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TECHNICAL INSTRUCTION SERIES
FT — P
PRACTICA
>AUL N. HAS Li
636.2.
M Z7S
HANDICRAFT SERIES.
A Series of Practical Manuals.
Edited by PAUL N. HASLUCK, Editor of "Work," "Technical Instruction
Series," etc.
Price 50 cfs. each, postpaid.
House Decoration. Comprising Whitewashing, Paperhanginq, Painting, etc.
With 79 Engravings and Diagrams.
Contents. — Colour and Paints. Pigments, Oils, Driers, Varnishes, etc. Tools used by
Painters. How to Mix Oil Paints. Distemper or Tempera Painting. Whitewashing
and Decorating a Ceiling. Painting a Room. Papering a Room. Embellishment of
Walls and Ceilings.
Boot Making and Mending. Including Repairing, Lasting, and Finishing. With
179 Engravings and Diagrams.
Contents. — Repairing Heels and Half-Soling. Patching Boots and Shoes. Re- Welting
and Re-Soling. Boot Making. Lasting the Upper. Sewing and Stitching. Making
the Heel. 1
How to Wi
Contents.-
FRANKLIN INSTITUTE
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JAMES T. MORRIS MEMORIAL
agrams.
's Outfit.
Lettering.
ter-Paint-
1 Engrav-
3h Polish-
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ig. Hard
ing Wood
FUND
Class
Making Sig
Shaded and
ing. Letter
Wood Finii
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Contents. -
ing. Fillers
Wax Finish
Stopping or
Varnishes.
Dynamos ;
Contents-
Simplex. Dj ^
Ailments of
motors with '
How to Mak
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Rear-drivini
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Decorativt
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Ornament,
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Mounting
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Making Ox Pictures.
Making Phc iging and
Packing Pictures.
Smiths' Work. With 211 Engravings and Diagrams.
Contents. — Forges and Appliances. Hand Tools. Drawing Down and Up-setting.
Welding and Punching. Conditions of Work: Principles of Formation. Bending and
Ring Making. Miscellaneous Examples of Forged Work. Cranks, Model Work, and
Die Forging. Home-made Forges. The Manipulation of Steel at the Forge.
Glass Working by Heat and Abrasion. With 300 Engravings and Diagrams.
Contents. — Appliances used in Glass Blowing. Manipulating Glass Tubing. Blowing
Bulbs and Flasks. Jointing Tubes to Bulbs forming Thistle Funnels, etc. Blowing and
Etching Glass Fancy Articles; Embossing and Gilding Flat Surfaces. Utilising Broken
Glass Apparatus; Boring Holes in, and Riveting Glass. Hand-working of Telescope
Specula. Turning, Chipping, and Grinding Glass. The Manufacture of Glass.
DAVID McKAY, Publisher, 1022 Market Street, Philadelphia.
H z rj S
Accession i54~0 r J . 8
Dynamo.
Dynamos.
1 Electro-
a Motor,
anchester
tuilding a
e. Build-
1 Accesso-
lairing.
Diagrams,
t. Greek
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HANDICRAFT SERIES {continued).
Building Model Boats. With 168 Engravings and Diagrams.
Contents. — Building Model Yachts. Rigging and Sailing Model Yachts. Making and
Fitting Simple Model Boats. Building a Model Atlantic Liner. Vertical Engine for a
Model Launch. Model Launch Engine with Reversing Gear. Making a Show Case for
a Model Boat.
Electric Bells, How to Slake and Fit Them. With 162 Engravings and Diagrams.
Contents. — The Electric Current and the Laws that Govern it. Current Conductors
used in Electric-Bell Work. Wiring for Electric Bells. Elaborated Systems of Wiring;
Burglar Alarms. Batteries for Electric Bells. The Construction of Electric Bells, Pushes,
and Switches. Indicators for Electric-Bell Systems.
Bamboo Work. With 177 Engravings and Diagrams.
Contents. — Bamboo: Its Sources and Uses. How to Work Bamboo. Bamboo Tables.
Bamboo Chairs and Seats. Bamboo Bedroom Furniture. Bamboo Hall Racks and Stands.
Bamboo Music Racks. Bamboo Cabinets and Bookcases. Bamboo Window Blinds.
Miscellaneous Articles of Bamboo. Bamboo Mail Cart.
Taxidermy. With 108 Engravings and Diagrams.
Contents. — Skinning Birds. Stuffing and Mounting Birds. Skinning and Stuffing
Mammals. Mounting Animals' Horned Heads: Polishing and Mounting Horns. Skin-
ning, Stuffing, and Casting Fish. Preserving, Cleaning, and Dyeing Skins. Preserving
Insects, and Birds' Eggs. Cases for Mounting Specimens.
Tailoring. With 180 Engravings and Diagrams.
Contents. — Tailors' Requisites and Methods of Stitching. Simple Repairs and Press-
ing. Relining, Repocketing, and Recollaring. How to Cut and Make Trousers. How
to Cut and Make Vests. Cutting and Making Lounge and Reefer Jackets. Cutting and
Making Morning and Frock Coats.
Photographic Cameras and Accessories. Comprising How to Make Cameras,
Dark Slides, Shdtters, and Stands. With 160 Illustrations.
Contents. — Photographic Lenses and How to Test them. . Modern Half-plate Cameras.
Hand and Pocket Cameras. Ferrotype Cameras. Stereoscopic Cameras. Enlarging
Cameras. Dark Slides. Cinematograph Management.
Optical Lanterns. Comprising The Construction and Management of Optical
Lanterns and the Making of Slides. With 160 Illustrations.
Contents.- — Single Lanterns. Dissolving View Lanterns. Illuminant for Optical Lan-
terns. Optical Lantern Accessories. Conducting a Lime-light Lantern Exhibition. Ex-
periments with Optical Lanterns. Painting Lantern Slides. Photographic Lantern
Slides. Mechanical Lantern Slides. Cinematograph Management.
Engraving Metals. With Numerous Illustrations.
Contents. — Introduction and Terms used. Engravers' Tools and their Uses. Ele-
mentary Exercises in Engraving. Engraving Plate and Precious Metals. Engraving
Monograms. Transfer Process of Engraving Metals. Engraving Name Plates. En-
graving Coffin Plates. Engraving Steel Plates. Chasing and Embossing Metals. Etch-
ing Metals.
Basket Work. With 189 Illustrations.
Contents. — Tools and Materials. Simple Baskets. Grocer's Square Baskets. Round
Baskets. Oval Baskets. Flat Fruit Baskets. Wicker Elbow Chairs. Basket Bottle-
casings. Doctors' and Chemists' Baskets. Fancy Basket Work. Sussex Trug Basket.
Miscellaneous Basket Work. Index.
Bookbinding. With 125 Engravings and Diagrams.
Contents. — Bookbinders' Appliances. Folding Printed Book Sheets. Beating and
Sewing. Rounding, Backing, and Cover Cutting. Cutting Book Edges. Covering
Books. Cloth-bound Books, Pamphlets, etc. Account Books, Ledgers, etc. Coloring,
Sprinkling, and Marbling Book Edges. Marbling Book Papers. Gilding Book Edges.
Sprinkling and Tree Marbling Book Covers. Lettering, Gilding, and Finishing Book
Covers. Index.
Bent Iron Work. Including Elementary Art Metal Work. With 269 Engravings
and Diagrams.
Contents. — Tools and Materials. Bending and Working Strip Iron. Simple Exercises
in Bent Iron. Floral Ornaments for Bent Iron Work. Candlesticks. Hall Lanterns.
Screens, Grilles, etc. Table Lamps. Suspended Lamps and Flower Bowls. Photo-
graph Frames. Newspaper Rack. Floor Lamps. Miscellaneous Examples. Index.
Other Volumes in Preparation.
DAVID McKAY, Publisher, 1022 Market Street, Philadelphia.
TECHNICAL INSTRUCTION.
Important New Series of Practical Volumes. Edited by PAUL N. HASLUCK.
With numerous Illustrations in the Text. Each book contains about 160 pages,
crown 8vo. Cloth, $1.00 each, postpaid.
Practical Draughtsmen's Work. With 226 Illustrations.
Contents. — Drawing Boards. Paper and Mounting. Draughtsmen's Instruments.
Drawing Straight Lines. Drawing Circular Lines. Elliptical Curves. Projection.
Back Lining Drawings. Scale Drawings and Maps. Colouring Drawings. Making a
Drawing. Index.
Practical Gasfltting. With 120 Illustrations.
Contents.— How Coal Gas is Made. Coal Gas from the Retort to the Gas Holder.
Gas Supply from Gas Holder to Meter. Laying the Gas Pipe in the House. Gas
Meters. Gas Burners. Incandescent Lights. Gas Fittings in Workshops and Theatres.
Gas Fittings for Festival Illuminations. Gas Fires and Cooking Stoves. Index.
Practical Staircase Joinery. With 215 Illustrations.
Contents. — Introduction: Explanation of Terms. Simple form of Staircase — Housed
String Stair: Measuring, Planning, and Setting Out. Two-flight Staircase. Staircase
with Winders at Bottom. Staircase with Winders at Top and Bottom. Staircase with
Half-space of Winders. Staircase over an Oblique Plan. Staircase with Open or Cut
Strings. Cut String Staircase with Brackets. Open String Staircase with Bull-nose
Step. Geometrical Staircases. Winding staircases. Ships' Staircases. Index.
Practical Metal Plate Work. With 247 Illustrations.
Contents. — Materials used in Metal Plate Work. Geometrical Construction of Plane
Figures. Geometrical Construction and Development of Solid Figures. Tools and
Appliances used in Metal Plate Work. Soldering and Brazing. Tinning. Re-tinning,
and Galvanising. Examples of Practical Metal Plate Work. Examples of Practical
Pattern Drawing. Index.
Practical Graining and Marbling. With 79 Illustrations.
Contents. — Graining: Introduction, Tools and Mechanical Aids. Graining Grounds
and Graining Colors. Oak Graining in Oil. Oak Graining in Spirit and Water Colors.
Pollard Oak and Knotted Oak Graining. Maple Graining. Mahogany and Pitch-pine
Graining. Walnut Graining. Fancy Wood Graining. Furniture Graining. Imitating
Woods by Staining. Imitating Inlaid Woods. Marbling: Introduction, Tools, and
Materials. Imitating Varieties of Marble. Index.
Ready Shortly :
Practical Plumbing Work.
Other New Volumes in Preparation.
DAVID McKAY, Publisher, 1022 Market Street, Philadelphia.
PRACTICAL GAS-FITTING
PRACTICAL
GAS-FITTING
{Including Gas Manufacture)
WITH NUMEROUS ENGRAVINGS AND DIAGRAMS
EDITED BY
PAUL jST. II AS LUCK
HONOURS MEDALLIST IN TECHNOLOGY
■ • • • •
. •£DI*OR JJFj'J^tlfK " jAjiD J" BtllLDj*I(J %%l;ti> J *
AujtlOR.'gjfc "»l^VBj0K^I»&!HANCIOR)t»'tj*" KfC. •
• • • p » *»••••••• • ••
PHILADELPHIA
DAVID McKAY, Publisher
1022 MARKET STREET
1903
TM
two
MORRIS FUNO
TKG GETTY CENTER
LIBRARY
PREFACE.
P-RACtical Gas -fitting gives, in a form convenient for
everyday use, a comprehensive digest of information, con-
tributed by experienced writers, and scattered over the columns
of Building World, one of the weekly journals it is my
fortune to edit, and supplies concise information on the general
principles and practice of the subjects on Which it treats.
Chapters on gas manufacture, on incandescent lighting, and on
stoves for warming and cooking, are included.
In preparing for publication in book form the mass of
relevant matter contained in the volumes of Building World,
much of it necessarily had to be re-arranged and re-written-
From these causes the writings of many contributors are so
blended that it is difficult to distinguish any for acknowledg-
ment.
Readers who may desire additional information respecting
special details of the matters dealt with in this book, or in-
struction on any building trade subjects, should address a.
question to Building World, so that it may be answered in
the columns of that journal.
P. N. HASLUCK.
CONTENTS.
CHAP. PAGE
I. — Manufacture of Coal Gas » • 9
II. — Coal Gas from Retort to Gas holder ... 25
III. — Gas Supply from Gas-holder to Domestic Meter . 46
IV. — Laying Gaspipe in the House . . 60
V.— Gas Meters 83
VI. — Gas Burners 97
VII. — Incandescent Gas Burners . . . .11!)
VIII.— Gas-fitting in Workshops and Theatres . . .127
IX. — Gas-fitting for Festival Illuminations . . . 137
X.— Gas Tires and Stoves for Warming and Cooking . 142
Index . . , - 157
LIST OF ILLUSTRATIONS.
«». PAGE
1. — Section of Retort Setting . . 15
2. — Stage Retort House . . .16
3. — Sectional Elevation of Bight
Single Retorts ... IS
4. — Longitudinal Section of Eight
Single Retorts . . .19
5. — Longitudinal Section through
Oven 20
6. — Horizontal Section through
Oven 21
7. — Vertical Section through Oven 21
3. — Hydraulic Main and Connec-
tions 26
9. — Section of Hydraulic Main and
Dip Pipe 27
10. — Condenser 29
11. — Exhauster . . . . - . 29
12. — Scrubber 29
13. — Pair of Tower Scrubbers . . 33
14. — Anderson's Scrubber and
Washer 35
15. — Washer Scrubber . . .36
16. — Purifiers 37
IT.— Station Meter . . . .37
IS.— Section of Station Meter . . 40
19. — Gas-holder 41
20. — Untrussed Gas-holder and
Puddle Tank . . . . 43
21. — Station Meter Governor . . 44
22. — Socket and Spigot Joint . . 49
23. 24.— Plan and Section of Main
Syphon 50
25, 26.— Methods of Drilling Mains . 51
27. — Front Elevation of Upward's
Safety Drill .... 52
28. — Side Elevation of Upward's
Safety Drill .... 53
29. 30.— Correct and Incorrect Posi-
tions of Drill . . . .54
31. — Taper Tap 55
32. — Plug Tap 55
33. — Drill Reamer Tap . . .56
34. — Syphon Box .... 57
FIG. PAGE
35. — Pipe Syphon .... 57
36. — Tubes and Fittings ... 61
37 — Pipe Vice 63
38. — One-wheel Pipc-cutter . .64
39. — Three-wheel Pipe-cutter . . 64
40. 41. — Improved Three- wheel Pipe-
cutters 64
42. — Stock and Die . . . .65
43. — Taper Die-stock .... 65
44. — Screwing Machine . . .67
45. — Pipe Tongs .... 68
46. — Pipe Wrench .... 69
47 — Method of Jointing Compo. Pipe 70
48. — Shave-hook .... 71
49. — Ball and Socket Joint . . 76
50. — Bridge-piece Pendant Fitting . 77
51. — Method of Sawing Floor Board 78
52. — Supporting Pipe against Joists 79
53 Gas-fitter's Pliers . . '.82
54. — Front Elevation of Wet Meter . S5
55. — Section of Wet Meter. . . 86
56. — Front Elevation of Wet Meter . -87
57. — Indices for Gas Meter . . S9
5S.— Back-nut 91
59. — Enlarged View of Valve . . 91
60. — Dry Meter in Glass Case . . 02
61. — Side View of Dry Meter . . 93
62. — Section of Dry Meter . . 94
63. — Front View of Dry Meter . . 95
64 — 70.— Bray's Union Burners . 104
71. — Governor Union Burner . . 104
72. — Bray's Batswing Burner . . 104
73. 74.— Sugg's Table-top Burners . 104
75, 76.— Comet Burners . . .101
77. — Veritas Burner .... 105
78. — Duplex Batswing Burner . . 105
79. — Bray's Adjustable Burner. . 105
80. — Goodsou's Burner . . . 103
81. — Peebles' Male Governor Burner 105
82. — Peebles' Female Governor
Burner 105
83. — Hawkins and Barton's Gov-
ernor Burner. , . . 105
8
LIST OF ILLUSTRATIONS.
no.
PAGE
FIG.
PAGE
84.
— Victoria or Ellis Regulator
103.
—Stage Footlights
132
105
104.
—Two-row Footlights for Stage .
133
85.
- Sugg's Governor Burner .
100
105.
—Footlights for Portable Stage .
133
80.-
-Bray's Street Burner.
100
106.
—Stage Footlight Reflector.
133
87-
-89.— Falk, Stadelmann & Co.'s
107.
-Stage Sidelights.
135
Street Burners
100
10S.
—Star for Festival Illumination .
138
90.-
-Combination Street Governor
109.
— " V.R.I." for Festival Illumina-
100
tion
139
91.
92.
—Tripod Street Burner
— Descending Cluster Street
100
110.
—"V.R.I." Monogram for Festi-
val Illumination .
140
Burner
100
111.
—Crown for Festival Illumina-
.93.
— .Argand Burner .
100
tion. . . . . ,
141
94.-
— Iinperator Argand Burner
107
112.
— " Charing Cross " Gas Fire
144
95.
— Sandringham Regenerative Gas
113.
-Section of Gas Fire in Coal
111
Grate :
—Channelled Bottom of " dialing
145
96.
— Strode's Sun Burner
115
114.-
97.
— Section of Albo - carbon Gas
Cross " Gas Fire .
146
117
1 15.
— " St. Martin " Reflecting Gas
98.
—Fitted Albo-carbon Gas Burner
117
147
99.
— " C" Incandescent Burner
123
110.
—Fletcher and Russell's Gas
100.
—Kern Incandescent Burner
123
148
101.
—Gas Cocks and Bye-passcs for
117.
— " Senegal " Gas Stove
149
130
118.
—Egg-shaped Clay Block .
150
102.
—Gas Cocks and Bye-passes for
119.
—Quadrant Gas Cock . .
151
131
120.
—Clark's Syphon Stove . .
152
PRACTICAL GAS-FITTING.
CHAPTER L
MANUFACTURE OF COAL GAS
Gas has, nowadays, a vast number of valuable applications. Its
usefulness is apparent in many manufactures ; it is employed for
the supply of power, heat, and light ; it is reliable and compara-
tively cheap, and is equally suited to supply the power that
works an engine of 150 horse-power or the small jet of flame
that lights a cigar. That gas is used largely at the present
day is obvious when it is stated that in England alone about
10,000,000 tons of coal are used annually for gas-making, and
of this quantity about one fourth is used in London— one
company that lights the larger portion of London north of the
Thames purchasing more than two million tons. The total
annual income of the metropolitan gas companies amounts to
about four millions sterling ; and in London alone there are
more than 2,000 miles of gas-pipes.
The first thing to arrange in a gasworks is an easy means of
transit for the purpose of getting the coals to the store ; and the
means of transit varies according to the extent of the operations.
Where the works are very large, it is necessary to make provision
for the simultaneous unloading of several large steam vessels ;
whilst in small country works all the coal is brought by cart and
shot in the yard close to the retort-house. Indeed, the details of
this matter depend so largely on local circumstances that further
reference to it here would be superfluous.
Bituminous coal is best for gas-making purposes ; caking
cherry, and splint coals are of this character. Suitable coal is
found in many places in the United Kingdom, but most abun-
dantly in Northumberland, Durham, Yorkshire, and Lancashire.
10
PRACTICAL GAS-FITTING.
The products obtained in the manufacture of coal gas are the
illuminating gas, the coke which remains in the retort after the
gas is driven off, the ammoniacal liquor, and the tar. With
regard to the quantities of such products obtainable from a ton of
coal, it is difficult to give an exact statement, as the amounts are
influenced by numerous considerations, such as the character of
the coal, the temperature at which it has been distilled, etc.
Common coals are usually classed as those which give on distilla-
tion a volume of gas of 9,800 cub. ft. to 11,000 cub. ft. per ton,
the illuminating power of the gas ranging from 14 candles to 17£
candles, and cannel coals as those yielding from 10,000 cub. ft.
to 15,000 cub. ft. of gas per ton, of an illuminating power
ranging from 20 candles to 45 candles or 50 candles. Owing
to the numerous varieties of common coal and cannel in the
market, it is almost impossible to give an average yield of
the products obtainable from each description, but the following
figures from Newbigging's "Gas Managers' Handbook" will
afford some indication of the different amounts. Wigan cannel
and common coal yield on an average per ton :—
Cannel. Common Coal.
™* • 10,900 cubic ft. ... 9.980 cub. ft.
Illuminating power 24 sperm candles... 15 candles
£ oke 14 36 cwt. ... 15-17 cwt.'
| ar 17 gallons ... 11 gallons.
Ammoniacal liquor 18 gallons ... 20 gallons.
Newcastle coal yields on an average per ton :—
jjf S 9,700 cub. ft.
Illuminating power 15 sperm can dl es .
~ oke 15-40 cwt.
Tar ••••• 9 gallons.
Ammoniacal liquor 10 gallons.
Of course, some of the rich Scotch cannels would yield more gas
and of a richer quality than Wigan cannel ; for example Thor-
burn coal yields 13,120 cub. ft. of gas per ton, of an illumi-
nating power of 36 candles. In practice it has been found that a
ton of ordinary Newcastle coal yields roughly :— Gas, 10 000 cub
ft. ; coke, 13 cwt.. ,to ' 14 cwt.; tar, 10 gal. to 12 gal. ; virgin
ammoniacal liquor, 16 gal. to 18 gal. The richest and finest gas
coal is brittle and friable. It has a greyish-black, shiny, resinous
MANUFACTURE OF GOAL GAS.
11
lustre, and is made up of laminations or layers of varying thick-
nesses. The common coals are practically a mixture consisting of
two descriptions of coal. The first is a bright glistening material,
somewhat resembling black glass, and having in the thicker
lamination a cross fracture that is more or less cubical. The
second variety is of a duller appearance, somewhat resembling
charcoal. The relative proportions of the glassy coal,- which is
known as jet coal, and of the duller variety, which is called smut
coal, determine the character of the bulk. Evidences of smut
are to be found in every laminated coal, and traces of it may also
be found in cannel. The bright coal is much richer in hydrogen
than the smut coal, and contains less ash. Very hard coals are
built up of alternate laminations of bright coal and of charcoal.
The finest caking coals do not contain more than 2 per cent,
of ash, which should be light, similar in' structure to the ash
obtained from wood, and varying in colour from white to a brick-
red. In the term cannel are included all hard, non-laminated
coals having a homogeneous character. When they give a flaky
fracture and have an earthy appearance, they are known as shales.
The richer classes of cannel are dull and brown, the poorer or
secondary cannels are generally bright and black, and the poorest
description are generally dull and black.
Cannel coal is used principally in gas manufacture to enrich
common coal, so as to bring up the illuminating power of the gas
produced from the latter description of coal to the necessary
degree. For instance, London gas must have an illuminating
power of not less than sixteen candles when tried at the testing
station, and this requirement implies that the gas leaving the
works must have an illumination power of not less than
seventeen candles ; and as the Newcastle coal from which the
bulk of London gas is made will only produce gas having a
power of from fifteen to fifteen and a half candles, the coal must
be enriched by some means, of which the use of cannel is one.
Modern substitutes for the use of cannel are— the mixing of the
gas made from common coal with a certain proportion of rich gas
made from oil, the method of effecting this being by the adoption
of the Peebles process of gas-making, invented by Mr. Young of
Clippens (the oils employed should be of a specific gravity of 850
to 890, and they are vaporised by the heat of steam in a
carburetter ; or oil gas can be made in special iron retorts and
then mixed with coal gas) ; by mixing a certain proportion of
12
PRACTICAL GAS-FITTING.
carburetted water gas with the coal gas ; or by the adoption of
the Maxim-Clarke system, which consists in impregnating gas
with the vapour of certain volatile hydrocarbons, such as
carburine or benzol. The method which is most commonly
adopted in English gasworks, in order to enrich gas otherwise
than by means of cannel, consists in mixing the gas produced
from common coal with a certain proportion of carburetted water
gas. Water gas is produced by passing steam over red-hot coke,
the result of the decomposition of the steam being a mixture of
carbon monoxide (CO) and hydrogen, and theoretically there
should be obtained equal volumes of the two gases, but in
practice this result is not obtained, there being always present
a certain amount of carbon dioxide (C0 2 ). The following equa-
tion shows the reactions involved :—
2 H 2 0 (in the form of steam) + 2 C (coke) = H 4 + 2 CO.
Cannel coal is also useful in an emergency, as when the
holders are suddenly found low, as it gives off its gas in much
less time than ordinary coal.
True cannel coal does not cake, but yields on distillation a
residue similar (with the exception of some cracks and fissures) to
the original material. These cracks, however, indicate the lami-
nated structure, which was not visible in the original cannel. The
amount of ash from cannel is greater than that from coking
coals, and often shows the laminated structure more clearly than
the coke. As compared with coking coals, cannels yield tar of a
lighter specific gravity, and more of it. Although the physical
difference between common coal and cannel is well marked, the
chemical difference is not so apparent, certain cannels having pre-
cisely the same elementary composition as some coking coals. As
a rule the sulphur and the carbonic acid impurities are lower in
cannel than in coking coals.
Coal analysis embraces the determination of moisture, ash,
sulphur, volatile matter and coke, and in order to effect such
determination the apparatus required would be : a balance with
weights, watch-glasses and clip, platinum crucible, and water-
oven. The balance is used for weighing out the coal to be
operated on, and consists essentially of a rigid beam suspended
near to and slightly above its centre of gravity. Suspended frqm
each end of the beam, and equidistant from its centre, are the scale-
pans. In order to diminish the friction at the points of suspension
the beam is provided with an agate knife-edge which works on an
MANUFACTURE OF GOAL GAS.
13
agate plane, the scale-pans being similarly suspended. The beam
of the balance is supported by a rest when not in use, and is
raised from its support by a milled-head disc. It is provided
with a pointer and an ivory scale for the purpose of indicating the
movements of the beam. The object to be weighed is placed in
the pan on the left-hand side of the balance, the weights occupying
the opposite pan. The watch-glasses and clip are employed for the
purpose of holding substances whilst weighing out for analysis,
and in the case of coal analysis they serve to hold the coal in the
experiment for the determination of moisture ; 100 grs. of coal
are weighed out into the two watch-glasses, the coal and glasses
are then placed in the water-oven, and weighed at intervals.
While weighing, the glass containing coal is covered by the other,
and the two are placed between clips to prevent contact with air.
The water-oven in which the coal is dried consists of a
copper vessel having, with the exception of the door, a double
casing. When in use, the casing of the oven is filled to about
three-fourths of its height with water. Heat is then applied by
means of a Bunsen burner, so that when the water boils the
upper part of the hollow casing becomes filled with steam, and
the interior of the oven attains a temperature of 212° F., which is
constantly maintained ; a gentle stream of air then passes through
the oven, drying the substance in the interior.
The platinum crucible is employed in the first place for
determining the amount of volatile matter, coke, and ash in
the coal. To determine the volatile matter and coke, about 2 grs.
of the finely powdered coal is spread out in an even layer on the
bottom of a weighed platinum crucible. The latter is covered
with a lid and placed on a pipeclay triangle over a Bunsen
burner. The gases issuing from beneath the lid take fire, and
the heat is continued for one minute longer than the gas flame
lasts. Then the Bunsen burner is removed, and the crucible is
allowed to cool, and, when cold, is weighed without the lid. The
weight obtained will represent the coke, and this subtracted from
the weight of the coal originally taken will give the volatile matter.
To determine the amount of ash, from 3 grs. to 5 grs. of coal is
placed in a shallow layer in an open platinum crucible, and heated
by a Bunsen burner until all carbonaceous matter is consumed.
The platinum crucible is also employed in the determination
of sulphur in the coal. In the first place about 10 grs. of coal is
mixed with a suitable fusion mixture and heated in the platinum
14
PRACTICAL GAS-FITTING.
crucible; when all carbon has been consumd, the mass is allowed
to cool, and when cold is extracted with distilled water. The
solution is then acidified with HC1 (hydrochloric acid), and
boiled, and the sulphuric acid is precipitated with barium
chloride, filtered, and washed : the precipitate is then placed in
the platinum crucible and ignited, and when cold is weighed.
From the weight of BaS0 4 (barium sulphate) is obtained the
amount of sulphur in the coal.
The first process in the manufacture of coal gas consists in
subjecting bituminous coal or cannel to the action of heat in a
closed vessel termed a retort. The operation is chemical, and is
known as destructive distillation, but in gasworks language is
spoken of usually as carbonisation. The effects of heat on coal
under the conditions mentioned are that the elementary com-
ponents of the coal are split up, and rearrange themselves to form
a large number of new bodies, which make up the gas, coke, tar,
and other products evolved during the process of carbonisation!
The retorts in which the coal is placed are usually made of fire-
clay, to enable them to withstand the high temperatures to which
they are subjected. The internal dimensions of retorts vary from
about 16 in. to 22 in. wide, 13 in. to 16 in. high, and from 9 ft. to
10 ft. long, the thickness of the vessel being 3 in. in the body and
4 in. at the mouth. Retorts are made of various shapes in cross-
section, the principal being round, oval, and, commonest of all,
D-shape. They are set horizontally in groups in a series of fire-
brick arches, termed benches, and are heated by a furnace and a
series of flues connected to a main flue and chimney. The
number of retorts placed in the arches varies from two to nine or
more, according to the size of the works. (Fig. 1 shows a section
of a retort setting) At each end of the retort is a cast-iron
mouthpiece with door b, sealed by a mixture of soap ash, or
clay and ashes, or by the self-sealing lid described on p. 19;
this lid is made by the jointing of two turned faces pressed
closely together by a cross-bar and cam, and has an outlet pipe
D on the upper side, through which the gas travels. The retort
when hot enough is filled by scoops, as described on p. 23, with about
3 cwt. of coal, which is laid in a fairly even layer over the lower
surface ; the door is then tightly closed, and the gases can escape
only by the rising pipe on top of the mouthpiece, the coal being
usually allowed to remain for six hours in the retorts. Seven is
the number of retorts generally grouped together in retort house
MANUFACTURE OF GOAL GAS.
15
in medium-sized works on the ground-floor principle, where the
furnace is on the same level as the floor from which the retorts
are charged ; while, in stage-floor houses provided with a coke
hole below the charging floor, it is usual to place the furnace in
the coke-hole, which has the effect of providing room for nine
retorts or more. A group of retorts disposed as described is
known as a bed or setting of retorts, while a continuous line of
arches containing settings is known as a bench.
Fig. 1. — Section of Retort Fetling.
Fig. 2 represents an outline sketch of a stage retort house. The
building is 70 ft. wide between the walls, which leaves a space of
25 ft. on each side between the walls of the house and the front
of the settings, which are 20 ft. "throughs" (described on p. 18).
The coal stores on each side are 15 ft. wide. The charging-stage
is 10 ft. above the coke-hole floor, which is paved with bricks on
16
PEAGTIGAL GAS-FITTING.
edge on a layer of concrete 12 in. thick. The depth of the
foundation of the walls will depend on the bottom met with.
The roof is formed as shown, each principal being 8 ft. 6 in. from
centre to centre. The stage is constructed of wrought-iron
girders, built into the wall of the house and into the division
wall, off-setting and resting on a column, as shown. The main
girders are 16 in. deep, placed about 10 ft. from centre to centre,
and the floor is constructed of cast-iron flanged plates, bolted
together. The columns supporting the girders are 9 in. diameter
at the bottom, tapering to 7 in. at the top, and of J in. metal.
The railway is supported by girders resting on columns, as
Fig. 2.— Stage Retort House.
shown. The height from the charging-floor to the wall-plate is
40 ft.
Fig. 3 shows a sectional elevation, and Fig. 4 a longitudinal
section, of eight single retorts heated by a regenerator furnace.
The retorts are 22 in. by 16 in., and 10 ft, long. The producer a is
provided with upper and lower doors, the upper being the
charging door and the lower the clinkering door. In the arch of
the producer a number of small openings are formed as shown,
through which the combustible gases pass to the combustion
chamber. Placed on each side of the outer part of the producer
is the regenerator b ; the direction of the air and gas is
vertical in both cases, the spent gases descending through the
MANUFACTURE OF GOAL GAB.
