total value of ^75,475,000. The total receipts of lumber (timber)
were 1,183,659,283 square feet (100,000,000 cubic feet), and of all
kinds of grain 88,426,842 bushels. Chicago is now, in short, by
far the largest market in the world for corn, timber, and pigs.

Chicago is the centre of a network of railways, thirty-nine of
which take their first name from the city.

The word " Chicago" in the Indian language eignifleB " the place of ekunks."

WATERWORKS IN THE UNITED BTATES.

The receipt of grain by rail alone at Chicago has reached '. « o
thousand one hundred cars per day. Besides being connected by
iron roads with all the harbours on the northern lakes and with
every seaport of note on the Atlantic coast from the St. Lawrence
to Florida, this great inland city is also in direct communication
with the shores of the Pacific and with the following important
stations on the banks of the Mississippi ; viz., Crow-wing, St. Paul,
Prescott, Winona, Prairie du Chien, Dubuque, Savannah, Fulton,
Rock Island, New Boston, Burlington, Keokuk, Quincy, Hannibal,
liouisiana, Alton, St. Louis, Chester, Grand-tower, Cairo, Columbus,
Hickman, Memphis, Helena, Vicksburg, and New Orleans.

10 of

The City of Chicago.

The city is bounded on the west by a prairie of vast extent,
and was originally built on swampy ground at a level of from
3 to 4 feet only above the surface of Lake Michigan. Its
600 miles of streets and thoroughfares — many of them 100 feet
wide, and lined with magnificent buildings of stone, brick, and
iron, are now raised, as a rule, to 12 feet above the lake.^ When

' The raising of houses to the level of the new streets was at one time an
important trade at Chicago, but it is now seldom practised. !n some cases ware-

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OTHER SELECTED PAPERS.

the f* fst settlers arrived, their huts were ' located ' on the banks
of the River Chicago and of its north and south branches, which
separate from the main stream at about 1 mile from the shores of
the lake. In process of time the river — which was formerly fed
by the clear waters of the lake, and therefore ebbed and flowed
according to the direction of the wind — became greatly polluted,
and it was determined to lessen the evil by discharging the sewage
matter and other impurities of the city into the Illinois and
Michigan canal, and thence into the Illinois river. This work
was completed in 1871, in the manner previously described.

Although there is now a constant stream from the lake up the
main river and its southern branch, to the great benefit of the city,
this is, unfortunately, not the case with the north branch of the
river, the foul and unwholesome condition of which is daily in-
creasing. The subject is now under the serious consideration of
the city authorities. One remedy suggested is to obtain sufficient
water from artesian wells' to cleanse the fetid creek; but it is
generally considered that the best plan is that of flushing the
stream by a covered canal communicating with the lake, through
which river or lake water might be forced by steam power as occa-
sion requires. This plan has since been adopted, and was being
carried out in February 1875.

The pollution of the river, not only by sewage matter, but by the
refuse and garbage thrown in from distilleries, tanneries, manu-
factories, and slaughter-houses, has always been a soui'ce of annoy-
ance and concern to the citizens of Chicago; but in 1863 the
nuisance was aggravated to such a pitch, that the water, supplied
to t'. a inhabitants by pipes from the shore of the lake, became no
longer drinkable. It was then that the Department of Public
Works determined to supply the city with uncontaminated water
froTu the lake at 2 miles from shore, in a depth of 32 feet, almost
directly at right angles to the shore of the lake at the pumping
works.

houses of iron and stone, six stories liigli, and weighing as much as 20,000 tons,
have been screwed up from 8 to 10 feet without accident. Wooden buildings
have also been frequently lifted and slid along bodily from one street to another.
* There are now upwards of twenty artesian wells in Chicago and its neigh-
bourhood. The average yield of each was at first about 600 gallons per minute.
The average depth is 1,300 feet, diameter of the bore at the bottom 4 inches, and
the cost $G,000. The maximum surface-pressure of the water is 35 lbs. per square
inch, which indicates a hydrostatic head of 77i feet. By the end of 1874, the
wells had fallen oflf so much that some hardly flowed at all above the surface :of
the ground, and the average flow had been reduced to 200 gallons per minute. ^^

WATERWORKS IN THE UNITED STATES.

This novel plan was designed and carried out by Mr. E. S.
Chesbrough, the Chief Engineer of the city, through whose
kindness the Author has been supplied with the principal part of
the following information.

It was found, by careful borings, that a bed of compact blue
clay, at least 100 feet thick, underlay the thin crust of silt and
sand at the bottom of the lake. The shaft on shore was begun in
March 1864, that under the iake eighteen months later. The
tunnel between them was driven from both ends. The most inte-
resting work was the sinking of the lake shaft through a depth of
32 feet of water, and then through 31 feet of clay. This shaft was
built, within a ' crib ' or breakwater of pentagonal form, 00 feet in
diameter, 40 feet high, and with walls 25 feet thick, leaving an
inner open well about 30 feet in diameter. The crib, which was
constructed on shore, consisted of 50,000 cubic feet of whole
timbers, 12 inches square, braced together. The inner and outer
walls, as well as the flooring, were caulked at the joints ; and
when the crib was towed to the intended resting-place, its fifteen
watertight compartments were filled, with 6,000 cubic yards of
stone to sink it to the bed of the lake. The top of the crib then
stood at 5 feet above the surface of the lake. Within the well of
still water a column of seven cast-iron pipes 9 feet in diameter,
making a total length of 63 feet, was sunk, through the clay, to
31 feet below the bed of the lake, without resorting to atmospheric
pressure, or even to pumps, though these were provided for in the
contract. On the removal of the clay the tunnel was started from
below. It falls 4 feet towards the shore end, where the land shf^t
is 70 feet below the surface of the lake, and 77 feet below tha' ;
the ground. The miners met at a quarter of the distance from
the crib to the shore. The vertical axis of the tunnel, which
is almost circular, is 5 feet 2 inches, and its horizontal axis 5 feet.
The arching consists of two rings of brick in cement 8 inches
thick.

The iron column forming the lake shaft is open at the top, and
has two inlet gates, the tops of which are 2 feet below low water.
Through the sides of the crib are three openings controlled by
gates. One is near the bottom of the crib, another midway between
the surface and the bottom of the lake, and the third near the
surface; so that water may be drawn from any desired depth.
Chemical analysis shows that the water at the surface is slightly
the purest ; in summer the water is coolest near the bottom. The
tunnel can bo pumped dry at any time from the shore end by
closing the inlet gates, each gate being under easy control from

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OTHER SELECTED PAPERS.

above. The cost of the entire work, which was completed in
March 18G7, was about £100,000.

Since that date the duty of the pumping engines, now five in
number, has been as follows : —

Average daily

Greatest daily

quantity pumped.

quantity pumped

Year ending

Oallons.

Gallons.

31 8t March, 1868 .

. . 14.724,999 . .

. 16,414,460

„ 1869 .

. . 18,633,278 . .

. 20,689,014

1870 .

. . 21,766,260 . .

. 25,712,589

1871 .

. . 23,464,877 . .

. 28,000,000

1872 .

. . 27,536,819 . .

. 31,485,000

1873 .

. . 27,500,000 . .

. 33,250,000

On the 9th of January, 1873, a new double-beam pumping
engine, designed by Mr. D. C. Cregier, C.E., and constructed by
the Knapp Ft. Foundry Company, Pittsburgh, commenced pumu-
ing to relieve the other four engines, and has worked continuously
since then. This pumping engine, which is said to be the largest
in the United States, has two 70-inch steam cylinders with 10-feet
stroke, and works two pumps of 57 inches diameter, delivering
36,000,000 gallons of water per twenty-four hours. The beams are
of cast iron, 28 feet long ; their weight is 20 tons each. The main
columns are 27i feet long, and weigh 17 tons each. The fly wheel
is 25 feet in diameter, with a rim 12 inches broad by 20 inches deep,
and the weight, including the eight spokes and ' hub ' (nave), is
33 tons. The engine was two and a half years in building, and
cost K 188,400, exclusive of foundations. The combined capacity
of the four engines is 75,000,000 gallons per twenty-four hours.

The wattr is pumped from wells connected with the tunnel
directly into the pipes. The pumping engines are guarded against
the danger of this system, not merely by air chambers, but by a
stand pipe, open at the top, 140 feet above the lake, supported as
well as protected by a stone tower 170 feet high. The pumps
are supposed to force the water to a height of 132 feet, but in
the day time, when the demand is at its greatest, the water does
not rise higher than the second story of the houses.

