PART XVI.

_Other products obtainable from Coal, namely:--Coal Tar--Pitch--Coal Oil--Ammoniacal Liquor, and conversion of the latter into Carbonate, and Muriate of Ammonia._

_Coal Tar._

The coal tar is so called from its resembling common tar in its appearance, and most of its qualities.

This substance is deposited in the purification of the coal gas, in a separate vessel destined to receive it. See fig. 3, plate I.

In the year 1665, Becher, a German chemist, brought to England his discovery for extracting tar from coal, this distillation he performed in close vessels. It is not mentioned in the records of the time, whether Becher obtained, or rather collected, any other articles than the tar.

Several works have been, at different times, erected both in England and on the continent, to procure from coal a substitute for tar; but they have turned out unprofitable speculations.

In 1781, the Earl of Dundonald invented a mode of distilling coal in the large way, which enabled him not only to form the coke, but, at the same time, to save and collect the tar. Even this process, however, for which a patent was taken out, gained very little ground. Its object was too limited; for though some of the proximate constituent parts of coal were procured, they were obtained at an expence that nearly balanced the profits; and no attention whatever was paid to the coal gas, which constitutes by far the most valuable part obtainable from pit coal.

Coal tar is now used with advantage largely in the Royal Navy, and also for painting and securing wood that is exposed to the action of air. The wood being warmed, the tar is applied cold, and penetrating into the pores, gives the timber an uncommon degree of hardness and durability.

The quantity of tar obtainable from a given quantity of coal, varies according to the manner in which the decomposition of the coal is affected. See page 122.

The tar obtained from Newcastle coal is specifically heavier than that produced from cannel coal; hence it sinks in water, whereas the latter swims on the surface of that fluid.

To render coal tar fit for use, it requires to be evaporated to give it a sufficient consistence. If this process be performed in close vessels, a portion of an essential oil is obtained, which is known by the name of

_Coal Oil._

To obtain this oil, a common still is charged with coal tar, and, being properly luted, the fire is kindled and kept up very moderate, for the tar is very apt to boil up in the early part of the process. The first product that distils over is principally a brown ammoniacal fluid, mixed with a good deal of oil. As the process advances, and the heat is increased, the quantity of ammoniacal liquor lessens, and that of oil increases, and towards the end of the distillation the product is chiefly oil.

The oil and ammoniacal water which distil over do not mix, so that they may be easily separated by decantation. The oil is a yellowish inferior kind of naptha, which is very useful in painting ships, and for making common varnishes. It has lately been employed as a substitute for whale oil, to be burnt in out door lamps.

The contrivance by means of which this oil is burnt in lamps[61] consists of a fountain reservoir to supply and preserve a constant level. The burner with its wick is placed in the axis of the lamp, and supplied with the oil from the fountain reservoir, placed on the outside of the lamp. The air is admitted by an aperture at the bottom of the lamp. The current of air in passing through the lamp envelopes the burner and urges the flame, which is extremely bright; but it is essential that the flame should be small. The draught tube proceeding from the centre of the reflector above the flame carries away the smoke.

[61] All the lamps on Waterloo Bridge, and the streets adjoining the bridge are lighted by means of tar oil.

1430 pounds of coal tar, produce 360 pounds of essential oil. The residue left after the distillation is

_Pitch._

If the coal tar is wanted to be converted into pitch, without obtaining the oil which it is capable of furnishing, the evaporation of it may be performed in a common boiler; but as it is extremely liable to boil over, the greatest precaution is necessary in conducting the evaporation. A spout or rim is added to the common boiler into which the tar spreads itself as it rises, and by this means becomes cooled, and the boiling over is checked.

1430 pounds of coal tar produce 9 cwt. of pitch. A subsequent evaporation with a gentle heat, converts the coal pitch into a substance greatly resembling _asphaltum_.