17
centre chamber, while the secondary air ascends on each side of
the spent gas chamber ; the two air passages join at the top end
of the regenerator to meet the issuing combustible gases from the
producer. The products of combustion travel over and around
the middle and top retorts, then descend and travel under the
bottom retorts, finally entering the regenerator, whence they pass
to the main flue, heating the secondary air in their course. The
air necessary for the production of the combustible gases, and
known as the primary air, is heated by one or more of the lower
passages before entering the producer. The scientific principles
involved are as follows :— On filling the producer a with coke,
and drawing in a regulated amount of air, the carbon of the fuel
combines with the oxygen of the air to form carbon dioxide (C0 3 ),
the position where this chemical action takes place being known
as the zone of combustion. The CO., loses some of its oxygen
whilst passing upwards through the thick mass of fuel contained
in the producer, and becomes carbon monoxide or carbonic oxide
(CO) —thus, CO, + C = 2CO. The carbonic oxide, which is a com-
bustible gas, attains a temperature of about 2,000° F. in the
producer, and passes out through the openings in the producer
arch into the combustion chamber. At the point where it
emerges from the producer, it meets the heated secondary air,
which has been raised to a temperature of about 1,800° F. by
passing through the generator b as previously explained, the
result being that the carbon monoxide is again burnt to carbon
dioxide-thus, CO + O, = CO, -the resulting products of com-
bustion giving out a heat of about 2,500° F. The products of
combustion then travel through the setting, giving out heat to
the retorts in their passage, and finally enter the regenerators at
a temperature of about 1,900° F.
The retorts are heated either by a furnace immediately under
them on the open-grate system, or by a producer into which only a
small portion of the oxygen of the air is allowed to enter. In the
latter system, the oxygen, combining with the carbon, forms,
as already explained aboVe, carbon monoxide, and a further
portion of air, previously warmed by the waste gases as they
leave the setting, is arranged to enter and mix with the carbon
monoxide and form carbon dioxide immediately under the lower
retorts ; and thus the greatest amount of heat is obtained where
it is required, and not, as in the open-grate system, in the furnace.
Dr. Siemens was the first to recommend this arrangement, which
B
18
PRACTICAL GAS-FITTING.
is the same in principle as the furnaces in use for smelting
iron.
The benches of retorts are usually made double— that is, back
to back, and frequently the retorts are continuous for a length of
from 18 ft, to 22 ft., having a mouthpiece at each end. The
retorts are then known as "through," in distinction to the
Fig, 3.— Sectional Elevation of Eight Single Retorts.
" singles," which have only one mouthpiece, their back ends being
closed. With the exception of this community of retorts, the
settings are distinct, aud have separate flues and furnaces. An
iron mouthpiece, bolted on to the clay mouthpiece of each retort,
projects out about 16 in. from the front of the setting, and serves
to support the lid that shuts off the retort from the atmosphere
during the operation of drawing and charging. There are two
MANUFACTURE OF GOAL GAS.
19
descriptions of lids employed in gasworks : one is of plate-iron,
and is made tight by means of a luting composed of spent lime
and clay, the lid being screwed against the face of the mouth-
piece. But, in modern works, self-sealing lids are employed ;
these have the rim faced and planed, the mouthpiece being
similarly treated ; the lid swings round on a swivel hinge, and is
Fig. 4. — Longitudinal Section of Eight Single Eetorts.
made tight against the mouthpiece by means of an eccentric lever.
The mouthpiece is provided with an opening into which fits an
upright pipe, known as the ascension pipe, which is connected to
the arch or saddle pipe, and the latter in turn to the dip pipe
which conducts the gas from the reto rt to the hydraulic main,
where it is prevented from returning to the retort.
20
PRACTICAL GAS-FITTING.
Figs. 5, 6, and 7 represent a setting of three retorts heated
on a modern system by means of a regenerative furnace ; the
system has been found to give good results in practical working.
The producer is placed inside the oven under the front of the
retorts, and is 2 ft. square inside by 3 ft. 6 in. deep. The waste-
gas flues forming the regenerator are four m number, and 9 in.
square ; they occupy the rest of the oven space, and extend 3 it.
outside the back of the oven, where they are earned to the
chimney by a cross flue. As shown in Fig. 5, the regenerator
is so arranged as to form three sets of flues, the top and bottom
sets being for the waste heat passing from the oven to the
chimney, and the middle set for the heated air. The air for the
hot-air flues is admitted at the back of the regenerator, and is
carried forward by two 4-in. fireclay pipes to nearly the front end
Fig. 5.— Longitudinal Section through Oven,
of the two centre air-flues. It goes back outside these pipes, but
still in the two centre flues, and returns to the front in the two
outside air-flues, entering the top of the producer by three ports
at each side. The combustible gases from the producer combine
with the heated air, and pass up the front portion of the retorts,
over a middle wall, down the back portion, and then enter the
upper set of flues, in which they travel forward and descend to
the lower set of flues, and thence to the main flue leading to
the chimney. The primary air is admitted at the door at which
the producer is cleaned out. Fig. 5 represents a longitudinal
section through the oven ; Fig. 6 is a horizontal section on the
line g H, Fig. 5 ; Fig. 7, a vertical section on the line J k,
Fig. 6. A denotes the air-flues, d d the floor line p flue, and w
waste heat.
It is necessary to test frequently the producer and flue gases
MANUFACTURE OF COAL GAS.
21
in order to ensure that the correct amount of primary and
secondary air is being admitted to the setting, otherwise there
will be a considerable waste of fuel. In the case of the producer
gases, an excess of primary air implies the production of carbonic
acid instead of carbonic oxide, and in the case of fine gases an
excess of secondary air implies a cooling of the setting, while a
deficiency denotes a waste of fuel due to carbonic oxide escaping
-a
Fig. 6. — Horizontal Section through Oven.
unconsumed. The theoretical composition of producer gas is 34 - 7
per cent, carbonic oxide, and 65'3 per cent, nitrogen, but this
result is never attained in practice, as hydrogen is always present,
due to the decomposition of the steam given off from the water
Fig. 7. — Vertical Section through Oven.
in the ash-pans, while the reduction of carbon dioxide CO L . (to
carbon monoxide CO) in the producer is never complete, with
the result that some C0 2 is always present in producer gas, but
it should never be allowed to exceed 6 per cent. The flue gases
should consist of COs and nitrogen, with from 1 to 2 per cent,
of oxygen. On no account should any CO escape.
±2
PRACTICAL GAS-FITTING.
High heats produce more gas of a poorer quality, and a
smaller quantity of tar of a high specific gravity, and, as the heat
is lowered, a smaller quantity of richer gas and a larger quantity
of lighter tar are obtained. High heats appear to break up the
combinations of hydrogen and carbon, the latter being deposited
on the sides of the retort in the form of scurf. When an organic
substance, such as bituminous coal, is distilled at a comparatively
low temperature, the carbon passes off accompanied by but little
hydrogen, liquid compounds of carbon and hydrogen being
formed in great abundance, and as a consequence plenty of tar
but little gas is obtained, the gas, however, being of a high
illuminating power. ' On gradually increasing the temper-
ature, however, the liquid hydrocarbon decreases, while
the gaseous products increase — that is, there is more gas
and less tar, the yield of gas increasing as the tempera-
ture increases, but the quality at the same time decreases.
The effects of temperature on the yield and quality of gas
have been very carefully investigated by Mr. L. T. Wright, F.C.S.,
and in a series of experiments conducted by him the following
results were obtained from four portions of the same coal when
distilled at temperatures which varied from a dull red heat to the
highest temperature obtainable in an iron retort :—
Temperature.
Cubic feet of gas
fer ton.
Illuminating
power
{candles).
Total, candles
'per ton.
1. Dull red
8,250
20-5
33,950
2. Hotter
9,693
178
34,510
3. „
10,821
16-7
36,140
4. Bright orange ...
] 2,006
15-6
37,460
The temperature of distillation greatly affects the tar pro-
duced both as regards quantity and quality, more especially
the latter. The quantity of tar obtainable from coal decreases
as the distillation temperature increases. When ordinary gas
coal is distilled at a temperature of about 800° F. the tar is
very thin, consists chiefly of hydrocarbon of the paraffin and
olefiant series, and contains but a very small proportion of
free carbon ; but if the temperature of distillation be raised, say
MANUFACTURE OF COAL GAS.
i>3
to about 1,700° F., the tar then becomes thick, and contains
much free carbon, while hydrocarbons of the benzine series take
the place of the paraffin and olefiant hydrocarbons. With regard
to the effect of temperature on the production of ammonia, it
would appear that at very low distillation temperatures the yield
of ammonia is low, and that a medium temperature produces the
greatest amount of the residual, very high temperatures reducing
the yield, as shown by Mr. L. T. Wright in the following way : —
Make per ton Yield of NH-^ Percentage by weight
(cubic feet). at per ton. of coal , as N H^.
11,620 7-411 0-331
10,162 7-894 0-352
9,431 7504 0-335
7,512 6-391 0-285
(iV// 3 = Ammonia.)
The impurities, carbonic acid, sulphuretted hydrogen, and
carbon bisulphide, are considerably increased in quality at high
temperatures, and the production of cyanogen, which must
now be looked upon as an important residual, is also very con-
siderably augmented when high heats are employed.
The operation of carbonising may now be described. It is con-
ducted somewhat as follows : — The charge of coal is placed in the
retorts either with shovels or with scoops, according to the size
of the works. In the London district the scoop is employed
exclusively. The scoops generally used are semicircular in cross
section ; they are made of the length of a " single " retort (shown
on pp. 15 and 16), and hold from 1 cwt. to 1| cwt. of coal. They are
furnished with a T-shaped handle, and are raised to the level of
the different tiers of retorts by a piece of round bar iron known
as a saddle, which is shaped in the centre to the curve of the
scoop. The scoop is laid lengthways on the charging floor and
filled with coal ; the handle is then raised by one man, while the
saddle is placed under the opposite end by two other men, who,
one on each side, raise it to the mouth of the retort, when the
saddle is removed and the scoop is propelled in and turned over
by the man at the handle, who is known as the scoop driver. It is
then withdrawn, refilled with coal, and again placed in the retort
and overturned, but this time on the opposite side of the retort,
so that the coal may lie in a thin even layer.
A retort usually holds 3 cwt. of coal, and is charged in from
40 to 50 seconds. The coal, having been deposited as described,
is next backed off the iron mouthpiece by the backing rake, and
24
PRACTICAL GAS-FITTING.
the iron door immediately closed, when the operation of gas-
making commences, and proceeds on an average for about six
hours, at the expiration of which time the coal will have given
off all the gas it is capable of yielding and have been converted
into coke. Ordinary bituminous coal is generally allowed to
remain in the retorts for six hours, and cannel coal for four
hours. As no air is allowed to get to the coal, the products
obtained are of the same weight as the coal. The hydrogen con-
tained in the coal is driven off by the action of the heat, and
passes off, combined with carbon, in various forms. Oxygen as
aqueous vapour, nitrogen as ammonia, sulphur as sulphuretted
hydrogen and also in the free state, C0 2 (carbon dioxide),
CS 2 (bisulphide of carbon), and nitrogen are also given off.
Sometimes slaked lime is mixed with the coal in the proportion
of J cwt. to the ton, for the purpose of acting on the impurities,
but it is very trying to the eyes of the stokers, and also spoils the
appearance of the coke
The next operation is to draw the charge in the following
manner : — The lever on the iron retort lid is first gently loosened,
while at the same time a piece of red-hot coke or ignited tarred
yarn is placed close to the edge of the lid in order to ignite the
gas remaining in the retort the instant the lid is opened. The
gas then burns away quietly ; whereas if the precaution mentioned
is not taken, and the lid is at once fully opened, cold air rushes in
and forms an explosive mixture with the gas, which shakes the
retort and is very detrimental to the setting generally. By means
of a long iron rake, the coke remaining in the retort is now with-
drawn either into iron barrows in which it is wheeled outside
the retort house to the coke heap, or, in the case of a stage-floor
retort house, it falls through an opening between the front of the
setting and the stage, into the coke-hole below, where it is
quenched with water. The retort is again ready for charging,
but before this is done it is necessary to see that the ascension
pipe at the junction with the iron mouthpiece is quite clear by
inserting a bent auger into the ascension pipe. With " through "
retorts, the operations described are performed simultaneously
by separate gangs of three men at each side of the retort
setting.
25
CHAPTER n.
COAL GAS FROM RETORT TO GAS-HOLDER.
The course of the gas from the retort to the outlet of the
governor may be thus described :— Leaving the retort, the gas
passes, by way of the iron mouthpiece, up the ascension pipe, along
the arch or saddle pipe, down the dip pipe into the hydraulic
main, bubbling through the liquid contained therein, with the
result that it is prevented from returning to the retort. The
crude gas as it leaves the retorts carries with it certain substances
which it is necessary to remove as soon as practicable ; these
consist of tarry matters (impure hydrocarbons), carbon dioxide,
sulphuretted hydrogen, ammonia, etc., as explained in the
previous chapter (p. 24). Now the first operation to which the
gas is subjected is that of cooling, which commences immediately
it leaves the retort, and in the act of cooling the vapours of
various hydrocarbons and water vapour condense into the liquid
form, hence the origin of the name condenser. The liquefied
hydrocarbon vapours constitute the well-known gas tar, and the
condensed water vapour, combining with the ammonia, carbonic
acid, sulphuretted hydrogen, etc., present in the crude gas con-
stitutes what is known as virgin ammoniacal liquor.
Fig. 8, p. 26, shows a hydraulic main with connections, A being
the ascension pipe leading from the mouthpiece, B the arch saddle-
pipe, c the dip pipe, and d the hydraulic main, which is supported
on a w r rought-iron girder spanning the retort setting, and is pro-
vided with a weir valve e for regulating the level of liquor. The
object of the hydraulic main is to prevent the gas from passing
back to the retort when the doors are opened for drawing and
charging, whilst at the same time the gas can freely escape during
the time gas-making is proceeding ; in other words, the hydraulic
main, in conjunction with the dip pipe, forms a self-acting
hydraulic seal. This result is obtained by filling the main to a
certain level with water and then causing the dip pipe c to dip
a short distance (say a couple of inches) into the liquid. The
gas, on coming from the retort, has to force its way, therefore,
26
PRACTIGA L OA 8-FI TTING.
through this light seal, but, having once passed the seal, it is
prevented from returning by reason of the large amount of liquid
contained in the hydraulic main, which in practical working is
made of such a width in proportion to the area of the dip pipes
and their distances apart as to provide sufficient liquid for
sealing them against the maximum back pressure that can reach
them.
Fig. 8.— "Hydraulic Main and Connections.
In Fig. 1, p. 15, the rising pipe is bent over until it looks
downward, and enters a trough-shaped pipe of much larger
dimensions, termed a hydraulic main, e ; this contains water
which is kept at a level rather above the bottom of the entering
or dip pipe. This arrangement is made so that when the door of
the mouthpiece is opened the gas may not find its way back
down the rising pipe. The pipe leading from the retort setting,
GOAL GAS FROM RETORT TO GAS-HOLDER. 27
shown on Fig. 1, p. 15, and finishing at x, would be joined to
the pipe shown on Fig. 10, p. 29, at the point marked x. As
soon as the gas enters the hydraulic main a considerable amount
of cooling takes place, thus causing a quantity of tarry matters
and other condensable substances to be deposited, these finding
their way by gravitation to the tar well.
A section of the hydraulic main and dip pipe drawn to a
larger scale is shown in Fig. 9, a being the dip pipe, b the
interior of the hydraulic main, c the take-off pipe, and d the weir
valve. The apparatus is constructed of wrought-iron or mild
Fig. 9.— Section of Hydraulic Main and Dip Pipe.
steel plate <\. in. thick, attached by 3-in. by 3-in. by § -in. angle
irons. The cover is of cast-iron, as are also the dip pipe and
take-off, the former being 5 in. in diameter. The apparatus is
22 in. wide ; the object to be kept in view when designing a main
being, as explained on the previous page, to seal the dip pipes
agunst back pressure.
In modern gasworks the hydraulic main is divided into
separate lengths, corresponding to either one or two settings of
retorts, each section being furnished with a separate valve, and
connected by a take-off pipe to a gas main on the top of the retort
bench, running behind and parallel to the hydraulic main, the
take-off pipe which conveys the gas from the hydraulic main to
the gas main being provided with a weir valve for regulating the
level of the liquid in the main, so as to give the requisite amount
of seal as shown in Fig. 9. The dip pipe usually dips for a
28
PRA GTIGAL G AS-FITTING.
distance of about 2 in. in the liquid in the hydraulic main, so
that after the gas has once forced this small amount of seal, it is
prevented from returning down either its own or other ascension
pipes when the mouthpieces are opened during the period when
the retorts are drawn and charged. Leaving the hydraulic main
at a temperature of about 150° F., the gas next enters the con-
densing plan*, where its temperature is reduced to about 60° F.,
and the remainder of the tarry bodies are eliminated, together
with considerable quantities of weak ammoniacal liquor.
The chief impurities in crude coal gas, for which qualita-
tive tests are required— namely, ammonia (NH 3 ), sulphuretted
hydrogen (SH 2 ), and carbon dioxide, commonly known as car-
bonic acid (CO 2 )— are detected by the following methods :—
The presence of ammonia is shown by its action on a moistened
turmeric paper or a reddened litmus paper. Turmeric papers are
prepared by soaking strips of filter or blotting paper in an
alcoholic solution of turmeric, made by digesting powdered
turmeric root in the liquid. They are allowed to dry, are cut
into strips, and are then ready for use, but must be kept in a
dark place. Turmeric papers thus prepared are of a full yellow
colour, which in the presence of ammonia changes to a brownish
tint, and sometimes to a deep crimson colour, according to the
quantity of ammonia present. The papers should be moistened
before use. A more sensitive test for ammonia is that of the
reddened litmus paper (glazed), which turns blue under the
action of ammonia.
Sulphuretted hydrogen is detected by causing a current of gas
to play on a piece of white paper previously dipped in a solution
of acetate of lead or nitrate of silver. The presence of sul-
phuretted hydrogen is shown by the paper changing to a
brownish black colour, due to the formation of lead or silver
sulphide, according to the reagent employed. Carbonic acid is
detected by causing a current of gas to bubble into lime or baryta
water, a white precipitate of calcium or barium carbonate being
formed if COo is present in the gas. Lime water is the solution
most commonly employed, and is prepared for use by placing
about 4 oz. of caustic lime in a quart bottle, filling up with
distilled water to dissolve the lime, and shaking the bottle
occasionally to assist the operation. When the water has taken
up as much of the lime as it is capable of dissolving, the excess
of lime is allowed to settle, and the clear liquid is transferred
GOAL GAS FROM RETORT TO GAS-HOLDER. 29
to another bottle, which must always be kept tightly corked
to prevent the acces3 of CO- 2 from the atmosphere. In order to
make a test, about 1 oz. of the lime water is placed in a test
o
tube or small bottle, and the
gas bubbled slowly through it
by means of a glass tube hav-
ing a very fine opening, this
latter tube being connected to
the gas supply by a piece of
indiarubber tubing. In prac-
tice, if a precipitate does not
form within the space of three
minutes, it is assumed that the
gas is free from C0 2 . If sul-
phuretted hydrogen is also
present in the gas being tested,
it will be necessary to interpose
a small oxide purifier, so as to
prevent any sulphuretted hy-
drogen entering the lime water,
since the presence of the latter
gas would vitiate the test.
The temperature of the gas
in the hydraulic main is usually
about 120° to 130° F., and this
must be reduced to atmos-
pheric temperature by means
of condensers (Fig. 10). These
are of many kinds, but may be divided into two classes —
namely, air condensers and water condensers.
30
PRACTICAL GAS-FITTING.
The gas is thus brought into a suitable condition for the
after process of purification. The tarry bodies and other sub-
stances thus eliminated would, if not removed at an early-
stage in the manufacture, clog up the purifying apparatus.
Condensation commences immediately the gas leaves the retorts,
with the result that water vapour and the vapours of various
hydro-carbons condense into liquids, producing what is commonly
known as tar, and a weak, impure solution of ammonia,
known as virgin ammoniacal liquor, due to the absorption of
ammonia, sulphuretted hydrogen, carbonic acid, and hydrocyanic
acid, by the liquefied aqueous vapour. These liquids collect in
the hydraulic main, where a very considerable amount of cooling
takes place, since, by the time the gas reaches the outlet of the
hydraulic main, it will have deposited from one-third to one-half
of its condensable constituents, and have been reduced in temper-
ature from, say, 2000° F. in the retort to from 150° F. to 110° F.
at the outlet of the hydraulic main. The remaining portion of
the work of condensation is next effected in the condenser proper,
the apparatus being usually placed between the retort house and
the exhauster. In some works the gas passes through a length of
main running round the retort house, and known as the foul main,
before it enters the condensers. The air condensers embrace the
vertical, the annular, the horizontal, and the battery, while the
pi'incipal water condensers are those of Morris and Cutler, and
Livesey. The action of these different forms of air condensers is
practically the same, the principle on which they act being that
they transmit the heat from the gas passing through them to
the external air in contact with their outer surface, with the
result that the gas and vapours are cooled, and the condensable
vapours deposited.
As a familiar instance of the process of air condensation, take
the simplest form of the apparatus, namely, the ordinary vertical
condenser, which consists of a series of vertical pipes attached to
a cast-iron chest or receiver at the bottom, and connected in pairs
by semicircular bends at the top. The cast-iron chest is provided
with a series of mid-feathers, which dip to a certain depth in
liquid, forming a seal, so that the gas is caused to pass up one
pipe and down the next right along the series ; the condensed
products are deposited in the chest, whence they flow by a sealed
overflow to the tar well. The battery condenser possesses one or
two features that render it a more efficient apparatus than the
GOAL GAS FROM RETORT TO GAS-HOLDER. 31
other types of air condensers— namely, that the gas is subjected to
more friction than is possible with the small amount of " skin "
contact which it undergoes in the ordinary form of apparatus ;
and as a certain proportion of the tar exists in the form of little
vesicles or bubbles, it is necessary, before all the tar can be elimi-
nated from the gas, that they should be broken up by some
means such as the battery condenser affords. The apparatus
consists of an oblong vessel of from 1 ft. to 2 ft. wide, 12 ft. to
18 ft. high, and of varying length. It is divided in the inside by
a series of mid-feathers placed at distances apart equal to the
width of the apparatus ; the mid-feathers extend to within a few
inches of the top and bottom of the chest alternately, the
gas passing from the inlet up and down each division to the
outlet. In order to increase its condensing power, a series of
small tubes of about 2 in. in diameter pass from side to side of the
vessel. These tubes are open to the atmosphere, so that the air is
capable of circulating freely through them ; this helps to cool the
gas, and further serves to break up the tarry particles as before
described. The water condenser is regarded by many eminent
authorities upon gas manufacture as being much superior to the
air condenser, inasmuch as it admits of easy regulation, while the
cooling agent (water) is much more powerful than air, since water
has a far greater power of absorbing heat than air has. As a type
of the water condenser, the Livesey may be mentioned. In the
Livesey condenser the gas passes through a series of pipes placed
in a tank of water divided into separate channels, with the water
flowing in an opposite direction from the gas, the cool water
entering the apparatus at the gas outlet end, and getting gradually
warmer as it approaches the gas inlet. According to the amount
of water admitted, so will the temperature of the gas be raised or
lowered.
On leaving the condensers, the gas is put through the
exhauster (Fig. 11, p. 29), which is a kind of rotary fan or
pump employed in order to overcome the resistance offered to
the passage of the gas on its way from the retorts to the gas-
holder. The whole of the apparatus through which the gas has
to pass offers a certain amount of resistance ; the seal of the dip
pipes, the friction of the condensers, the seal of the washer, the
filling material of the scrubber, the rotating bundles of the
washer-scrubber, the materials in the purifier, the measuring
wheel of the meter, and finally the weight of the gas-holder, all
32
PRACTICAL GAS-FITTING.
exercise an amount of back pressure as it is termed, and the
combined resistance of the whole apparatus is sometimes very
great, so that if means were not taken to overcome this, the whole
of the gas would not find its way to the gas-holder, but a great
portion of it would pass through the porous walls of the retort
and be burnt in the furnace. The exhauster overcomes or
neutralises the resistance of the seal of the hydraulic main, and
causes a partial vacuum in all the pipes in the retort-house and
condenser. On the outlet of the exhauster, however, a pressure
is given sometimes equal to 42 in. head of water, or a little under
2 lb. per square inch ; this is required to force the gas through
the remaining purifying apparatus, and to fill up the holders.
Another reason for employing the exhauster is that its use lessens
the deposition of carbon on the walls of the retort. When gas
passes over hot surfaces under such a pressure as results when
an exhauster is not employed, it is partially decomposed, and the
carbon thus set free settles on the retort in the familiar form of
carbon or scurf, which takes up retort space and entails a waste
of fuel, in addition to impoverishing the quality of the gas. The
exhauster is usually turned either directly from the axle of a
steam engine, or, in some small works, by a gas engine, the tarry
matters remaining in the gas serving as lubricants to the fans. ]
The next step is to arrest the remaining tarry vapours and
some of the ammoniacal liquor. This is done by means of tar-
extractors or washers ; in these the gas is made to pass through
inverted troughs with serrated edges just below the level of weak
ammoniacal liquor, which causes the latter to bubble up and
expose a large surface to the gas. The reason of the use of weak
ammoniacal liquor, instead of clean water, is the affinity it has
for carbon dioxide, sulphuretted hydrogen, and other sulphur
compounds, and the fact that the liquor is brought up to the
requisite commercial strength.
Scrubbers are of many kinds, but in all the patterns the gas
is made to pass in finely divided streams between wetted surfaces.
This is done by the scrubber shown at Fig. 12, p. 29, which is a
cylindrical vessel on end, in which layers of thin boards are
placed on edge with small spaces between, and are set to cross
one another. Water is distributed from the top over the boards,
and trickles down their sides ; while the gas, entering at the
bottom, is broken up into finely divided streams, and thus a
large surface is exposed to the wetted faces of the boards. An
GOAL GAS FROM BE TOUT TO GAS-HOLDER. 33
overflow, suitably trapped, is provided at the bottom to carry off
the ammoniacal liquor to wells generally built underground.
The most common form of scrubber is that known as the
tower, so called because it is frequently of a considerable height.
A pair of such scrubbers is shown in Fig. 13. They are cylindrical
in shape, and are constructed of cast-iron plates, with faced or
caulked flanges, the plates varying from 6 ft. to 20 ft. in diameter ;
they are put together in sections, attaining a height of from 20 ft.
to 80ft. The plates are from fin. to 1 in. in thickness, with
mouldings as shown. Strong cast-iron brackets are fixed at the
Fig. 13. — Pair of Tower Scrubbers.
top for the purpose of supporting a circular gallery, which con-
nects the scrubbers together, two or more being usually so con-
nected. E.ich scrubber is provided with a penthouse, which
contains the water-distributing machinery, to which ready access
is obtained by a spiral staircase. In the interior of the scrubber
is a series of iron grids, on which are placed various materials,
usually coke, but sometimes thin boards set on edge. The gas
enters the scrubber at the bottom, and leaves it at the top
through a pipe which occupies the centre of the apparatus. The
action of the apparatus is as follows : — The gas enters at the
bottom, as previously stated, and a fine stream of water or
ammoniacal liquor descends from the top, and in its course,
having to descend through the material in the vessel, thoroughly
c
34
PRACTICAL GAS-FITTING.
wets it, with the result that the ascending gas is deprived of its
ammonia. The resulting ammoniacal liquor collects at the
bottom and passes away through a seal pipe sealed in a seal pot
to the liquor well. The usual practice is to work two scrubbers
in series, the first one being supplied with weak liquor from the
hydraulic main and condensers, and the liquor resulting from the
other scrubber, which is supplied with clean water. By making
scrubbers in this way the liquor is concentrated and the absorp-
tive power of virgin ammoniacal liquor for the impurities
SH 2 + C0 2 is fully utilised, while the gas, coming in contact
finally with clean water, is rendered quite free from ammonia.
Another type of scrubber is shown in section by Fig. 14, and
is called (after the inventor, Mr. George Anderson) Anderson's
brush scrubber. The apparatus consists of a rectangular cast-
iron vessel, 4 ft. by 10 ft. inside, and about 24 ft. high, standing
upon end, divided into a series of shallow pans or tanks contain-
ing ammoniacal liquor. These tanks are arranged one above the
other, each one being provided with a drum, which revolves
within the tank, the circumference of the drum being fitted with
a brush of whalebone or other suitable material. The brush
drums are made to exactly fit their respective chambers, while
their lower side dips into the liquor contained in the tanks.
Motion is given to the drums from the outside by means of a
vertical shaft and gearing actuated by a line-shaft and worm-
wheel, and each drum revolves in the contrary direction to that in
which the gas is passing. Hand-holes are provided in the side of
the vessel for the examination or replacement of the brushes as
they wear out. The apparatus is usually combined with one of
Anderson's washers, and stands on the last-named apparatus. The
direction taken by the gas is shown by the arrows— on first enter-
ing the Avasher at a (Fig. 14), it comes in contact with the serrated
edges on the underside of the first horizontal plate ; it rises at the
end and returns among similar serrations in the plate depending
from the cover, and thence" passes up into the first compartment
Containing the brushes. The washer is charged with weak
ammoniacal liquor, and the passage of the gas through the liquor
causes an increase of pressure at the inlet as compared with the
outlet end, so that, according to the pressure at which it is
desired to work, the teeth at the inlet end are made proportion-
ately longer, in order that they may be parallel to the inclined
plane which the passage of the gas causes the water to assume.
GOAL GAS FROM RETORT TO GAS-HOLDER. 35
Means are provided for raising or lowering the water line, in
order to raise or lower the pressure according to requirements.
The gas on entering the scrubber proper passes about two-
thirds round the lower brush
and thence out at the opposite
end to that at which it entered,
and similarly with each of the
brushes, until finally it escapes
at the outlet b (Fig. 14). The flat
pipe communicating with the
several brush compartments ex-
tends nearly the whole length
of the brush, and is cast on a
portion of the outer case, with
the object of ensuring an equal
distribution of gas. Each com-
partment contains liquid to the
height of the pipe that brings
the gas from the compartment
below. Pure water is run into
the upper compartment, ulti-
mately finding its way down
the pipes up which the gas
passes, until it arrives in the
washer at the bottom. The
shafts of the several brushes
are provided with driving-gear,
so that the brushes move
in opposite directions, and
always in the reverse direction
to that in which the gas is
passing in any particular com-
partment. The efficiency of
the machine depends to a
great extent on the speed
at which the brushes re-
volve, but in practical
working from three to five
revolutions per minute will
ensure the removal of all the
NHs from the quantity of
ftp rir^r^^^ 1 *
Fiar. 14.
-Anderson's Scrubber
Washer.
and
PRACTICAL C AS-FITTING.
gas for which the machine is designed. The brushes by revolving
with their lower side dipping in liquid lift a quantity of
the latter in their fibres, through which the gas has to pass,
leaving a portion of its impurities, which is washed off by
the continuous revolution of the brush. The liquid in the several
compartments is therefore of different strengths, that at the
bottom being the strongest, whilst pure water is found at the top.
When purifying gas made by carbonising Newcastle coal, from
10 to 12 gallons of pure water are run in at the top of the appa-
ratus for every ton of coal carbonised, and the weak ammoniacal
liquor from the hydraulic main is poured into the sealed pipe in
the top of the washer. The merits that the inventor claims for
this over other types of scrubber are, that for the same quantity
Fi£. 15.— Washer-
Oerflow to scrubber.
Tar Tank
of gas to be purified the vessel can be made much smaller, that
the distance through which the gas has to travel is about double
for the same height, and that there is no risk of the gas failing
to come into intimate contact with the scrubbing liquid, the
result being the complete removal of the whole of the ammonia.
Another form of scrubber that has been very largely adopted
is called a " washer- scrubber " (Fig. 15). This is also a cylindrical
cast-iron vessel ; it is fixed horizontally, and divided into sections,
in which a series of discs or chambers containing wooden balls,
or other filling, is made to revolve slowly on a central shaft. The
liquid is at a different height in each chamber, but averages about
one-third up the discs, which are wetted as they rise from it,
whilst the gas passes between them and gives up its ammonia and
a portion of its other deleterious compounds. The clean water
entering at one end meets the gas that enters at the other,
GOAL GAS FliOM RETORT TO GAS-HOLDER. 37
through a space in the middle of the discs, and increases in
strength as it flows from one chamber to another, until it reaches
the desired amount, generally known as 10 oz. or 12 oz. ammo-
niacal liquor ; the gas passes on, and, meeting the cleaner water,
gives up in each compartment a portion of the ammonia, until
the latter is all eliminated.
The bulk of the carbon dioxide, sul- £L N
phuretted hydrogen, and bisulphide of
carbon, however, still remains in the gas,
and must be removed. This is most
effectually done by what are called
purifiers (Fig. 16). These are usually
rectangular boxes containing several
layers of wooden grids, on which the
purifying material is laid, and through
which the gas has to pass from the inlet
at the bottom to the outlet at the top.