During the year 1872-3 the engines consumed 13,562 tons of
coal, at an average price of 28». per ton, and the cost of delivering
water per million gallons amounted to 47«., as compared with
32«. and 62«. respectively for the nine years ending 1872, The
water is supplied through 380 miles of mains, the largest of
which has a diameter of 36 inches. Owing to the require-
ments of the navigation, the pipes cannot be carried over the
river and its branches (which are spanned by thirty iron and

WATERWORKS IN THE UNITED STATES.

wood swing bridges), and therefore cross the bed of the stream.
With the view of preventing damage to the pipes by anchors and
by piles driven into the bed of the river, the mains are now being
laid down from bank to bank in tunnels, five of which are already
built. The last one was completed six months ago, between
Michigan Avenue and Pine Street, whore shafts, 84 feet and
68 feet respectively, were connected by a tunnel 492 feet in
length. The whole is of circular brick masonrj', the shafts being
8 feet, and the tunnel 6 feet in diameter. A 24-inch iron water
pipe has since been laid through it. The cost of the work was
B 13,279 (£2,600).!

Before describing the new arrangements for increr.sing and
insuring a sufficient supply of water to Chicago, under all eventu-
alities, a few facts should be stated relative to the great fire of
October 1871, by which the loss of property was greater than had
ever occurred before, from an accidental cause, in the history of
the world, amounting, according to the most trustworthy esti-
mates, to K200,000,000 (£40,000,000). The number of people
rendered homeless and destitute by this fire is calculated to have
been one hundred thousand. It originated in a stable on tho
west side of the river, on Sunday night, the 8th of October, 1871,
in a section of the city composed almost entirely of wooden build-
ings. Aided by a furious south-west wind— so strong as to blow
down a church steeple — it spread in a north and east direction
with wonderful rapidity, and finally terminated, at a little before
midnight, on Monday, the 9th, having in one day destroyed
nearly every building in its course, over a space 4 miles long and
about § mile wide. It reached the pumping works early on
Monday morning, when the machinery was so badly damaged
that it stopped working ; thereby cutting off the supply of water,
and leaving the city without the means of checking the pro-
gress of the flames. By extraordinary exertions on the part of
Mr. Cregier and his staff, the repairs to the engines and the
buildings were so far advanced, that eight days after the fire the
north engines were started afresh, and continued to supply the
city without cessation for a period of two months, when the
other two engines were again in working order.

' In addition to the water tunnels, the rivet is crossed by two subways in
masonry for carriage and passenger traffic. These street tunnels were built with
great caro and skill by Mr. Chesbrougli. The steepest gradient in the Washington
Street tunnel (which was built first, and proved of immense service during tho
great fire) is 1 in Iti, and in the La 8alle Street tunnel 1 in 20. The top uf the
brick axching in both tuiiDels is upwards of 20 feet below the bed of the river.

OTHER SELECTED PAPERS.

This is only a single instance, among many, of the energy with
which the citizens of Chicago began to rebuild a new city on the
still burning ashes of the old site. The Author found hardly a
gap over the area of 1,700 acres which had been swept, only two
years before, by the greatest conflagration of modern times. The
rebuilding of the " burnt district " was then all but completed,
and public opinion was unanimous in declaring that the Chicago
of to-day is far grander than the old Chicago of 1871, before her
busiest and wealthiest quarter fell a victim to the flames.' It has
often been alleged that the wooden block pavement of the streets
added fuel to the flames, and thus hastened the great calamity,
but this was not the case. The Author has the City Engineer's
authority for stating that the blocks were not burnt, and indeed
that they were hardly damaged by the fire.

The chief lessons taught to waterworks engineers by the fire
were, Ist, to make engine-houses fireproof; 2ndly, to have as much
open space round them as possible ; 3rdly, not to keep a large
city dependent on one set of pumping works only, for a supply of
water, especially, if, as at Chicago, there is no suitable ground on
which to build a largo distributing reservoir.

' A rejident of Chicago th'is graphically described the characteristics and
achievementH of the city of his adoption at the time of the Author's visit : —
" It has been a distinguishing characteristic of Chicago, that all her under-
takings and accomplishments were phenomenal. Her modes of action were
original and sensational, both as regarded individuals and the body corporate.
She took counsel of no precedents in anything she did. When she wanted to
raise the grade of her streets, she elevated the city upon screws and reposed it
upon higher foundations. When a supply of fresh and pure water became a
necessity of our rapidly augmenting population, she carried an immense aqueduct
out miles from the shore, and gathered a pellucid stream from the far-oif bosom
of Lake Michigan. When the river became a receptacle of the sewage of
350,000 people, and generated an insufferable stench, she carved out a connection
with the Mississippi, turned into the channel the crystal floods of the lake, and
created a perennially-flowing and purifying current, sweeping away the whole
accumulation of impurities, and permanently transforming a cesspool into a
stream of cleanlii 'ss. And when on the woeful Sunday night of our black
October, she departed partly to the skies in flame and smoke, and partly to tht
earth in ashes and ruins, she maintained her plxenomenal reputation, and
signalised her exit by a conflagration which outvies every one of history in all
that is weirdly sublime, appallingly terrible, and amazingly destructive. Out
of that broad extent of blackened desolation arose suddenly, as by the wand of
enchantment, a new city, more imposing in its architecture, more colossal in its
proportions, more enduring in its structures, more extraordinary in its accessories,
more expansive in its enterprise, more ambitious in its projects— a phenomenon
of reconstruction so preternatural, that strangers are overwhelmed with the idea
that the miles of magniKcent buildings before their eyes stand on ground lately
occupied by heaps of smouldering and unsightly rubbish."

I !. w;

WATERWORKS IN THE UNITED STATES.

The erection of duplicate pumflng works in another part of the
city, and the construction of a second lake tunnel, to meet the
constantly increasing demands for more water, were decided on
before the fire. The new land tunnel, 7 feet in diameter, to
connect the present waterworks with the proposed new pumping
engines, will extend 4 miles westward, at a depth of 71 feet
below the lake level. It is estimated that the cost of this tunnel,
of the new pumping works, and of the necessary extension of
mains, will be Kl,000,000, The construction of the second lake
tunnel and the second lake shaft was in full progress when the
Author visited them on the 25th of October, 1873, in the company
of Mr. Chesbrough, the Engineer, and of Messrs. Steel and
McMahon, the Contractors of the work. The excavation of the
new tunnel, which is to run parallel to, and at a distance of 50 feet
from, the old tunnel, is now half completed from the bottom of a
hev brick shaft, 10 feet in diameter, already sunk at the shore end.
The present rate of advance is 20 feet per day through compact
blue clay, in which there is not a drop of water. It will be lined
with bricks in three rings together 11 inches thick. The lake
shaft of the new tunnel is being sunk within 9 feet only of the
first shaft, in the old crib ; and, owing to this close proximity, a
disturbance of the ground has taken place between the two shafts,
an inconvenience which was aggravated by the plan at first fol-
lowed of sinking the new iron cylinder, 8 feet in diameter and
2^ inches thick, b;;' pneumatic pressure.

The prices paid to the contractors are as follows : —

Main tunnel and galleries per lineal foot, including bricks 29 '50

Land sliaft „ „ 50 • 00

Lake shaft „ „ 253-00

Three gates and bulk- \ 4500*00
head at lake shaft . /

The top of the lake crib above 3 water line is now being
made permanent with substantial masonry.

The total cost of the waterworks, including all expenses on
work in progress to the Isi, of April, 1873, has been ^5,212,508,
and the entire receipts during the puoi, year were ^^44,465. The
money for the payment of the cost of the works has been derived
principally from 6 and 7 per cent, bonds.

Both the new tunnels above described — the one under the lake,
2t miles long, and the one under the land, nearly 4 miles long —
were finished in 1874. Their estimated capacity for supplying
water, combined with that of the first lake tunnel, is 150,000,000
U.S. gallons daily.

(

OTHBB SELECTED PAPERS.

Tho following table, showing the number of United States
gallons consumed by each inhabitant daily in America, as com-
pared with London, Paris, and Glasgow, is abridged from a table
prepared by Mr. Chesbrough.

I860.

1862.

1864.

1866. { 1868.

1870.

1871.

1872.

Chicago

43 58

New York . .

••

••(

62 \
in 1867 j ••

• •

••

Brooklyn .

26 33 43

• •

Jersey City. .

■•

•• \inl865/ ••

••

Pliiliulclpliia .

, ,

Washington

, ,

134

Boston ,

^ ,

Albany .

, .

Detroit .

Buffalo . . .

• •

, ,

Cincinnati . .

, ,

, ^

• •

, ,

Montreal .

, ,

• •

, ,

London. . .

••{

38 \
in 1867/

••

• •

Paris

, ,

Glasgow . .

• •

••

Mr. Chesbrough remarks, that the past rate of consumption in
London and Paris is very small as compared with that of most
American cities, and that only Glasgow is supplied after tho
American fashion. He is of opinion that the fairest comparison
of the water supply of diflferent cities would be by showing the
quantity furnished to each water-taker, instead of supposing it to
be used by the entire population ; and ho is fully aware that the
enormous demand for water in some cities i^ to be attributed
largely to leakage in the mains and distributing pipes.

IV.— LAKE HARBOURS.