_Manufacture of Carbonate of Ammonia from the Ammoniacal Liquor of Pit Coal._

The ammoniacal liquor obtained in the gas light manufacture, is employed for the production of carbonate of ammonia. The average quantity of this liquor, obtainable from a chaldron, (27 cwt.) of Newcastle, or Sunderland coal, amounts to from 180 to 220 pounds. It is chiefly composed of carbonate and sulphate of ammonia. The quantity of ammonia contained in it, varies considerably. The strongest liquor is obtained from coal that readily cake, (page 45); a gallon (or eight and a half pounds weight) of ammoniacal liquor usually requires for saturation, from fifteen to sixteen ounces of sulphuric acid of a specific gravity 1,84. The weakest ammoniacal liquor is obtained from those species of coal which do not cake, and which by a single combustion are reduced to light ashes. It requires only from eight to ten ounces of sulphuric acid, of the before mentioned specific gravity for its saturation.

The following process is employed in the large way, for obtaining carbonate of ammonia from the ammoniacal liquor. To 108 gallons[62] of the liquor contained in a cask, are added 125 pounds[63] of finely ground sulphate of lime, which has been previously deprived of moisture by heat. The cask is bunged up, and the mixture after being stirred together for a few minutes, is left undisturbed for three or four hours. Sixteen ounces of sulphuric acid are then added, the mixture is again agitated, and is again suffered to stand undisturbed for four or six hours. If the liquor be now examined, it will turn blue litmus paper, red.

[62] One gallon of the strongest ammoniacal liquor, weighs eight and a half pounds.

[63] This quantity is evidently too large, but the workmen assert, that an excess of sulphate of lime causes the carbonate of lime which is formed, to subside more readily, and the excess of sulphate of lime can do no injury.

In this operation a double decomposition takes place, the sulphate of lime yields part of its sulphuric acid, to the carbonate of ammonia of the liquor, to form sulphate of ammonia, and the carbonic acid of the ammonia, combines with the lime of the sulphate of lime, to form carbonate of lime, which falls to the bottom, the supernatant fluid contains in solution, sulphate of ammonia.

When the liquor has become clear, it is pumped out of the barrel into shallow cast iron boilers, where it is evaporated slowly. During this process, a portion of sulphate of lime is deposited which is removed, and as the liquor becomes more concentrated, part of the sulphate of ammonia begins to crystallize and falls to the bottom. It is shovelled out from time to time into wicker baskets, placed slanting over the rim of the boiler, that the liquor which drains off from the crystals may not be lost, and lastly the whole fluid is evaporated to dryness.

108 gallons of ammoniacal liquor from Newcastle coal, produce upon an average, one and a half cwt. of dry sulphate of ammonia. To decompose it, one cwt. is mixt with one quarter of a cwt. of finely ground chalk, previously deprived of moisture by heat. The mixture is introduced (as expeditiously as possible) into cast iron retorts,[64] heated nearly to a dull redness, and when the lid of the retorts have been rendered air tight, the fire is raised gradually till the retorts are of a strong red heat. The carbonate of ammonia developed from the contents of the retorts, is made to sublime into a leaden barrel-shaped receiver, connected with the retorts, by means of a pipe four inches in diameter, proceeding from the upper extremity of each retort, and opposite to the mouth piece. The leaden receiver is furnished with a leaden cover, fitting into a groove, where it is made air tight by lute. The receiver which is supported upon a stand is provided at its base, with a small pipe, furnished with a stopper. This pipe is left open till the liquid products are got rid of during the sublimatory process. In the centre of the cover, or at any other convenient part of the apparatus, is made a small hole, slightly stopped with a wooden peg, to give vent to the elastic fluid that becomes evolved during the process.

[64] Of the usual form and dimensions, described page 58.