In London, where the law requires that
the gas shall be in a high degree of
purity, no sulphuretted hydrogen what-
ever is allowed to be in the gas. Of
other sulphur compounds not more than
17 grains in 100 cubic feet of gas is
allowed in summer, and not more than
22 grains in 100 cubic feet of gas in
winter, while the maximum amount of
ammonia (NH ;! ) must not exceed 4 grains
per 100 cubic feet. It is therefore
necessary to carry the puri-
fication much further than
is considered sufficient in
other parts of the country.
Whether this great refine-
ment is necessary need per-
haps hardly be discussed
here ; suffice it to say that
the cost of removing the
impurities to such an extent
is considerably more to the consumer than would be the case
if only the same portion had to be taken away that is suffi-
cient in the country. In some country works only lime is
38
PRACTICAL GAS FITTING.
used for purification, and in others oxide of iron only is used.
Each of these can be made to remove what for all practical
purposes it is necessary to eliminate ; but where more than this
has to be done, it is usual to employ a combination of the two,
arranged in what may at first sight appear to be a rather peculiar
manner. To work this system successfully, eight purifiers are
required. In the first two, hydrated lime is used, and the gas in
passing through them gives up all the C0 2 that it contains ;
it then passes on to the next two vessels, which are filled with
hydrated oxide of iron, this material having a great affinity
for sulphuretted hydrogen, which it effectually removes. The
gas then passes through two more vessels containing lime, and
it is here that the peculiarity just mentioned occurs.
Hydrated oxide of calcium (lime), which has great affinity for
CGa (carbon dioxide), is useless for removing the sulphur com-
pounds, principally in the form of bisulphide of carbon ; but
hydrated oxide of calcium, which has been sulphided by means
of sulphuretted hydrogen, has this power, and therefore, in
preparing a set of purifiers for use, the gas is passed first through
the two purifiers containing the lime (CaO) for the removal of
the COo, and then through the two others, which also contain
lime. These latter take up and assimilate with themselves the
ELS, forming a sulphide of lime, which is then used in its proper
turn to remove the CS 2 ; but in doing so a certain quantity of
sulphuretted hydrogen is given off from the sulphided lime, and
to prevent this passing along with the gas two check purifiers are
used, filled with oxide of iron, or in some cases Weldon mud— a
substance containing a large proportion of oxide of manganese.
Below is a diagram explaining this. Gas contains C0 2 H 2 S, CSo.
Purifier
Purifier
Purifier
Purifier
containing
containing
containing
containing
lime re-
iron oxide
sulphided
iron oxide
moves CO.,
removes
lime re-
or Weldon
and some
remainder
moves
mud re-
H 2 S.
of TPS.
CS 2 .
moves IPS.
Gas contains
Gas contains
Gas contains
Gas clean.
H 2 S, GS S CSa. small quantity
TPS from lime.
GOAL GAS FROM EE TORT TO GAS-HOLDER. 39
All that now remains to be clone is for the gas to be measured,
which is done in an apparatus which is in all respects similar to
the wet meter found in many houses, but, of course, on a very-
much larger scale, as shown at Fig. 17, p. 37. An ordinary wet
meter is a drum of a known size, with partitions so arranged that
while the gas is entering one compartment it is being passed out
from that portion previously filled, a direct communication
between inlet and outlet never being possible. The revolution
of the drum causes certain wheels to turn, and pointers affixed
on it to indicate the number of revolutions made, thus showing
the quantity of gas passed through.
The station meter is employed to measure the gas made on a
gasworks, so as to enable the engineer to see that he is getting
the proper amount of gas from his coal ; it also serves to tell the
amount of leakage or unaccounted-for gas. The station governor
is employed for the purpose of controlling the pressure under
which gas is supplied at the works to the amount necessary for
the proper supply of the district and no more. The station meter
is shown in section in Fig. 18, p. 40; and consists of a round or
rectangular cast-iron outer case containing a cylindrical vessel of
tinned iron known as the drum, which revolves on a horizontal
shaft resting on suitable bearings. The drum is immersed to a
certain height in water contained in the outer case. The drum
varies in size according to the capacity of the meter, and is
divided by partitions into four longitudinal compartments
arranged somewhat after the fashion of the four blades of an
Archimedean screw. The inlet-end or unmeasured gas is isolated
from the outlet or measured gas, by the contrivance known as
the "spout and bottom cover," shown at v. Owing to the
manner in which the partitions that form the compartments or
chambers are arranged, there is not a clear way through the
drum, since the opening at one end of a measuring chamber is
above the water line at the same time that the corresponding-
opening at the other end is below it, so that two of the com-
partments are constantly above the water-line, the one filling
with gas and the other discharging. The openings at the ends
of the chambers through which the gas passes are known as
hoods. The action of the apparatus is briefly as follows:— The
gas enters at w through the spout above the level of the water,
and enters one of the measuring chambers, causing it to revolve.
As soon as the chamber is filled with gas, its inlet has passed
40
PRACTICAL GAS-F1TTIJSG.
beneath the water level by the revolution of the drum, with the
result that the gas is sealed up, while the inlet of the next
chamber rises at the same time above the water level, and thus
allows gas to enter. As soon as the inlet to each chamber is
sealed, a corresponding outlet slit that opens into the space
between the drum and the outer case is unsealed, and water
entering by the inlet forces the gas through the slit to the meter
outlet. Each chamber in rotation as it fills with gas turns the
drum round a quarter of a revolution, and expels the gas from
the chamber that has preceded it. The cubical space in each
Section of Station Meter.
chamber when out of the water and full of gas is known. Four
times this space represents the total capacity of the drum, or the
contents for one revolution. The shaft of the drum is . connected
to a train of wheels provided with pointers traversing the meter
dials, by which the number of revolutions made by the drum is
recorded and the amount of gas passed is registered. In order to
maintain the water in the meter at the proper level, a small
continuous supply of water is constantly admitted, a syphon
overflow pipe being provided to take off any excess.
The gas, not being required in all cases immediately it is
made, is stored in what are commonly known as gasometers, but
which are more correctly termed gas-holders (Fig. 19)~ These are
vessels made of thin sheet-iron, free to travel up or down in a
vertical direction as they are filled or emptied. They are worked
GOAL GAS FROM RETORT TO GAS-HOLDER, 41
n circular tanks, which, in small works, are the same depth as
the gas-holder is high ; but in large works the gas-holder is made
in two or more lengths, each smaller than the other, so that when
down they may telescope into one another. To prevent the gas
escaping, what are known as a "cup" and ".grip" are made, the
one at the bottom of each " lift," as each length is called, and the
other at the top of the next outer lift. The cup is formed so
that the lower end of the lift is bent outwards and up a certain
height all round, thus making it a concentric vessel, which, as it
rises from the water in the tank, takes up with it sufficient of the
latter to fill the cup. At the same time it engages with or
catches the grip of the next outer lift, which is made so that the
upper end is bent outward and downwards about the same depth
as the cup, thus, owing to the sealing of the grip in the water in
the cup, preventing the passage of the gas from the gas-holder to
the outer atmosphere.
Most gas-holder tanks of any size are made with what is
known as a dumpling in the middle ; this is shown at f (Fig. 19).
It is merely a certain quantity of the ground left in when the
remainder was being excavated, so as to save work and to lessen
the quantity of water required. Some also are made with con-
centric tanks, space for the lifts to fit in only being allowed
Fig. 19. — Gas-holder.
12
PRACTICAL GAS-FITTING.
Others, again, have cast-iron tanks when the ground is much
saturated, and these are generally placed above ground.
Fig. 20 gives a sectional elevation of an untrussed gas-holder
and puddle tank. The holder is telescopic and in three lifts ; the
tank is 230 ft. in diameter by 50 ft. 6 in. deep from bearing stones
to top of coping, and is built of brick set in Portland cement
mortar in the proportion of one part of cement to two of sand.
The sides and bottom of the tank are both puddled to the thick-
ness of the puddle behind, the side walls being 24 in., and on the
bottom 15 in. The holder when not inflated rests on a timber
framing, as shown in the illustration, the size of the timbers being
12 in. by 1 2 in. for the uprights and diagonals, and 13 in. by 7 in.
for the curved portion of the framing. The outer lift is 226 ft. in
diameter and 50 ft. deep ; middle lift, 223 ft. diameter and
50ft. 3 in. deep; inner lift, 220 ft. diameter and 50ft. 6 in. deep.
The crown has a rise of 15 ft., and is untrussed. The curb is
formed of f-in. plates, bent to a radius of 2 ft. 3 in., and is
strengthened by a plate-girder and gusset stays. The standards
are of the lattice-girder type, and are braced together by three
rows of girders, as shown, and by diagonal flat bars. The
thickness of the roof sheets is as follows : — Outer row, forming-
part of curb, f in. thick, of mild steel plates, 3 ft. wide ; next row,
No. 7 B.W.G., then follows another row of No. 9 b.w.g., the
remainder being all of No. 10 b.w.g., the latter being riveted
with x %-m. rivets of 1-in. pitch. The No. 7 b.w.g. sheets are
riveted to the 5-in. curb, plated by f-in. rivets 2s-in. pitch. The
side sheets are of No. 11 b.w.g., secured to each other with T %-in.
rivets, 1-in. pitch, lap of sheets U in. ; the bottom and the top row
of the sheets in the outer lift are i in. and T R g in. thick respectively,
in the middle lift j^in., and in the top lift fVin. and Jin.
respectively, being riveted to the other sheeting with |-in. rivets,
li-in. pitch, f-In. lap. Inlet and outlet pipes, 36 in. diameter.
A gas-holder throws a pressure varying acccording to its
weight and the area covered by it, but the pressure is nearly
always more than is required to be sent out on the district, and,
if delivered, would cause escapes at many of the fittings in the
consumers' houses otherwise, sufficiently sound. A governor is
therefore used ; it is in reality a small gas-holder, which rises and
falls according to the pressure of gas on the district, opening or
closing a valve, as may be desired, by means of a cone.
The station governor in its simplest form consists of a small
GOAL GAS FROM RETORT TO GAS-HOLDER, 43
cast-iron tank, which is tilled to a certain height with water, and
through the bottom of which the gas from the gas-holder enters by
a pipe provided at the top with a flanged seating. Surrounding
> : . ■ n
this inlet pipe is the outlet pipe, whose open end projects some
distance above the level of the water in the tank, the gas passing
to the street mains by way of the annular space between the two
pipes. The governor usually employed is shown in Fig. 21, p. 44,
and consists of a small cast-iron tank x, which is filled to a certain
44 PRACTICAL GAS-FITTING.
height with water. Firmly floating in the tank is a tinned iron
gas-holder y, having suspended from its crown a parabolic plug z.
The gas inlet pipe is in the centre of the tank, and is provided at
the top with a flanged seating that exactly fits the parabolic plug.
The outlet pipe is concentric to the inlet pipe, and rises some dis-
tance above the level of the water in the tank. The gas-holder is
balanced by means of an air chamber placed inside the vessel
round its lower curb, so that when the water in the tank is at its
proper level the holder rises, carrying with it the suspended para-
Fig. 21. — Station Meter Governor.
bolic plug ; and, supposing all the weights on the top of the holder
to be removed, the holder would ascend to its full limit, carrying
with it the suspended plug, which would ultimately fill the orifice
of the inlet pipe and consequently shut off the gas supply,
reducing the pressure in the shut mains to nil. Since a certain
pressure is always required, however, iron or leaden weights are
placed on the crown of the holder, equivalent to the pressure
needed to supply the district, so that the holder only ascends a
certain distance, while the suspended plug fills the orifice in the
inlet pipe to such an extent as will allow sufficient gas to pass and
give the outlet pressure required, which is rigidly maintained, no
matter what variations may take place in the amount of gas con-
sumed in the district ; for in the event, say, of a sudden demand
on the street maius owing to a fog, or to other causes that would
involve an increased consumption of gas, the pressure in the
COAL GAS FROM BE TOUT TO GAR-HOLDER. 45
mains would be reduced, and as the governor holder commu-
nicates by means of the outlet pipe with the shut mains, this
reduced pressure would cause the holder to descend ; in doing so,
the parabolic plug would also descend, and thereby increase the
valve opening and allow more gas to pass through, although not in
any way affecting the initial pressure, but only maintaining it at a
constant quantity. Similarly, should the consumption in the
district slacken, the gas-holder would rise and lift up the sus-
pended plug higher into its seating, thus reducing the gas -way and
equalising the pressure. Of course, the governor is not intended
to control the initial pressure which is required for supplying the
district ; this is regulated by adding or taking off weights from
the crown of the gas-holder.
16
CHAPTER IH.
GAS SUPPLY FROM GAS-HOLDER TO DOMESTIC METER.
Gas-fitting is not an exact science in which, for the guidance of
beginners, a complete code of undeviating rules and regula-
tions can be laid down. A gas-fitter requires to be something
more than a mere mechanic. He must be not only able and
willing to employ his hands in various forms of skilled labour,
but must also make use of his wits and exercise his ingenuity.
In these days of competition, brainwork counts for more than
skilled labour ; and the gas-fitter who can point out correctly
and convincingly the most effective and, at the same time, the
most hygienic methods of lighting a building is much more
likely to succeed in business than the man whose ability is
purely mechanical.
Gas, even though an old and well-tried servant of the
public, has, for some reason or other not quite clear, been
unfairly disparaged, every conceivable argument against it being
eagerly and incessantly advanced. This state of affairs is mainly
owing, not to the shortcomings of the gas as an illuminant, but
rather to the ignorance of its advocates. The intelligent workman
must be able to prove by argument and to demonstrate in practice
that the case against gas— particularly with respect to the allega-
tions as to its unhealthiness — has been grossly exaggerated.
A good gas-fitter should not only be thoroughly acquainted
with the minutest details of his own trade, but it is necessary
that he should also possess a sufficient general knowledge of
certain other trades, so that he may be enabled to meet the
requirements or to direct the operations of those workmen
with whom his business brings him in most frequent and most
direct contact.
Houses differ so much in shape and size that, with respect to
fitting them with gas, only general principles can be advanced.
In all cases the number of lights to be fed and the distance from
the supply govern the size of the pipes used. The pipes are of
GAS SUPPLY FROM GAS-IfOLDER TO METER. 47
three kinds — wrought-iron barrel, lead, and compo. One of the
advantages of iron is that nails cannot be knocked into it when
it is buried in a wall ; but it is much more difficult, and takes
considerably longer, to fit up a house with iron pipe than with
compo., owing to the fact that with the former material bends
have to be fitted, and the pipes must be cut to the exact length
and threads screwed on. Lead pipe is generally used only for the
connections to the meters.
In laying mains, great care should be taken that all the joints
are sound and well made, in accordance with the instructions
given in this chapter, and that the pipes are of good quality.
The mains should be tested under high pressure, and when
tapped with a hammer should ring ; they should be quite free
from sand-holes, air-holes, scabs, and blisters, and should be of
cast iron, which can be easily tapped and drilled. Where it
happens unavoidably that the pipes are laid in ground containing
ashes or any chemical refuse, they must be properly protected
either with clay or asphalt. Clay should never be put only under
the pipe, as it then stops the water and keeps the pipe wet.
The durability of mains depends greatly on the nature of the
soil in which they are laid, clay being the best subsoil for this
purpose, and ground containing ashes, slag, and clinker the
worst.
It is necessary, therefore, to note carefully the description
of soil in which the pipes are to be laid, and if it is of an
injurious character, to imbed the pipes carefully in a good
common soil, or to puddle them round completely with clay,
protecting especially the upper side with a thick covering of the
material. The pipes should have a covering of at least 2 ft. of
soil over them in order to protect them from climatic influences
and from heavy traffic such as steam rollers, etc. The excava-
tion to receive the pipes should be of the least width practicable,
so that the labour of filling in may not be excessive. If the
bottom of the trench on which the pipes rest is not already even
and firm, it should be thoroughly consolidated by pressing. The
soil should be scooped out at the various points in the trench
where the sockets come, so that the body of the pipe may be
laid solid throughout its entire length.
Another subject for early consideration is the size of main
required for delivering a specified quantity of gas. In calcu-
lating the size for a gas main capable of delivering a specified
P'BA GTIGAL GAS- FITTING.
(liiantity of gas through a given length of main, the following
formula is employed : —
^> (1350)' 2 A, where
d= diameter of pipe in inches.
Q = quantity of gas in cubic feet per hour.
I = length of pipe in yards.
h = pressure in inches of water.
■s = specific gravity of gas, air being 1.
The above formula can easily be calculated by the aid of a table
of logarithms. Thus, log. d = | (2 log. Q +log. s + log. 1-2 log.
1 350 + log. h). Suppose, for example (to take an actual case),
that a gas main is required for a building of somewhat straggling
construction, and situated at about 500 ft. from the company's
main, about 900 burners being required, some in groups of two or
three. The burners may be taken as burning 5 cub. ft. per hour
each ; then the nearest size of main required would be 4 in.
Supposing the reader to be unacquainted with the use of
logarithms, the following formula, where the size of main is
assumed in the first instance, will probably be found more
useful : —
that is, multiply the pressure in inches of water by the diameter
of the pipe also in inches. Divide this product by the specific
gravity of the gas multiplied by the length of the pipe in yards.
Then find the square root of the quotient and multiply this by
the constant 1,350 and the square of the diameter of the pipe in
inches, and the result will give the number of cubic feet dis-
charged per hour. Using this formula to check the result
obtained by the one first given, the specific gravity of the gas
is assumed to be "4, and the pressure ] in. or ten-tenths. Then
the query is, to find the number of cubic feet of gas of the specific
gravity - 4 capable of being delivered in one hour through a main
4 in. in diameter and 500 ft. or 166 yds. long under a pressure of
1-in. head of water. Then, Arf = 4Xl=4. while d 2 = -i x 4 = 16, and
•2453. Therefore 1350 d 2 </ ~= 1350 X 16 X '2453 = 5298,
which shows that the main would be amply large ; the next
h d
s I
— = "0602, the sq. root being
GAS SUPPLY FROM GAS-HOLD KB TO METER. 49
lower size (3 in.) would be too small. It is necessary to note
that in the case of small service pipes the actual discharge
is less than the calculated quantity, so that it is necessary to
increase the diameter of the pipe by one-third if of lead and by
one-half if of wrought iron.
Yet another important subject for consideration in laying-
mains is the way in which ordinary gas lighting is affected by
difference of level between the gasworks and the houses sup-
plied. The specific gravity of coal gas varies with its richness
or illuminating power, but in all cases it is less than that of the
atmosphere. If one portion of a town is below and another
above the works, the gas will rise to the higher parts by reason
of its lightness, but will have to be forced to the lower parts by
the weight of the gas-holder. In other words, for a pressure of
1% or -fo in a valley the mains
must be so charged as to exert
double or more, or say -}§ to
fg in higher places. If a high
building is supplied from one
rising main only, the gas will so
rise to the upper floors as to
necessitate the use there of
burners different from those on
the lower floors ; or, alterna-
tively, gas pressure governors
may be fixed on the various floors. The gas should escape at
a certain pressure to form a solid flame, the burners being
selected in accordance therewith. If the gas escapes feebly^
a flickering flame will be the result, and a quantity of smoke will
be given off.
The general method of making joints in gas mains is illus-
trated by the section shown by Fig. 22. It is called the socket and
spigot joint, and is sometimes known as the open joint system.
In making a joint of this description, the spigot of the pipe
about to^ be laid is placed in the socket of the pipe already
laid, leaving an annular space between the spigot and the socket.
The inner portion of the annular space is then filled with twine
gasket to about half the depth of the socket, the gasket being-
driven well in with the caulking tool. The outside face of the
joint is then tightly closed by means of a belt of plastic clay,
which completely encircles the pipe and presses up against the
D
Ffe. 22.-
-Socket and Spigot
J oint.
50
PRACTICAL GAS-FITTING.
face of the socket, leaving an opening known as the lip on the
upper side of the pipe. Through this opening molten lead is
poured, filling up the remaining space between the gasket and
the clay, the excess of lead flowing over at the lip. The clay is
then removed, and the joint when cold is set up, as it is termed,
with a blunt caulking tool and hammer, so that the ring of lead
Figs. 23 and 24.— Plan and Section of Main Syphon.
is wedged sufficiently tight to prevent any escape of gas. Each
pipe should be laid with the proper inclination or fall (say 1 ft.
in 200 yd.), and there should be a cast-iron syphon or drip-well
at the lowest point of the incline to collect the condensation
water deposited from the gas ; this would eventually clog the
main, if allowed to accumulate. As a rule, gas leaves
the works at a higher temperature than that to which it is
exposed when passing through the mains underground; conse-
GAS SUPPLY FROM GAS-HOLDER TO METER. 51
quently it holds more vapour in suspension as it leaves the works
than it is capable of carrying with it through the district mains,
the result being that the excess of vapour due to the difference in
temperature deposits in the main and finds its way to the syphons.
Fig. 23 shows plan, and Fig. 24 a section, of a syphon with its
accompanying standpipe, to which the syphon pump is attached
when pumping out the accumulated condensation products. There
is no definite rule with regard to the number of syphons required
for any length of gas main ; the principal factor governing their
disposition is the inclination of the ground in which the main
is laid. In refilling the trench in which a main has been laid,
shovel in the soil in layers, and ram firmly and equally all
round and above the pipes.
The hole for inserting a service pipe into the main should not
be cut with a chisel, but should be drilled. The best position
for the hole is at the top of the main ; a bend should be screwed
in the hole drilled, proceeding thence with the ordinary piping,
Only when the main is too high should the wrought-iron tubing
be inserted at the side ; but it is better to lower the main than
to insert pipes at the side. Care should be taken that the
hole drilled in the main is not too large for the size of the main,
52
PR AG TIG AL GAS-FITTING.
as a disproportionately large hole weakens the pipe, and renders
it more liable to crack,
For drilling mains very simple tools are used, such as the
ratchet-brace with an ordinary flat drill or with a twist drill ;
the twist drill is preferable, the ratchet being fixed in a bent iron
hook as shown by Fig. 25, p. 51 ; or the apparatus shown by Fig. 26,
p. 52, can be employed. These are the simplest forms of appar-
atus, but in using them the gas can escape when the hole is just
through ; and it is usually then the practice of fitters to close the
E.
space round the drill with a lump of clay or a piece of oily waste,
keeping it pressed down to the main pipe with the left hand
while the right hand works the ratchet handle. The loss of gas
is not the most serious consideration, for it has been a frequent
occurrence that men when working in a small hole excavated in
the ground, with but little wind stirring, having been overcome
by the fumes of the gas ; and if this should happen when no one
was near to render aid, it is very possible that death might ensue
from asphyxiation. Should a man be overcome by the fumes of
gas, milk should be given at once, as this is the best antidote.
OAS SUPPLY FROM OAS-HOLDER TO METER. 53
la recognition of this danger, many inventions have been brought
out for preventing the escape of gas when drilling and tapping
mains. In some of these the drill passes through a hole in a
sheet of indiarubber that covers the top edge of a cylinder, the
latter being made to fit given sizes of mains by means of india-
rubber rings ; and the whole apparatus is screwed down tightly
to the main by chains with tightening screws affixed being passed
under it.
Another type of safety drilling apparatus is that known as
Fig. 28.— Side Elevation of Upward's Safety Drill.
Upward's patent safety drill ; this is shown in front and side
elevation by Figs. 27 and 28. For use, it is placed on the pipe in
the required position for drilling the hole, the chain f being-
passed round the pipe and secured by the hook H ; this is tight-
ened up on the bridle a until the apparatus is firmly fixed. A
roll of clay is placed around the bottom of the chamber B, to
prevent the escape of gas, and the valve K is then opened with
the handles N n, and the drill piston o, with the proper sized tap
and cutter d in it, is placed in the chamber b. The drill is
54
PR A G TIOAL GAS-FITTING.
allowed to drop on to the pipe, and the piston o is pushed down
until it touches the spring p, the screw c being then tightened
up. The ratchet handle is put on to the head of the drill at Q,
the feed screw e is screwed lightly down on it, and drilling is
commenced in the usual way, care being taken to feed the drill
gently until it bites properly. As soon as the hole is through, the
set screw c is loosened and the drill pressed down by the screw e
until the tap bites. The completion of the tapping is ascertained
by the tap coming home on the collar at its upper end. When
this is done the drill is drawn up as high as it will go, and
the slide valve k is closed carefully, to prevent the valve being
injured in case the drill should by accident be left too low
in the chamber b. To prevent the escape of gas during the
operation the valve k passes through leather packings ll at
the ends of the valve chamber. By the use of Upward's
Figs. 29 and 30. — Correct and Incorrect Positions of Drill.
appliance, the hole is both drilled and tapped at the one
operation ; and it is obvious that, if the above instructions are
carried out, there can be no escape of gas through the hole
made in the main.
Great care should be taken to ensure that the hole is being
drilled in a radial direction from the centre of the pipe — that is
to say, if the hole is being drilled in the top of the pipe, the
ratchet and drill must always be kept truly vertical or upright,
whilst if a side hole is being made, the drill must be truly
horizontal. See that the drill invariably points to the centre of
the pipe, as shown in Fig. 29 : then the drill must necessarily
be vertical. If the drill is held incorrectly, as in Fig. 30, the result
will be that when the hole is drilled and tapped, the pipe that
is screwed into it will not point in the proper direction. In
feeding the ratchet-brace with the feed-screw, be careful not to
exert the whole strength upon it, more especially when the drill
is nearly through. The surface of the main being convex, the
Fig. 29.
Fig. 30.
GAS SUPPLY FROM GAS-HOLDER TO METER. 55
hole at that time is not exactly round ; hence, if forced too
rapidly, the drill is apt to catch and bind.
When drilling a small main, and a service is required of
nearly the same size, it is advisable to drill a hole some sizes
smaller, putting in a short piece of small-sized pipe and increas-
ing immediately to the size required. The short length of pipe
of small diameter does not sensibly reduce the quantity of gas
passed by the larger pipe.
Fig. 31.— Taper Tap.
Hall's patent drilling and tapping machine is a strong and
efficient tool, and its working principle is simple. Under the top
flange of the machine is placed a circular revolving plate, through
which the drill shank and cock carrier shank pass and rest in a
seat, being held in place by a flat ring properly packed and bolted.
The object of this plate is to enable the operator, after having
drilled the hole and backed out the drill, to bring the cock
immediately into position by revolving the plate, the holes in
Fig. 32.— Plug Tap.
which are so placed that when it is revolved it brings either the
cock or the drill over the same part of the main.
When a large hole is to be cut in a main a diamond-shaped
chisel is commonly used— not, however, when the holes are after-
wards to be tapped.
The taps employed for mains are of two kinds, taper and plug,
as illustrated in Figs. 31 and 32, the taper being used first and
then the plug. Before the tap is put into the hole it is advisable
to see that the hole is cut cleanly through the main, as very often
P RA C! TIOAL GAS- FITTING.
there remains a portion at the sides that has not been cut away
by the drill : such portion must be cut away with a hammer and
cold chisel before the tap is inserted.
Very great care is necessary to ascertain that the drill used is
of exactly the size necessary for the pipe that is to be inserted,
and the best way of gauging the precise dimensions is to calliper
the thinner end of the taper tap in the part that is of the largest
diameter. The drill should then be made a shade larger than
this, so that the taper tap may be inserted a short way into the
hole, or a combination tool, as shown by Fig. 33, may be used.
When the tap is in, a light blow on the top will cause the
threads upon the tap to slightly enter the iron round it, and
when turned by a key or spanner the tap will gradually force or
cut its way into the hole, making the threads as it enters.
Plenty of oil must be used on the tap, which must not be turned
Fig. 33.— Drill Reamer Tap.
steadily in one direction, but must be taken, say, half a turn
forward and then a short way back. Thus the cut is very
gradual, and the metal cut away falls back into the grooves in
the tap, leaving a clear way for that which is to be removed.
Having turned the taper tap until it is as far in as the teeth will
permit (being careful not to allow the tap to pass right through
and drop into the main and so get lost), turn it gradually back
until it is entirely free, and substitute the plug tap. Screwing
this in and out again leaves the hole threaded ready for the pipe
to be inserted.
During the whole of these operations it is usual to keep a
piece of oily waste round the taps, ready to stop the hole when
they are removed. Having plugged the end of the bend, either
with a proper iron plug or cap, or with some of the waste before
mentioned, and painted the thread with red and white lead paint,
screw the bend into the main with the pipe tongs (see p. 68)
until it will turn no further without great force, finishing with
GJ.S SUPPLY FROM GAS-HOLDER TO METER. 57
the end of the bend pointing in the direction desired. Lead
paint for gas-fitters' use is prepared by mixing about three parts
of ordinary white-lead in paste with one part of red-lead in
powder. For use as paint for threads of screws, boiled linseed
oil is added to the mixture.
The service pipes should be of the best quality, and be allowed
to fall towards the main. If that inclination is not possible,
they should fall the other way, and a bottle syphon or drip-
well be inserted at the lowest point to receive the condensa-
tion water, which accumulates as explained on p. 51. The
service should be laid with a fall of at least 1 in. in every 12 ft. ;
and where the distance from the main is so great that this fall
cannot be secured without bringing the service pipe too near the
SERVICE PIPE.
Fig. 30.— Pipe
Syphon.
surface of the ground, it is best to rise from the main as far as
possible, and then start falling again, putting in a syphon-box
(as shown in Fig. 34) where the depth of the pipe is considered to
be too great. In using the syphon-box, the pipes are connected
to the tee shown at a, the upper portion of the tee forming a
portion of the length of the service, the longer vertical pipe being
carried up to an inch or so below the ground-level and a cap
(not shown) screwed on it. This cap is usually made by using a
plug fixed into a plain socket, the squarehead of the plug giving
greater facility for removal for pumping.
With reference to the slope of the service pipe, it may be well
to point out that, whereas in a wet meter the water condensed
from the gas would help to keep the water in the meter at the
PRACTICAL GAS-FITTING.
proper level and be an assistance, in the case of a dry meter its
presence is decidedly objectionable ; consequently, in laying the
service to and the pipes from the meters, note must be taken of
the class of meter which it is intended to fix, and when either
the service or the pipes leading from it to the house happen to
fall in the direction of the meter, a syphon should be used ;
this may be the syphon-box described on the previous page, or
may be a pipe syphon as shown in Fig. 35, the condensation
being removed from the bottom of the syphon from time to
time, merely by turning the tap. These remarks with refer-
ence to meters will be more intelligible if taken in conjunc-
tion with the information given in Chapter V.
In pathways and where traffic is likely to be great, a cast-iron
box with hinged lid should be fitted over the rising pipe of the
syphon to preserve the pipe from damage. The service should
not be allowed to come nearer than 1 ft. 6 in. to the surface of
the road, as a covering of ground less than 18 in. thick is very
porous, letting in sufficient moisture and air to ruin the pipe-
metal within a comparatively short period. Greater depth also
prevents rapid alteration of temperature and consequent con-
densation of the gas and deposition of naphthalene, which in
time may be so great as to cause a stoppage in the pipe. Another
reason why the service should be at a good depth is that the
weight of any heavy road roller or any great load passing along
the road will then be less likely to damage the pipe.
Services are usually made of wrought iron, and the tubes and
fitting comprising them, such as tees, bends, elbows, sockets, etc.,
should be perfectly cylindrical, with no ribs or flat places, and
internally as smooth as possible. The welding should be scarcely
discernible from the other parts, and the screw should be equally
deep throughout the thread. In laying wrought-iron pipes, the
coupling or socket at the end, which is supplied along with the
pipe, should always be removed and replaced after painting the
thread with white- or red-lead paint. All service pipes, when
laid in the ground, may be protected from the oxidising
influences of the soil, moisture, and air, by being encased in a
V-shaped or Ll-shaped wooden trough, and filled in with hot
pitch and sawdust, to preserve the pipes, and, in fact, make
them last more than double the time that they would if left
unprotected.
The service of iron pipe having been carried through until it
GAS SUPPLY FROM GAS-HOLDER TO METER. 59
has entered the house, a cock should be fixed, and thence a short
piece of iron pipe leading just above the level of the meter and
about a foot away from it. All meters should be fixed in posi-
tions where they will not be subject to rapid changes of tempera-
ture, but the place in which they are kept should not be so warm
as to injure the leather bellows of the dry meters. The meter
should be fixed on a wooden bracket attached to the wall
of a passage inside the house, where it can be easily seen, so
that any defect can be quickly noted and repaired ; it should
never be fixed in an inaccessible position, nor in a small cup-
board with other things, for if a leakage occurred the cupboard
would rapidly fill with a mixture that would instantly explode in
contact with flame. The meter, especially a wet one, should be
carefully put level, and fixed up with sufficient firmness to
prevent shifting of position.