The lake harbours, of national importance in the United States,
are designed by, and constructed under the superintendence of, the
Engineer officers of the Army ;^ and in Canada by Civil Engineers
in the employment of the Government.

With hardly pn exception, the protecting works and quays consist
of timber boxes, or cribs, iilled with stones, and joined to each other,

' This distinguished corps consists of one hundred and six officers, the ma-
jority of whom are engaged on public vorka and eiureys, and the minority on
fortifications.

LAKE HARBOURS IN THE UNITED STATES.

after they have finally settled down, by a continxious timber supor-
Btructuro carried up a few feet above the level of the water. By
this simple expedient, breakwaters, piers at the mouths of rivers,
and wharves, have been erected within the last fifty years, at a
comparatively small cost, at the most important points along the
shores of the great chain of inland lakes, as well as at most of the
river harbours communicating with the Atlantic ; and experience
has hitherto proved, that no cheaper and better system could have
been devised for providing efiicient harbour accommodation, in loca-
lities where timber and stone abound, and where every workman is
skilled in the use of axe, hammer, and saw — the only tools required
in putting cribwoik together. It is superfluous to add that American
engineers are well aware that, in building provisional works of
this description, the expense of maintenance is much greater that
if, in the first instance, the work had consisted of durable materials
only, and that therefore it often costs more in the end. They per-
fectly understand that the advantage gained in the meantime by
the construction of a cheap and simple work, which can readily be
made permanent when required, far outweighs the element of ulti-
mate economy in the abstract, in a young country where an imme-
diate and strictly economical use of the slender means at the
disposal of the inhabitants, to attain the end in view, is a necessity.
In consideration of the above circumstances, and on the assumption
that a full description of the most approved style of cribwork now
built in America will be read with interest by English engineers
employed abroad, the Author would draw their special attention to
the specifications in the Appendices II. and III., which embody the
results of the best experience in this class of work up to the present
time ; and to the remarks which follow on the same question.

As the lake harbours greatly resemble each other, the Author's
" Notes " need only be given here concerning the two principal lake
ports, viz., Chicago and Buffalo, which, moreover, offer the best
types of harbour works in general on the shores of what may justly
be termed the great inland seas of North America.

Port of Chicago. — The great importance of this harbour, which
has not yet been in existence half a century, is strikingly evi-
denced by the following statistics, of the Chicago custom-house
authorities, for the year ending the 30th of June, 1873 : —

No.

Tonnage.

Vessels arrived .

. . 12,394

• •

3,062,979

Vessels cleared . .

. . 12,324

• •

3,142,169

Totals .

. 24.718

6,205,148

* •

60 OTHER SELECTED PAPERS.

■ ' BUVENUE CULLEGTEU.

Duties on imports 2,150,1G0

' • ' Marine Hospital moneys 7,859

•• Tonnage dues 8 , 530

Steambout inspector fees 6,2'.)3

Fines CG5

' ■ -• ■ ■ -= ' • > ^.- Total . . . 2,173.507

From tho establislimont of Chicago as a port, when there was only
a depth of 2 or 3 feet of water on the bar at the mouth of the river,
to the end of the year 18«?5, tho town spent large sums of money
in keeping the mouth open by constant dredging, and by frequent
extensions of the piers, to keep pace with tho growth of the land.
From 1821 to 1866, the coast line immediately to the north of the
north pier advanced 2,400 feet into tho lake, or at the rate of
56 feet per year. " There is a shingly shore north of Chicago, and
hence largo annual accretions behind the north pier. The Chicago
river is not muddy." ^ In the autumn of 1865, General T. J. Cram,
U.S.A., recommended a further prolongation of the north pier for
600 feet beyond the extension made by the city of Chicago in 1864
and 1865, and the rebuilding of the old south pier, and its extension
for a length of 610 feet. In August, 1866, Colonel Wheeler, U.S.A.,
then in charge of the works, reported as follows : — " The accretion
of tho sand on the north side of the pier goes on rapidly, and there
appears no better way of counteracting its destructive influence on
the channel than to extend the north pier. I see no reason for
building the south pier. The object of parallel piers is to confine
the volume of water pouring out of a river, and to make use of tho
current to scour out and maintain a channel. There is no use in
attempting this plan with the Chicago river ; for I may say there
is no perceptible current in that river. We are limited, then, at
present to the prolongation of the north pier, and to removing
any bars that may form in the channel by dredging."

In pursuance of this opinion, the extension of the north pier for
a length of 608 feet was let to a contractor, in the au+amn of 1866,
for the sum of K86,874. The work was to consist of nineteen cribs,
each 32 feet long, 30 feet wide, and 28 feet high, the depth of water
in which they were to bo built varying from 17 to 23 feet. The
contents of the entire work amounted to 18,295 cubic yards. On
this basis the accepted tender was at the rate of J8143 per lineal

General Humphreys, Ex. Doc. No. 220. 43d Gocgrcss.

LAKE HARBOURS IN THE UNITED STATES.

foot, or K^i (18«,) por ciihic yard.* Before the extension was com-
menced in 1807, the Chicago Canal and Dock Company suhniitted
a project, which was approved by the Secretary of War, for an
entrance to their basin at the end of the pier. In his annual report
of 1867, the officer in charge recommended a reduction of the length
of the new pier to 300 feet, as that would carry the extremity
of the extension to the point originally proposed; but sufficient
materials having been collected to build 400 feet of pier, it was
thought best to use them to complete that length. In October,
1869, General Humphreys reported that the building of the south
pier, and its extension as far as the Lighthouse Pier, a distance
of 610 feet, had been contracted for, and that the greater portion
would be executed by the end of the season. Ho at the same
time recommended that it should bo carried on until it was equal
to the north pier. By October 1870 the south pier had an exten-
sion of 1,224 feet, except the superstructure, which was then only
built on the 614 feet of cribwork sUnk in the previous year. On
the 11th of July, 1870, an Act was passed for the enlargement of
harbour facilities, and for a harbour of refuge at Chicago, according
to plans submitted from the office of the Chief of Engineers.
On this account the work on the south pier was suspended.

The Act takes into account the construction of a commercial
harliour, designed by Colonel Wheeler, as follows : — " My plan is
to inclose a portion of the lake, forming an outer harbour that
would meet the present wants, and capable of being enlarged as
the future might require. The extension of the sotith pier should
bo continued until it is equal in length to the north, then build a
breakwater at right angles, and extending southward for 4,000
feet, and then join this breakwater to the shore by a pier. An
opening of 300 feet or more to be left in the pier forming the north
side of the basin, to admit vessels from the harbour entrance.
This basin would contain an area of about 275 acres, one-third of
which would have a depth of over 12 feet of water, and the re-
mainder of over 7 feet, that can be easily deepened to 12 feet,
affording a splendid harbour of refuge for all classes of vessels
sailing to and from this port at the present time. To make this
basin would require, besides the extension of the south pier, already
estimated for, the construction of 4,000 feet of breakwater for the
eastern side, and 3,460 feet for the southern side. The eastern

• The cost of tho concrete blocks, now employed at New York for the new
quays, composed of 1 of English cement to 7 of broken stone or gravel, is
48«. per cubic yard.

OTHER SELECTED PAPEI18.

If '

eido should connist of cribs not less than 30 feot wido, 50 foot long,
and at least 8 feet above the surface of the water. This would
require them to bo 30 feet high. The southern side, for the first
half from shore, should be made of cribs 20 feot wide, 32 feet long,
and 17 feot high ; the remaining half of cribs 25 feet wide, 60 feet
long, and not less than 5 feot above the surface of the water, or
24 feet high on an average.

" Coat of tbo breakwater at $150 per lineal foot ,

„ shoro end of the pier, 1,7G0 foot, at $.'55 .
,. ' outer half of the pier, 1,700 feet, at $99 .
„ dredging say

'' " Total . . .

= per
cubic yard.

4-43
4-40

$
600,000'

90,800
108,300 ■
34,900

900.000"

Colonel Wheeler's plan was duly approved by the Department of
Public Works, and during the fiscal year ending the 30th of Juno,
1871, twenty -nine cribs, 50 by 30 feet, were sunk, making 1,450 feet
of breakwater, including 300 feot at its north end running west.
The first crib was placed in 24 feet of water, and none in less than
18 feet. By the 30th of June, 1872, 2,250 feet of breakwater had
been constructed at a total cost of ^200,000, or K8B-88 per running
foot, and it was then estimated that the whole work would not cost
more than ^100 per foot, including covering and contingencies.