The time requisite for the operation depends on the mode in which the retorts are set, the temperature kept up and other practical circumstances. A charge of 120 pounds of the mixture of sulphate of ammonia and chalk in one retort, is usually decomposed in twenty-four hours. When the operation is at an end, and the receiver having become cold, the cover is taken off, and the sublimed carbonate of ammonia adhering to the sides of the receiver is detached by a chissel and mallet, and after being freed from any casual impurities, is packed up in stone jars for sale.

One cwt. of dry sulphate of ammonia, produces from sixty pounds, to sixty-five pounds, of pure carbonate of ammonia. In some establishments, the carbonate of ammonia is subjected to a second sublimation by means of a gentle heat; but this is quite unnecessary if the process has been conducted carefully.

_Manufacture of Muriate of Ammonia from the Ammoniacal Liquor of Coal._

It must be obvious that the ammoniacal liquor may be employed with great advantage for the production of muriate of ammonia. For if the solution of sulphate of ammonia obtained from the ammoniacal liquor by means of sulphate of lime, as before stated, be mixed with common salt, (or any other muriate) another decomposition takes place. The muriatic acid of the common salt, unites to the ammonia of the sulphate of ammonia, and produces muriate of ammonia, and the sulphuric acid of the sulphate of ammonia, combines with the soda of the common salt, and produces sulphate of soda, or glauber salt.

The liquor containing these two salts being evaporated, the glauber salt begins to crystallize, and is removed from time to time. The evaporation is continued till as much as possible of the glauber salt has been separated, and the muriate of ammonia begins to crystallize on the surface of the fluid in the form of a feathered star. The remaining fluid is then run off into coolers, and deposits little else than muriate of ammonia, till it gets below the temperature of 76° Fahr. at which time the crystals are to be removed, lest they should be mixed with glauber’s salt which now begins to be again deposited. After the muriate of ammonia has been suffered to drain in baskets, it is heated in shallow pans to drive off as much water of crystallization as possible. It is then removed whilst still hot, into earthenware jars, glazed within, and fitted with a cover, (having a hole of about half an inch in diameter in its centre,) luted on with clay. The jars are put in a cast iron pot over a strong fire, in a furnace capable of containing from six to eighteen jars, surrounded with sand up to the edge of the pot, and also having about two and a half inches of sand on the cover, confined by an iron ring about three inches deep, and two inches less in diameter than the cover, in order that if the luting should give way in any part, it may be repaired without suffering the covers (which should be kept during the sublimation at about 320° Fahr.) to be cooled by the removal of a large portion of the sand.

These earthen jars may be filled to within two inches of the top, with the dried salt gently pressed in, but not rammed close; and the fire which has been lighted some time before, is now to be raised gradually till the iron pots are of a pretty strong red heat all round, being so placed by mean of flues in the furnace that the upper part may be first heated, the bottom resting on solid brick work.

During the first impression of the heat, a portion of the salt carrying with it a quantity of watery vapour not separated during the drying of the salt, will escape through the hole in the cover, which must be left open till all the aqueous part is exhaled: this is known by bringing a piece of cold smooth iron plate near the hole, in order to condense the sublimate, which becoming more and more dry, at length attaches itself firmly to the plate, in the form of a dry semi-transparent crust.

At this time the hole is to be stopped with lute, more sand is to be put on the cover, and the heat continued till it is judged that nearly the whole of the muriate of ammonia is sublimed. The time requisite for this purpose depends on the construction of the furnace, the size of the pots, the briskness of the fire, and other circumstances only to be learnt by experience.

The process should be stopped before the sublimation has entirely ceased, as the heat in some parts of the jar may be too great when it is nearly empty, and either by volatilizing a part of the salt itself, or elevating a portion of foreign matter from which it can never be kept wholly free, and thus giving the cake a yellow tinge, and a scorched, opake, crackled appearance.