60
CHAPTER IV.
LAYING GASPIPE IN THE HOUSE.
The preceding chapters having been devoted to the consideration
of means and methods of supply, it is now convenient to deal
with the means and methods of providing for the consumption of
gas— namely, with the materials and operations relating to domestic
gas-fitting. The requirements of the case having been ascer-
tained, and the scheme of service having been carefully planned
and arranged, measure up the lengths of iron piping required,
making due allowance for threaded joints, bends, elbows, or
tees. Bends should always be used where possible, as the quick
alteration in the direction of the flow of the gas in elbows causes
friction, and a consequent loss in the pressure obtained at the
burner end of the piping. Then mark off the length with a piece
of chalk, and fix the barrel in a pipe vice. Bends, elbows,
tees, and other small fittings are shown in Fig. 36. Pipe vices
are usually of the kind illustrated in Fig. 37, p. 63. The next pro-
ceeding is to hang the pipe-cutter on the pipe. The pipe cutter
is a claw-shaped tool, with one or more hard steel cutting discs
on the inside which can be made to screw in and out. A one-
wheel cutter is illustrated by Fig. 38, p. 64 ; a three-wheel cutter by
Fig. 39, p. 64 ; and two patented shapes of three-wheel cutters by
Figs. 40 and 41, p. 64. Screw up the handle of the cutter until
the wheel is exactly on the chalk mark, and give the cross-
bar a slight turn so as to make the cutter-wheel enter the
iron a little. Having put some oil where the cut is to be
made, turn the pipe-cutter round the pipe once or twice,
and take another slight turn on the cross-bar, continuing
in this way until the pipe is cut through. A little oil on
the cut assists greatly in the severing of the pipe, and, while
saving the wear and tear on the wheel, also lessens the labour of
turning the apparatus round. Several shallow cuts are much
better than a few deep ones, as the deep cuts cause on the ends
of the pipe a considerable ridge, which must be filed off before
the dies can be used for threadins; ; and as the thread at the end
LAYING GASP WE IN THE HOUSE.
61
of the pipe has to be made somewhat smaller and tapered, this
ridge is especially objectionable. Having cut the pipes to the
required lengths, it will be necessary to put the threads on them
so that a gas-tight connection may be made with the sockets
(see Fig. 36) which are obtainable ready screwed.
Fixing the pipe as before in the pipe vice, with a few inches
of the end which is to be screwed protruding, pass a file round
Fig. 36. — Tubes and Fittings.
the edges of the end to remove the burr caused by the cutter, and
continue the tiling until the portion of the pipe to be threaded is
of even diameter.
The following table shows the dimensions of Whitworth's
standard gas threads, with particulars of the diameters at the
top and bottom. These threads are always used for gas and
water pipes. The vulgar fractions in the third and fifth columns
of the table are not exact, being to the nearest B \ in. only.
62
PRACTICAL GAS-FITTING.
"3825
3
8
"336
I 2 1
6 4
1 2
6~4
28
x
•518
n_H
6 4
"451
19
3
"6563
2.X
3 2
"589
1SL
3 2
J!)
i
'825
5 3
6 4
•734
-47
6 4"
1 3
1 6
14
1
"9022
5i
6 4
"811
14
3.
1 "041
1A
6 4
"949
6 1
64
14
7
T189
a
1 1 (i
T097
1 6 4
I 3
1 1 6
±8
±3 2
J 8
14
1
1 "309
1t-
1 1 6
1*192
] 1
u
T492
li
1 '375
1 1
x 4
1'65
ill
1 3 2
1-533
11
If
1745
14
j -628
J ]
H
1'882
1 K4
1 '705
1 i A
x 64
11
If
2-022
Z 6 4
1-965
1 3i
1 32
■°6 4
21
11
If
2-16
2 ¥2
2'042
11
J 8
2-245
2i
2'128
11
2
2-347
2H
2-23
24
11
2|
2-467
Z 3 2
2'351
923
^B4
11
24
2 587
93 7
*6t
2-47
nl 6
■^3 2
11
2§
2-794
951
■ i 64
2-678
94 3
^64
11
2k
3
3
2-882
9»7.
Z 64
11
2f
3-124
31
3-009
3
11
2^
3-247
• 3i
373
31
11
2|
3-367
3t
3-251
34
J 1
3
3-485
3M
3 368
31
11
34
3 698
04 B
3 581
m
11
3',
3-912
Z 32
3/795
3fi
11
3f
4-125
4^
4-008
4
11
4
4-34
4M
1
4-223
44
11
Three kinds of stocks and dies are in use for screwing the
pipes. Those that are most commonly employed are the
straight stocks and dies, as shown in Fig. 42, p. 65. These can be
made to perform all the operations of which the others are
capable. The taper die-stocks (Fig. 43, p. 65) are quicker to
1 work, for they give a full thread at one threading, and, unlike the
straight dies, these have guides which keep them square when
starting the screwing of the pipe. This is a great advantage, as
connections on which the threads have not been properly and
LAYING GASPTPE IN THE HOUSE.
63
squarely made are very unsightly. Again, with the taper
dies the two halves of the dies are tightened together before
commencing the screwing, whereas with the straight dies the
two halves have to be opened sufficiently to allow the pipe to
enter between, and, when straight, must be screwed up gradually
as the thread is being made on the pipe.
If the thread is not exactly straight at the start, the remainder
of the work will be thrown still further out. To avoid this mishap
place the pipe vice on the edge of the bench, and fix a pipe in it,
screwing down the vice so that the pipe is at right angles with
the face edge of the bench ; then the stocks and the dies can be
held horizontally, and it can be easily seen whether they are
parallel with the edge of the betich.
LAYING GAS PIPE IK THE HOUSE.
65
Having inserted the pipe
end between the two halves
of the dies so that the end
of the pipe is about flush
with the face of the dies,
screw up with the hand the
handle of the stock as tight
as it will go, and then, in-
serting a short bar into the
hole in the handle, give it
about an eighth of a turn
more ; this will cause the
dies to s'ightly enter the
iron. Next thoroughly oil
the dies and the pipe to be
cut, and take a steady turn
or so with the stocks so as
to start the threading, when
the dies may be tightened
slightly more. In this oper-
ation, as in cutting pipes,
avoid deep cuts, which tend
to wear out the dies, whilst
the thread cut is not nearly
so clean ; and care must be
taken that there is always
a good supply of oil at the
cutting point. It is desirable
to give the thread a slightly
taper shape, and this is done
by slightly and gradually
tightening the dies as the
stocks are worked off the
thread. In turning round
the stocks take half a turn
and then go back, say one-
eighth of a turn, so as to clear
the dies and allow the cut-
tings of metal to get into
the grooves made in the
dies, and thence to fall out.
66
I'll A C TK'JAL GAS-FITTING .
It is better to tighten up the dies at different parts of the
thread and at different parts of the turns, so that the deeper
cutting in of the thread shall not commence always in the same
place. The error indicated is one which the gas-fitter is very apt
to commit, as he usually places the short lever in the same place
each time he uses it, and consequently stops at the nearest points
of the turn to this place when he again wishes to tighten up the
dies. When the thread is considered to be cut sufficiently deep
to allow a socket to fit on it, the dies must be either run off by
turning the stock round, or else the handle must be loosened,
when the dies can be opened out. It is well to have a socket or
tee of the right size ready at hand to test the size of the thread,
the said pipe having about six to eight threads on it, thus
ensuring a really good joint. One of the great advantages of the
taper dies is that the threads are certain to be cut down to the
proper size at the first operation, so that the stocks have never to
be placed again upon the thread, as is the case with the straight
dies. Straight dies, however, must sometimes be put on the
thread again, to reduce the diameter of the thread, and then
great care must be taken that they are put into the old threads,
or new threads will be cut on the old ones, and consequently
the whole thread ruined. To avoid such a disaster, proceed as
described on p. 63 for first putting on the stocks, by holding them
parallel to the edge of the bench.
The third method of screwing pipes is that by means of a
screwing machine; this is usually made with adjustable dies,
which not only effect a considerable saving in time, but ensure
much better and much more even work than either of the two
methods already described. Unfortunately the machine is not
very portable, but in a workshop where sufficient pipe-screwing
is done to justify the purchase of the machine, it is most valu-
able, as, during periods of slackness odd portions of piping can
by its means be screwed and made into nipples, short pieces, or
connectors ; in fact, in some shops it is usual to keep a boy
constantly employed on such work.
The screwing machine shown in Fig. 44 needs but little
explanation. The pipe is fixed in the vice and tightened by the
screw shown at the top of the figure ; the end of the pipe is
then brought close to the dies by means of the arms at the
side, which actuate a pinion that gears into a rack on the
under-side of the vice. When the pipe has entered the dies,
LAYING GAS PIPE IN THE HOWE.
67
which are tapered, and should be set to the exact size of the
thread required, the handle that gears with the disc containing
the dies is turned, the dies cutting their way gradually into the
pipe until the thread is completely formed, whilst the pipe is
drawn gradually into the dies. A large number of these
machines are also fitted with a cutter, which can be used for
dividing the pipes into the lengths required. Some of these
machines are so arranged that there is no backing off the dies
when the thread is finished ; all that is necessary being to open
out the dies and run the pipe vice back.
Fig. 44. — Strewing Machine.
The joints in the iron pipes are usually made by threading
externally the ends of the pipes and fixing sleeves or collars, or
sockets as they are usually termed, on these ends, the sockets
being threaded internally to suit the thread on the pipes ; and
for ordinary purposes this joint will be all that is required. But
there are occasions — as, for instance, when two outlets are
required somewhat close together— when some other means will
be desired, and then the common method is to put in what is
called a nipple, which is nothing more than a. 1| in. length of
pipe, threaded externally from end to end (see Fig. 36, p. 61).
This, having been painted, is screwed half-way into one of the
tees, and then the other is screwed on to the remaining half, a
68
PRACTICAL GAS-FITTING.
few strands of yarn being twisted round the joint before it is
screwed up tight. This is by no means the only way in which
the nipple is useful, but will serve as an example of the ordinary
method of employing it.
There are several kinds of pipe tongs in common use, but
Fig. 45 shows the one generally employed. Some are made with
a screw so as to suit several sizes of pipes ; a parrot-bill pipe
wrench is shown by Fig. 46. The professional gas-fitter will
require a complete set of pipe tongs, and when purchasing these,
care should be taken to see that they are of good quality and
strongly made, otherwise they will be in frequent need of
straightening.
The screwing in of the nipple is sometimes a matter of
difficulty, especially when the nipple, or the tee, or the elbow,
has become slightly rusty. The common method of screwing is
to fit the nipple into the proper dies, clamping them tight on the
Fig. 45. — Pipe Tongs.
half that will be left outside the first tee, thus holding the nipple
securely without the threads. But the time taken in getting the
proper dies into the stocks and screwing them up again into the
nipple is considerable, and consequently an impatient or careless
workman is liable at times to use his tongs on the thread, which
may be ruined thereby. The thread is slightly injured even
when the stocks and dies are used, as the cutting edge of
the die is sure to enter the metal to a greater or less degree,
according to the amount of pressure applied to the lever
for tightening the dies round the nipple. A comparatively
new appliance, called the Ashley nipple-holder, obviates all
these defects. Sockets of different sizes are provided, into
which one half of the nipple is screwed ; when it is sufficiently in,
a plunger is forced into contact with the edge of the nipple, and
the teeth on the plunger enter into the metal where they can
do no damage, but at the same time they prevent the nipple
turning and ensure its entry into" whatever socket is ready
for it.
LAYING GASPIPE IN TEE HOUSE.
The connector is a joint of very great use, and should be
employed far more frequently than it is, especially where
extensions or alterations are at all likely. The connector costs
rather more than the socket, but is of great value when
from any cause piping has to be taken up. The few pence
expended on its purchase will be repaid the first time a leak
occurs or that the piping has to be cut to fix a connection
for, say, a gas stove or an extra light. As pointed out
on p. (i6, with reference to the screwing machine any short
pieces which may remain from the cuttings in the shop can
quickly be made into connectors, which are simply short pieces
of pipe externally threaded at both ends, but with the thread at
one or both ends cut sufficiently far to allow the ordinary socket
and a back nut to be screwed wholly on to the piece of pipe.
The great advantage of the connector is that by its use certain
lengths of pipe can be screwed up together, and bends and tees
fitted on and connections led from them, and these can afterwards
be joined together by means of the connector. This advantage
is best appreciated when the gas-fitter is working in close
quarters or in awkward corners.
The pipes having been cut and joined up at the far ends to
the fitting or supply, a connector is chosen of the exact length
to go into the space between the two pieces of pipe, and the l ack
nut and "socket are screwed right up on the connector, the other
end of which is then screwed in the ordinary manner into the
socket of one of the pipes ; and then the end of the other pipe is
brought exactly opposite the free end of the pipe. When this is
on tight, the back nut is brought close up to the socket, and
after a few strands of yarn have been wrapped between, is
screwed up quite tight against the socket, thus effectually
preventing any escape of gas, which would otherwise take place
owing to the socket being somewhat loose on the pipe forming
the connector. Paint made as described on p. 57 is required
on the connector as well as on all other joints in iron piping.
70
Pit A 0 TIG A L GA S -FITTING.
The chief points to be observed in the manipulation of iron
tubing having now been dealt with, it will be convenient, before
treating of special fittings, to describe the use of composition (or,
as it is usually called, compo.) pipe, which is made from an
alloy of tin, lead, and antimony, the proportions varying greatly.
In making the pipe, the alloy is placed in a reservoir or con-
tainer over the piston of a hydraulic press, so arranged that it can
be heated by an annular fireplace. The reservoir is filled with
molten alloy by a spout through an aperture in the top ; when the
reservoir is full the spout is taken away and the orifice closed
tightly by an iron plug kept in position by an iron key. A steel
die fitted at the top has in it a hole of the size of the outside of
the compo. pipe, and this regulates its external diameter, the
internal diameter of the pipe being determined by a mandrel,
which passes directly through the centre and is moved upwards
Fig. 47. — Method of Jointing Compo. Pipe.
by the rising piston, the semi-fluid metal being at the same time
forced through the die. The metal cools down as it is forced
away from the foot of the mandrel and cone, until at a certain
distance it becomes sufficiently cool and hard to be coiled round
a drum.
In the first place, it is desirable to describe the usual method
of connecting the compo. pipe to the end of the iron tubing.
The end of the iron tubing having been screwed in the usual
way, a union, made of brass, is fitted to it ; these unions are of
two kinds, the barrel union and the cap and lining union. The
barrel union consists of a sleeve of brass tubing, with an internal
or socket thread suitable for screwing on to the end of the pipe,
and a short outside or spigot thread at the other end of the
sleeve, on which screws a hollow nut which serves to draw up a
second sleeve of brass, which is usually tinned. The hole at the
LAYING GASPIPE IN THE HOUSE. 71
top end of the nut is smaller than that where the thread is, and
this prevents the collar on the second sleeve from passing
through, a gas-tight joint being made by means of a ring of
leather between the collar and the nut.
The cap and lining union is similar, except that in this the
nut screws directly on to the iron piping and the first-mentioned
sleeve is not required. It having been ascertained that the union
will fit the iron tubing, the union should be removed, and re-
tinned so that the solder may quickly join to the metal ; the
tinning done by the makers is rarely sufficient to ensure a
good gas-tight joint. In re-tinning with a soldering-bit, the sleeve
is held on its side by a pair of pliers or pincers, and the sleeve
having been well powdered with resin, a hot soldering-bit is
passed round it until the solder has run all over the part that
will afterwards be required to be joined to the compo. pipe,
Fig. 48.— Shave-hook.
plenty of solder being kept on the bit. When the re-tinning is
done by means of a blowpipe, the solder is made to flow round
the sleeve in the same manner, a spear of flame being directed on
to the solder and on to the part to be tinned. By this means a
smooth and at the same time thin layer of solder is run over the
sleeve, which will quickly make a joint with the solder used
when the joint itself is being made. The methods of using both
soldering-bit and blowpipe are described in detail below.
Joints between compo. and lead pipe, or between two pieces
of compo., or between either of these pipes and brass piping, can
be made in either of the two ways just described— that is, with a
well-tinned soldering-bit or with the blowpipe. In joining two
pieces of compo. pipe of equal size, it is usual to turn the one end
of the compo. pipe until it points directly upwards, then, with a
plumber's top (b, Fig. 47), usually made of boxwood, the end is opened
by lightly tapping the top with a hammer, or simply by twisting
the top, keeping a pressure downwards on the pipe, taking care to
hold the compo. pipe just below the part being opened out (as at a,
72
PRA G TIG A L GA S -FITTING.
Fig. 47). The pipe should be made sufficiently large at the end
to just allow the end of the other piece to be inserted in it.
Then the opened end should be cleaned with a scraper (Fig. 48
p. 71), or with a penknife. The scraper, which is really a plumber's
shave-hook, is also of use in cutting off the length of pipe req lired
from the coil. Having cleaned the inside of the opened end, cut
off the top edge cleanly, and carefully clean and scrape the 'end
that is to be inserted for about \ in. up, scraping off more near the
end, so that it is slightly bevelled (c, Fig. 47, p. 71). Put it into
the opened end, and, holding one piece in each hand, force them
tightly together until they hold of themselves. A little powdered
resin and oil, mixed, is put into the joint to act as a flux. This
mixture is prepared by melting resin in a ladle over a fire and
adding any common oil to it, and well mixing, taking care that
it does not become too thick. If a blowpipe be used— and this
is certainly the quickest method— the solder required is specially
prepared, and is known as blowpipe solder. If a spirit blowpipe
is not available, an ordinary mouth blowpipe, also some rushes
soaked in tallow, or an ordinary tallow candle, may be employed.
The rushes or candle are held in the left hand, the mouthpiece of
the blowpipe is placed in the mouth, and a strip of solder is held
in the right hand. Blowpipe solder is made in thin sticks, so as
to be more readily heated and bent close to the point at which it
may be required. Such blowpipe solder should consist of two
parts of pure tin to one part of lead, while ordinary solder seldom
contains more tin than lead, and plumbing solder contains only
1 part tin to 2 parts of lead. A simple test for the quality of
solder is to bend the stick close to the ear, when, if the solder be
good— that is to say, if it contains a fair proportion of tin -a
distinct crackling will be heard; whereas a common solder will
bend without any noise at all. Having bent the solder so that
it wdl easily get into the joint, light the tallowed rushes, and
hold them a short distance from the solder ; with the blowpipe
blow a clear and steady blast, and so cause a small spear of flame
to stand out from the remainder. This spear will be of an intense
heat, owing to the excess of oxygen supplied. The point of the
blowpipe is kept about iin. from the flame, which must be
directed on to the joint in process of making, the solder at the
same time being held against the joint until it begins to melt.
Hold the extreme end of the stick of solder in tlie spear of flame,
and dip it, when heated, into powdered resin until a small
LAYING GAS PIPE IX THE HOUSE.
73
quantity adheres to it. Now hold this resined end of the solder
close to the compo. pipe at the joint, and with the blowpipe and
rushes send a spear of flame upon it and the joint ; this will melt
the solder, and at the same time beat the compo. pipe sufficiently
to cause the solder to adhere to it. Then work round the joint until
the cavity is filled up and the two ends of the tubes are fastened
together and neatly flushed up all round (d, Fig. 47, p. 71). By a
slight movement of the blowpipe the solder can easily be made to
run round the joint, and, adhering to both pieces, join the two
together. This, when a blowpipe is used, can be as easily done
on the side as vertically, but with a soldering-bit an upright
position is desirable. With new pipes resin is not so necessary ;
it will suffice to rub the rushes round the joint or put a little
Russian tallow upon it. when the solder will run easily round
the joint. Even with old pipe a rub with tallow is advisable ;
by its use the joint can often be made neater, and may require
less solder. To make a really good blowpipe joint a fair amount
of practice is required ; but even an unskilled person will
probably succeed if the pipe be painted just above and below the
joint with a mixture of size and whiting, so as to keep the heat
from the pipe, except just at the joint.
Blowpipe lamps, of which many varieties are now sold, are
very handy, and save both time and money. In many of these
benzol is used, and while some are only lamps with tubes
attached, which have to be blown through in the same manner
as the ordinary pattern blowpipe, others have an arrangement
by which the heat of the flame causes a current of air
to pass through and direct the spear of flame on to the part
to be soldered.
When a soldering-bit is used, the same method as that
described with reference to the blowpipe joint is adopted for
cleaning, scraping, and joining the two ends ; but when the ends
are pressed together, preparatory to the use of the soldering-iron,
the edge of the lower has to be covered with resin, and, the
worker holding a stick of solder in one hand and a hot, well-
tinned soldering-bit in the other, the coinpo. pipe and solder
are heated and joined, the soldering-bit being slowly carried
round the joint and the solder made to flow evenly round after
it. Care must be taken that the iron is not too hot, and that it
is not kept too long in one place, or the compo. tube will be
melted ; melting also occurs when the blowpipe is used, if the
7f
PRACTICAL GAS-FITTING.
flame be kept playing too long on the pipe. In all shops where
compo. pipe is used there are plenty of short pieces that can be
utilised by the novice in practising. Many apprentices are kept
making joints in pieces of compo. pipe. This practice serves to
utilise the shorter pieces, as well as to render the apprentice
proficient in this, the most difficult of gas-fitting joints ; but in
other respects it does not pay to join up these pieces, as the cost
of compo. pipe is so small, and a fair price can always be obtained
for the old material.
When cutting off a length of compo. pipe, allow sufficient to
bend upwards in making the joint if a soldering-bit is to be
used ; and when bending compo. pipe care must be exercised
lest in the process the pipe becomes closed up and rendered use-
less. The usual way is to make the bend with a very easy curve
at first, and gradually to reduce this until a bend of the required
size is obtained. Hold the pipe in the left hand, with the thumb
on the inside of the bend, and, using the thumb as a fulcrum,
bring the remainder of the bend slightly round ; then shift the
thumb a short distance and proceed as before.
It is sometimes found difficult to measure from the roll the
compo. pipe required for a given position. When the operator
is working single-handed, the best way- is to put a moderate
weight on the free end, and roll the remainder along the floor,
when the pipe will come out practically straight ; but when a
mate is present, by each holding the ends of the piece to be cut
off, and giving a good pull, the pipe can be made perfectly
straight and the exact length carefully measured. The length
of a coil of compo. may be roughly calculated by counting the
number of coils and multiplying by three times the average of
the inside and the outside diameter. This is only roughly correct,
as it should be three and one-seventh times, or, to be still more
exact, 31416 times. Compo. pipe should always be unrolled, not
lifted off ring by ring, or it will become twisted, and probably the
passage-way for the gas will be reduced in area.
In fixing compo. pipe on walls and in floors, care must be
taken that it is laid in such a way that no sagging or loops shall
develop in the future, as these form most effective traps for the
catching of any condensation which may be caused by variation
of temperature, and so in time stop the passage of the gas
through the pipe. To prevent this, the pipe hooks should be
driven in at short intervals, and hammered in so far that they
LAYING GAS FIFE IN THE HOUSE.
75
bold the pipe close to the wall, yet without the head or hook of
the nail bruising the pipe.
In straightening the pipe, slight blows with a hammer are very
useful, the pipe being supported in the hand. When working in
a corner or close to the architrave of a door or window, the pipe
maybe driven well home by means of light hammer blows; to
ensure good appearance, the pipe should be made perfectly
straight. Apiece of compo. pipe which does not follow the exact
line of the corner or the woodwork against which it is laid looks
very unsightly.
In putting compo. pipe in a house which has been plastered
and papered, and in which the pipes are to be laid outside the
finished walls, it is well to follow either the architrave of
door or window or a corner of the room, as the projection
of the wood in the former case hides most of the piping. An
advantage in laying gas-piping on the outside of walls is that,
should leakage at any time occur, the pipes can be readily
examined, and any escapes promptly stopped. To prevent the
pipes showing, an excellent plan, when designing a new house,
is to arrange the woodwork so that a portion can be readily
removed, and the pipes laid in behind. Many houses have boards
laid up the walls, behind which the supply pipes are carried.
The various branch pipes, being carried along under the flooring,
do not require boxing in, and the only portions of the pipe
not readily accessible are those leading to brackets on the
walls.
Many escapes are caused by people hammering nails in the walls
on which to hang pictures, the nail penetrating the compo. piping
and causing leakage ; when, therefore, pipes are to be laid in the
plaster, iron pipes should be used, even if compo. pipe be used in
the ceilings. A most useful accessory for gas-fitters using compo.
pipe is a length of pliable cane ; by probing with this the gas-fitter
can readily ascertain whether a length of compo. pipe can be
made to pass. Anywhere that the cane can be made to go the
compo. pipe can easily be made to follow. The cane is also
useful for measuring the length of compo. pipe required for
traversing corners or curves.
When pipes, either compo. or iron, are laid in walls before
plastering has been commenced, or where the plaster has been cut
to allow the pipe to be afterwards embedded in it, care should be
taken to ascertain that all the pipe hooks are properly driven.
PR A G TIC A L a A S-FITTING.
home, so that none of the heads protrude beyond the finished
line of plaster.
Various ways of making joints in both iron and compo. pipes
having been described in sufficient detail, the next subject to
consider is the fitting up of the various lights in a building.
The usual, and perhaps the best system of lighting— especially
in a dwelling-house— is to fix a pendant in the centre of the
ceiling ; and the light from this, which may contain any number
of arms, is sometimes augmented by brackets placed round the
room.
In fixing pendants in a finished building it is often found that
a rose or centre-piece fixed on the ceiling defines the exact posi-
tion for the hanging light ; but when the gas-fitter has to decide
the matter he is fortunate if the centre of
the ceiling is found near a joist.
Most pendants (often erroneously called
chandeliers, which signifies, literally, candle-
holders) have, and all should have, a ball
and socket joint. The ordinary pattern of
such a joint is shown by Fig. 49 ; this joint
enables the pendant to swing in any direction,
so that it may, on occasion, be held out of the
Fig. 49.— Ball and way of a passing object, or, in the event of
Socket Joint. an accidental knock, allow of play or move-
ment of the pendant, and thus prevent loosen-
ing or breakage. The ball and socket joint should be taken to
pieces in the shop, well greased with tallow at the movable joint,
and if the joint is found leaky, a little powdered emery should be
ground in. This should afterwards be carefully cleaned off, more
tallow laid on, and the whole put together again and tested. Very
firms supply their fittings of such quality as to be always gas-
tight, but first-class linns test all their fittings most carefully
before selling. Each end of the ball and socket joint is usually
fitted with an internal thread, so that the pipe from the pendant
can be screwed into one end, and a short piece of pipe, to pass
through the ceiling, into the other. This short piece of pipe
should be of sufficient length to reach a tee on the pipe running
across the joists, thus connecting the pendant to the gas supply,
and should also serve to carry the weight of the pendant, the
supply pipe being carried beyond the tee with a short piece of
pipe having a capped end, which will lie on the next joist, and so
LAYING GASI1PE IN THE HOUSE.
77
form an additional means of support, Should it be decided,
however, to use compo. pipe, or should the iron supply pipe be
running in the same direction as the joists, the best method to
adopt is to fix what is known as a bridge- piece between the
joists, and the simplest manner of doing this is to nail a narrow
strip of wood to each joist, and rest the ends of the wooden bridge-
piece on them as in Fig. 50. In the exact position over the hole
in the ceiling, a hole should be drilled, through which the short
piece of pipe from the ball and socket joint can pass, with a fairly
close fit, and if a long thread be put on the upper end of the pipe,
a back-nut can be put on before the union of the cap and lining-
is screwed on ; the back-nut should then be turned back until it
forms a guard to the union to prevent the latter unscrewing
(see Fig. 50).
As it often happens that gas-
fitters are required to clean old
pendants, brief instructions in the
method of doing such work may be
fitly given here. A common form of
pendant is selected as an example.
Take the principal parts to pieces,
screw the arms out of the centre
body, and remove the bottom knob,
etc., taking notice of the way in
which the several parts are fitted, as this knowledge will be
useful when putting together again. Then remove the
old lacquer by immersing in a strong hot lye, consisting of
] lb. of carbonate of soda or potash to 1 gal. of water.
Take out the plugs, and mark them so as to be able to re-
place them in their proper tops, and be careful not to lose the
screws. Tie loose parts to pieces of copper wire, and dip in
aquafortis, swilling quickly afterwards in running water. Alter-
nate the dipping and the swilling until the parts are thoroughly
clean, and finally swill well in water. Finish by dipping in clean
water made slightly acid with cream of tartar, and dry out in saw-
dust of box or beech. Dip each arm, outside and inside rod, pulley-
frame body, and watercup separately. The smaller parts, such as
screws, can be dipped together in a porcelain or wicker basket.
Burnish prominent parts with a hard steel burnisher, using oxgall
or stale beer to lubricate the burnisher. Hold in wooden clamps
while burnishing; swill occasionally in water containing cream
Fig. 50. — Bridge-piece Pen-
dant Fitting.
78
PRACTICAL GAS -FITTING.
of tartar, and, when finished, dry out in sawdust as before,
remembering to keep everything perfectly clean when burnishing.
Lacquer on a hot plate or in an oven. To put the pendant
together, place white-lead mixed with oil on all the screws, and
beeswax on the plugs. Screw the arms up very tight, outside
rod and ball joint, exhaust the air with the mouth in order to
test the joints for soundness, and blow water down as a test for
leakage. It is often advisable to procure new brass chain, as the
old one is apt to become rotten.
In a building in which the floor-boards have been laid, the
common method of finding which board should be removed is to
drive a gasfitter's long gimlet from below straight up through
the boards into the room above. To remove a floor-board that has
been laid down is a somewhat difficult matter, unless the proper
method is followed, and that is to drive the nails, right down
Fig. 51.— Method of Sawing Floor Board.
into the joist by means of a carpenter's punch ; the nails will not
be required again, as, after the work is done, the board should
be fastened down by screws, preferably of brass, and with brass
countersink cups or washers, so that the screws may be easily re-
moved when it again becomes necessary to examine the gas-pipes
underneath. When the board runs the whole length of the room
and under both skirtings, there are two usual ways of proceeding.
One way is to lever up the board from each side until a piece
of iron pipe, or a hammer-handle, is inserted under the board
to be removed, and resting on the boards on each side, and
then with a saw cut through the board over the centre of a
joist. If the joist cannot be seen, the old nail-holes will be
a sufficient indication. When the board has been cut in two,
either piece can be easily taken up. The other method— particu-
larly useful when only a short piece of board is to be removed-
consists in cutting the board with a keyhole saw on the slope close
to the joist, as shown in Fig. 51 ; to start the saw, bore a hole
LAYING GAS PIPE IN THE HOUSE.
79
with a large gimlet. When refixed, the board cannot be tipped
up, and nails can be put in on the slant into the portion of the
board already fixed, and right into the joist.
Where the pipe runs at a right angle to the joists in the floor,
the usual method is to cut a groove in the joists sufficiently large
to allow the pipe to lie in it and not be injured when the boards
are nailed down over it. These grooves should never be cut
deeper than necessary, and should always be cut as near the
points of support of the joists as possible, so as not to weaken
the beam ; but it may be pointed out that all parallel beams are
stronger near the points of support than is absolutely necessary,
the strain diminishing as the side approaches. It will be seen,
therefore, that at the sides of the room where the joist rests on
the walls a portion of the joist can be removed with safety, but
that nothing should be cut away from the middle. The adoption
Fig 52. — Supporting Pipe at Side of Joists.
of this precaution will often necessitate the use of a greater
length of pipe, but in many cases a careful survey of the premises
will enable the gas-fitter to arrange his pipe so as to suit the joists
in the floors, and at the same time to obviate the necessity of
using more pipe than would be required if it could be carried
through the centre of the joists. When compo. pipe is being
used, and has to be carried along the side of a joist, it should not
be allowed to lie on the ceiling-laths, or a dip would occur,
with consequent accumulation of moisture and stoppage of the
gas supply. The pipe should always be fixed to the side of the
joist by means of blocks of wood of one of the patterns shown by
Fig. 52, which illustrates two sections of a floor at right angles to
the joists.