In November, 1871, Colonel D. C. Houston, who then, and at
the time of the Author's visit, had charge of the harbour works at
Chicago and other ports in Lake Michigan, submitted a modified
cross section for the breakwater for the approval of the Chief of
Engineers.^ Colonel Houston gave the following reason for the
proposed modification : — " In nearly all the harbours under my
charge the natural bed for cribs is sand, and it is found that even
in the greatest depth of water, when cribs have been sunk (as at
Marquette, in 28 feet of water), the sand moves during storms,
causing the cribs to settle unevenly, to tilt outwardly (toward
the exposed side), and, in some instances, to shift their position.
It is indeed, a rare case that a crib maintains the exact position in
which it was at first placed. The grillage bottom, which allows

» A detailed estimate of the cost of one of the cribs for this work will be
found in Appendix IV., and its mode of construction is shown in the isometrical
sketch of a crib 50 x 30 x 27i feet (Appendix II.).

' Col. Houston kindly presented the Author with various designs for cribwork
and with upwards of forty plans of harbours in lakes Superior, Huron, Michigan,
Erie, and Ontario, where jetties have either been recently carried out or are
in progress.

LAKE HARBOURS IN THE UNITED STATES.

a portion of the stono to work through tho Band, is a very partial
roniody for these ovils. Tho dovico of placing aprons of loose
stone on tho outside of the cribs has boon resorted to with great
benefit, but it is not satisfactory, and in many cases a storm
comes up and shifts tho crib by the undermining process before
the riprapping can be put in." . . . " It has boon my object to
devise some economical plan of foundation for cribs on such
bottoms to prevent this universal displacement." . . . "In the
actual construction of piers during tho past season, tho oflBcaoy of
' stono foundations ' for cribs has been incidentally demonstrated."
Colonel Houston therefore recommended the employment of rubble
stono foundations for crib work at Chicago, and stated his opinion
that, at that place, stones would rest undisturbed by the waves at
a less depth than 10 feet in the most exposed situations. After
some correspondence. Colonel Houston's proposal was agreed to,
and carried out with the best results.^

During the year ending the 30th of June, 1873, the east break-
water was extended 800 feet by the Illinois Central Eailroad
Company, and up to tho same date a length of 3,050 feet had been
constructed, including the return at the north end. It was then
estimated, that, during the following year, an additional length of
1,100 feet would bo added, leaving only 150 feet of this work to be
completed according to tho original design.

In the annual report on the works for 1873, it was stated by
Captain Hinman, U.S.A., that the following method of building
a foundation for a crib had been adopted, and had answered
admirably. " As soon as the crib is in position, it is loaded
with stone until it settles to within about 4 feet of the bottom of
the lake. Fine rock is then thrown in, which, passing through the
grillage bottom, settles evenly under and around the sides and
ends of tho crib ; the latter is then filled up with coarse stone and
riprapped with about ten cords of heavy rock. In order to hasten
the building of a foundation, it is suggested that a portion of the
fine rock be put in through a dump-scow just before the crib is
brought up ; in this case coarse rock would be used."

With reference to the south breakwater, it is now a question
whether it should be constructed or not ; for if the east break-
water is to be extended beyond the length originally proposed, the

' In corroboration of Col. Houston's views regarding the utility and economy
of rubble foundations for cribwork on a yielding bottom, tbe Author has given a
short account, at the end of these Notes, of his own experience of cribwork
on the shore of the Black Bea.

OTFTSB SELECTED PAPERS.

former would not only be unnecessary, but injurious to the harbour.
According to Colonel Houston, the decision of the question depends
upon whether the lake front is to bo used for dock purposes or not.
If not, then the basin will, as it is designed, meet all the require-
ments of a roadstead for many years to come. In case, however,
of the construction of wharves and of the transfer of business
to the lake front, an extension of the east breakwater will be a
necessity.

As regards further extensions of the north pier, Mr. E. S. Little-
field, U.S.E., foreman in charge of the work, " whose experience and
observations entitle his opinion to consideration," reported as fol-
lows, in April, 1873 : —

" The works on both sides of the entrance to tht iver are out an
equal distance into the lake, and during N., N.E. and N.W. blows
a heavy sea rolls in along the return, and into the entrance to the
harbour-basin formed by the breakwater, making it difficult, and
at such times dangerous, to take out stone and other materials to
the works.". . ." Canal-boat men would not take the risk of towing
across the opening between the south pier, and the return, with any
sea on outside. At such times, too, the sea sitrikes the return, and is
deflected across and into the slip at the north pier, making difficult
navigation from E. of the lighthouse, espec ially where the water ie
14 feet depth and less, as loaded vessels are likely to strike.". . .
" Adding to the return would not prevent the rough sea between
the north pier and it, and only partially give protection to the
entrance into the basin or harbour, while it would injure ma-
terially by narrowing the entranc ). Lengthening the north pier
400 or 500 feet would aiford all the safety needed to docks inside
the basin, and would save the present width between the return
and end of south pier, and make it comparatively easy for vessels
from outside to sail into the outer harbour or basin. Likely it
is only a question of time that the north pier will be extended,
and not at greater cost now than at some future time. If done at
present the breakwater can be extended with greater economy
afterwards."

The above opinion is confirmed by the experience of Colonel
Houston, and he has therefore included the cost of extending the
north pier 400 feet in his estimates for 1873-74.

Buffalo Hakbour is situated at the north-east xngle of Lake Erie,
and is therefore greatly exposed to the violence of south-west winds,
in which direction the lake has a ' fetch ' of 200 miles. Thus
more than ordinary care is needed, to provide safe harbour accom-
modation, for the large fleets of vessels constantly arriving at

LAKE n<VniJ0UR8 IN THE UNITED STATES. '

I • • •

onel
the

Erie,
inds,
Thus
3Com-
g at

Buffalo from the upper lakes. The number of vessels outorod and
cleared at the port, for the year ending the 30th of June, 1873,
was ten thouband five hundred, and forty-seven, of an aggregate
capacity of 4,832,142 tons. The population of the city of Buffalo
was only eight thousand in 1830 ; it is now one hundred and eighty
thousand.

The first improvement made at the mouth of the Buffalo
Creek, 1^ mile above Black Eock Harbour, the original entrance
to the Erie canal, was in 1820 and 1821,* when two piers were
built. The south pier was carried out ^ mile into a depth of
13 feet of water, and was built of timber cribs filled with stone
and brushwood. The north pier consisted of a double row of piles,
with stone and brushwood in the interval. These primitive works
only cost K 14,000, and they were considered so successful that the
Erie Canal Commissioners were induced to extend their canal to
1 Buffalo from Black Rock.

In 1826 Congress appropriated Kl 5,000 for the improvement of
'the harbour; and, from that time to 1865, the central Government
expended K251,794 on the works, under the direction of their own
i Engineers. The total outlay from 1820 to 1865 was thus K280,794,
for the construction and maintenance of a south pier 1,500 feet
:long, and a north pier 630 feet long-, built of cribs filled with
rubble under water, and of stone masonry hearting with cement
concrete above water. With a view to protect a basin in which
vessels could lie with safety during S.W. winds, the State of New
York built a breakwater, at great expense, at right angles with,
and immediately adjacent to, the north pier. Previous to the con-
struction of this work, if a vessel, coming in under the influence of
these winds, did not haul up in time to enter the harlnjur, she
grounded on the soft bottom near the shore, but sustained no
damage ; since the breakwater was constructed, projecting as it
does so near to the north pier, vessels attempting to enter under
stress of weather are liable either to Strike on the breakwater
or on the south pier head. In this manner many valuable vessels
with their cargoes have been lost. The breakwater has a stone
superstructure similar to that of the south pier. Such masonry,
it is considered, is not so capable as a framing of timber, fortified
by rubble stones, to resist collisions, besides being more liable
to damage by the waves, and, when so damaged, more expensive
to repair.

The chief difficulty is caused by the littoral current, which moves
sand along the shore in a northerly direction. At first, the evil
was arrested by the south pier, but ao sooner was an accretion
[1874-76. N.S.] F

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formed behind it, than the sand crept round the head of the
pier, and thus a bar was soon thrown up at the very mouth
of the pass. 'J\) mako the matter worse, a current draws the
sand farther into the harbour, the current being occasioned by
the indraught of lake water to supply the upper level of the
Erie canal, and the numerous mills in the direction of Black
Kock. Under these circumstances the flow of Buffalo river is
not sufficient to scour out the entrance channel, and hence the
city is oblige^, to spend large sums annually in dredging to get
rl . of the new deposit.

In June 18G7, General T. J. Cram, U.S.A., recommended the
Government to execute the following works : —

1. Repair and protect the existing piers.

2. Extend the south pier 300 to 600 feet.

3. Eomove from 200 to 400 feet of the south end of Erie basin
breakwater.

4. Construct a new work in 25 feet depth of water, about 4,000
feet long, to shelter the harbour from prevailing winds, and to
secure a larger space for refuge.

5. Ascertain, by careful examination, the practicability of opening
a ship channel from the lake at South Cut directly to Buffalo
Creek.

Thif ^icheme was submitted to a board of Engineers, who on
the 27th of March, 1 868, recommended —

1st. That the existing piers be thoroughly repaired, the south
pier extended, and the channel alongside the extension dredged to
15 feet.