The same defects are likely to happen, when any part of the luting having given way, is obliged to be repaired by wet lute, when the sublimation is pretty far advanced: consequently glass vessels are preferable, except on account of the expence, as they must always be broken to pieces in order to get out the cake: the earthenware jars on the contrary will serve for several sublimations, even the covers, if well glazed, will last two operations. The sublimation being finished and the apparatus having become sufficiently cool, the tops of the jars are to be taken off, and the cakes of sal-ammoniac that are found adhering to them are to be separated, and placed for a day or two in a damp atmosphere, which softens their surface a little, and thus facilitates the removal of any superficial impurities. Lastly, the cakes are packed up in casks for sale.

The excise laws have hitherto operated strongly against the establishment of manufactories of muriate of ammonia in England. Hence an immense quantity of sulphate of ammonia obtained from the gas light ammoniacal liquor, is exported from this country to the continent, solely from the extreme rigour of the excise relating to the use of common salt, and it is only this that has hitherto prevented the establishment of manufactories of sal-ammoniac from the ammoniacal liquor of the gas light process upon a large scale.

Chemical manufactories, of all others, will least bear excise, because many of them are worked according to secret processes, which, if made public, must pass into other countries; and the greatest part of the profit ceases together with the export. The vexatious introduction of excise officers into manufacturing laboratories, it is evident, puts an end to all secrecy of operation. There are several chemical processes which interruption will extremely injure, and others which it totally destroys, and as on the whole they in general are of a nature in which interference of others is most peculiarly vexatious, in all probability, if the excise be extended to manufactures of this nature, it will eventually put a stop to most of them, and greatly injure the revenue by causing thereby to cease the duties which at present arise from the exports and imports to a large amount, now depending on the chemical trade of Great Britain.

We have now gone through all the improvements by which the gas light manufacture has been distinguished during the interval which has elapsed since the publication of our former work[65] on this subject; and perhaps the reader may be inclined to think, from the extraordinary height to which improvement has been carried in this art, that little or nothing more remains to be desired with regard to it. Let it be remembered, however, that the whole art is only in its infancy. There is yet a wide field for improvement in the construction of the apparatus. Ingenious men may speculate from what has been done, to what remains to be effected, which no doubt will lead to objects of the greatest utility, and most extended national importance.

[65] A practical treatise on gas light.

DESCRIPTION OF THE PLATES.

PLATE I.

PAGE.

Elevation of the Revolving Gas Holder at the Westminster Gas Works 181

PLATE II.

Gas Light Apparatus at the Royal Mint.

Fig. 1, Perpendicular Section of one of the Horizontal Rotary Retorts with its Furnace 112

Fig. 2, The Purifying Apparatus 150

Fig. 3, The Tar Cistern 117

Fig. 4, The Gas Metre 214

The roof of the building surrounding the Gas Works is furnished with a projecting Louver to let out the smoke.

PLATE III.

Fig. 1, Represents a perspective view of a Portable Gas Metre 219

Fig. 2, Perpendicular Section of the Horizontal Rotary Retorts at the Royal Mint Gas Works--at Chester--Birmingham, &c. 112

Fig. 3, Perpendicular Section of the Gas Holder Valve and Siphon, or Water Reservoir 222

Fig. 4, Perspective View of the Governor, or Regulating Guage, for maintaining the Flames of Gas Lamps and Burners of an uniform intensity 225

Fig. 5, Plan of the Horizontal Rotary Retorts at the Royal Mint--Chester--Bristol--Birmingham--Kidderminster, &c. 115

Fig. 6, Transverse Section of the Gas Metre at the Royal Mint--Chester--Birmingham, &c. 219

Fig. 7, Perpendicular Section of the Gas Holder Valve 221

Fig. 8, Front elevation of the Gas Metre, at the Royal Mint, shewing the registering train of Wheel Work 218

Fig. 9, Perpendicular Section of the Gas Holder, Governor, or Regulating Guage, at the Bristol--Birmingham--and Chester Gas Works 171

Fig. 10, Transverse Section of the Air-Box, and Lime Trough, See purifying apparatus 152

Fig. 11, Perspective View of a Portable Governor or Regulating Guage 232

Fig. 12, Coal Tray of Horizontal Rotary Retort 116

Fig. 13, A jointed swing Bracket Lamp 257

Fig. 14, A Mercurial Universal Joint for Pendent Gas Lamps 256

PLATE IV.