In fitting up brackets, it is usual to carry the compo. pipe to
the spot at which the bracket is to be fixed, which should be at
least 2 ft, 6 in. from the ceiling, or the latter will become quickly
blackened by the accumulation of dust on the vapour that the
80
PRACTICAL GAS-FITTING.
burning of the gas causes to condense on the cold ceiling. Never-
theless, the bracket should be kept sufficiently high to be out of
the way of people's heads.
The spot having been selected, the compo. pipe is brought to
within 2 in. of it, and then what is commonly known as an
elbow tube-bit is fixed to it. This is usually made of a piece of
brass or copper tube of about T % in. or f in. diameter. It is made
in the form of an elbow, the short end being screwed and the
long end tinned ; the tinned end is for connecting to the compo.
pipe. Tube-bits can be bought ready-made at about a penny
each, and are ready tinned, but time and trouble may often be
saved by re-tinning (see p. 71) them before attempting to make the
joint. By the expression tinning is understood the coating of the
tube with a thin layer of solder, which is done by dipping the end
of the tube into resin, and then subjecting it to the heat either of
the blowpipe or of the soldering-iron, when the solder is made to
flow all round. By tapping the end of the tube on the bench while
still very hot all the surplus solder is shaken off. During these
operations the elbow tube-bit should be held by a pair of pliers
or pincers, as the metal, being a good conductor of heat, will very
quickly become too hot throughout its entire length to be held
by the hand. If the tube-bit is made from a fresh piece of tube,
and has never been tinned, it is necessary to thoroughly clean
the metal wherever the tinning is required to adhere before the
above process is started.
The compo. pipe is now opened out with the plumber's top or
turn-pin, as described on p. 71 for the connecting of two pieces
of compo. pipe, and well cleaned ; then the tube-bit is
inserted in the open end and pressed into it until it holds of
itself, when, by means of a blowpipe or a soldering iron the fine
solder is carried carefully round the edge of the compo. pipe, thus
forming a good joint between itself and the tinned side of the
elbow tube-bit. The wooden block or pattress is now placed
over the tube-bit, the screwed end being passed through the hole
in the centre, from which it will protrude about |in. These
pattresses, finished to represent mahogany or ebony, are to be
bought very cheap, and can be had either with a groove at the
back for the compo. tube to lie in, or without the groove when
the pipe is carried through the wall or partition. Should the
groove be required and only ungrooved pattresses be at hand,
the groove can be made easily by fixing two pattresses
LAYING GASPIPE IN THE HOUSE.
81
back to back, with some paper or other soft substance over
the faces, in the vice ; then the pattresses can be drilled up to
the centre with a f-in. centre-bit, half the cut being taken out of
each block, and forming a semicircular groove in which the
small-bore compo. pipe can lie.
In fixing the pattress to the wall, if the latter be of wood, it is
of course only necessary to screw the block direct to it ; but the
wall, if of brick, must be plugged before putting in the screws. It
is best, when gas-fitting is being done before plastering, to cut
blocks of wood the size of half a brick and have these tightly set
into the wall with mortar ; after the wall is plastered and painted,
however, smaller wedges, into which the screws are driven, must
suffice. The screws should invariably be countersunk into the
blocks, so that nothing may prevent the back-plate of the bracket
from lying flat on the pattress ; and the same instruction applies
to the holes to be drilled in the back-plate of the bracket, which
is not supplied ready drilled, as the holes cannot be made until
the position of the pipe-lead and of the screws in the pattress are
known. Another reason for countersinking these screws is to
remove any rough edge, which, if left, might afterwards catch
the hands or dusters when cleaning the bracket.
Having decided on the positions of the holes in the bracket
back— generally three in number— so that they shall miss both
the pipe and the screws already in the block, screw the bracket
on to the protruding end of the tube-bit (previously painting the
thread of it with the red-lead paint mentioned on p. 57)
until the back-plate is close to the wooden block and the bracket
is the right way up ; then drive in the three screws, and the
bracket is fixed ; the screws are short, as they have to go only
into the block. When drilling the holes in the back-plate, it is
usual to take the swivel out of the socket by undoing the small
set-screw at the bottom, being careful not to lose the little washer
which fits on the bottom of the swivel ; by thus removing the
swivel the gas-fitter has ample room to drill the holes with a
brace or with a machine drill, and at the same time the oppor-
tunity may be taken to wipe and clean the swivel and socket
and re-grease them before fixing, as many of the joints in the
brackets now made are not very carefully ground in ; the conse-
quence is that shortly after the work is done complaints are
made that there is an escape of gas— a contingency that might
have been avoided if the grease that is always put on by the
F
82
PRACTICAL GAS-FITTING.
maker, but which gets hard when laid by in stock, had been
removed, and fresh grease (tallow) substituted.
Sometimes a bracket is fixed for the purpose of connecting
the supply of gas, by means of flexible tubing, with a pedestal
lamp on a table or shelf, and when it is known that this is to
be done the bracket and pattress should be fixed more firmly, as
the moving of the lamp is likely to cause a considerable pull on
the connection. In such a case the bracket must be firmly
attached by means of .wooden wall-plugs, into which the screws
Fig. 53. — Gas-fitter's Pliers.
are inserted ; better still, a wooden block should be set into
the wall. The gas-fitter will need for almost constant employ-
ment a good pair of pliers; their uses, though chiefly in con-
nection with the screwing in of burners, are- too many to be
enumerated here, but the usual shape of these tools is illustrated
by Fig. 53.
83
CHAPTER V.
GAS METERS.
The structure of the gas meter should be thoroughly understood
by the gas-fitter, and the subject is of considerable importance to
the general public, whilst the number of gas consumers to whom
the gas meter is nothing but a box of mystery is very large. Not
only should the methods of testing meters be made clear, but it
should also be understood that this testing is done by a public
official in accordance with the provisions of the Sales of Gas Act,
in which it is enacted that any meter for measuring the quantity
of gas delivered to a consumer, besides being incapable of access
for the purpose of tampering, and having means of sealing to
prevent such fraudulent access, must not be capable of register-
ing more than 2 per cent, fast (that is to say, 2 per cent, in
favour of the gas company or supplier) or 3 per cent, slow (in
favour of the purchaser). In all large centres of population an
inspector is appointed, whose duty it is, on payment of a small
fee, to examine any meters that may be submitted to him, and
to certify whether or not they comply with the requirements of
the Act. Should a meter at any time be thought to be register-
ing incorrectly, it is in the power of either the purchaser or the
seller of the gas to have the meter removed and forwarded to the
nearest inspector for testing ; and a certificate, duly signed by
such inspector, can be obtained. If the meter is found to be
correct, the parties who have claimed the examination of the
meter must pay the costs of carriage and the fee ; but if it is
found to be incorrect, the other side must pay the costs.
The meter in the consumer's house is, as a rule, though so
often found fault with, a most efficient measurer, each meter
being stamped by a Government official as being only liable
in the most extreme cases to the variations mentioned above.
Meters are of two kinds, known respectively as wet and
dry, and the methods of testing are explained later at
pp. 89-92, 95 and 96. Meanwhile it is expedient to describe first
the older form, or wet meter. The course of the gas through the
84
PR AG TIG AL GAS-FITTING.
wet meter is as follows :— The inlet pipe is on the front, and the
gas passes down through the valve-box, which contains a conical
valve with the seat fixed to a float, so that should the water in the
meter fall below a certain level the valve is closed ; and the same
effect results from an excess of water. From the valve-box the
gas passes up through the bent tube or spout into the outer
casing of the drum, which is open and common to all the com-
partments, but sealed by the water from direct passage to the
outside. The gas now enters that one compartment which has
its inlet above the water, the slight pressure of the gas causing
the drum to revolve so as to make a greater space for the gas,
and this revolution has the effect of immersing the previously
filled chamber more deeply into the water, and consequently the
gas is pushed out into the case and thence to the consumer. Of
course, the height of the water regulates the capacity of the
compartments. Many inventions have been brought out for
replacing the water lost through evaporation, some using a spoon
that delivers a small quantity of water at each revolution, others
having a compensating drum within the ordinary one so as to
allow a certain quantity of the gas to pass back when the low
level of the water has permitted too great a quantity for the
amount registered to go forward. The index is controlled by a
train of wheels set in motion by the revolutions of the drum,
which acts by means of a screw and pinion-wheel. A consumer's
wet meter, then, consists essentially of three parts. First, work-
ing partly in water, is a hollow drum or wheel, through which
the gas passes, producing a rotation, the registration of which on
an index indicates the quantity of gas being consumed ; secondly,
an arrangement for keeping the water at constant level; and
thirdly, the index. The drum is divided by cross partitions into
three or four chambers, into each of which the gas enters in
turn, the pressure of the gas causing the drum to revolve, and
the gas, from the chamber which has been filled just previously,
to leave by an opening on the further side from that in which it
was filled ; the water forming a seal by which the gas is prevented
from escaping direct into this outlet. The level of the water,
which must always be above the centre of the drum, is the
regulator of the quantity to be registered, as it may readily be
understood that if the water fills up a portion of the chamber
into which the gas is passed there will not be so much room for
the gas, and therefore the meter will register faster than was
GAS METERS.
85
intended. To prevent this occurrence to more than a stipulated
extent (2 per cent.) an overflow is provided, and as soon as the
full quantity of water has been put in an overflow provides a
passage for any further water which may be poured in, thus
preventing the meter from registering faster than it is set for.
To prevent the meter from registering slower than it is desired
(3 per cent), a valve (b, Fig. 54) is placed on the inlet, somewhat
after the fashion of a ball-cock in a cistern, the valve being fixed
upon a float c, which falls as the water grows less, from evapora-
tion or other cause, until the valve gradually closes, and the gas
can no longer pass into the meter at all.
Fig. 55, p. 86, is a cross section and Fig. 56, p. 87, a front view
of a wet meter. The reference letters indicate the same parts in
each figure : a A is a hollow drum which revolves in an outer casing
on the axis B. The drum is divided into four sections which
radiate from the axis. Each of these sections is filled in rotation
with gas passing through the pipe c into a box, from which it
o
o
Fig. 54. — Front Elevation of Wet Meter.
86
PR A G TIGAL OA S- FITTING.
passes through the pipe d. e e is the water-line, and f is the
gas exit pipe leading to the burners. G is a pipe with a screw
cap for filling with water, h is an overflow pipe for any excess
of water to run into J, whence it can be drawn through the pipe
with cap K. l is a ball float which closes the valve above and
stops the gas from passing when the quantity of water is too
little. M is a spindle, turned by the rotation of the axle B, and
Fig. 55. — Section of Wet Meter.
connected to the dials at jst. With too little or too much vater
in the meter, the quantity of gas passing through is not properly
registered. An objection to wet meters is the liability of the
water to freeze, stopping the supply of gas. Common salt has
been recommended as a convenient substance for preventing the
water in a wet meter from freezing, but it has the disadvantage
of rusting the inside works. A little glycerine mixed with the
Avater will generally answer the purpose. The addition of only a
GAS METERS.
87
small quantity of glycerine is sufficient, 2 per cent, being
suggested by some, or about two tablespoonfuls for a three-
light meter. It is said that the glycerine, however, has the effect
of reducing the illuminating power of the gas ; but this drawback
would be only temporary, as after a while the glycerine would have
absorbed all the hydrocarbons from the gas which it could hold
in suspension, and afterwards would not affect the illuminating
Fig. 56.— Front Elevation of Wet Meter.
power of the gas. The Royal Artillery authorities suggest the
use of a mixture of methylated spirit 7 gal., distilled water 3| gal.,
mineral oil I gal, and carbonate of soda 250 gr. to prevent freezing
in their hydraulic jacks ; but this would probably have a still
greater effect on the illuminating power of gas than would
the addition of glycerine. A good plan is to enclose the meter
in a large box, which may be packed with horse manure, felt,
slag wool, or other low conductor of heat, on the approach of
winter.
88
PR A C TIGAL GA S-FITTWG.
When a gas meter is actually frozen, probably the readiest
means of obtaining a light is to supply the meter with warm
water until the ice thaws, when the surplus water will escape by
the overflow. The water should be poured all over the meter,
and afterwards in through the hole which, covered with a screw
plug, is generally to be found on the right-hand side of the index-
box. The plug should be removed, as well as a smaller one at the
bottom of the front box on the meter, either at the side or in
front. The bottom hole is the outlet for the surplus water.
After as much as possible of the water has run out, return
both the plugs to their places. Water is sometimes carried with
the gas, causing the flames at the burners to jump or flicker.
The same kind of counting apparatus is employed in both
forms of meter. The initial measure of gas is the capacity of
one quarter of the measuring drum in a wet meter and of one
of the chambers in a dry meter (for description of dry meter, see
pp. 93 to 95), so that in the case of a wet meter four measures
or quarters constitute a complete revolution, and in a dry meter
usually four motions constitute also a revolution. The index
dials of a small gas meter up to 10-light are usually three in
number ; there are four circles or more on meters beyond that
size. In addition to this, there is often a small circle divided
into single feet, and indicating either 5 ft. or 10 ft. per revolution,
used for ascertaining the capacity of the meter ; it also enables
the consumer to find the hourly rate of consumption of all or
any part of his burners or fittings. The gas company, however,
in making out their bill, take no notice of this circle. The four
circles in Fig. 57 represent the indices of an ordinary gas meter.
The first circle at the right hand of the dial represents 1.000
cub. ft. per revolution of the hand, the subdivisions being
hundreds of feet. The pointer travels as do the hands of a clock!
The second circle from the right represents 10,000 ft. per revolu-
tion oftiie pointer, which travels in an opposite direction to the
first. The third circle represents 100,000 cub. ft. per revolution,
and the pointer travels in the same direction as that of the first
dial. Each pointer in succession travels in the reverse direction
from that of its neighbour, and the figures on the top of the
dial plate show each cubic foot of gas that passes through the
meter, whether consuming or escaping. The drum of a 3-light
meter (the capacity of a meter is indicated by " lights"— a light
= 6 cub. ft. per hour — a term explained more fully at p. 90) is
GAS METERS.
89
supposed to make 144 revolutions per hour, and this works out
to 18 cub. ft. per hour as the measuring capacity of the meter,
thus 125 X 144=18"0. The capacity per revolution refers to
one complete revolution of the measuring arrangement of the
apparatus, and this is transformed into even feet by suitable
gearing, so that one complete revolution of the small circle
indicates the passing of 10 cub. ft. of gas.
To take the state of a meter, commence at circle 1, and which-
ever number the hand has last passed will indicate hundreds.
In the case illustrated it is 7 or 700. (Bear in mind that it would
have to go right round to be 1,000.) In circle 2 the hand is
between the 4 and 5, but, although it is nearest to the 5, it is
called 4, which makes it 4,700. The reason why it is called 4,
and not 5, is because the hand has not reached 5, but has passed
the 4 and about three-quarters, or 700, over. In circle 3, the
hand is between the 8 and 9, very nearly half-way, which makes
the reading 84,700. The small circle above merely indicates
units, and, for reasons already explained, need not be regarded.
The indices of both wet and dry meters sometimes vary slightly
with different makers.
The testing of a wet meter is proceeded with as follows : — The
meter is filled with water until by its running over it is shown
that sufficient has been put in ; the meter is then placed on a level
bench, and the gas supply, at 3- in. pressure of water, brought
to it by bent pipes and connected to the inlet pipe A, Fig. 54,
p. 85, by rubber tubing, the outlet being connected in a similar
way to a line of gas burners, which are turned on and to which a
5.
Fig. 57.
Indices for Gas Meter.
90
PRACTICAL OAS-FITTING.
light is applied. When the gas has expelled all the air in the
meter and pipes, a condition indicated by the burners giving
a proper flame, all the burners are turned out except such a
number as will allow the consumption of not more than one-
twentieth part of the measuring capacity of the meter, and not
less than ^ cubic ft. per hour ; a small jet of gas is applied to all
joints and parts of the meter where leaks may be anticipated,
and if any show themselves they immediately take fire and are
easily detected, but if none are seen the meter is said to be
tight or sound. The next operation is to test the quantity of
gas capable of being passed by the meter, to ensure that it is
possible to obtain the amount of gas for which the meter is
intended ; and this is done by passing air from a holder of special
construction, graduated to a very fine degree, and verified and
stamped by Government officials. It is usually of 5| cubic ft. or
11 cubic ft. capacity, and throws a constant pressure of x 5 o m -
It is then noticed what quantity is passed during, say, one
minute, and this quantity multiplied by sixty gives, of course,
the capacity per hour. As during this test the outlet of the
meter is wide open, the amount passed should be considerably
more than the size of the meter would indicate. (It may be here
mentioned that meters are spoken of as for so many lights — a
somewhat misleading method of indicating the size, as lights are
of many different sizes, and consume very varying quantities of
gas, but it should be borne in mind that a light is supposed to
consume 6 cubic ft. per hour ; consequently, when a meter is
called a five-light it will pass easily 30 cubic ft. per hour, and
this will be useful to recollect when gas-stoves are being fixed
and the size of meter desirable is wanted.) A cap with a hole in
it, to restrict the passage of the gas, is fitted on to the outlet of
the meter, and allows just the quantity to pass which the meter
is intended for ; and if the meter be a new one, it is usual to
test it before it is quite complete — that is, before the upright
spindle, connecting the axle of the drum with the index, is
mounted with the small leaden drum which is to be seen above
the index dial in all such meters when complete. In this case
a brass disc of some 3 in. in diameter is mounted in its place,
this disc being carefully divided so that the revolution of the
spindle can be accurately gauged. It is now easy to see whether
the amount passed from the holder is being registered by the revo-
lution of the spindle, and the percentage fast which the meter is
GAS METERS.
91
now showing can be easily ascertained ; by passing, say, an exact
cubic foot by the revolution of the disc, it will be found, if the
meter be correct, that T §oth s less than a cubic foot only have
passed out of the holder. If this amount is not indicated, but
a less quantity only has left the holder, the water level has to
be raised, and this is done in different ways. In the usual form
of meter the overflow consists of a tube threaded some distance
up, and screwed into the division-plate between the water space
and the overflow chamber. The top of this tube forming the
water level in the meter, it can screwed up or down, and fixed
to its correct height by a back-nut (see Fig. 58).
In the case just mentioned the meter was measuring too fast,
and therefore the water level was too high ; the overflow tube
would have to be screwed lower down, the back-nut being
Fig. 58.— Back-nut. Fig. 59.— Enlarged View of Valve.
loosened first, and tightened when the proper level was obtained.
Another form of wet meter has the overflow tube made of tin-
plate, and bent so that it can be raised by a screw from the outside
without damage to the pipe or the trouble of undoing the meter
front to correct the position of the water-line; in fact, it is
common to use a piece of plate-glass fixed to the front of the
meter with putty and lashed to it by cord until the water-level
has been correctly ascertained. All this is avoided by the above-
mentioned arrangement, shown in Fig. 54, p. 85, and in detail at
Fig. 59, in which the head of the screw is afterwards embedded
in sealing-wax with an impression upon it to prevent tampering.
So much suffices for the capacity at high-water level. Now the
water has to be syphoned off until it is found that the valve b
(Fig. 54) above the float c has closed, when water is returned to
the meter until the valve is sufficiently opened to allow the full
quantity of gas for which the meter is constructed to pass;
Fig. 58.
92
PRA C TICAL OA S-Fl T TING.
then the holder is again connected, and the comparison made be-
tween its record and that shown by the disc. If it be found that
the holder registers more than 3 per cent, above that shown by
the disc, the position of the valve b, Fig. 54, p. 85, has to be altered
Fig. 60. — Dry Meter in Glass Case.
— raised or lowered on the float spindle by screwing it up or down,
or by soldering it in a fresh position on the spindle, according as
the percentage is greater or less than the 3 per cent, allowed by
the Act. The meter is now ready for the official prover, who
tests it at both high and low water level before certifying. When
GAS METERS.
08
the meter is complete and the leaden drum is fixed, it will be
noticed that there are divisions and figures on it which repre-
sent cubic feet, and these have to be used instead of the brass
disc.
The action of the dry meter depends upon the alternate
expansion and contraction of flexible leather chambers of a
definite capacity, the motion of these chambers being communi-
ng. 61. — Side View of Dry Meter.
cated by a series of levers and cranks to the wheelwork of the
index. Dry meters are made with either tinplate or cast-iron
cases, and contain two or more circular measuring chambers, one
on each side of a centre plate, to which they are attached. The
ends of these chambers are made of a special white metal, and
the sides consist of diaphragms of flexible leather, usually
Persian sheepskin. These open and shut like circular bellows,
and when fully extended regulate the measuring capacity of the
meter. Connected to each chamber is a slide-valve, through
which it is alternately filled with and emptied of gas, the move-
94
PR AC TIC A L GA S-FIT HNG.
rnent of the circular metal ends being communicated to the
index by an arrangement of cranks and levers. Figs. 60 to 62
illustrate such a meter, made with a glass case, and afford very
clear views of the mechanism of one of the best-known meters.
Fig. 60, p. 92, gives a front view of this meter, Fig. 61, p. 93, a side
view, whilst Fig. 62 gives a sectional view of the valves and passages.
The internal construction of a very similar meter is shown in
the front view (Fig. 63), in which o is a tinned iron case with an
Fig. 62. — Section of Dry Meter.
upper chamber p, in which are the valves and gearing for the
passage of the gas to and from the measuring chambers. These
latter are in the lower part, and consist of two flat discs (one
is shown at q) of tinned iron, with flexible leather sides at E jr.
The back edges of the latter are fixed to a central vertical parti-
tion which divides the lower part of the meter into two. The
discs and leathers act similarly to a bellows, and alternately
fill and empty. As the bellows fill, the gas in the chambers in
which they work is expelled ; and, as the bellows empty, the
chambers re-fill. The capacities of the chambers being known,
the quantity of the gas passing is registered by the dials s, which
are turned by gearing attached to the discs, or moving parts of
GAS METERS.
95
the bellows. Dry meters are now much used in preference to wet
meters, as they do not require so much attention, and contain no
water to freeze. They should, however, be periodically tested, as
they become defective by the constant wear of the leather and
the liability of the latter to become hard and brittle by age.
The principle of the dry meter is that of a pair of circular
bellows into and from which the gas passes alternately : which
bellows are capable of being regulated to open only to such
Fig. 63. — Front View of Dry Meter.
a degree at each filling that they may thus contain a certain and
defined quantity ; then, with a means of registering the number
of times the bellows are filled and emptied, the meter becomes a
recording measurer of the amount of gas passed through it.
Now, as to testing such a meter. The bellows, made of
Persian sheepskins, having been tied on to the rims with wire,
and thoroughly oiled with fish oils, all surplus being allowed to
drip off, are fixed to the meter, which is then taken to the testing
98
PRACTICAL GAS-FITTING.
holder, gas is passed into each of the bellows alternately, and a
light is applied all round them to see if there is any leakage.
If all is satisfactory, the casing-in of the meter is proceeded with ;
and when this is completed, and the slide-valves of white metal
have been ground to fit accurately against the gratings provided,
gas is again passed through the meter to ascertain if the slide-
valves, which cause the gas to enter and leave the two chambers
alternately, are quite tight. This is most important, as any leak
here may cause jumping lights or an irregularity in the regis-
tration of the meter, p. 89. If they be found tight, the next step
is to test the case for soundness in the same manner as was de-
scribed for the wet meter. This proving correct, the meter is tried
for correctness of registration. There being no water-line or float
to these meters, they are only capable of giving one defined
quantity— namely, that for which they are set ; but they must
nevertheless conform to the Act by not registering more than
2 per cent, fast nor more than 3 per cent. slow. If on examina-
tion they err in this respect, the extent to which the bellows is
allowed to open must be regulated accordingly as the meter is
registering too fast or too slow. This can be done by moving
the small pin on the crank, to which the levers attached to the
outside of the bellows are joined, and which causes the index of
the meter to revolve by means of a worm and wheel. The longer
the crank the greater distance the bellows can expand, and vice
versa. This being put right, the official inspector has the meter
passed into his hands, when he again tests for soundness and
accuracy of registration, stamping the top cover of the meter in
such a way as to ensure that the registration cannot be again
altered without breaking the seal. He enters the number of
the meter in his book, and, if required, grants a certificate of the
exact result of his test.
It will now be sufficiently clear why, as remarked on
p. 59, care should be exercised in the choice of the position
in which the meter should be placed ; and the gas-fitter who has
carefully followed the foregoing descriptions of the wet and the
dry meters, will be the better able to advise when his opinion
upon the subject is asked for.
!»7
CHAPTER VI.
GAS BURNERS.
While much has been written upon the principle involved in
obtaining a light from gas, very little is generally known by the
public as to what is required and what is the best means to adopt
to secure the greatest amount of light at the least cost, and with
the least vitiation of the atmosphere of the room where the light
is required. Many and various improvements have been brought
forward for the accomplishment of these objects ; some require only
a very slight alteration to the existing fittings and yet give very
excellent results, while others secure a very high illuminating
effect and at the same time not only remove the vitiated air
which has been used to support the combustion of the flame,
but at the same time carry off the air rendered useless for sup-
porting life by the inspiration and absorption of the oxygen.
Before describing the various types of gas burners, the prin-
ciple which is involved in the burning of gas may with advantage
be mentioned ; it has been touched upon in former chapters. Coal
gas contains many very different substances ; about one-half of it
is hydrogen, one-third marsh gas, and perhaps one-tenth is carbon
monoxide. The absolute composition of London gas, as stated by
Professor Vivian B. Lewes, is given at the top of the following
page.
The three gases mentioned in the statement are of no value
as regards the light they will give by themselves, but they are
capable of giving a great heat when ignited, and this heat is
utilised for the purpose of rendering white hot the small quantity
of hydro-carbons in the gas, and it is this incandescence of
the very finely divided carbon particles which makes the flame
luminous
(t
98
PEA O TIGAL GAS-FITTING.
Professor Lewes's statement is as follows : —
Per cent.
Hydrogen
about 52 0
Unsaturated hydro-carbons
3'5
Saturated hydro-carbons
34-4
Carbon monoxide
„ 6-25
Nitrogen
33
Carbon dioxide
o
Oxygen
... ,\ -25
nil.
Sulphuretted hydrogen
ioo-o
When a gas burner is lighted, the rush of gas from the orifice
of the burner causes a current of air to pass upon each side of
the flame, and thus supply the oxygen necessary to support com-
bustion ; the portion of the flame nearest to the burner is almost
non-luminous, and is, in fact, unignited gas enclosed in a thin
envelope of bright blue flame. That this is really unconsumed
gas can be shown by placing the lower end of a glass tube into
this portion of the flame and applying a light at the upper end,
when the gas issuing from it is seen to burn with an ordinary
flame. The reason that this portion of the gas is not luminous is
that the quantity of oxygen which is able to get to the flame at
this point is only sufficient to cause the outer portion to be in a
state of incandescence. That there is solid carbon in the flame
may be seen by inserting a piece of cold metal or porcelain in
the white portion of the flame, which, by reducing the temper-
ature of the carbon, becomes coated with soot upon the under
side. The same effect takes plate when the cold air is allowed to
blow upon the surface of the flame, the excess of oxygen pre-
sented to the flame causing a cooling of the heating gases and a
consequent loss of light, as the particles of carbon are not then
sufficiently heated to be made white hot and to give off light,
and they then allow the carbon to pass off in the form of soot
and to blacken the ceilings and paint of the rooms. This is
more likely to occur with high quality gas, which contains more
particles of hydro-carbons ; and if there be an insufficient supply
of oxygen to the flame a larger proportion of s"oot will be allowed
to escape and settle upon the ceilings, etc. Another source of
blackening of the ceilings is the nearness of the burners and
GAS BURNERS.
99
the absence of a guard (such as a coronet or bell glass) over them
to deflect and spread the products of combustion over a large
space. The real explanation of this effect is that aqueous vapour
formed by the burning gas is condensed on the ceiling, and dust
particles which are floating in the air are thereby caused to adhere
to the ceilings. With high quality gases small burners should
be used, so that the gas may be more thoroughly consumed.
It appears that the first burners were simply pieces of pipe
with one end stopped up. In the centre of the end was drilled
a small hole ; and the light given off, principally owing to the
shape of the flame, was very small. Then was invented the
batswing burner, which has a slot cut in the dome-shaped top,
and this gave a flame somewhat of the shape of a bat's wing,
hence the name. Then came the union jet, which is an arrange-
ment very generally in domestic use at the present day. It
consists of a piece of brass tube plugged with a piece of steatite
or porcelain with two holes in it drilled at such an angle that
the two streams of gas issuing from them meet, and cause the
flame of gas to spread and form a flame of horseshoe shape.
One of the special points to be noticed in these burners is that
the holes in them should be of comparatively large size, and the
pressure of the gas when delivered from the burner reduced
to the lowest point at which a firm flame can be maintained ;
this can be done best by means of what is known as a governor,
which is in effect a self-acting valve which allows only just so
much gas to pass as may be required.
Passing on to the more modern styles of burners, of which
there are many patterns, such as the regenerative burners of
Sugg, Wenham, Deimal, and many others, it is found that all
these embody the same principle, which is to use the heat gener-
ated by the flame to heat the gas supply and the air supply so
that the cooling effect of the air, which causes the blue portion
of an ordinary flat flame, is considerably reduced, and the
particles of carbon are rendered more rapidly incandescent, and,
being heated to a greater temperature, attain greater luminosity
and are kept for a longer period at this white heat.
The earliest arrangement of such a burner was invented in
1854 by a Rev. Mr. Bowditch ; and his burner consisted of an
argand with two chimneys, one outside the other, the air supply
to the flame having to pass down between the two glasses, and
so to become heated before it was led to the bottom of the burner.
100
PRACTICAL GAS -FITTING.
This answered very well, but the breakage of the chimney glasses
was a considerable expense, and debarred many from adopting
the system. This trouble is quite overcome in the modern re-
generative burners, as the chimneys are made of metal and the
burner is inverted, so that the flame is spread outwards instead
of, as in the argand burner, upwards. The regenerative
burner gives a light having four times the illuminating power
of the flat-name burner.
With the incandescent burners, quite a modern invention, the
principle of admitting air to mix with the gas before lighting is
employed as in the Bunsen heating burner, and this, while taking
away the luminosity of the flame, causes it to give off a much
greater amount of heat, this heat being utilised to render a
mantle of rare earths incandescent or white hot. These mantles
are made conical in shape, and when made white hot emit a
most pleasing white light, which is about five or six times
more intense than that given off by the ordinary flat flame
burner.
With a properly arranged ventilating regenerative burner,
consuming 20 cubic feet of gas per hour, and properly fitted,
not only can all its own products of combustion be removed,
but also the air vitiated by breathing can be removed at the
rate of more than 5,000 cubic feet per hour from the upper
part of the room.
The comparative quantity of air vitiated by different illuinin-
ants giving the same amount of light is shown by the following-
table : —
Gas burnt in union jets 1
Lamp burning sperm oil 1'6
„ paraffin oil 2"25
Sperm candles ••• 2 ' 65
Tallow candles 4 ' 3r >
From this table it will be seen that paraffin lamps use up more
than twice the amount of the oxygen of the air that gas does,
while tallow candles use more than four times the amount.
Professor Vivian B. Lewes found that, for a light of thirty-two
candle-power, sperm candles would vitiate as much air as would
be required by about twenty-two adult persons ; paraffin oil
lamps as much as fifteen adults ; while London gas varied from
an amount of air required for nine and a 'half adults when a
GAS BURNERS.
101
batswing burner was used, to eight and a half when an argand
burner was used, and to two and a half when a regenerative
burner— in which the products of combustion were allowed to
pass into the air of the room— was employed. In these experi-
ments not only was the quantity of oxygen consumed taken into
consideration, but carbon dioxide and the water vapour were all
taken account of.
Special attention must be directed to the necessity of having
burners suitable to the quality of gas which is being used. It
may be taken as a fairly general rule that the higher the illuminating-
power of the gas the smaller the burner should be. With London
sixteen candle-power gas, the 5-ft. per hour, or No. 5 union jet, is
very suitable, but with a sixty candle - power gas a No. 0 or
No. 00 burner is much more efficient. With unsuitable burners,
not only blackening of the ceilings, but a far lower state of
efficiency as regards the illuminating power of the light obtained
from a given quantity of gas will result.
The effect of using bad burners is primarily that the light
capable of being developed from the consumption of a definite
quantity of gas is not obtained : consequently more gas is burnt
than necessity requires ; in other words, gas is wasted, and with
imperfect combustion, deleterious products are given off, vitiating
the atmosphere and endangering health.