2nd. That the breakwater be built in the position recommended
by General Cram.

3rd. That it be constructed of cribwork, filled with rubble, in
conformity with the principles already laid down by the board of
1853, for similar localities, as to dimensions of cross sections and
length of cribs. ^

They also stated their belief that, whenever i+ s made, the
proposed new ship canal from the lake to the ini. r harbour, thus
giving an additional ingress and egress, will add greatly to the
convenience of commerce.

These recommendations having been approved by General
Humphreys, orders were given to proceed with the work, and the
following estimate of the board for the breakwater was accepted
as a basis for its cost.

* Vide " General Description of Cribwork " in Appendix II.

LAKE HARBOURS IN THE UNITED STATES.

Estimated Cost op one Cbib op 50 fef.t.

11,406 cubic feet of 12-iuch square timber, ftt 25 cents . . 2,851-50

5 , 580 feet (board measure) for decking and sheathing, at $25 . 139 '50

14,335 lbs. of IJ-inch square wrought-iron bolts, at 5 cents . . 716"75

350 lbs. wrought-iron spikes, at 7 cents 24 • 50

1,750 cubic ftet of rubble stone, at $2 3,500-00

11,871 cubic feet of framing, at 15 cents 1,780-05

Contingencies 10 per cent 901-50

Total . . . 9,914-40
(Cost of 4,000 feet, say $800,000, or $220 per lineal foot.)

Ry the end of the fiscal year ending the 30th of June, 1869, the
repairs of the piers, which had been much damaged by storms
during the winter, were not quite finished, and on account ol
unusually bad weather a length of only 150 feet of the new break-
water had been constructed. The extension of the south pier
for 318 feet had been completed. The difficulty of this work
was thus described by Colonel W. McFarland, the successor of
General Cram : — " The cribwork was made much stronger than
was originally intended, and the cost much exceeded the original
estimate. Owing to the difficulties of the site, yielding sand con-
stantly shifting under the influence of •'. cross current, the settle-
ment of the cribs continued throughout the whole working season.
The work was finally completed only after the constant building
up of the cribs as tbey settled, and when the nature of the site haiJ
been practically changed from sand to stone, by the constant
settling of the crib filling through the grillage intervals of the
crib bottoms. The pier-head crib settled 7 feet bodily on its
original site in the course of the season, besides sifting out through
its bottom about half its stone filling. A like action, to a lesser
extent, took place throughout the whole extension."

During the year ending the 30th of June, 1870, costly repairs were
made to the new prolongation of the south pier, on account of
further settlement, and of serious damage from storms ; the dredg-
ing alongside the pier was completed ; and the new breakwater had
advanced 950 feet, of which a length of 400 feet was provided with
its superstructure. At the expiration of the following year the
breakwater had attained a length of 1,711 feet, of which 1,183 feet
were completed. By the 30th of June, 1872, the breakwater had
reached a length of 2,136 feet, of which 1,853 feet were completed.

On the 20th of September, 1872, Colonel Harwood, U.S.A., who
had been in charge of the work for two years previously, reported
that, during the last season the cribwork had passed from a founda-

F 2

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tion of sand and rnbblo, on which there was scarcely any appreciable
settlement, to a soft clay stratum, on which, under the influence of
heavy weather, cribs had settled as much as 4 feet in twenty-four
hours, after having been well placed on their bed. He therefore
calculated that, henceforward, it would be safe to estimate the cost
of the work at 60 per cent, more than that which had been already
performed. On this basis it was estimated, therefore, that a
sum of K600,000 would still be required for the breakwater, and
that a further sum of K300,000 would be wanted for the proposed
south entrance.

Towards the close of the working season of 1872, much difficulty
was experienced in keeping the newly-placed cribs in position on
their yielding foundation. Six cribs, each 50 feet long, filled with
stone and docked over, were left to settle till the opening of the
navigation in 1873. A heavy gale displaced these cribs, and,
owing principally to this inteiTuption in the regular progress of
the work, and to the time occupied in repairing the damage,
the breakwater was only 2613 feet longer on the 30th of June,
1873, than at the same date the year before. On the 10th of April,
1873, a board of Engineers, who then examined the state of the
breakwater, reported that that portion of it which had been built
on a firm bottom was a fine specimen of cribwork, and recom-
mended that the remainder of the work, on account of the yield-
ing nature of the bottom, should be founded on a bank of
rubble 4 feet high, extending 24 feet exterior to the cribs, and
1 5 feet beyond them on the harbour side ; leaving it to the
Engineer officer in charge to vary these dimensions as experience
might dictate for the best.

In his annual report of 1873, Colonel Harwood recommended
the immediate construction of the south entrance, and accordingly
included the sum of K 150,000, to be spent on this work, in his
estimate for the year ending the 30th of June, 1874.

The commencement, he said, of the south pier of the proposed
south channel is a matter of pressing necessity, to arrest the
alarming amount of acci-etion of sand which has already taken
place, and which threatens, if not arrested, " to nearly block up the
entrance to Buffalo River, and prevent access to the city wharves,
unless large sums are spent, annually in dredging. This accretion
would appear to be due to the confining of the littoral current
between the breakwater and the shore without preventing the
sand in suspension from beir^; carried along and deposited at the
lake-front and behind and aboui the end of the south Jnited States
pier.". . ."Just in proportion to the extension of this pier, the sand

LAKE HARBOURS IN THE UNITED STATES.

will be arrosiad in its northward progress along the beach. If
several hundred feet of piering could be built next season, it would
be of the greatest advantage to commerce in performing the func-
tion of sand-catcher."

The Author visited the new breakwater at Buffalo on the 1 6th of
October, 1873, whe' it had attained a length of 2,600 feet, and was
being built in a depth of 30 feet of water. At that time the
damage to the six cribs had been effectually repaired as follows : —
A crib 220 feet long, of irregular width, so as to rectify the
inequalities in the line of the interior facing of the four cribs
which had suffered most by the storm, was floated to the spot,
lashed alongside steam-tugs, which held it in place whilst it was
sunk with stones to the bed of the lake. It was then secured
by piles and iron tie-rods to the old work, and finally a timber
superstructure was raised on the combined work in line with the
breakwater already completed.

It is worthy of remark that some of these displaced cribs were
moved as much as 15 feet towards the sea front by the gale, after
having been properly placed and filled with stone up to the level
of 2 feet above the water line. Mr, Muehle, C.E., Assistant En-
gineer to Col. Harwood, attributed this phenomenon to the effect
of the alternate battering action of the sea on the shore side, and
* the recoil of the waves on the sea side, of the cribs, thereby pro-
ducing a vacuum. Mr. Muehle assured the Author that, during
the progress of the works, none of the cribs had moved an inch
laterally after the superstructure had been carried up to the full
height of 8 feet and joined to the old work. This fact is a strong
argument in favour of continuity of structure in works built
with the same end in view and under similar circumsiances else-
where.

The Author cannot better conclude this Paper than by repro-
ducing literally from his journal the following " Note," which was
written at Providence on the 23rd December, 1S73 : —

" Mr. Corliss called at ten o'clock, and drove me in his buggy
to the American Screw Company's establishment, where I re-
mained for more than an hour in company with Mr. Angel, the
President of the worlts, who explained everything to me in a most
obliging manner — one more proof, of the hundreds I have had
already, of the hearty readiness and good-will displayed by
Americans of all classes in giving strangers every species of in-
formation they possess relative to their own particular line of
pursuitB."

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The Author experienced the same unwavering civility up to
the last day of his stay in America ; and, after a long experience
of continental travel, he can safely say that there is no country
where an unprejudiced Englishman is better received, and more
generously treated, than in North America, and certainly not one
he can visit where the application of science to industry in all its
phases is so well understood and practised. *

The communication is illustrated by Plates 6 and 7.

[AFPENmCES.

PUBLIC WORKS IN THE UNITED STATES AND IN CANADA. 71

APPENDICES.

APPENDIX I.

Crevasse at Bonnet Caure, Louisiana.

Kxtract from the Report of General James Longstieet and Mr. W. CJ. R. Bayley,
two of the three members of the Levee ComnuHsion of Engineers, to the
Governor of Louisiana, on the iUst of December, 1874.