Fig. 1, Transverse Section of the Retort Ovens, at the Westminster and City of London Gas Works, showing the mode of setting and arranging Cylindrical Retorts 69

Fig. 2, Longitudinal Section of the same 69

PLATE V.

Fig. 1, Front elevation of the Retort Ovens at the Westminster and City of London Gas Works 69

Fig. 2, Perpendicular Section of the Gas Holder, without Specific Gravity Apparatus, at the Birmingham Gas Works 177

Fig. 3, Plan of the same 177

Fig. 4, Perpendicular Section of Mr. Malam’s Lime Machine 143

Fig. 5, Plan of the same 146

Fig. 6 and 7, Mouth Piece and Cover of cylindrical, parallelopipedal and semi-cylindrical Retorts, (exhibited fig. 1, plate IV,) drawn to a larger scale 71

Fig. 8, 9, 10, 11, 12, and 13, Gas Lamps and Burners 253

Fig. 14 and 15, Profile View and Section of Gas Mains, and mode of connecting them 240

Fig. 16, 17, and 18, Perpendicular Section of the parallelopipedal, ellipsoidal, and semi-cylindrical Retorts 53

Fig. 19, 20, 21, and 22, Union Joint, and circular bends for connecting Gas Pipes 266

Fig. 23, Test Apparatus for certifying the proper manner of working the Lime Machine 157

PLATE VI.

Fig. 1, Plan, showing the Fire Place and Flues, of the Horizontal Rotary Retorts 113

Fig. 2, Longitudinal Section of the Collapsing Gas Holder, and the Tank of ditto 189

Fig. 3, Transverse Section of the same 189

Fig. 4, End View of the same 189

Fig. 5 and 6, Horizontal plan shewing the mode of connecting the end plates of the Collapsing Gas Holder 192

Fig. 7, Perpendicular Section of the Gas Holder, without specific gravity Apparatus, at the Chester Gas Works 175

Fig. 8, Perspective View of the Revolving Gas Holder, at the Westminster Gas Works 181

Fig. 9, Perspective View of the Reciprocating Safety Valve 196

Fig. 10, Plan of the Purifying Apparatus, or Lime Machine, shewing the Air Trough of the Apparatus, with its axis and claws 152

Fig. 11, Sliding part of a Pendent Gas Lamp, which may be raised or depressed 257

PLATE VII.

Exhibits an economical arrangement of a Gas Apparatus, for lighting a town, or large districts. The central building exhibits the Retort House. The roof is furnished with a projecting Louver to let out the smoke. The gable ends, and one side of the building, are of brick-work, the other side of the house is open, and supported on iron columns. The building to the right hand side of the Retorts, is the Purifying House, it contains the Lime Machine, page 149. The trap door, marked A, indicates the Cistern or Reservoir for receiving the Waste Lime. The third and smallest building in the design, serves for an Office of the Director of the Works. The front wall is represented as taken away, to show the position of the Gas Metre, the axis of which drives the agitating shaft of the Lime Machine. The axis of the Metre and the shaft of the Lime Machine, are for that purpose connected by a strap, (page 213.) The small building-on the left hand side of the Retort House, is a Smith’s Shop. T, shows the situation of the Main Gas Holder Valve (page 221.)

INDEX.

A.