That the burners which are most economical in gas consumption
are the most expensive at first cost is certainly the case to some
extent; but the amount of the saving effected by their use
quickly repays the first cost, and thereafter the money saved
goes directly into the pocket of the user of the burner. The
incandescent burner is the most economical burner that is at
present known, and where gas is at a high price it is a very
distinct advantage, as the quantity of gas required for a given
amount of light is only about one-fifth of that used witli the
ordinary burner. The regenerative burners come next in point
of economy, and these are of many patterns, all very much on
an equality. Then comes the argand burner, which is superior
to the union jet or flat-flame burner ; but in all these an arrange-
ment known as a governor is generally to te found, by which is
regulated the quantity of gas that can find its way to the point
of ignition, and, if only just sufficient is allowed to pass so
that none is wasted, gas is economised. These governors are
also made for use with the ordinary flat-flame burner.
102
PRACTICAL GAS-FITTING.
As Las been said, the principal gas burners now in use are the
flat-flame, argand, regenerative, and incandescent. Flat-flame
burners embrace the union jet, or fishtail, and the batswing. In
the union jet or fishtail the gas issues through two apertures in
a steatite plate inserted in the top of a cylindrical brass tube,
screwed at its lower end for the purpose of attaching to a gas-
bracket. The holes in the steatite tip through which the gas
issues are inclined towards each other at an angle, so that the
gas issues in two streams which unite into one flat flame at right
angles to a plane passing through the two holes. One of the
reasons of the adoption of steatite for the tip of the gas burner
was the fact that it required a very high heat to harm it. Steatite
is a natural stone found in various parts of the world, principally
in Germany. Chemically it is a double silicate of magnesium,
and a substitute for the natural substance may be obtained by
mixing silicate of magnesium and silicate of potash. Natural
steatite is of a very fine grain, and softer than ivory ; it admits
of being worked to a very fine polish, but after it has been
burned in a kiln it becomes harder than the hardest steel, and
will resist a very high temperature— say 2,000° F. (1,093° C). In
forming the steatite into burner tips, the material is finely
powdered, moistened with water, and kneaded into a plastic
condition, after which it is moulded to the requisite shape and
finally burnt to harden it. The diameter of the orifices in the
steatite tip, through which the gas issues, differs in size, the aim
being in each case to produce a flame of a thickness suited to
the quality of the gas the burner is intended to consume.
The batswing burner resembles the fishtail or union in its
general features, but differs in the manner in which the gas issues
from it. In this form of burner the hollow tip is made dome-
shapecl and has a narrow slit cut across it and extending some
little distance down. The slit varies in width to suit different
qualities of gas. The batswing burner requires less pressure than
the union jet, with the result that the gas issues with less force,
so that the flame produced in burners of this class is not so stiff
as that obtained with a union burner. Consequently it is neces-
sary to employ globes with burners of this description in order to
protect them from draught, which would cause them to flicker
and smoke.
Sugg's table-top burners (Figs. "73 and 74, p. 104) are prevented
from flickering by providing a rim just below the steatite tip,
Bray's Burners.
Regulation Union Jet
Special Union Jet_ ...
Regulator Slit Union
Special Slit Union ...
Regulator Batswing...
Special Ratswing
GAS BUHNERS.
103
while the large batswing burners employed in street gas lamps
have side wings, or lugs, for the same purpose.
The gas consumption in cubic feet per hour, and the
illuminating power in candles of Bray's flat-flame burners, the
gas being supplied under a pressure of ten-tenths, or one inch,
are shown in the table below. Some of the figures may appear
inconsistent, but all are based on tests made by Mr. T. Fairley,
at the instance of the Leeds Corporation.
Gas Consumption. Illuminating Poicer.
No.l.
No. 3.
No. 5.
No.l.
No. 1.
No. 3.
No. 5.
No. 7.
39
4-8
7-97
8-65
4-72
0-9
20
25
4-02
4-9
6-67
8-05
8 '3
15-6
24-4
30-2
4-8
637
8-14
9-04
14
20-2
28 % 4
37-2
353
461
6 37
8-6
10-2
16-4
23-4
33-4
4-26
5-64
G-93
10
10
16-6
20-4
39-8
3-86
5-25
5-85
8-72
13-2
20-4
22-6
38
Whilst it is thought advisable to illustrate the better-known
flat-flame burners now in use, limitations of space will not allow
a detailed description of them. In most cases, their construction
is simplicity itself, and the illustrations, taken with the principles
just set forth, should provide sufficient explanation.
Dealing first with union or fishtail burners, Fig. 64 shows
Bray's ordinary burner ; Figs. 65 and 66, Bray's special unions ;
Figs. 67 and 68, Bray's slit-unions, which outwardly resemble
batswing burners; Figs. 65 and 68 show burners screwed for
supporting the gas globe holder. Of regulator union burners,
Bray's slit - union is shown by Fig. 69 ; Bray's adjustable
union burner, shown by Fig. 70, is in two parts, and by sub-
stituting for the lower tip one larger or smaller, the pressure
of the gas may be regulated as required ; thus Fig. 70 represents
a No. 3 lower tip in a No. 6 upper tip. Hawkins and Barton's
governor union burner is shown by Fig. 71 .
-Batswing burners are of many makes ; Bray's is illustrated by
Fig. 72. Sugg's well-known table-top burners are shown by
Figs. 73 and 74. Falk,' Stadelmann and Co. make and sell a
variety of batswings, among them being the "Comet" burners,
Fi«a 75 and 76, the "Veritas" burner, Fig. 77, and the duplex
GAS BURNERS.
105
106
PRACTICAL GAS-FITTING.
GAS BURNERS.
107
batswing, Fig. 78. Of regulator batswing burners may be
mentioned Bray's adjustable burner, Fig. 79 (constructed on the
same principle as is the union jet, Fig. 70). Goodson's patent
governor burner is shown by Fig. 80, Peebles' male and female
governor burners respectively by Figs. 81 and 82, the former
being in section, and Hawkins and Barton's governor batswing
Fig. 94. — Imperator Argand Burner.
burner by Fig. 83. The "Victoria" or "Ellis" burner, illus-
trated by Fig. 84, has a regulator inside the gas chamber.
Sugg's governor burner having a steatite float is shown by
Fig. 85. •
Burners for street lighting are, of course, larger than those for
domestic use. Bray's "Standard" burner for street lighting is
illustrated by Fig. 86 ; street burners sold by Falk, Stadelmann
and Co. are shown by Figs. 87 to 89. Fig. 90 shows Goodson's
108
PRACTICAL GAS-FITTING.
combination street governor. A tripod burner without a
governor is shown by Fig. 91, and a descending cluster by Fig. 92 ;
all the street burners mentioned above are of the batswing type.
The argand burner differs from the flat-flame burner principally
in the manner in which the burner obtains its air. This is by a
glass chimney, and air is also directed by a special contrivance on
to the flame. In the argand burner gas is conveyed into the interior
of the hollow ring, the steatite top being perforated on its upper
surface with a number of holes for the emission of gas (see
Fig. 93). Through these holes the gas issues in a series of
Jets which immediately coalesce to form one cylindrical sheet of
flame. Surrounding the burner is a glass chimney, supported on
a brass gallery connected with the lower portion of the burner.
The chimney serves to shield the burner from draughts of air, and
also to draw up on to the surface of the flame the air necessary
for its proper and complete combustion; a small metallic cone
placed between the chimney and the burner orifices also assists
the action of the chimney by directing the air supply upon the
surface of the flame. Fig. 94 illustrates the " Imperator " form
of argand burner.
The argand burner is constructed in such a manner that
the combined sectional area of the tubes which supply gas
to the hollow ring is less than the aggregate area of the holes
in the burner through which the gas issues, the result being that
the gas issues from the burner at a considerably less pressure than
that at which it enters.
The regenerative system lends itself admirably to purposes of
ventilation, as by its use a room can be freed from any obnoxious
vapours, and fresh air, warmed if desired, can be drawn in.
Again, the products of combustion need no longer vitiate the
atmosphere in the room which is being lighted, as these can be
carried off direct into the open air. The methods adopted for
this purpose will be described in the following pages.
It might be well to point out that with the incandescent
gas burner the necessity for removing the products of combustion
is considerably lessened, owing partly to the diminished quantity
of gas used, and partly to the more perfect combustion of the
gas and a lesser generation of heat. The incandescent burner is
free from the objection to the regenerative system in that all the
reflective power of the ceiling is brought into use. Its con-
struction and use form the subject of Chapter VII., pp. 119— ]-2C.
GAS BURNERS.
109
In regenerative burners the waste products of combustion
from the flame are employed to raise the temperature of the gas
before it is ignited, and also of the air necessary for the combus-
tion of the gas. This not only results in an increased efficiency,
but also in a great improvement in the quality of the light,
which, being emitted by incandescent carbon at a higher
temperature than with open-flame burners, is much whiter and
more brilliant.
The principles set forth above are utilised in regenerative
burners in the following manner. The burner itself, _ which is
circular, somewhat resembles an inverted argand without its
chimney, and is arranged so that the name is enclosed in an air-
tight glass shade and is prevented from coming into contact with
the outside air. The name is deflected by a plate of porcelain,
and passes in an upward direction towards the interior of the
burner. The gas and air flow through separate pipes to supply
the burner, and they are heated by the waste products of com-
bustion as they pass through a series of pipes, or flues, the walls
of which are in contact with the heated products. The method
in which this contact is brought about is the chief difference in
the various patented burners of the regenerative class.
The advantages of the regenerative system of improving the
illuminating power of gas are well known. In practice it can be
said that, by means of the regenerative system, an equal quantity
of light can be obtained by about one-third the consumption
effected by the flat-flame burners in the usual type of fitting;
while for a given consumption it is safe to reckon upon almost
treble the light from regenerative lamps as from ordinary burners.
It must, however, be borne in mind that there are certain incon-
veniences connected both with the fitting and with the
maintenance of regenerative lamps, and that there is also some
risk of failure arising from bad fitting.
The principle is very simple. All that has to be done is to
exclude cold air from contact with the flame, and to supply
instead a stream of heated air, warmed by the waste heat
generated by the flame itself; then, by turning the argand
burner upside down, a double or treble duty is got from the gas.
If an equal quantity of light is obtained from less than half the
quantity of gas, it follows that less vitiation of the atmosphere
results ; and further, when the source of light and point of con-
sumption of the gas is very much nearer the ceiling, the room must
110
PRACTICAL GAS -FITTING.
be healthier to a corresponding degree. Thus much may be claimed
for the ordinary non-ventilating regenerative lamp, which dis-
charges the products of combustion near the ceiling. The funnel-
shaped top to these lamps leads to the inference that a greater
quantity of the deleterious products of combustion is given off
through that top, while the hygienic consequences of the fact that
the quantity of gas used is far less than in the case of the
ordinary burners are quite ignored. It is true that the heat of
the air near to the lamp itself will probably be greater than it
would within the same distance of a gasalier ; but the objection
otten urged against gas-lighted rooms refers less to their thermo-
metnc heat than to the vitiation of the atmosphere and the
consequent feeling of oppression ; and this evil is not present
when a regenerative lamp is employed.
The incandescent burners, with the greatly increased duty
per cubic foot of gas which they afford, have rendered the sale of
the ordinary regenerative lamp comparatively small ; still, the
advantage of the ventilating type of lamp is great. So efficient is
it in this respect, that plants and flowers may with safety be left
in rooms where it is in use ; whereas gas burned in the ordinary
way has a marked injurious effect.
Sugg's " Sandringham " regenerative lamp, a handsome fixture,
is illustrated by Fig. 95, and from a sectional view given at the
top may be gleaned the principle that governs the less elaborate
lamps as well as the one illustrated. There are many obstacles to
absolute efficiency in the ventilating regenerative system. For
instance, the difficulty of getting access into the proper chimney ;
and there is always uncertainty as to securing a good up-draught
W hen joists and angles prevent connection with the chimney of
the room in which the regenerative lamp is to be fixed, flue pipes
are sometimes led into an adjoining chimney; but to do this is to
court failure, or at best the success will be accidental. A point
which is often overlooked is the securing of an efficient fresher
inlet to the room, which is as essential as a good outlet. So
uncertain is the result of connecting ventilating lamp flue-pipes
with the chimney flues that, where possible, it seems better to
carry separate flue-pipes to discharge above the roof. But it is
always necessary to pack non-conductive material round the flue-
pipes their entire length, and to use an exhaust ventilator, double-
cased and packed in the same way, otherwise the best ventilator
will, under certain conditions, act as a refrigerator, and prevent
112
PR A G TIGAL GAS-Fl TTING.
the exit of the heavier gas. When it is impossible to carry a flue
direct from each lamp to the top of the building without running
into the ordinary chimney, the object may be effected by cutting
out a hole in the chimney, and putting a course of bricks, prefer-
ably with a bevelled edge to prevent the accumulation of soot, so
placed as to project, say, 1 in. or Ik in. into the chimney space,
and thus reduce the area of the flue immediately below the
entrance made for the introduction of the flue-pipe from the lamp.
By this method the amount of draught available for the coal fire
below is somewhat reduced, it is true, but not to such an extent
as to appreciably affect the proper burning of the stove ; the flue,
if used solely for a gas lamp, would be sufficiently large if it were
only about 3 in. or 4 in. diameter.
Too much stress cannot be laid on the necessity of carefully
packing with either asbestos or slag wool, or some other suitable
non-conductor of heat, the flue pipes carrying the products of
gas flame, more especially when these flue pipes are in close
proximity to timber. It must be remembered that, although the
heat given off by the pipes is not sufficient in the usual way to
set fire to any woodwork, still, in time soot may accumulate and
get heated ; and, in any case, a continuance of the temperature
that occurs near the flue-pipes is exceedingly hurtful to timber,
causing it to lose its nature and to decay. A good plan of
preventing any trouble in this way is to coat the pipe with non-
conducting composition and then fit a sheet-iron pipe over this
composition ; or the smaller pipe can be placed inside the larger,
and the intermediate space packed with slag wool before it is
placed in position between the ceiling and floor. An efficient
ventilator cowl must be used, so that a down-draught cannot
possibly occur. There is a considerable choice of these cowls, but
with any of them the recommendation made previously as to
packing the outside of the ventilator with some non-conducting
composition must be followed.
The ventilating tubes should be so laid that any moisture
from condensation may find its way to a drip-box. Glazed
earthenware soil pipes for flues are good and lasting, and these
may be carried up inside the chimney flue to the top ; they will
be kept warm by the gases from the coal fires, and so assist in
the ventilation. But the necessity for a drip- box for the con-
densation water must not be overlooked.
The flue should be of such a size that it will carry off just as
GAS BURNERS.
113
much air as the lamp will remove— no more and no less ; and to
do this the height of the flue, the diameter, the number of curves,
and the size and position of the room chimney in respect to the
lamp's position, and again the quantity of the fresh air which is
to be admitted into the room, should all be taken into considera-
tion. If sufficient fresh air is not admitted to supply both the
coal-fire chimney and thegJamp, the probability is that the lamp-
flue will be called upon to supply the deficiency, a down-draught
will ensue, and then the lamp will prove an utter failure.
For the supply of fresh air to a ventilating regenerative lamp
there is nothing more simple nor more effective than the Tobin
tube, which can be fitted up in any room at little expense. This
consists of a rectangular tube, say 9 in. by 3 in. or 4 in., fixed
against an inside wall, reaching to about 6 ft. above the floor, with
a hinged lid on top, and through the wall at the floor level an
opening to the bottom of the tube. By this air is drawn in and
let out above the heads of the occupants of the room, and draughts
are avoided. The tube can be made to fit in the corner of a room,
and need then only consist of a flat board fixed in the angle.
It has been found that a vertical fine, 6 in. diameter, 12 ft.
long, when a gas burner consuming only 1 cub. ft. per hour is
burning inside it, will remove 2,460 cub. ft. of air per hour. Thus
it will be seen that a cubic foot of gas in a ventilating shaft can
be made to remove more than 2,400 times its own bulk of air, and
the gas which is consumed in rooms might thus become a most
valuable adjunct to the ordinary means of ventilation, and
improve sanitary conditions. If each room in which gas is used
were connected to a flue in which a gas-burner could be kept
alight, the products of combustion arising from the use of the gas
might be carried away as rapidly as made, and with them might
be taken the vitiated atmosphere exhaled from the lungs; the
flue should be made of such a size as to allow of a complete
change in the air of the room every ten minutes. Thus, given ten
rooms, each 12 ft. by 12 ft. by 10 ft., of which it was desired that
the air should be changed entirely every ten minutes : this could
be done with the use of some 36 cub. ft. of gas per hour. But this
is far more than need be allowed in most cases, and it would
probably suffice to allow for only one third of the air to be
changed once every twenty minutes, which would require about
6 cub. ft. of gas. By the consumption of this quantity, absolutely
fresh air might be obtained iu the rooms of a ten-roomed house.
H
114
PRACTICAL GAS-FITTING.
The atmospheric and the illuminating flame appear to have the
same effect in all cases where a large quantity of air has to be
heated to a low temperature. The maximum consumption of
gas in a ventilating flue should not exceed 5 cub. ft. per hour for
each circular foot area of section. The remarks previously made
with regard to the necessity of admitting fresh air to equal the
quantity taken out apply in like manner in this case, and the
object may be effected by the same means.
The gas consumption and illuminating power of Sugg's
regenerative lamps are stated by the makers to be as follows :—
Size.
Hourly Consumption of
Vo-candle-power gas.
Illuminat ing Power
with Reflector.
3 cubic feet
28 candles
4 „ ,-,
37 „
1
6 „ »
72 „
2
10 „ „
150
.3
15 „
240 „
4
20 „ „
320 „
The following table gives the duty obtainable from burners
of different types when burning 16-candle coal gas :—
Burner.
Light Obtained per
Cubic Foot of'Wcandle
Gas Consumed.
Caudle Units.
Incandescent
14"9
Regenerative
io-o
Stand ard argan d
3-2
2-9
Ordinary argand
Flat-flame, No. 7
2-44
» 6
2-15
>' ; > ■••
1-87
4
T74
>) ■>■> ^
» 3
1-63
2
1-22
» 1
0-85
„ o
0-59
Following these remarks on the ventilating regenerative
burners, it is appropriate that Strode & Co.'s "Sun Burner"
should receive consideration. This burner was introduced many
years ago, but the patented gas burner and ventilator now on the
Fig. 96. — Strode's Sun Burner.
116
PR A GT1GAL GA S-FITTING.
market is a great improvement on the original invention. V>y
an arrangement of cones, heated air is introduced to support the
combustion of the gas, thus obtaining high illuminating power
and good ventilation of the apartment, the whole of the products
of combustion being carried off through the perforations which
surround the Sun burner cones ; a flue running through the
ceiling is connected to the Sun burner, and discharges the un-
desired gases. Thus the inside atmosphere is not vitiated by
the burning gas, but an efficient system of ventilation is provided.
Of course, the very utmost attention must be given to the ar-
rangement and putting in of the flue, as on the efficiency of
this rest the illuminating power obtained and the working of
the ventilating system. Fig. 96, p. 115, illustrates a pattern
of Strode's Sun burner fitted with an outer ventilating shaft and
an extract wind-guard. The sizes and principal dimensions of
the new patent Sun burners are given in the following short
table, compiled from particulars furnished by the makers :—
Number
of
Jets.
Extreme
Diameter
of Sun
burner.
Diameter
of Inner
Cone.
Diameter
of Out-
side Case.
Diameter
of
Flue Pipe.
Illum-
inating
Power in
Candles.
Diameter
of Gas
Supply
Pipe.
6
9
15
32
41
65
16 in.
24 in.
29 in.
38 in.
48 in.
58 in.
10£in.
14fin.
18^ in.
27 in.
34 in.
42 in.
16 in.
24 in.
29 in.
38 in.
48 in.
58 in.
5 in.
6 in.
10 in.
12 in.
14 in.
16 in.
144
220
360
800
1,000
1,500
% in.
lin.
| in.
1 in.
U in.
H in.
The principle of the albo-carbon light depends upon the
carburetting of the gas with the vapour of a hydro-carbon
obtained from a solid substance, which may be naphthalene.
Naphthalene is obtained from coal-tar, and has the formula C l2 H 3 ;
it melts at 175° F., and boils at 410° F., but when it is raised
to a temperature of 212° F. a hydro- carbon vapour is given off
sufficient to saturate the gas with its full amount of carburetting
material. Fig. 97 is a sectional view of a common form of
albo-carbon fitting. In most of these fittings is an aperture
for charging the vessel with the small fluted cylinders ; the
aperture is closed by a screwed plug. The gas-supply pipe in
the interior of the vessel is carried sufficiently high to be above
GAS BURNERS.
117
the melted naphthalene, and is bent down, or a hole is made in the
under side of the pipe, so that the gas shall blow directly on the
surface of the carburetting material. The outlet pipe is usually
taken from near the top of the vessel, and is bent downwards 4 in.
or 5 in., and again bent so that a burner may be fixed in a vertical
position. From one side of the vessel, and immediately above
this burner, projects a blade of copper which, being heated by the
flame of the burner when alight, conducts an amount of heat to
the body of the vessel sufficient to vaporise the naphthalene ; so
Fig. 97. Fig- 98.
Yig. 97.— Section of Albo-carbon Gas Burner. Fig. 98.— Fitted
Albo-carbon Gas Burner.
that the flame of the burner performs the work of vaporising the
hydrocarbon for its own enrichment. When the gas is first
lighted, the material in the vessel is in the solid form, and it
requires several minutes before the effect of the carburation is
seen ; but gradually the light assumes a peculiar brilliancy,
and the illuminating power of the gas is raised from eighteen or
twenty to about thirty-seven candles. The albo-carbon gasdight
is adaptable to various ways of fitting ; for instance, in Fig. 98
the burners are arranged in a circle above the carburetting
chamber instead of being below it.
The shape of the gas globe has a great effect upon the amount
118
PRACTICAL GAS-FITTING.
of light given by an ordinary burner, either union jet or batswiug.
For many years Mr. Sugg has been showing the necessity of
having a large opening at the bottom of globes in place of the
restricted space which until recently was thought desirable. Now,
the old-fashioned pine moon and open-top globe is falling into
deserved disuse. The advantages of the more modern type are
many, among the foremost being the fact that the light from the
burner can pass unrestricted down upon that portion of the room
which requires the greatest amount of light, and the upper
portion of the globe forms an excellent reflector to aid in the
diffusion of light downwards. As in most cases the gasalier is
fixed in the centre of the room over a table, it is generally
required that the light shall be greater immediately underneath
the burner than in the remaining portion of the room. Another
advantage is that a sufficient amount of oxygen is permitted to
pass into the globe to allow of complete combustion of the gas
without unnecessary draught, which would cause the flame to
flicker and take a form in which the perfect combustion of the
gas would be impossible. This is one respect in which the
flat-flame differs from the argand, the latter requiring a draught
to cause a perfect flame. Some time back an invention for im-
proving the light from a fiat-flame burner when used with the
ordinary globe was brought out by a Mr. Spencer, who designed
and patented a modification of the old-fashioned corona, upon
which he placed a second cap, which was movable, and which
could be made to open or close the apertures in the corona proper,
through which the products of combustion passed. The cause
of the improved lighting effect was no doubt the warming of the
air during its prolonged contact with the heated globe.
The respective amounts of light obscured by the different kinds
of globes ordinarily in use have been stated thus : —
Clear glass globe obscures about 12 per cent.
Glass with slightly ground flowers „ „ 24
Globes of about usual pattern „ „ 35
Globes ground all over ... 4,3
Opal globes „ 60
Opal globes painted „ G4
119
CHAPTER VH.
INCANDESCENT GAS BURNERS.
All gas burners that emit light have as much claim to the term
"incandescent" as have those combinations of Bunsen burner
and mantle which now alone are known by that name. The
"incandescent" gas burner differs from any burner described in
the previous chapter in this respect— that in the ordinary burner
the light emitted is due to the raising to incandescence of the
carbon particles of the gas itself, whilst in what is known, as
the "incandescent" burner the gas is used merely as a heating-
agent to raise certain oxides of the rare earths fo incandescence.
The incandescent burner consists of two portions, the burner
itself and a cotton hood or mantle which, in the case of the
Welsbach mantle, has been dipped in a solution of the oxides of
rare earths— 98 per cent, of thoria to 2 per cent, of ceria. On
burning away the cotton, the oxides remain, and retain the shape
of the original mantle. This is then supported over a Bunsen
burner which, when the gas is lit, fills the body of the mantle
with flame, producing incandescence on its surface, and causing
it to give out a brilliant bluish-white light. The mantles are
about 3 in. long, 1 in. in diameter at the bottom, and are some-
what conical in shape. Across the upper end of the mantle a
thick loop of the material stretches ; this is for the purpose of
supporting the mantle when in use on the fork of a thin fireclay
prop, which passes up the long axis of the mantle and fits into
a cavity in the central conical-headed rod of the burner. A
chimney, 2 in. in diameter externally, and about 8 in. long, fits
over the mouth of the upper end of the burner, which is provided
with a contrivance for diminishing the risk of lighting back.
The ordinary form of incandescent burner is arranged for
a gas consumption of about 3| cub. ft. per hour at a pressure
of 1 in. ; the pressure at which the gas is burnt is a most
120
PRACTICAL GAS-FITTING.
important factor in the results obtainable from this type of burner.
The pressure should never be less than 1 in.
In manufacturing the mantles, ordinary cotton is knitted in
a machine into a cylindrical form, and, to free it from impurities,
it is washed in a solution of hydrochloric acid and ammonia.
It is then placed in a 14-per-cent. solution of the metallic oxides
of some rare earths ; thoria is usually the basis of the light-giving
properties. The mantles are squeezed until only sufficient liquid
is left upon them to soak into all the pores, and are then left to dry.
The upper ends are then sewn so that the mantle may be hung up.
On considerable heat being applied, the cotton fabric is burnt
away. The mantles are very fragile, and so, in order to ensure
their safety in transport, they are dipped in a solution of collodion,
which has the effect of giving them the necessary stiffness and
toughness to enable them to withstand ordinary handling.
Before the gas is lit, but whilst the new mantle is in position,
this stiffening solution is burnt off by means of a spirit torch ;
tapers or matches deposit soot on the mantle and chimney.
In the 1885 and 1886 patents granted to Welsbach, pre-
scriptions for the mantles are given as in the table on the next
page. The other particulars there tabulated are the results of
subsequent experiments.
In the table given on p. 122, Professor Lewes has brought
together the oxides which have been used in the manufacture of
incandescent mantles, and his results show the amount of light
emitted by each under the conditions existing in the mantles.
The Welsbach incandescentburnerisillustratedbyFig. 99, p. 123.
As before explained, it consists of a Bunsen burner in which air
and gas are admixed before the flame-point is reached, forming a
flame of very little illuminating power but of great heat. This
burner should be tightly screwed upon the gas fitting, either
bracket or pendant, the small cardboard washer being put on
first to make the joint tight. The Bunsen burner, when fixed,
must be absolutely plumb, otherwise the flame will not be of the
proper shape, and the mantle, being unequally heated, will in
a short time break up. The lowest pressure at which the in-
candescent gas burners work well is in. of water, but as a
general rule 1-in. pressure is about the best, and this of course
should be measured at night when the lights are likely to be
most in use. If the screw upon the Buusen burner tube is too
small for that on the fitting, a double screw-piece called an
INCANDESCENT GAS BURNERS.
121
adapter which is supplied with each burner, should be fixed
with the cone-shaped end into the fitting. A disc is also sup-
plied ; this is intended to prevent lighting back in the Buusen
tube. " Lighting back " is the term used for the lighting of the
WELSBACH 1885 PATENT.
O.r ide.
Percentage
Composition.
Cubic Feet
of Gas
Consumed.
I
Illuminat-
ing Power
in Candles.
Candle-
power per
Cubic Foot
of Gas.
[Zirconia
I. 1 Lanthania ...
(. Yttria
j Zirconia
\ Lanthania ...
60
20
20
50
50
\"
12-9
9'4
2-4
1-7
WELSBACH 1886 PATENT.
Oxide.
Percentage
Composition.
Cubic Feet
of Gas
Consumed.
Illuminat-
ing Power
in Candles.
Candle-
power ver
Cubic Foot
of Gas.
T (Thoria
i- | Magnesia ...
[Thoria
II. 1 Zirconia
( Yttria
[Thoria
III. < Zirconia
1 Lanthania ...
[ Thoria
IV. < Magnesia ...
1 Lanthania . . .
( Thoria
V. •! Magnesia ...
(Alumina ...
60
40
333
333
333
30
30
40
40
20
40
60
20
20
| 4-4
I 4-5
)
' 4,
j
1»
1 4-0
9'0
15-0
12-2
12'2
3'6
2-0
3 3
2'5
2'7
0-9
small inner gas-supplying tube before the admixture with the
air has taken place ; lighting back heats the fittings unnecessarily
and causes a disagreeable smell. When lighting back happens
the gas should be turned out, and in a few seconds it can be
122
PRACTICAL GAS-FITTING.
re-lighted. The next portion to fix is the gallery, which carries
both the mantle and the chimney. It is as well now to light up
the gas and find out if the fitting is upright and the flame correct
in every particular— a very important point. The correct flame
is of a clear reddish colour, about 4 in. high, and should crackle
and bubble. If the flame does not reach this height when the
gas is fully turned on, enlarge the gas holes at the top of the gas-
supplying tube with a broach or fine reamer ; make the enlarge-
ment from the same direction as that in which the gas enters.
If, on the other hand, the gas-flame be too large, the gas-supplying
holes should be burred over until only 3| cub. ft. of gas will pass
PROFESSOR LEWES's TABLE.
Group.
Oxide.
CANDLES PER CUBIC
FOOT OF GAS.
Pure
Oxide.
Commercial
Oxide.
Metals
Earth Metals
Alkaline
Earth Metals
j Zirconia
1 Thoria
' Cerite Earths \9 ev '\\ ■
{ Lanthania
- Ytterite Earths {|J^ a -
Common f Chromium
Earths \ Alumina
j Baryta
< Strontia
(. Magnesia
V5
05
0-4
0-6
0-4
0'6
33
5-2
5-0
31
6-0
0-9
6-0
5-2
17
0-4
0'6
33
5T)
5-0
at 1-in. pressure. It should be mentioned that only a small
difference in size is necessary, and that all the gas-holes should be
equally enlarged or closed. The mantle should be gently shaken
out of the box or cardboard tube and held by the loop by which
it is then suspended over the fork on the porcelain rod, while the
bottom of the mantle hangs over the neck of the gallery. The
gas must not be turned on and lit until the flame of a spirit lamp
has been held to the bottom of the mantle, when the toughening
coating upon the mantle will be quickly burnt off and leave the
mantle ready for use. All that remains to be done is to fix the
chimney straight upon its gallery.
INCANDESCENT GAS BURNERS.
123
The form of incandescent burner most to be preferred is one
with a bye-pass— that is, a small pilot light, which should only be
I in. high ; Figs. 99 and 100 show bye-pass burners, the former
an ordinary burner, and the latter the new type. In fixing an
ordinary bye-pass burner, take care that the bye-pass tube up
the centre of the Bunsen burner fits properly into the groove in
the gallery, or imperfect combustion, and an unpleasant smell,
will result. The gas consumption of the bye-pass or pilot light
124
PRACTICAL GAS-FITTING.
is insignificant, and is regulated to a nicety by a little screw at
the bottom of the burner. A small lever is fitted to these
burners for the purpose of lowering the light ; sometimes, as in
Fig. 99, the lever has chains. Where this form of burner is in
use no torch is required, as immediately the gas is turned on at
the tap the burner is alight. The bye-pass burner is more
economical as regards mantles, as the light is applied to the gas
at the best point, and no explosion occurs.
A new Welsbach burner known as the Kern is illustrated
by Fig. 100, and differs as is apparent from the older kind or
"C" burner, illustrated by Fig. 99. It is supplied with or
without the bye-pass, the one illustrated having this important
accessory, however. Though the Kern burner differs from the
" C " burner in general construction, yet in broad principle it is
the same, inasmuch as both, of course, are Bunsen burners. The
advantages of the new burner are :— (1) An illuminating power
of from 25 to 30 candles per cubic foot of gas as compared
with the 16 to 18 candle-power of the " C " burner. (2) A
governor is not necessary ; increase of pressure involves increase
of light, whereas in the "C" burner, increase of pressure in the
absence of a governor causes the deposition of soot on the
mantle. (3) The new burner does not require a chimney.
The ordinary ("C") Welsbach burner is of three types.