This crevasse occurred, as we were informed, in consequence of the washing out
of a muskrat hole, or burrow in the levee, on the 11th of April, at 5 o'clock A.M.
It enlarged too rapidly to be checked or controlled, and remained open during
the remaining portion of the Hood season. The break occurred when the river
there was at its highest fetage. The width "f tlie opening when measured at
low water, in August, from levee to levee, was l,:i70 feet. A channel 550 feet
wide by about 30 feet deep at low water, and about 50 feet deep at high water
—measured on a line with the levee — was scoured out through the firm clayey
bank of the river by the rushing torrent, and this wash-out extended, witli a
somewhat reduced width and depth however, for a distance of about 1,400
feet. The sectional area of the crevasse, as measured at low water, was 34,8!t5
square feet, to the top of the levee. The area of the washed-out channel,
to the level of the bottom of the crevasse channel on each side, between the
ends of the levee, was 16,700 square feet ; leaving 18,195 square feet as the
area of crevasse opening exclusive of the crevasse channel. Allowing 2 feet for
depression of surface of the water in the opening, we have about 32. 000 square
feet as the present area of discharge of this crevasse at high water, and say
15 455 square feet as the actual area of discharge, exclusive of the crevasse
channel. We think that at a high stage of the river this crevasse would now
discharge about one-tenth of the quantity of water flowing in the river channel
to this outlet. The opening gradually enlai'ged to its present capacity, after tlu;
riviT reaihed its highest stage, and while it was slowly declining. We have not
the data necessary for estimating how much water escaped through this outlet
between April 11 and July 15. the latter date being about the time when it
ceased to run through, but, of course, it was very much less than the quantity
which will flow through it at the next flood stage of the river, if the gap is left
open In order to ascertain the effect of tlie reduction of quantity in the river
below this crevasse, Mr. Bayley, of this commission, on the 20th to the 22nd of
September last, measured two sections of tije river above, one opposite tlie upper
end and two below this crevasse. At that time the river was nearly at its
lowest stage, and the river water had ceased to flow through the crevasse for
more than two months.

A section taken about one mile above this crevasse, the river b(,ing then
20 feet below the high-water mark, showed the then low-water width to be

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2,886 foct, the maximum depth 110 fcot, and the area of waterway 184,653
Hquaro feet, with a firm clay buttom, into which an U-lh. Bounding-Icad Bank
from 1 to 2 inches only. The high-wutor width had been 3,120 feet.

Section No. 2, taken about three-fourths of a mile above tho crevasse outlet,
showed a low- water width then of 3,014 feet, a maximum depth of 79 feet, and
waterway area of 104,107 square feet. Tho high-wuter width was 3,210 feet.

The average depth of tho upper section was 64 feet, of section No. 2, 54 feet.
Tile average of the two upper sections waij, depth 59 feet, width 2,950 feet, area
174,410 square feet.

Section No. 4 was taken about 750 feet below the lower side of tho crevasse,
and No. 5 about 1,500 feet btslow. No. 4 showed a low-water width of 2,406 feet,
maximum depth of 62 feet, waterway area of 96,640 square feet, average depth
40 feet ; bottom, except near left bank, very soft oozy mud, into which lead sank
from 1 to 2 feet. Section No. 5 showed a low-water width of 2,452 feet, a maximum
depth of 64 feet, area of waterway 106,150 square feet, average depth about
42*3 feet, bottom same us No. 4. The average of the two lower sections was,
depth 41" 65 feet, width 2,429 feet, area of channel 101,395 square feet.

The reduction of channel below, evidently caused by the crevasse outlet (as
shown by tiie hnrd or firm bottom where the two upper sections were taken, und
the soft oozy mud or new deposit where the two lower sections were taken, as
well as now sand bars on the right bank shore opposite same), taking the
averages of the two upper and two lower sections, amounts to 17*35 feet in
average depth, 521 feet in width of low-water channel, and 73,015 square feet in
sectional area.

The iiigh-water widths of channel on sections 4 and 5 were found to be
3,300 and 3,430 feet respectively, and tlie average high-water sections for
sections 1 and 2, and 4 and 5 were 232,003 and 156,918 square feet respectively ;
the average of the lower sections, to the high-water line, being 75,090 square feet
less than the average of the two upper sections.

It was also noted that there had been very extensive new deposits, forming
sand bars out several hundred feet from the shore line in the river bend, next
the right bank, below tho Bonnet Garrd crevasse outlet ; und it is known that
these were made, principally, during the flood of 1874.

Should tho Bonnet Carrd outlet not be closed before the next high water, a
still further contraction of the channel-way below it may be anticipated. That
such was the eflect this year is incontrovertible.

APPENDIX II.

Specification fob Gribwobe fob the Improvememt of Lake Habbours

IH THE United States.

General Specification. — The cribs should have a length of from 30 to 50 feet,
a breadth never less than 20 feet, even in the shoalest water, and never less than
their total height from their foundation to the platform. That the platform
should rise at least 5 feet above high-water level of the lake. The bottom of the
crib should be of grillage, and all the timber and iron employed should be of a
quality to warrant the ultimate construction of u masonry superstructure ; should

PUBLIC WORKS IN THE UHITED STATES AND IN CANADA. 73

tliat plan be considered proforablo to an entire renewal of the timber-work when,
from natural decay, the ' old ' superstructure is no longer Bcrviceablo.

General Details. — The timber to be of pine, free from rents, splits, shakes, rot
or other imperfections ; to be accurately sawn or hewn to the required dimensions ;
if hewn, to require no counter-hewing in framing.

The iron Imlts to be of best quality of wrought iron.

The stone to bo of a hard, good (]uality, and of a size to permit of its easily
passing through the intervals in the grillage bottoms in the cribs. ,

ISOSTETRICAL ViEW OF CbIBWOUK.

The framing to be done iu a workmanlike manner ; the dovetails of ties and
cuts iu side timbers to be fitted accurately. The holes for the reception of the
bolts to be bored to the full depth to which the bolt is to be driven, and to be
1| inch in diameter.

The timber in a crib is of uniform size (12 inches by 12 inches), except that in
the lower course, which is 12 iuches by 18 inches; the bolts whJ^h hold the
timbers together are made by cutting 1^-inch square iron into lengths of 20, 24,
and 32 inches.

The cribs are built in still water, iu the mauner about to be described, until
their height is a little greater than the depth of the water on the proposed site of

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the pior ; they nro tlion towod to thtHr places aud placed in sucoeesion on the line
of the piur from tbo Hhorc outward, their ends joining and the clianncl sides of all
as nearly na possible in the same piano ; as soon ns a crib is in position it is
weighted with stone until it touches tlio bottom, then it is filled witli the same
material to the lovcl of the top. When the cribs have sett'ed in their places, the
structure is continued to a height of 5 or G feet al)ove the water surface and tilled
with stone. This portion of the structure is called tlio ' superstructure.'

Details of the Framing. — The end walls are placed 2 feet from the ends of the
side walls to secure greater strength from the framing. It will bo observed that
the bottom is not close, but is a ' grillage.' Before driving a bolt, a hole IJ inch
in diameter is bored for the whole distance the Iwlt is to be driven. The first
l)olts in a crib are driven in the second course, and are each 24 inches long ;
32-inch bolts are driven in all the remaining courses to the upper one, in which
20-incli bolts are placed. Bolts are also driven at the intersection of the timbers
in the interior of the crib. The timbers in the two interior cross walls and in the
interior longitudinal wall aro called ' tics.'

In selecting a place f(^r framing the cribs it is mainly important that it should
be in ijuiet water, that the shore sliould be about level and but little above tlie
water's surface, and that there should bo a deptli of 10 or 12 feet of water within
a few feet of shore.

Three or four courses are framed and bolted together on shore, where the strtic-
ture is launched and additional courses put on until the hei}?ht is 2 or 3 feet
greater than the depth of the water where it is to be placed. As it is usually
desired to obtain a depth of 10 or 12 feet of water in tlie channel, the site of the
proposed pier should be dredged to that depth wherever the original depth of
water is less. "When three or four cribs are tinislied, if there is a sufficient supply
of stone at hand to fill them, they are put in place and filled.

The placing of a crib is attended with considerable risk, for perfectly smooth
water is requisite to enable the workman to put it in exactly the proper place. It
often happens that a sea arises wiien the crib is but partially filled, and it is
swept from its place and washed iishore.

The bottom on which the crib is to be placed must be level, or nearly so ; if
ther*- is a variation of more than 1 foot in the depth of water nt diiForent points,
the bottom must be dredged to a level. The first crib is towed out by a tug, or by
lines leading to shore, to the inner or shore end of the work proposed, and is
earefidly placed so that its face shall be in the direction required ; a scow on which
are piled 8 or 10 cx)rds of stone being brought alongside, some slabs or boards aro
laid across the corners of the crib and stone piled upon them in such a manner as
to keep the crib level as it sinks ; when it rests on the bottom, stone is thrown
in as rapidly as possible until it i tilled, 4 or 5 scow-loads being necessary to
fill it.

The scow being again loaded with stone, and the bottom levelled for the second
crib, it is placed with its end against the outer end of the first one, and sunk and
filled in u similar manner. Various devices are used to keep the crib in place
while sinking. One of the best consists of two iron rods, each about 3 or 4 feet
in length, with one end turned down at ri<j;ht angles so as to form a hook, and
having the other end connected by a swivel screw, by turning which the distance
between the hooks may bo varied at pleasure ; when the crib is brought into
posiiion, this apparatus is placed so that the hooks embrace the end walla of the
adjacent cribs, and the swivel is turned until the cribs are brought closely
together ; a pair of these clamps are used, and they hold the crib firmly in place
until it is filled.

PUBLIC WORKS IN TIIE UNITED STATES AND IN CANADA. 75

In tlio snmo manner the remaining cribs aro placed. •

After being plncod and flUed, they are allowed sometime to settle; it is deemed
advisable to let them remain during the winter wlien possible, but sometimes the
Buperatructuro is put on in a mcmth or two. The cribs often settle very irregularly
on account of the uneven texture of the bottom, aa when one portion of the crib rests
on hard sand and another on quicksand, as well ns of the shocks of the waves and of
their action and the action of the currents in washing out the fuundution. They
are constantly watched, and the load ia shifted from side to side as occasion
requires, to induce a more rapid settling of any part; they generally settle in the
sand a foot or two after being placed, and often much more ; after a month or two
they become pretty firndy fixed in place. Should none of them bo out of level
more than a foot, or a foot and a hall", tlie result is deemed very satisfactory.

When they have settled, they are 'levelled up' by putting on the wedge-
sliaped pieces until the tops of all are in the same horizontal plane, and the
8Ui)orstrncture ia then adilcd; this being continuous from crib to crib, serves to
bind the pier together. It is usual to place a larger crib, 30 or 32 feet square, at
tho outer end.

The interval between the end walls of adjacent cribs is filled with slabs or
edgings to the water's surfaoe, and thence to the top of tho pier with stone.

APPENDIX III.

Specification fob the Construction of a Bbbakwateb, Landing Pieb, etc.,
OF Gbibwork at Ghantbt Island, Lake Hdbon, Canada.

The works for which ' tenders ' aro invited, consist in the construction of a
breakwater on the easterly side of the roadstead, starting from a salient point of
the mainland, and extending outwards in a slightly curved line about 1,800 feet,
or to within 450 feet of the extreme end of the protection works already formed on
the westerly side of the island — the construction of a landing pier from the shore
outwards to a depth of 14 feet at low water at a place from 300 to 500 feet south
of the breakwater.

Breakwater. — To be carried up to tho height of 7 J feet over the water level of
September 1868 ; at the shore, and out to a depth of 3 feet water it is to be
formed chiefly of gravel, well faced, and protected with boulder stones on both
sides ; tlience outwards it is to be of cribwork up to within 1 foot of low- water
line, where a continuous superstructure is to be commenced and carried to the
heiglit above stated.

The interior of the work throughout must be filled with a good class of mode-
rate-sized stones ; and where the depth of water exceeds 15 feet, a talus of stone
is to be placed along both sides of the cribwork up to within 12 feet of tho water
surface, with an outer slope of 1 horizontal to 1 vertical.

For 300 feet at the inner end, the structure is to be 20 feet in width — the next
300 feet, 25 feet in width, outside of this it is to be made 30 feet wide, except at
the extreme end, where a crib 50 feet square is to be placed, connected with the
other work, and arranged so as to form the eastern heading pier of the northern
channel.

Cribwork. — To be of the widths above stated for the respective places, and in

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^^ v.t

lengths of at loast 30 foot. Tlio HidoB niul ondu to bo of timber not leas than
1 1 inches square, straight, sound, and full on tho edges, carried up vertically to
within 2 feet of the water surface, whore a batter of 1 in 12 is to be commenced
on l)oth the front and roar sides.

Framing. — The outer timbers of the cribs are to bo framed so as to loovo a
space of 2 inciics hotwoeu the differunt couraes, and at the angles they are to be
connected by double bevelled dovetails, arranged so that ovtry end timber shall
be dovetailed into two side timbers, and the side timbers bo similarly placed
between those fuiraing the ends.

At each corner in every course a rag bolt 12 inches long nnd J inch diameter
is to be driven through the dovetail.

Cross Tie*. — To be at least 10 inches thick, of uufHcient size to square 10 inches
by 12 inelies at both ends, and of the full length (respectively 30 feet, 25 fiet, and
20 foot) of the outside width of the different cribs. They are to be pliiced not
more than 10 feet ajMirt, nnd so arranged that the ties resting on the diii'erent
rounds of timber shall be midway between those of the courses immediately
below and above.

'I'heir ends arc to be dovetailed 3J ir.ches into the timbers under and over them,
tlio dovetail to spltiy I^ inches on both sides, so as to stand 8 inches at the neck,
und 1 1 inches at the outer end.

Under the head of uueh tie, at the joint between the courses immediately below
it, a block 2 inches by 11 inches by 11 inches is to be inserted to give u
uniform bearing, and o rag bolt 2J feet long, I iiicii diameter, is to bo driven
through tlio head of each tie, passing down through the course on which it
rests, tlio block and course under it, and 4 inches into the head of the next
cross tie.

LoTujitudinal Ties. — In all the cribs longitudinal ties, 10 inches thick, are to be
framed into, and dovetailed between the alternate tiers of end timbers, have
blocks under them, and be secured by bolts of similar dimensions, nnd in like
manner as described for the transverse ties, into which tliey are to be notched and
fastened at the crossings by means of white oak tree-nails, 2 inches diameter and
IG inohes long.

In cribs 25 or 30 feet in width they are to be arranged as shown on section ;
and in those 20 feet wide they will generally be carried up in the centre.

In the cribs forming the terminations of the piers, there must be longitudinal
ties in every course placed alternately 10 feet and 20 feet from the face side.

The cribs are to be further secured fey vertical ranges of plank plact d inside ,
and extending from the lowest side timber up to the water line. There are to be
three ranges on a side, that is to say— one at, or near each angle, and another in
the centre ; making in all six vertical ranges in a crib. The planks are to bo
4 inches thick, and 10 inches in width, fastened from the inside with 10-inch
spike, I inch diameter, two driven through each plank into each of the lowest side
pieces, and one at every crossing of a side timber from the floor upwards. They
may be put on in lengths of Irom 8 te 10 feet or more : but they must bo bo
arranged that the upper length in all cases shall reach down at least 2 feet lower
than the top of the plank of the same range below.

Ballast Iloors. — To consist of flatted timbers, 10 inches in thickness, and of the
full length of the width of the respective oribs, i.e., 30 feet, 25 feet, and 20 feet.
They arc to be laid transversely from 5 to 6 inches apart, and rest on either the
tirst or second course of side timbers, as may be directed, and to which every
alternate piece is to be fastened at each end by a bolt I inch diameter, and
18 inches long. In cribs 30 feet, or 25 feet in width, there are to be two longi-

PTTBLIO WORKS IN TTIE TTNTTED BTATES AND IN CANADA, 77

tiKliiml timbors dovf idiled into and sociirod to tho ond pieces at tlio proper height,
to form iKiiirings for tlio floor. In cribs 20 feet wide there will bo only one longi-
tudinal boaror under tlio floor.

The cribs, from tho bottom upwards to low-water lino, may bo formed cither of
pine, cednr, ash, tamarac, or elm timber ; but whatever kind is used, it must be
straight und of good quality, free from shakes, sapwoml, unsound knots, or other
defects.

Before a crib is put together, Iho contractor must take correct close soundingH
over the place it is to occupy when sunk, and where such inequalities orcur as
unnnot bo removed, the bottom of tho crib miist bo adapted to them, so that when
placed in its berth the sides and ends shall be plumb, and the whole fonn a line
corresponding to that marked out by the officer in charge.

Immediately after a crib has been moored in tho right position, the contmctor,
if so directed, must lay a platform of plank over it of sufficient size and strenjjth
to carry enough stone to sink it. and when thus sunk, and ascertaineil to bo on tho
proper line and place, the crib is to bo filled with an approved class of moderate-
sized stone, closely packed.

As before mentioned, when the depth of water exceeds 15 feet, a talup .if stone
is to be formed nlong eofh side of tho breakwater, up to within 12 fix-t of tho
water surface. The stones must be placed as compactly together ns possiblo, and
arranged so as to have on the respective outer sides a uniform slope of I J hori-
zontal to 1 vortical. This work to be proceeded with simultaneously with tho
sinking of the cribs, and must be conducted in such a manner that there will bo
fit no time more than two cribs sunk in advance of it.

When the whole of tho cribs shall have been sunk, well filled with stone, and
settled in their respective berths, tho sides must be brouj^ht to a uniform height
nt low-water line, either by cutting down and removing the top timbers, or using
suitable levelling pieces as may be required.

Tfie Superstnidure is then to be commenced, and carried up with a batter of 1
in 12 to the height of 7^ feet over the water level of September 18G8, or to such
other height as directed. The face timbers to be of pine 12 inches square, gene-
rally not less than 40 foot long, or of such other lengths as will break joint
properly over and upon tho difierent cribs. They aro to be scarfed at tho ends
where they connect ; the scarf to be squore at heel and toe, and have o lap of
18 inches, with a block underneath, and bo secured with a bolt 18 inches long
and 5 inch diameter. Tho timber must be counter- hewn, if required, and laid so
OS to leave a space of 1 J inch between tho courses.