First, the actual "C" burner, consuming about 3i cub. ft. of gas
per hour, and giving a 60-candle-power light; second, the " S,"
consuming 2h cub. ft. of gas, and giving a light of 35 candles ;
and third, the "Gent" burner, consuming If cub. ft. of gas, and
yielding a light of 35 candle-power. The " New " Welsbach
burner is made in the following sizes : —
No. of
Burner.
Gas Consumption
at 1 in, pressure.
Cubic feet.
Illuminating
Power
in Candles.
1
20
1
1
30
2
2-2
50
3
3
80
4
38
105
7
6-5
185
INCANDESCENT GAS BURN EES.
125
In transferring a mantle from its box to the burner, take
the two ends of the string in one hand and lift the mantle out of
the paper tube. By holding the top part of the burner in the
other hand and below the mantle, the latter can safely be lowered
into position. Before fixing the chimney, examine the mantle, as
a faulty one will be exchanged by the dealer if returned before
being lit. A mantle is made up of a regular series of loops, each
row connected to the one above, and if at any point a loop does
not join the row above, the mantle should be returned as faulty,
as it is almost certain to develop a break as soon as used. Other
faults, such as broken collars, broken suspending loops, fractured
sides, and torn bottoms, are noticeable at a glance.
When lighting incandescent burners, a spirit torch should be
applied from underneath the chimney, but above the disc which
prevents lighting back; the spirit torch does not blacken the
chimneys as do tapers or matches. Some people prefer to light
from the top of the chimney, in which case the gas should be
turned on sufficient time before the light is applied to allow the
gas to expel ail the air in the chimney, so that little or no
explosion shall take place, and the mantle may be free from
consequent damage.
The breakage of mantles when in position may be avoided by
attention to a few rules. Fix incandescent burners only on good
sound and clear gas fittings. Where there is much vibration, use
one of the anti-vibration frames now on the market ; these
frames are specially suitable for hanging lights, such as the arc
lamps etc All pendants for the incandescent light should be
supplied with cup and ball joints, and they should never be
screwed stiff, or the mantle will break if it gets the slightest
knock. In draughty places, such as lobbies, passages, and
corridors, a mica chimney is desirable, so as to avoid breakage
of the chimney, and to preserve the mantle.
If a newly fixed burner gives an unsatisfactory light, either
there may be an insufficient gas supply, or the mantle may be
much too wide ; perhaps both conditions exist. In the first case the
mantle will be well lit all round the bottom with the light getting
worse towards the top. If two of the four air-holes in the Bunsen
tube are covered by the fingers, the light will at once improve.
Therefore either reduce the amount of air admitted, or increase the
quantity of gas supplied. To reduce the amount of air, unscrew
the Bunsen tube and fix inside it a piece of card or tin to cover
126
PRACTICAL GAS-FITTING.
two opposite holes. To increase the gas supply, remove the
burner from the fittings, and unscrew the Bunsen tube, when the
gas regulator nipple will be seen to consist of a brass tube having
a soft white metal top with five small holes, which should be very
slightly enlarged. Very handy for this purpose is a hat-pin, ground
to a long taper and passed up from the under side. When a mantle
is too wide, one side only is incandescent, the other side hanging
away from the gas ring. This fault is, of course, easily seen
before the burner is used ; if, however, the mantle has been lit,
the light can be improved by slightly lowering the mantle and,
as this is tapered, presenting a smaller surface to the flame.
Take off the mantle, lifting it by a wire under the suspending loop.
Then place the wire across a glass tumbler with the mantle
suspended inside. Take out the support, nick it with a file about
J in. from the plain end, and break it off. Finally replace the
mantle, etc.
It is noticed that the brilliant light given by a new burner
does not last, the light after a fortnight probably commencing to
decrease ; if kept in use, the mantle top becomes coated with soot
and a smoky flame issues. The burners go wrong in a much
shorter time if used in a room in which a fire is constantly
burning. The cause of this is simply dust, which is drawn in at
the air-holes and carried up the Bunsen tube. It cannot pass
away owing to the gauze, to which it adheres, thus preventing
the gas getting away quickly enough to draw in the proper
amount of air. To remedy this, take off the mantle and, with
a small brush (an old nail- or tooth-brush), remove the dirt,
blowing through the gauze afterwards. Then replace the mantle,
clean and replace the chimney, unscrew the Bunsen tube, and
brush the nipple clean. Blow the dust from the tube and then
refix the top. If the mantle is covered with soot, leave the gas
half on until the soot is removed. To keep the burners at their
best, this process should be clone at least monthly. If the burners
are in a dusty place they will require more frequent cleaning.
Failure of the bye-pass is a common fault, even in new
burners. The bye-pass light may go out after the gas is turned
on. In a new burner this is often caused by one of the two set-
screws on the side of the burner being inserted too far; in this
case, after unscrewing a complete turn, the burner will most likely
work. It is sometimes necessary to take out both screws and to
remove the grease adhering inside the end of the hole.
127
CHAPTER VIII.
GAS-FITTING IN WORKSHOPS AND THEATRES.
In fitting workshops with gas, it is important that strong
materials" be employed, and it is desirable to use iron pipes
throughout. Where a row of benches is fixed upon each side of
a workshop, it is usual to run a pipe along just below the ceiling,
with tees between each window ; from these a small pipe is
carried down to either a single or double swing iron bracket.
Some firms who make gas-fittings supply iron brackets, but they
can be made up quickly from the brass fittings and short pieces
of iron pipe purchasable from any dealer. Brass swivels wear
considerably better than those that are made of iron, and do not
corrode and stick in the working parts.
' When the lights are to be fitted, say, down the middle of a
workshop where lathes or other machine tools are used, the
only brass parts are the taps and burner elbows, the ordinary
iron tee being very suitable for the centre of the pendant.
Where more than one floor is to be lighted, fix on the supply
pipe a governor for regulating the quantity of gas delivered ;
otherwise the pressure due to the height of the upper floors
will cause a lowering of the light in the ground floor or base-
ment. It is also an advantage to have each floor separately
supplied from the main, so that each floor may be shut off
entirely without interfering with the others ; and if a separate
meter be supplied for each floor, the quantity of gas consumed in
proportion to the work done after dark may be checked, and any
escape noted. Where a pipe falls, a pipe syphon or syphon-box
should be fixed, as the temperature is subject to extreme changes
and the quantity of condensation is much greater than in private
houses.
When the pipes are run through the floor and up the legs ot
the lathes or other machinery, it is usual to bend the pipe to the
PEA G TIC A I GAS-FITTING.
exact curves taken by the machine, and to fix the pipe in its
place by means of bands of iron bent to the curve of the pipe,
and fixed to the machine by two small set screws. These bands
may also be found useful in fitting up houses where the nature
of the wall or floor will not permit the use of the ordinary pipe-
hook.
It is often found necessary to fit up in a workshop over each
machine a bracket arranged so as to move in any direction to suit
the convenience of the workman. One way of making these
fittings is to make the elbows of the brackets of two double swing
swivels— one upright and one on its side. Another way is to,
have two lines of pipes from the support, and to connect both at
each end to double swivels ; whilst between the upper and lower
pipe, and laid at an angle, is a thin bar, which is fixed on to the
upper pipe, and can be clamped to the lower one when the exact
position required has been obtained. This form of bracket is
useful in drawing offices, where the burner and shade commonly
in use cause the other pattern of bracket to gradually fall down-
wards on to the table ; whereas the second arrangement always
keeps parallel, and, if tightly clamped, cannot change its position
without breaking the thin metal bar, which should be made
sufficiently strong to withstand the strain due to the weight
of the heaviest burner, chimney, and shade likely to be placed
upon it.
In making brackets and pendants, it is convenient to know a
quick and efficient way to bend iron pipes. The exact shape
required having been drawn full size upon paper, the latter is
tacked or pasted on to a rough board. Strong cut nails are then
driven in to follow the desired curve, the nails being half the
outside diameter of the pipe from the drawn line, so that the
centre of the pipe, when bent, may lie directly over the drawn
line. The iron pipe is heated in a forge fire or in a draw-furnace ;
the latter heats the pipe equally over the length required. The
end is inserted between the lines of nails, and, with the aid of a
pair of pliers, is quickly made to follow the curves indicated by
the nails. Nails are not necessary on the outer side of the
curves, except at the starting point, where a firm grip of the pipe
must be insured. Where many pipes are to be bent to the same
shape, the board is replaced by a square plate, with holes all
over it, cast- or wrought-iron curves replacing the nails. The
saving in time and the accuracy of the bending soon repay the
GAS-FITTING IN WORKSHOPS.
129
additional outlay. In bending iron pipe, proceed gradually, and
make only small curves at a time, or the pipe will collapse.
For workshop brackets, the ordinary circular back or wooden
pattress is not employed generally, metal backs being found
stronger and more suitable. These metal backs are supplied with
the fittings, and are drilled and countersunk ready for erection,
space being left for the pipe to screw into the top of the swivel
joint. A metal back makes a strong job, and answers every
purpose where very neat finish is not necessary.
In all workshops ventilation is a prime requisite, and must be
provided for, more especially where the rooms are low and a
considerable number of workmen and gas lights are employed.
Gas is an excellent draught inductor ; an ordinary batswing or
union jet burner (see pp. 99 to 10*7) consuming 1 cub. ft. of gas per
hour, when placed in a 6-in. ventilating tube 12 ft, long, will
cause 2,460 cub. ft. of air per hour to pass up the tube ; and this
induced draught can be easily adapted for the removal of the
heated and vitiated air from the upper portion of the room.
Each person present will give off per hour about 17 7 cub. ft, of air,
of which from '6 to "8 of a cubic foot will be carbonic acid (C0 2 ) ;
the amount of C0 2 evolved from the combustion of coal gas
practically is equal to one-half the quantity of gas burnt ; and an
ordinary gas burner may be considered as being equivalent to at
least three adults in its effect upon the atmosphere. The air-
space required in a workshop is 250 cub. ft. for each person
during the day and 400 ft. at night. Again, 500 cub. ft. of fresh
air per person should be delivered into a room during each hour,
and therefore the same quantity of vitiated air must be drawn
away by some means ; no method is more suitable or so effective
as the one above proposed, in which a lighted gas burner is
enclosed by a ventilating shaft. A well-constructed Sun burner
(see pp. 115 and 116) has an excellent effect upon the ventilation
of a room, workshop, or hall, when a properly arranged vertical
shaft, usually of sheet iron, is carried up through the roof, and
will at the same time assist greatly in the general illumination of
the apartment.
Many of the above remarks are equally if not more applicable
to the fitting up of theatres and places of public entertainment,
whose ventilation is an important matter. In these places, the
object to be attained is complete ventilation without loss of
lighting effect;
I
ISO
PEA GTIGAL GAS- FITTING.
In theatres, it is usual to bring the supply up on the wall on
the prompt or right-hand side of the stage when looking from the
auditorium, and there to branch off with a tee which has on each
side other tees fixed as close together as possible, and all
pointing upwards, From the outlets of these run the various
supplies to the different parts of the house. This arrangement
provides against fire, and is indispensable when it is necessary to
lower lights in certain portions only of the stage and auditorium.
Each pipe has a cock upon it, and also a bye-pass with a small
tap, so that, on turning clown the lights, sufficient gas flows
through the bye-pass to keep only the smallest flicker in each
burner, and then, when the cock is turned on again, the lights are
quickly at their full power without the trouble of re-lighting.
The usual way of fixing these bye-passes is to screw an elbow
nose-piece into a hole drilled and tapped in the pipe below the
cock, and to screw another in the pipe above the cock, taking-
care that the distance between the two ends, when turned
towards each other, is the exact distance to suit a small cock with
a union on one end. Fig. 101 explains the arrangement. Each
supply pipe is labelled with the name of the portion of the house
which is being served by it, so that the gas may be turned off or
on as may be required.
Fig. 102 illustrates another form of bye-pass arrangement. It
is fixed about 5 ft. from the floor of the stage, as handy as
possible. The reservoir is filled direct from the main by the
GAS-FITTING IN THEATRES.
131
pipe L, whose size depends principally upon the quantity of gas
required for the stage. The footlights, gas battens, and side-
lights are all kept separate : E controls the footlights ; F, side-
lights ; ft, batten No. 1 ; H, batten No. 2 ; I, batten No. 3.
Should there be any lights in the front of the house controlled
from the stage, they should follow batten 3 or 4, as the case may
be, as at k. For a stage with a 15 ft. by 20 ft. opening, the
reservoir D should be 2 in. gas barrel, reduced to lh in.,
with reducing socket on to the main. E, F, ft, H, i, k would
be f in. barrel. The letters n n denote the bye-passes of
§• in. barrel tapped into the f in. pipes. The taps, of course, must
fit the different sizes. It will be seen at a glance how easy it is to
Fig. 102. — Gas Cocks and Bye-passes for Theatre.
regulate the gas with this arrangement. The bye taps n
must be kept full on ; the main taps may be turned as low as is
wished — right off, if need be, the bye taps preventing the light
going out.
It is usual in theatres to guard all bracket lights in the
passages and corridors, behind the proscenium, leading to the
dressing rooms, property and painting rooms, as well as the lights
in these places and the carpenters' room, by means of a wire
frame made of the same shape and size as an ordinary glass globe.
So many inflammable articles are moved about in a theatre that
every possible precaution has to be employed.
A theatre stage must be lighted so as to ensure a broad open
light, in order that shadows may not be cast on the floor or
scenery by the actors or by any articles on the stage. Thus, a
132
P It A < ! TIG Ah GA S- FIT TING.
stage is lighted from the front, at the top, and at the sides, the
respective names of these lights being : footlights, gas battens,
and sidelights. All these must be protected to prevent accident
from fire.
Stage footlights are formed of 1 in. or 1 J in. gas barrel. Strike
a chalk line from one end of the gas barrel to the other, and on
this line holes should be drilled and tapped to receive the ordinary
5 ft. per hour gas burners, which should be from 4 in. to 6 in. apart.
It is often found useful to have more than one row of foot-
lights upon the front of the stage, as in Fig. 103, and then argand
Fig. 103.— Stage Footlights.
burners are usually employed, each row having different-coloured
glasses, so that the light thrown may be of the desired tint (see
Fig. 104). The usual colours employed are green and red, these
forming useful evening effects when the exigencies of the play
require them.
Footlights should be laid about 4 in. or 5 in. lower than the
stage floor (see Fig. 103), so that the bottom part of the actual
light may be on a level with the floor of the stage to prevent the
floor being in shadow, as it would be if the lights were
too low. The lights are guarded from the view of the audience
by means of a board on edge or a strip of scolloped sheet zinc.
The side nearest the stage is guarded usually by means of brass
GAS-FITTING IN THEATRES.
133
uprights and two or more brass tabes running through them, and
to this is sometimes fastened brass-wire gauze to prevent small
articles and ladies' dresses from catching fire. The trough in
which the gas barrel lies should slope down from the stage The
Fig. 104.— Two-row Footlights for Stage.
reflectors are fixed to the front of the stage behind the light (see
a, Fig. 103).
In fixing footlights to a portable stage, the trough should be
hinged to the front of the stage and supported by acute angle
brackets (b, Fig. 105), which allow the trough to hang down to the
Fig. 103.— Footlights for Portable Fig-. 106.— Stage Foot-
Stage, light Reflector.
required level. The reflectors, which are fixed to the upright
front of the trough (see Fig. 103), should be of zinc, and may be
separate or in one length, and scolloped to break the line as desired.
For a portable stage it is usual to have separate reflectors, as
illustrated by Fig. 106, in which c c are two pins soldered in the
zinc for fixing in holes made at regular intervals behind each
134
PR A G TICAL GAS-FITTING.
light. The end of the gas barrel is connected by indiarubber
tubing to the main supply pipe.
When rehearsals take place in the daytime and there is
insufficient light to properly watch the action, it is usual to fix up
a T-light standard upon a cock in the centre of the footlights.
This standard may be made of 1-in. or lj-in. pipe, and should be
about 4 ft. 6 in. or 5 ft. high. Upon this is screwed a T, and a
piece of pipe about 18 in. to 2 ft. long is screwed into each end of
the T and drilled and tapped, burners being put in about 5 in. or
6 in. apart. This will usually give sufficient light for the
purpose.
The flies, as the portion of the stage where the sky borders
usually hang is called, is lighted by gas battens, the arrangement
consisting of a length of pipe the full width of the stage, with
holes drilled as before described, and burners inserted. These
pipes, which are hung across the stage between each border, are
usually connected to the side and rising supply pipe by means of
rubber tube, and are hung on pulleys so that they can be easily
raised or lowered as required. The gas battens must always be
hung with chains, not only to guard against fire, but also because
the gas so soon rots cord that the batten might fall at any time,
with dangerous results. These lights, again, are guarded with
gauze wire, a sheet of wrought iron being fixed on the side
nearest the border or audience, and the portion facing back
being guarded with iron-wire gauze.
Of sidelights there are either three or four behind each wing.
A perpendicular gas barrel rising from the stage is tapped for the
burners. Sidelights must always be protected with wire globes
(see Fig. 107). Sidelights may be dispensed with, particularly
on a small stage, as they are dangerous in a limited space. Side-
lights are for illuminating the wings, so that the shadow of one
wing shall not fall on the other ; but this effect may be gained by
the proper arrangement of footlights and gas battens.
For lighting the auditorium it is customary to use a large
gasalier, often of very great weight, which requires extremely
careful fixing, as should it fall it might possibly kill many people.
Another system of lighting is by means of a Sun burner (see
pp. 115 and 116) in the centre instead of the gasalier ; and no
matter which arrangement is adopted, a large wrought iron flue
should be constructed, with a cowl on top to prevent down-
draught and the entrance of rain. This not only serves to remove
GAS-FITTING TN THEATRES.
135
the products of combustion from the gas-burners themselves, but,
by the heat engendered, will cause a strong upward current of the
vitiated and warm air from the body of the theatre. In some
cases in which electric light has been fitted in theatres it has
been found necessary to retain the gas centre-light so as to ensure
efficient ventilation.
In the larger theatres it is often found necessary to supple-
ment the centre gasalier by brackets, having two or more arms,
fixed around the fronts of the different circles and galleries ;
these brackets are served generally by a. pipe carried from the
Fig. 107.— S^age Sidelights.
general supply centre on the prompt side of the stage, around the
inner side of the balustrade and along the immediate foot of it,
Where the galleries are deep, brackets are fixed frequently on the
back wall of the auditorium, so that the back portion of the
house is not in absolute darkness, and the way out of the theatre
may be seen more easily. Much, of course, depends on the
amount of money which it is intended to spend upon the
lighting ; but every effort should be made to ensure the work
being carried out "in a thorough manner, as a great deal of
expense may be saved if the work be properly done in the first
instance.
In almost all large size theatres a gasman is kept on the
136
PRACTICAL GAS-FITTING.
premises, who is answerable for the soundness of the pipes and
fittings ; he is required to test periodically the pipes and fittings
for leakages. This testing must not be done with a light, but at
a time when gas is not being burnt anywhere in the theatre ; then
by carefully noting if any gas is passing through the meter (by
noting the movement, if any, of the small leaden disc above the
ordinary index, or the small dial if it be a dry meter) it may be
ascertained at once if any gas is being lost through leakages in
the pipes. Another way of detecting leakage is to use a pressure
gauge, and note the pressure (1) when the gauge is first fixed on
the outlet side of the meter (the latter should be closed off), and
(2) after the lapse of say half an hour, when if there be any
leakage the pressure will have fallen to nothing. There are smail
meters with large hands for the sole purpose of testing for
leakage, and these, by indicating to a very fine degree, readily
show the rate of leakage. One prominent firm manufactures a
small holder which can be connected to the outlet side of the
cock to the meter, and filled with gas before the gas is shut off ;
then any leakage is made up out of the holder, which lowers
quickly, as it is only made to contain one-tenth of a cubic foot of
gas— a scale upon the side showing the actual quantity which has
been required to make up for the gas which may have leaked
away.
In treating upon theatre lighting by any method, only
generalities can be touched upon, as so many different arrange-
ments are now found in theatres and music-halls, each depending
to a large extent on peculiarities of the building and on special
requirements.
137
CHAPTER IX.
GAS-tflTTING FOR FESTIVAL ILLUMINATIONS.
On occasions of public rejoicing, it is customary to illuminate
the streets and the fronts of houses. Gas is the illuminant
commonly employed, and the work of preparing and fixing the
fittings is entrusted, as a rule, to the ordinary gas-fitter. An
effective system of lighting up buildings is to employ rows of pipes,
with arches over doors and windows, the pipes being of wrought
iron of about f in. to 1 in. bore, with holes drilled at intervals of
6 or 9 in., into which holes short pieces of brass pipe are screwed.
These pieces of pipe are bent with the free end upwards to hold
a burner and to support a gallery carrying a moon or globe,
generally of opal, but sometimes of ground glass. This system of
lighting up buildings is very effective when a large front has to
be covered; but, should rain fall, the hot globes will quickly
crack.
In making gas illuminations with an elaborate motto or
device shown out in flame, the first requirement is a large-sized
pipe, so that an ample supply of gas may reach the burners ; an
insufficient supply of gas will spoil the device. The pipes leading
to the different parts must be sufficiently large and numerous to
ensure plenty of gas at all parts of the design, at (as nearly as
possible) equal pressure.
The design to be attempted may be a star, a crown, initials, or
a portrait, or perhaps a combination of all, with a motto on a
ribbon entwined about the stars, etc. As regards the making of
a star, the first thing is to make a full-sized drawing in ink, on
paper, of the device. This drawing can be enlarged from a small
sketch by means either of a pantograph or of small squares ruled
upon the sketch and also upon the paper in proper proportion,
each square being numbered. The various lines crossing each square
can be easily drawn to cross the similar square on the larger paper.
138
PRACTICAL GAS-FITTING.
Having completed the design, decide how the gas can best be led
to the different parts of the design so that ail may be equally well
supplied ; in this lies the secret of success. A good working rule
is to consider that there cannot be too many sources of supply.
The usual plan is to make an inner circle of copper tubing, copper
being used because it can be bent easily and yet can stand the
heat of the gas burning from holes in it. This inner circle is
then brazed where the ends of the ring meet. The method of
Fig. 108. — Star for Festival Illumination.
brazing is to place the copper pieces on a tray of charcoal and
then to turn the blowpipe burner upon the parts until they are
red-hot ; place some spelter and powdered borax upon the part
where the joint is to be made, and continue the heating until the
spelter runs, more spelter being added until the joint is complete.
Where two ends are to be joined together, it is usual to put a
thin coating of spelter upon each before bringing them together,
when the joint can be quickly made.
The ring being completed, the connection for the gas is
usually brought up to the centre, an iron T-piece lixed there
GAS-FITTING FOB FESTIVAL ILLUMINATIONS. 139
for the supply, and copper pipes screwed into each end of
this T. These copper pipes, after being cut to the right length
and shaped at the ends, are fitted into the ring (which has also
had two holes cut in it, opposite each other), and then are brazed.
The foundation of the device is now complete, and if a simple
star is required, the radial pieces are cut to the necessary length,
and each is shaped to the curve of the pipe of which the ring is
composed — usually of a somewhat larger diameter than the radial
pieces. The outer ends of the radial arms may be closed by
being squeezed tightly together in a vice until the two sides
become almost as one piece.
The drilling of the holes, if the device is only a small one, is
Fig. 109. — " V.R.I." for Festival Illumination.
done when the construction is complete (see Fig. 108). This
operation requires care, and the drills used must be very small
in diameter. They are usually only about the size of an average
needle, and, for drilling copper, are best sharpened not, as might
be supposed, upon an oilstone, but better upon the ordinary
grindstone, or with a fine file. Sharpened in this way, they last
much longer and cut more quickly. Of course, in large factories
where these devices are made, special machines are to be found
which revolve at very high speeds and do the drilling very
rapidly ; but where only a few are to be turned out, probably one
of the Archimedean or American drill stocks will be used, and
the drills themselves will be made from ordinary household
needles. If the holes are too large, the general effect is greatly
spoiled ; whilst if the holes are too small, the wind will easily
140
PRACTICAL GAS-FITTING.
blow out parts of the gas-fiame. Holes of the same diameter
as are found in a No. 1 or No. 1| gas-burner will suit the
purpose.
When all is finished, the device should be tried with gas-
under, if practicable, the same pressure as it is likely to receive
when fixed in position — and the general effect noticed. Any
holes that are too small can be reamed out, or re-drilled, and any
that are too large may be closed by a tap from a hammer.
Perhaps the simplest form of illumination device is one made
by merely bending the copper pipe in the hands. This flexibility
Fig. 110. — "V.E.I." Monogram for Festival Illumination.
is one of the advantages of copper over iron or brass ; iron,
moreover, has the disadvantage that it rusts, and the holes get
cpaickly clogged up when exposed to the weather. By arranging
that the bends are never too sharp, a series of letters can be made
without the necessity of brazing, except, perhaps, here and there,
to give an even supply. By remembering that curves can be left
undrilled if necessary, much can be done in this way, especially if
the uniting form of letters is adopted. Fig. 109 is an example of
this class of work. The designs shown by Figs. 110 and 111 are speci-
ally suitable for street illumination, while others are the Prince of
Wales' feathers, crosses, and stars of all patterns and of various
GAS-FITTING FOB FESTIVAL ILLUMINATIONS. 141
numbers of points, suitable dates composed of numerals, V.R.
and V.R.I, in all kinds of letters, from the plain block to the
most ornately flourished, with ornaments and portraits. These
last require more special care in order to catch the likeness,
and necessitate very expert bending and drilling.
Transparencies also provide a favourite form of illumination,
as they do not burn so much gas, and are nevetheless very
effective. They should be painted in oils on thin and even-
**••<»•« toeitaillllOMIItlt^
Fig 1 . 111.— Crown for Festival Illumination.
textured canvas, using only such colours as are transparent, and
avoiding most, if not all, of the earth colours. The canvas is
stretched upon a frame, and a sheet-iron band is fixed all round
this, to prevent the gas jets, which are placed behind, being seen
from the side, and so spoiling the effect of the transparency.
It is customary for gas-fitters who are likely to be fixing gas
illumination devices to give early notice to the gas companies of
the requirement of special services from the main.
142
CHAPTER X.
GAS FIRES AND STOVES FOR WARMING AND COOKING.
An examination of the principles of gas stoves, and a consider-
ation of the advantages and disadvantages of these heating
appliances, may appropriately precede any description of gas
stoves themselves. A point often ignored in the heating of
rooms is that a room will not feel warm until its walls reach
the same temperature as the air which it contains. Until this
occurs, the room will feel draughty, owing to the fact that the
walls are depriving the air of the heat given out by the stove.
It is necessary to examine the conditions of the room or
building to be heated before making any calculation as to the
amount of gas required to heat it. Architects calculate the
cubical contents of the room, and gauge from this the size and
character of the heating appliances required. This method,
however, has been shown by that expert in gas fuel, Mr. T.
Fletcher, F.C.S., to be fallacious, and his contention has been
borne out by independent observation. A better plan is to
calculate the area of the wall surface, and, in ordinary dwelling-
houses, allow that one-half a thermal unit is absorbed by each
square foot per hour for each degree Fahrenheit rise after the
necessary warming up is complete.
The number of heat units generated per cubic foot of gas of
sixteen candle-power, as supplied in London, theoretically is 670
to 680 ; therefore, to raise the temperature in a room which has
been once warmed, it is necessary to allow a consumption of
1 cub. ft. for every 1,300 sq. ft. of wall surface. For the preliminary
heating, however, considerably more than this is required ;
and as there should be a change of air in the room about every
twenty minutes, practically three-fourths of the heat produced
by the stoves passes away by ventilation, and consequently about
four times the above-mentioned quantity of heat is required to
GAS FIRES AND STOVES FOR WARMING. 143
raise the temperature of a room from the commencement, when
it is at about the same temperature as the external air.
It was at one time recommended to fix a row of Bunsen
burners in front of or underneath an ordinary coal fire-grate, filled
either with black fuel, made of fireclay, or with small coke. The
coke was suggested by Dr. Siemens ; it gave a very cheerful
appearance, but it was found that the quantity of coke used,
together with the consumption of gas, rendered the plan
uneconomical. Many persons set a high value upon the cheerful
appearance of this arrangement, and are willing to pay for it ; and
makers have brought forward improvements by which a saving of
gas is effected. Still, gas fires in ordinary coal grates can only be
recommended in preference to gas stoves when economy is not
essential.
Sugg's "Charing Cross" gas fires, Fig. 112, p. 144, are constructed
on the principle just explained. A section of a somewhat similar gas
fire is shown by Fig. 113, p. 145, in which A indicates the special
fireclay back, the lower part of which forms the channelled bottom
of the grate (see Fig. 114, p. 146). The bottom layer of asbestos
lumps is laid on the ridges, the channels being left unobstructed.
The burner flames play into the channels and are directed towards
the back of the fire. By means of the projecting back the whole of
the fire is brought to the front of the grate, and the heat, instead
of passing up the chimney, is deflected by and radiated from the
back, and so made to assist in raising the asbestos to incan-
descence. A four-burner "Charing Cross" gas fire (Fig. 112,
p. 144) is stated by the makers to consume at full power not more
than 27'7 cub. ft. of gas per hour ; but, even on a cold night,
a bedroom containing 1,920 cub. ft. of air space, after being-
warmed to 60° F., can be kept at that temperature by the
hourly consumption of only half that amount of gas.
Stoves in which air passes over heated surfaces are more
economical than ordinary gas stoves ; but, on the other hand, they
are more liable to cause unpleasant odours through the heating of
the dust particles. With these stoves, as also with hot-air and
hot-water pipes, as distinct from grates, the heated air has a great
tendency to rise to the top of the room, leaving the feet cold
while the head is too warm. The same effect is noticed where
enclosed stoves are set forward some distance into the room ; but
these stoves are very economical, and where fuel is dear this is
a paramount consideration. One pound of coal burnt in an
U4
Tit A C TIGAL GAS-FITTING.
ordinary grate requires, for its proper combustion, 300 cub. ft. of
air having a temperature of 620° F. ; and 1 volume of gas for
complete combustion requires 5| volumes of air. In atmospheric
Fig. 112. — '-Charing' Cross" Gas Fire.
or Bunsen burners the average mixture of gas and air is 1 volume
of gas to 2'3 volumes of air ; consequently, a further supply of all-
around the flame is necessary to cause complete combustion, and
an analysis of the gases, taken from the centre of the glowing fuel,
shows that often 10 per cent, of carbon monoxide exists, and, should
GAS FIRES AND STOVES FOB WARMING. 145
down-draughts occur, this must find its way unnoticed— for it has
neither smell nor colour — into the room ; hence the necessity for
ensuring a good draught from the stove, and for the use of a good
Fig. 113. — Section of Gas Fire in Coal Grate.
cowl, as described in connection with the regenerative lamp, in
order to prevent down-draught. Curiously enough, however, the
analyses of gases in the flue during the burning of the gas stove
do not show a trace of this deadly gas. An average of some
twenty-four stoves tested in this way showed the presence of
J
146
PEA G TIG A L GA S- FIT TING.
12 per cent, of oxygen, 84 per cent, of nitrogen, aucl 4 per cent,
of carbonic acid, thus proving that all the carbon monoxide had
been converted into carbonic acid before leaving the stove when
burning in the proper manner. This shows conclusively that
flues are a necessity with gas stoves in which Bun sen burners are
in use, although they need not be so large as the usual coal-grate
flue ; but where flues are not possible, only such stoves as employ
ordinary lighting burners and utilise the heat radiated from a
polished surface should be fixed.
With Sugg's "St. Martin" reflecting stove (Fig. 115) it is
advisable to employ a hue, though this can be dispensed with
Fig. 114.— Channelled Bottom of "Charing Cross" Gas Fire.
in a well-ventilated room. This stove has luminous fiat-flame
burners, each fitted with a separate governor and tap, which
ensure a uniform gas consumption however the pressure may
vary; it has a bright and cheerful appearance.
Where a smoky chimney exists, a gas stove will not cure it,
unless the fault is due to a contraction of the flue, by which
the flow of the draught is impeded. In that case a much
smaller flue for carrying off the products of combustion being
sufficient with a gas stove as compared with a coal fire, the
trouble will probably disappear ; but it would be well to ascer-
tain the, origin of the fault before recommending the adoption
of a gas stove as a remedy.
Most authorities are agreed that radiant heat is the best and
GAS FIRES AND STOVES FOR WARMING. 117
healthiest, and therefore such stoves as afford this kind of heat are
preferable to those that impart heat by convection. By radiant
heat is meant beat that radiates directly from glowing coals or
other incandescent material and passes through the air without
influencing its temperature to any appreciable degree. Radiant
heat coming in contact with persons, walls, furniture, etc., warms
Fig. 115. — "St. Martin" Reflecting- Gas Stove.
these objects, but leaves the air comparatively cool. Heat by
convection warms the air itself.
The cleaning of the burners and rearrangement of the asbestos
or clay blocks is a necessity in all gas stoves, and such stoves as
are fitted with separate burners, each controlled by its own tap,
are much to be preferred to those in which only one burner is
fitted, and which have a pipe with a series of holes from which
the gas issues. These latter are all right when turned full on,
and with a good pressure ; but should the pressure fall from any
148
PRACTICAL GAS-FITTING.
cause, or should it be desired to turn down the gas, the burner
is very liable to "light back" — that is, the light runs back to the
point inside of the Bunsen burner where the gas issues before it
has set up the injecting action by which it becomes mixed with
Fig. 116. — Fletcher and Russell's Gas Fire.
air — and when this is the case a most objectionable smell is given
forth. Several inventions have been brought forward with the
object of preventing this lighting back, principally by means of
wire gauze inside the burner, and these contrivances are effective
so long as the pressure does not fall below T % in. of water ; but
the arrangement with separate burners allows of a much larger
OAS FIRES AND STOVES FOB WARMING. 149
range of temperature, and consequently of much nicer adjustment
of the heat of the room.
Fletcher, Eussell & Co.'s H.R pattern gas fire (Fig. 116) is an
example of a stove giving radiant heat only. It has an incan-
descent iron fire, to which gas is supplied by a i-in. pipe. Made
Fig-. 117.— "Senegal" Gas Stove.
by the same firm is the "Senegal" stove (Fig. 117), which gives
forth both radiant and convected heat. In the latter kind of gas
stove, and, indeed, in all stoves using clay or asbestos fuel, the
position of the blocks is of much importance. They should always
be so placed as to ensure that the flame has a free flow and is not
checked too rapidly, or it will prevent the proper combination
] 50
PEA OTICAL OAS-FITTING.
with oxygen of the air to form carbonic acid, a portion of the
heating power of the stove will be lost, and a quantity of carbon
monoxide will be allowed to escape either into the room or up the
flue. Clay blocks have been found, after a series of tests, to be
superior in heating power to either asbestos fibre or iron grids ;
and there is a form in which fibres of asbestos worked up with the
fireclay enable the blocks to be made much thinner, and at the
same time, acting in the same way as the hair that is mixed with
plaster, keep them from breaking. The asbestos or clay may
vary in shape, but as a rule it is in the form of balls or eggs ; the
egg-shaped clay blocks are hollow, as in Fig. 118; generally the
Fig. 118. — Egg-shaped C!ay Block.
asbestos-clay balls are solid with one large hole through them.
Also, the fuel is in the form of baskets, etc. A bowl of water-
should always be kept in front of the gas stove, so as to com-
pensate by its evaporation for the drying effect on the atmosphere.
It is essential that, wherever gas is burned, the pressure shall
be ascertained at which the greatest economy can be obtained ;
and it is then advisable to try to obtain an even supply of gas at
that pressure under all conditions. Where several gas stoves are
in use, this point demands attention still more urgently. To
ensure this even supply, a governor should be fixed, either at each
stove or near the meter, by which the pressure may be regulated.
Gas fires are usually fitted in the fireplace of the room. The
wrought-iron Hue is carried up into the ordinary chimney, the
supply being brought along under the floor to the side of the
OAS FIRES AND STOVES FOE WARMING. 151
hearth, and connected to the supply pipe on the stove by a piece
of tube bent so as to fit into the angles of the mantelpiece and
stove. This tube has upon it a small cock, either close alongside
the stove or— what is better— a cock is fitted under the boards and
a little sunk plate is let into them, in which the T top of the cock is
protected from harm ; a small hinged lid giving access to the tap
as required; A convenient form of quadrant cock for connecting
the supply pipe to the gas fire or stove is illustrated by Fig. 119.
With this cock the supply of gas can be regulated to a nicety.
The hissing noise heard in the burners of gas fires is caused by
the velocity with which the gas issues through the orifices of the
burners. The defect may be remedied to some extent by fixing a
Fig. 119. — Quadrant Gas Cock.
governor on each burner, or by checking the gas supply when the
burners are turned full on by means of the main tap on the meter.
A plan which has been tried with success is to have a tap fixed on
the service supplying the fire, some 8 ft. or 10 ft. away from the
latter, to turn the burners full on, and to reduce the pressure by
the tap. Sometimes a gas fire will roar because the interiors of
the burners are rough, the result of a burr in the tube or of an
accumulation of deposit caused by the burners firing back.
It is frequently found that the supply of gas to stoves is much
too small. No gas stove should have less than h-m. bore
pipe leading to it, and this pipe should come direct from a supply
pipe of at least f-in. bore, so as to ensure a free flow of gas and a
sufficient supply direct to the stove. In many cases it is advisable
to run direct from the outlet of the meter, so as to prevent the
152
PRACTICAL GAS-FITTING.
lowering of the lights when the stove is turned on, which might
occur if the pipe were taken off one that was heavily drained to
supply other burners. The meter must be of sufficient size to
enable the consumer to have an adequate supply for the whole
Fig. 120. -Clark's Syphon Stove.
house. ^ For this purpose a pressure-gauge should be employed to
ascertain whether there is a naturally high pressure which will
supply sufficient gas without an increase in the size of the meter,
or whether a larger meter is necessary. A gas stove should not
have less than four-tenths pressure, and the pipes should be tested
to see that at least more than this is available. It may even be
OAS COOKING STOVES.
153
necessary to go still farther back for sufficient gas, and to have a
larger service.
It is impossible in the limited space available to describe all
the many types of gas stoves and gas fires on the market
Mention must be made, however, of Clark's "Syphon" stoves,
which serve to warm the room and to a limited extent to light
it as well. As may be seen from Fig. 120, the light and heat
are obtained from an argand gas burner, and in the larger stoves
there are two of these burners. Through the holes in the top of
the stove water may be poured, and the evaporation of this water
will compensate for the drying effect exerted by the lighted stove
on the atmosphere.
Gas cooking stoves are of two classes : (1) those in which the
heat is obtained from non-luminous or atmospheric burners, and
(2) those in which the ordinary luminous flames are employed.
The " Eureka " gas cooking stove may be constructed entirely
of cast-iron, or partly of enamelled iron or galvanised steel plate.
The enamel used does not chip, crack, or scale, and is entirely
free from injurious properties. The surface is smooth, and can
be readily washed and wiped free from grease . The "Eureka"
stoves are double cased at the sides, back, and door, and the
space between the casing is filled with a low-conducting material,
which prevents loss of heat by radiation, the result being that the
gas-consumption is only one-half that of a single-cased stove.
The top of the oven is a slab of fire-brick, and the hot air from
the oven passes up at the front and over the upper surface of the
brick and to the flue pipe at the back. This arrangement
economises heat and adds greatly to the efficiency of the oven by
preserving equal degrees of heat at the top and at the bottom. The
wrought-iron hot plate has movable iron bars polished on the top
edge, the whole forming a flat surface on which saucepans and
other utensils can be easily moved about. The grilling burner
is capable of toasting the two sides of a piece of bread in seventy-
five seconds. The " Eureka " stove is fitted with Wright's patent
" gate " fittings, by means of which the inside shelf supports are
attached to frames, one for each side, which can be lifted out
leaving the inside perfectly clear from ledges or recesses. This
facilitates cleaning and the removal of grease, etc., another
advantage being that the whole space in the oven can be ren-
dered available for baking a large joint.
The atmospheric or Bunsen burner principle in its simplest
154
PRACTICAL OAS-FITTING.
form is applied to Fletcher, Russell & Co.'s cooking stove, which,
in its more complete form, embodies perfect arrangements for
high-class cookery, and is a very quick heater. The oven top is of
enamelled porcelain, and is arranged to hold any liquid or grease
accidentally spilt, without risk of its running down and disfiguring
the front of the stove. The hot plate has an extra simmering
burner, and the regulating taps are in front and entirely out of
the way. The patent hot-plate bars are fixed or movable at will,
as are also the burners and grill plate, the grill being
reversible. This stove is supplied in three forms : (1) Single-
cased ; (2) Double-cased, the space being filled with a low-
conductor — slag wool ; (3) Double-cased, air replacing the slag-
wool .
The- "Acme" cooker is claimed to have the following advan-
tages : The removable burners have air chambers similar to fixed
burners ; the removable burner supports (for carriers) rest in
pockets, are self-fitting, and do not require screws ; the griller is
fitted with rising and falling plates ; the grill burner is made up
of two burners cast in one piece and gives a level flame from end
to end ; the oven linings are interchangeable, and have incor-
rodible screw fasteners : the oven gates are interchangeable, so as
to be used on either side ; but few holes are drilled and tapped,
Nettlefold's steel nuts being cast in, so that it is very unlikely for
a thread to be stripped.
In the fixing of a gas cooking stove it is of primary importance
to see that the gas is supplied at proper pressure Atmospheric
or Bunsen flames give best results at a pressure of \%in. or 1 in. of
water pressure ; any lower pressure is liable to cause, lighting-
back. The stove makers usually state the maximum amount of
gas consumed by the stove, and the makers' requirements should
be complied with. As a general rule, the gas supply pipe must
be at least a size larger than the main pipe of the stove, and
should come direct from the meter outlet, whilst the pressure
should be separately controlled by a governor to a pressure of
in. Ventilation is a point to be attended to in the fixing of a
cooking- stove. A chimney breast, similar to that used with a
coal fire, is necessary for the most efficient service, and when
a spare chimney is available, a very neat appearance is secured by
lining the sides and back with white tiles. A recess on either
side of the kitchen chimney breast can be easily adapted for a
gas stove by carrying the stove flue pipe through the side into the
GAS COOKING STOVES.
155
chimney. The stove should be provided with a hood having at
its top a full-size pipe, which must not be carried into the chimney
at right angles. A questionable custom is to put on an elbow and
a horizontal pipe. The bend on the top should be easy, and from
it the pipe should rise at an angle of not less than 45° above the
horizontal, so as to interfere as little as possible with a free up-
current into the chimney. One or two elbows and a moderately
short length of horizontal pipe on the outlet from the oven are
not objectionable, because the draught from that part is strong
enough to fan them, but even then the pipe must be as short and
direct as possible.
Sometimes a chimney is not available for receiving the flue
pipe, and in that case it must be taken through the wall into the
open air, a job requiring considerable care and intelligence,
especially as regards the top hood ; there must be a rising pipe
about 8 ft. or 10 ft. high, and this must not be exposed to cold.
A sheet-iron pipe exposed to the open air acts as a condenser
rather than as a ventilator, by cooling the products of combustion
and separating the moisture from it. The deposition of moisture
in the pipe gives rise to much annoyance, and the passage is
speedily corroded and choked with dust. In order to overcome
this difficulty it is necessary to cover any flue pipe exposed in
the open air with boiler coating composition. Any pipe that is
required to act as a ventilating pipe must be kept warm through-
out or its action will be interfered with greatly. The top of the
pipe should be covered with a cap or cowl in order to keep out
the rain, and should be at least 12 in. away from any wall
that may be higher than itself. As ordinary wrought-iron will
not last for many years, it is a good plan to use enamelled steel
pipes similar to those used on the stoves.
Cooking stoves, wherever practicable, should be fitted so that
the smells from the meat or other foodstuffs may pass away up a
flue. A hood of sheet iron may be fitted above the stove, at a
sufficient distance from the top to admit the largest and highest
saucepan likely to be used upon the stove, and a sheet metal flue
may be carried from the apex of the hood to the nearest chimney
flue. It is usually sufficient to carry this into the kitchen chimney
flue, fixing a butterfly valve in the iron flue to shut it off when
not in use. The fact that the gas stove is seldom required when
the kitchen fire is in use will ensure the proper working of the
Hue, which should have an elbow turned upwards in the chimney
156
PRACTICAL C AS-FITTING.
to prevent back draught. There is usually a small exit provided
from the gas stove oven, which may with advantage be connected
to the same flue. This is usually provided with a butterfly valve
in the stove proper.
There are one or two points which require attention in order
to get satisfactory results from a gas cooker. Sometimes the
atmospheric burners of a gas cooking stove will not burn properly,
and give rise to smoke and smell, this nuisance being usually attri-
butable to the burners being choked with rust, dirt, or grease. If the
trouble continues after they have been properly cleaned, it may
be found either that the supply pipes are too small or that they
are choked. If the oven burners show a liability to be easily
extinguished by shutting the door, or from no apparent cause, the
fault is either that the dripping pan fits too closely at the bottom
so that there is not sufficient air supply, or else that the flue pipe is
choked up. There should be no smell discernible where a stove
is in use ; the cause of any smell that may arise will be found to
be accumulations of dirt or grease, or the boiling over of pans or
kettles. Care must be taken that all taps are shut off when the
stove is not in use. The grilling burners must not be left with
the heat deflected downwards unless the grilling tin is in its place,
otherwise the heat may injure the top of the oven. The oven
burners must be lighted all along, and not at one point only, and
the door should be left slightly open for a few minutes after
lighting, to allow condensed moisture, etc., to escape. The oven
should always be properly warm before anything is put into it.
Should the atmospheric burners light back at any time, they
should be turned right off for a few seconds, and then relighted.
When ordering stoves, care should be taken to state the
quality of the gas being supplied in the district in which the
stove is to be fitted, as this condition largely affects the size
of the stove burner, all the best-known makers fitting their
stoves with burners suitable to the" quality of the gas.
INDEX.
Acme Cooking Stove, 154
Air Condensation, 31
Vitiated by llluminants, 103
Albo-earbon Burner, 11(3-118
Ammonia, 23, 28
Ammoniacal Liquor, Virgin, 25, 30, 34
Analysis of Coal, 12-14
Anderson's Scrubber and Washer, 34
Argand Burner, 108
, Air Vitiated by, 100
, Illuminating Power of, 114
, Iniperator, 108
Asbestos Fuel, Arrangement of, 140-150
Ash in Coal, 11, 13
Ashley Nipple-holder, 08
Asphyxiation, Avoiding, when Drilling-
Mains, 52
Back-nut, 61
Ball and Socket Joint, 76
Barrel, Iron (see Pipe)
Union, 70
Batswing Burner, 99, 102
■ , Air Vitiated by, 100
Bell Glass over Burner, 9S, 99
Benches, Gas Fittings over, 127
Bend, 61
Bending Compo. Pipe, 74
Iron Pipe, 128
Bisulphide of Carbon, Removing, 38
Bituminous Coal, 9
Blowpipe Lamps, 73
Solder, 72
Blowpipes for making Joints, 72
Bowditch's Regenerative Burner, 93, 100
Boxwood Top, 71
Bracket Pattresses, 80
, Fixing, 81
Brackets, Double Swing, 128
, Fixing, 79
, Making, 12S, 129
, Wire Guards for, 131
Brass Pipes, Joining, to Lead or Compo.,
71, 74
Unions, 70
, Tinning, 71
Bray's Burners, 103
Brazing Copper Tubing, 13S
Bridge-piece between Joists, 77
Brush Scrubber, 34
Burners, 97, 126 (see Respective Names)
■ -, Air Vitiated by 101
, Bad, 101
, Bell Glass or Coronet over, 9S, 99
, Early, 99
■ for Gas Stoves, 147
, Governors for, 99, 101
, Soot from, 98
, Tips of, 102
Bye-pass Incandescent Burner, 123
Bye-passes, Theatre, 130, 131
Caking Coal, 9
Candle power (see Illuminating Power)
Cane, Use of, with Compo. Pips, 75
Cannel Coal, 10, 11, 12
Cap, 61
and Lining Union, 70, 71
Carbon Dioxide, Removing from Gas, 3S
in Gas Flame, 98
Monoxide, 17
Carbonic Acid in Gas, 29
Carbonisation, 14, 23
Carburetting Gas, 117
Chandeliers (sec Pendants)
Charing Cross Gas Fire, 113
Cherry Coal, 9
Chimney, Smoky, remedied by Gas Stove
146
Clark's Syphon Stoves, 153
Clay Blocks, 150
Cleaning Incandescent Burner, 126
Pendants, 77
Cluster of Burners, 10S
Coal, 9-12
Analysis, 12-14
, Ash in, 11, 13
, Products of, 10
Scoops, 23
, Sulphur in, 13
Tar, Naphthalene from 116
Cock, 61
, Quadrant, 151
Cocks and Bye-passes in Theatre, 130, 131
Coke Fire, Siemens', 143
, Withdrawing, from Retort, 24
Comet Burner, 103
Compo. Pipe (see Pipe)
Condensation, Air, 30
in Mains, 50, 51
, Water, 31
Condensers, 29-31
Connector, 69
Converted Heat, 147
Cooking Stoves, 153-15J
-, Flues of, 155
, Gas Supply to, 154
, Hoods of, 155
Copper Tubing, Brazing, 138
, Drilling, 139
Coronet over Burner, 9S, 99
Cross, 01
Crown for Festival Illumination, 141
Cutters, Pipe, 60
Cutting Iron Pipes, 60
Deimal's Regenerative Burner, 99
Dials of Meters, SS, 89
Dies for Screwing Pipes, 62, 63
Dip Pipe,. 27, 28
Distillation, Temperature of, 22
Drawing Offices', Gas Bracket for, 128
Di ill Reamer Tap, 55
Drilling Copper Pipes, 139 '
Mains, 51-56
153
INDEX.
Drilling-machine, Hall's, 55
, Upward's, 53, 54
Drills, 52-54
Drig-well on Main, 50, 51
Service Pipes, 57
Dry Meter (see Meter)
Elbow, 61
Tube-bit, SO
Ellis Burner, 107
Eureka Cooking Stove, 153
Exhauster, 31, 32
Falk Stadelmann's Burners. 103, 107
Fall of Mains, 50
Festival Illumination, 137-141
Fires, Gas, 142-152
Fish-tail Burner, 90, 102
, Air Vitiated by, 100
Flame, Gas, 97, 98
Flange, 01
Flat-tlame Burners, 102-108
Fletcher Russell's Gas Stoves, 149, 154
Flies of Theatre, Lighting, 134
Floor Boards, Removing, 78
■ , Running Pipes under, 78, 79
Joists, Fixing Pendant to, 77
Flue Gases, 21
Flues of Cooking Stoves, 155
Regenerative Burner,110,112,113
Footlights, Stage, 132-134
Frozen Meter, Remedying, SS
Furnaces, Retort, 16-21
Gas, Ammonia in, 2S
Battens for Stage, 134
, Carbonic Acid in, 29
, Carburettingi 117
, Composition of, 98
, Enriching, 11, 12
Fires, 142-152
Flame, 97, 98
, Flue, 21
, Illuminating Power of, 22
, Impurities of, 25, 2S
, Luminous Properties of, 97, 119
Manufacture, 14-24
, Products of, 10
Meters (see Meter)
, Producer, 21
, Specific Gravity of, 49
, Sulphuretted Hydrogen in, 28
, Testing, for Impurities, 28
, Water, 12
Gas-holders, 40-44
Gasometers, (see Gas-holders)
Gasworks, Means of Transit to, 9
Globes, Gas, lis
, , Light Obscured by, US
Goodson's Burners, 107, 108
Governor for Burners, 99, 101
, Station, 39, 42-44
Grooving Pattresses, 80, 81
Hall's Drilling and Tapping Machine, 55
Hawkins and Barton's Burners, 103, 107
House, Laying Pipe in, 60-S2
, Retort, 15
Hydraulic Main, 25-2S
Hydro-carbons in Gas, 97
Illuminating Power of Argand Burner, 114
Illuminating Bray's Burners, 103
— Flat-tlame Burners, 114
■ Gas, 22
Incandescent Burner, 1 14
Regenerative Burner, 114
■ Sun Burner, 110
Welsbach Burners, 124
Impurities of Crude Gas, 25, 28
Incandescence of Gas Flame, 97. 119
Incandescent (see also Welsbach)
Burner Bye-pass Failure, 120
Burners, 100, 119-120
, Advantage of, 108
, Cleaning, 120
, Lighting, 125
Mantles, 119, 120
Breaking, 125
, Oxides for, 121, 122
Index Dials of Meters, SS, 89
Iron Pipes (see Pipe)
Jet Coal, 10
Joint System, Open, 49
Joints (see Socket, Elbow, etc.)
between Brass and Compo. Pipes,
71-74
in Iron Pipes, 67-09
, Lead Paint for, 57
in Mains, 49
Joists, Fixing Pendant to, 77
Kern Burner, 124
I Lacquer, Removing, from Pendants, 77
] Lamp, Pedestal, Gas Supply to, 82
, Regenerative, 110
i Lamps, Blowpipe, 73
| Lead Paint for Screwed Joints, 57
Light Obscured by Gas Globes, lis
.' Lighting Back, 120, 14S, 156
[ Lime Water, 28
' Livesey Water Condenser, 31
I Mains (see also Pipes)
| , Condensation in, 50, 51
, Drilling Holes in, 51-56
, Inclination or Fall of, 50
, Joints in, 49
, Laying, 47
I , Pressure in, 49
, Sizes of, 47, 48
, Socket and Spigot Joint for, 49
, Syphons on, 50, 51
, Tapping Holes in, 56
, Testing, 47
Measuring Roll of Compo. Pipe, 74
Meter, Dry, 93-95
, , Testing, 95, 96
, Fixing, 59
, Index Dials of, SS, S9
Inspector's Duties, 83
, Position of, 59
, Reading, 89
, Station, 39
Testing Compulsory, S3
, Wet, 84-88
, , Evaporation from, 84
, , Measuring too fast, 91
I ■ , , Preventing Water Freezing in,
S6, S7
I , — Remedying Frozen, 88
INDEX.
159
Meter, Wet, Testing, 89-93
Music-halls or Theatres, Gas-fitting in, 130-
136
Nails, Danger of Compo. Pipes from, 75
Naphthalene, 110
Newcastle Coal, 10
Nipple, 61, 67
, Screwing in, 68
Nipple-holder, Ashley, 68
Oil Gas, Enriching Coal Gas with, 11
Lamp, Air Vitiated by, 100
Opal Globes, Light Obscured by, 118
Packing Fines of Regenerative Burner, 112
Paint, Lead, for Joints, 57
Paper, Turmeric, 28
Paraffin Oil, Air Vitiated by, 100
Parrot-bill Pipe Tongs, 6S
Pattresses, 80
■ , Fixing, 81
, Grooving, SO, SI
Peebles' Burner, 107
Gas Making Process, 11
Pedestal Lamp, Gas Supply to, S2
Pendants, Ball and Socket Joint for, 76
, Burnishing, 77
, Cleaning, 77
, Fixing, 76, 77
, Making, 128
, Putting together, 78
, Removing Lacquer from, 77
Pipe (see also Mains)
— -, lJias'Sj fJoinyig jLead or ,Conjpp. to,
, -* — , Connecting, 'io'Irbfl Barrel,™,
71
, , Daugeuof, from Nails, 75
1 , Fixing, J7jj» ' o ' ° ,"j ", '
, , Joining] 7 1 -7*4' • • 0 ■
, , — — Bsass joi> Loral l ipo to,
71-74
, , Tube-bit to, 80
, , Making, 70
, , Measuring Roll of, 74
, , in Plastered Walls, 75
, , Straightening, 75
, , Uncoiling, 74
•, Copper, Brazing, 138
, , Drilling, 139
Cutters, 60
, Dip, 27, 2S
, Fixing, to Joists, 79
under Floor Boards, 7S, 79
■ Hooks, Inserting, 75
, Iron. Advantages of, 47
, , Bending, 128
, , Connecting, to Compo. Pipe,
70, 71
, , Cutting, 60
, , Joints in, 67-69
, Threading, 61-67
between Joists, 77-79
— , Kinds of, 47
, Laying, in House, 00-S2
, Lead, Joining, 71-74
, Screwing, 61-67
, Screwing m idline for, 6 i, 6<
Pipe, Service, Depth below Ground Level
of, 58
, , Fall of, 57
, , Syphon or Drip-well.for, 57
■ , , in Wooden Troughs, 58
, , Wrought-iron, 58
, Stocks or Dies for, 62, 63
, Syphon for Service Pipes, 57
Tongs, 68
Vice, 60
Plastered Walls, Compo. Pipes in, 75
Pliers, S2
Plug, 61
Tap, 55
Plugging Brick Wall for Pattresses, 81
Plumber's Shave-hook, 72
Solder, 72
Top, 71
Producer Gas, 21
Puddle Tank, 42
Purifiers, 37
Quadrant Cock, 151
Radiant Heat, 147
Reading Gas-meter, S9
Red and White Lead Paint, 57
Reducing Socket, 61
Reflecting Stove, 146
Regenerative Burner, 99, 108-114
, Air Vitiated bv, 100
, Fixing, 110, 112
, Flues of, 110, 112, 113
— >V , -i — , IHumin«ti«g Powepof, 114
> —J-*! — " J , Slin4's ianilrijigfiaii, 110
' ' lj— Tbbfti Tube* for, •Hi?* - *
, Ventilating Effect of, 100, 113
, Ventilating-tubes of, 112
] '-^-J— IleteiJt.-lJiJnatie, 20
? ' RjgulalJorJB Jijie/5* # 103, 107
5 K«k>r£, Capacity of>23
, Charging, 23
, Drawing Charge from, 24
Heating Systems, 16-21
House, 15
Lids, 19
, Lighting Gas in, 24
Temperatures, 22
, Withdrawing Coke from, 24
Retorts, 14-20
Round Elbow, 61
Saddle, 23
Safety Drilling Appliances, 53, 51
St. Martin Gas Stove, 146
Sales of Gas Act, 83
Sandriugham Regenerative Lamp, 110
Scoops, Coal, 23
Scraper, 72
Screwing in Nipple, 6S
Pipes, 01-67
Screwing-machine for Pipes, 66, 67
Scrubbers, 32-36
Service Pipes (see Pipe)
Shave-hook, Plumber's, 72
Side Lights, Stage, 134
Siemens' Gas Coke Fire, 143
Retort Arrangement, 17
Smoky Chimney remedied by GasStove', 146
160
INDEX.
Socket, 61, 67
and Spigot Joint, 49
Solder for Joining Pipe, 72
, Testing, 72
Soot from Gas Burners, 98
on Incandescent Burner, 126
Specific Gravity of Gas, 49 1
Sperm Candles, Air Vitiated by, 100
Oil, Air Vitiated by, 100
Splint Coal, 9
Spring, 61
Stage, Theatre, Lighting of, 131-134
Retort House 15
Star for Festival Illumination, 137
Station Governor, 39, 42-44
Meter, 39
Stocks and Dies, 62, 63
Stove Burners, 147
, Hissing Noise in, 151
Supply Pipes, 151
Stoves, 142-156 (see Respective Names)
Steatite, 102
Burner Tips, 102
Street Burners, 107, 10S
Festival Illumination, 137-141
Strode's Sun Burner, 116
Sugg's Burners, 99, 102, 107-110
Stoves, 143, 146
Sulphur in Coal, 13
Sulphuretted Hydrogen, Detecting, 28
, Removing, 37, 38
Sim Bumj^, SjtfodeX JJ6
in Thea'i*;, 134* • • • * *
Tfortsliop; 129 I i •*
Syphon 911 »M^n, 59, 5f • • *•"
Stove, 153
Syphon-box for Service Pipes, 57
Table-top Burners, Smf^'s.ltri*, ^
Tallow Candles, Air V^itfiJ If/* 190
Taper Die Stocks, 6* .... ...
Tap, 55
Tapping Holes in Mains, 56
Taps for Mains, 55
Tar, 22, 23
Extractors, 32
, Naphthalene from, 116
Tee, 61
Tee-light Stand for Stage, 134
Telescopic Gas-holders, 41, 42
Testing Dry Meter, 95, 96
Gas for Impurities, 28
Mains, 47
Meters Compulsory, 83
Solder, 72
Theatre Gas Fittings, 136
Wet Meter, 89-93
Theatre Auditorium, Lighting, 134
, Sun Burner for, 134
Bracket Lights, Guards for, 131
, Cocks and Bye-passes for, 130, 131
Fittings, Testing, 136
Foot-lights, 132-134
Gas Battens, 134
Sidelights, 134
Theatre Stage, Lighting, 131-134
Tee-light Standard, 134
Theatres, Gas-fitting in, 130-136
Thorburn Coal, 10
Threading Pipes, 61-67
Threads, Whitworth's Gas, 62
Tinning Brass Unions, 71
Tube-bits, 80
Tobin Tubes, 113 j
Tongs, Pipe, 68
Top, Boxwood, 71
Tower Scrubber, 33
Transparencies, Illuminated, 141
Tripod Burners, 107, I OS
Troughs for Service Pipes, 5S
Tube-bits, 80
, Tinning, 80
Tubes (see Pipe)
Turmeric Paper, 28
Union, 61
, Barrel, 70
, Brass, Tinning, 71 '
, Cap and Lining, 70, 71
Jet Burners, 99, 102, 103
■ , Air Vitiated by, 103^
Upward's Safety Drill, 53, 54
Ventilating Effect of Regenerative Burnei
100, 113
Ventilating-tubes of Regenerative Burnei
112 "
Veritas Burner, 103
\jce, Pipe.(j0 ... . ..**!
Viatioiiia B«rnw,.l£» •• J • . •
^i/gJilAinliMiJaTslJIji'ij'tir,^.?, 30*. 34
VrthtttohVfTAif fey ilfeunhrtints, 100
| Walls, Gas Pipes in, 75
, Plugging, to recaive Pattresses, 81
*i. YJaruling wjtj CaJ,.;4J
:*. w.ft s > H : :*: :
• A»i«Uiis(«n.s,«S4 •
Washer-scrubbers, 36
Water Condensation, 31
Freezing in Wet Meter, 86, 87
Gas and its Use, 12
Water-oven, 13
Weldon Mud, 38
Welsbach (see also Incandescent)
Burners, 120-124
with Bye-passes, 123
, Fixing up, 120-122
■ Mantles, 120-122
Wenham's Regenerative Burner, 99
Wet Meter (see Meter)
Whitworth's Gas Pipe Threads, 62
Workshop, Air-space in, 129
Benches, Fittings over, 127
, Gas Lights in Middle of, 127
, Sun Burner in, 129
- — , Ventilation of, 129
Workshops, Gas-fitting in, 127-129
Wright's Investigations, 22, 23
Patent Gate Fittings, 153
Wrought-iron Service Pipes, 58
Young's Gas Enrichment Process, 11
Printed by CaSoELL & Company, Limited, Ludgate Hill, London, E.G.
ENGINEER'S HANDY-BOOK.
CONTAINING
FACTS, FORMULA, TABLES AND QUESTIONS
ON POWER, ITS GENERATION, TRANSMISSION AND MEASUREMENT;
HEAT, FUEL AND STEAM ; THE STEAM-BOILER AND ACCESSORIES ; '
STEAM-ENGINES AND THEIR PARTS ; THE STEAM-ENGINE IN-
DICATOR; GAS AND GASOLINE ENGINES; MATERIALS,
THEIR PROPERTIES AND STRENGTH:
TOGETHER WITH A
DISCUSSION OF THE FUNDAMENTAL EXPERIMENTS IN
ELECTRICITY,
AND AN EXPLANATION OF
DYNAMOS, MOTORS, BATTERIES, SWITCHBOARDS, TELE-
PHONES, BELLS, ANNUNCIATORS, ALARMS, Etc.,
AND ALSO
RULES FOR CALCULATING SIZES OF WIRES.
BY
STEPHEN ROPER, Engineer,
AUTHOR OF
" Roper's Catechism of High-Pressure or Non-Condensing Steam-Engines,"
"Roper's Hand-Book of the Locomotive," "Roper's Hand-Book of
Land and Marine Engines," " Roper's Hand-Book of Modern
Steam-Fire Engines," "Young Engineer's Own Book,"
"Use and Abuse of the Steam-Boiler," "Ques-
tions and Answers for Engineers," etc.
FIFTEENTH EDITION.
REVISED AND GREATLY ENLARGED BY
EDWIN R. KELLER, M. E.,
AND
CLAYTON W. PIKE, B. S.,
Ex-President of the Electrical Section of the Franklin Institute.
PHILADELPHIA :
DAVID McKAY,
1022 Market Street.
1903.
PRICE, POSTPAID, p.50. SEND FOR CIRCULARS.
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