Transverse Ties of flatted pine timber, of a size to square 10 inches by 12 inches
at both ends, and of a sufficient length to extend across the pier are to be plocod
not more than 10 feet apart, in every course of the superstructure. They are to
bo dovetailed, and let into the side pwHies over and under them — have a block
1^ inch by 12 inches by 12 inches inserted between tiie two courses under the
head of each, and be secured by meant: of rag bolts, J inch in diameter, in a
similar manner to those described for the cribs.

Longitudinal Timbers of flatted pine are to be carried up between the alternate
courses of like dimensions, be framed, notched into cross ties, and secured gene-
rally as those described for the cribs.

Binding Pieces, of 4 inches by 10 inches pine plank, are to be placed vertically
inside for the entire height, and fastened with spikes, J inch diameter, and
10 inches long— one at every crossing of a face timber. They are to be not more
than 14 feet apart, and are in every cage to form continuations of the respective
ranges underneath.

OTHER SELECTED PAPERS.

Stringern. — To form bearings for tlio top covering, five stringers, eacli 7 inches
by 10 inches of pine, arc to bo laid the whole lengtli of tho breakwater, secured to
the cross tics, and placed at u like height as the side timbers.

The whole interior of tho superstructure must bo filled with a good class
of stone, carried up as the timber-work proceeds, and care taken to pack them
well around and between the ties, as well as to have the top part properly
levelled.

Top Covering to be of 3-inch pine plank of sufficient length to pass over the
side timbers and meet on the centre stringer. Tbsy are to bo laid crosswise,
1 inch apart, and bo fastened at the ends, and at every crossing of a stringer, with
7-inch pressed spikes.

Tho covering is to be further secured by chamfered cap pieces of white oak or
rock elm, each 10 inches by 6 inches — one range laid along each side of the
breakwater, and another in the contro over the joinings of tlio plank. Tho cap
pieces to be fastened with rng bolts, ^ inch diameter, und 18 inclies long.

In case it should he deteriiiinod to put mooring jwsts in tho brcrkwater, they
are to be of white oak or rock elm timber, 10 feet long, and 16 inches diameter,
properly dressed, covered on top with a cast-iron cap piece, and placetl so as to
stand 18 inches over the top covering. Tliey are to be notched at bottom to
receivj cross pieces 5 feet long, be secured to the cross ties with screw bolts of
IJ-inch rouL.a iron, and have the ballast aroimd them properly packed.

The outer faces of the superstructure, from the top to low-water line, must be
hewn down noBtly to lines corresponding to the position of the work, and every-
thing done that is necessary to leave the whole in a finished and satisfactory
condition.

Landing Pier to be made 30 feet wide and about 400 feet long, placed in tho
position indicated on the general plan.

The cribwork of the pier is to bo built of a like class of timber, framed, put
together, secured, sunk, and filled with stone, with a superstructure of pino
timber, of like dimensions, arrai ged, framed, secured, and ballasted with stcne,
have the sides dressed down to water surf'iee, the top covered with 3-iiich pino
plank, and the whole work executed and completed as described for the break-
water.

The works are to be commenced immediately after the person or persons whose

' tender ' is accepted shall have entered into contract with the Department of

Public Works, and must be proceeded with in such a manner that tiie landing

wharf, and approach to it, shall be finished on or before tiie 1st day of September,

1874, and at least one-half of the cribwork connected with the breakwater sunk

by the Ist day of November, 1874 ; and the whole work completed by the 1st day

of October, 1875.

JOHN PAGE,

Chief Engineer P'tllio Works.
Departn.ent of Public Works, Ottawa,
30th August, 1873.

PUBLIC WORKS IN THE UNITED STATES AND ZN CANADA. 79

APPENDIX IV.

Estimate of the Cost of Constrticting and Stoking a Crib 50 feet by 30 feet by
30 feet in 24 feet of Water in the line of the Breakwater to the Outer
Harbour at Chioaqo.

9,442 cubic feet of pine timber, 12 inches by 12 inches,

at 22 cents per cubic or lineal foot 2,077 24

4,000 feet, board me.-oure (12 inches by 1 inch), of

white oak plank, 8 inches by 3 inches, for deck of crib

. at $30 per mbtre 120 00

8 sills to support the flooring, each 30 feet long, and

9 inches by 6 inches, 90 cubic feet at 22 cents. . . 19 80

12,772 lbs. of iron bolts, IJ inch square, at 4 cents

perlb 510 88

275 lbs. of wrought-iron spikes, g inch by J inch square,

at 8 cents per lb 22 00

247 cords of stone,' crib ballast, at $6 50 cents per cord 1,605 50
28 ditto for intervals, nt $0 50 cents per cord 182 00

. Estimated cost of materials 4,537 42 '

Superintendence and workmanship 2,306 40

Add.lO per cent, for contingonces 684 33

* ■

Estimatedcostof onecrib, 50 feet by 30feet by 30feet 7,528 15
= $150 56 cents per lineal foot, or $4 52 cents per
cubic yard.

A cord of stone or timber is equivalent to 128 cubic feet.

OTHEIl 8ELE0TKD PAPERS.

No. 1,413a. — " Cribwork in the Black Sea." By Sir Charles A.
Hartley, M. Inst. C.E., F.R.S.E. .

In the construction of the provisional piers at Sulina, in 1868,
it was first of all intended to build cribs from 30 feet to 60 feet
long, to load them with stones, and to sink them at intervals of
20 feet along the line of works, filling the space between with
piling, driven from staging, supported by the cribs, the whole being
protected at the foot by rubble stones. After sinking a few cribs
of unusual strength,^ the mixed system was abandoned in favour
of piling and ' pierre perdue ' work only. This decision was come
to owing to the experience that had been gained of 'the serious
risk and loss of time involved in placing the cribs in position in
an open seaway, and of thb' expense incurred in adding timbers
to the superstructure until settlement had ceased. The settle-
ment was very unequal : as much as 4 feet on one occasion after a
heavy gale. It was entirely produced by the scour of the sea on
the foundation of hard sand, before there had been time to sur-
round tho crib with a wide bank of rubble stones. When cribs
were placed on a bank of rubble in the first instance, as occurred
on three occasions at the head of the piled piers at the end of the
working season, no scouring action took place, and, consequently,
the cribs never moved from their original position, whilst they
served admirably as breakwaters or temporary pier heads during
the stormy months of winter.

Although the Author's experience of the use of cribwork in a
very exposed seaway was not encouraging, it was such as to
convince him that, in a country where timber and stone are plen-
tiful, where cheap cement is not to be obtained, and where an
economical stuoturo in the first irstanco is a sine qud now, no
better plan can be adopted of building a pier or breakwater in
greater depths than 15 feet, on a sandy or yielding bottom, and
where heavy seas and the ' teredo navalis ' are not to be feared,

' Vide sketch of cribwork in vol. i. of Atlas attached to the first " M^moire sur
les travaux. d'ameliuration execute's aux embouchures du Dauube," in the library
of tho Institution. ,

CRIBWORK IN THE BLACK SEA. 81

than that of first of all throwing down a bank of rubble to a depth
dictated by the nature of the locality, and then to Burraount it
with cribwork up to a level of a few feet above the water line. It
was this conviction that induced him, nearly fifteen years ago, to
propose the construction of a provisional mole, in a comparatively
sheltered position on the north-west coast of the Black Sea.

This work was not constructed ; but, on comparing its cost, at
Chicago prices, with that of a Chicago crib of 1871, in the same
depth of water, and therefore 30 feet high and 30 feet wide, it will
be found that whilst the cost of the latter plan is K150 per lineal
foot, that of the former is only ^115 per lineal foot, with the great
advantage, moreover, that, by adopting the stone foundation, the
expense and inconvenience attending the raising of the super-
structure of the cribs, on account of settlement produced by scour,
is altogether avoided.

In comparing the cost of works in England and North America,
the much higher wages paid to workmen in the latter country
must always be kept in view. The following information on this
question was gathered by the Author from various sources in the
United States and Canada.

Wages per day in the United States.

$
Foremen 4J to 6

Mechanics, blacksmiths, masons, and brickhiyers . . 3 to 4

Carpenters 2 to 2J

Quarrymcn 2J

Labourers 1 to 2

Horse, cart, and driver 3i to 4

In Canada the wages are about 25 per cent, less ; but clothing
is far dearer, and taxes are more than 25 per cent, higher in the
United States than in Canada ; thus, in buying-power, the wages
received in Canada are fully equal to those paid in the States.

In 1873, the approximate currency .alue of the United States
dollar was 3«. 8d., and that of the Canadian dollar, 4«.

The cost of clothing, washing, houbo-rent, spirits, and beer is
more than double as much in the United States as in England,
■whilst in the former the ordinary articles of food are somewhat
cheaper than in the old country.

[18V4-75. N.S.]

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