Advantages of the art of procuring light by means of coal gas 1

Air box of lime machine 153

Ammoniacal liquor, quantity obtainable from a given quantity of coal 303

Ammoniacal liquor, quantity of sulphuric acid, required for saturating a given quantity 303

Ammoniacal liquor, conversion of, into carbonate of ammonia 303

Ammoniacal liquor, conversion of, into muriate of ammonia 303

Apparatus for obtaining carburetted hydrogen gas from coal tar 285

Apparatus for purifying coal gas 141

Apparatus for certifying the proper mode of working the lime machine 157

Argand gas lamp 253

Argand gas lamp, quantity of gas consumed by different kinds 275

Art of procuring coal gas, theory of 33

B.

Bat’s wing gas burner 255

Bends, for connecting gas pipes 267

Burner, argand 253

Burner, bat’s wing 255

Burner, cockspur 255

Branch pipes 239

Branch pipes, dip of 243

Branch pipes, mode of connecting 263

Branch pipes, mode of proving 265

Branch pipes, corrosion of 260

C.

Carbonate of ammonia, preparation of, from ammoniacal liquor of coal 303

Cement, for connecting gas mains 241

Chandelier, sliding, for burning gas 257

Chester gas holder, description of 175

Coal, analysis of, by destructive distillation 35

Coal, chemical constitution of 42

Coal, classification of 41

Coal, comparative facility with which different species are decomposed 106

Coal, chiefly composed of bitumen only, varieties of 42

Coal, chiefly composed of bitumen, maximum quantity of gas obtainable from them 43

Coal, containing more carbon than bitumen 45

Coal, containing more carbon than bitumen, maximum quantity of gas obtainable from them 48

Coal, destitute of bitumen 42

Coal, maximum quantity of gas obtainable from them 44

Coal, Gloucestershire 49

Coal, Kilkenny 44

Coal, Lancashire 44

Coal, Newcastle 47

Coal, Scotch 109

Coal, Warwickshire 109

Coal, Welch Stone 48

Coal, Yorkshire 44

Coal oil 300

Coal oil, quantity obtainable from a given quantity of coal tar 302

Coal tar 298

Coal tar, quantity obtainable from a given quantity of coal 122

Coke, quantity obtained in the gas light process from a given quantity of coal, by means of cylindrical retorts 132

Coke, quantity obtained by means of horizontal rotary retorts 132

F.

Flue plan of setting cast iron retorts 59

Flue plan, report on a series of operations, made with retorts worked on the flue plan 61

Fuel, minimum quantity required for the complete decomposition of coal, by means of cylindrical retorts 61

G.

Gas, average cost of manufacturing it upon a large scale, in London 106

Gas, apparatus for lighting a town, best situation of, as far as it regards the most economical distribution of the pipes 249

Gas, apparatus for lighting a town, arrangement of 319

Gas, apparatus for lighting a town, at the Royal Mint 112

Gas, burners, different kinds of 253

Gas, quantity of, evolved during different periods of the distillatory process employed for decomposing coal, in cylindrical retorts 77

Gas, observations on the progressive evolution of, during different periods of the distillatory process with cylindrical retorts 79

Gas flame, mode of regulating the magnitude of 234

Gas holder, construction of, originally employed 164

Gas holder, sheet iron, best adapted for it 180

Gas holder, sheet iron, best adapted for it, cost of 164

Gas holder, sheet iron, lately adopted without specific gravity apparatus 169

Gas holder, at Birmingham without specific gravity apparatus 177

Gas holder, at Bristol without specific gravity apparatus 175

Gas holder, at Chester without specific gravity apparatus 175

Gas holder, collapsing 185

Gas holder, collapsing, rule for finding its capacity 195

Gas holder, revolving at the Westminster gas works 181

Gas holder, collapsing, rule for calculating its capacity 185

Gas holder, valve 221

Gas from coal tar 286

Gas from coal tar, average quantity obtainable from a given quantity of tar 286

Gas from oil 289

Gas from oil, quantity obtainable from a given quantity of oil 297

Gas from vegetable tar 284

Gas from vegetable tar, average quantity obtainable from a given quantity of tar 284

Gas illuminating power of 271

Gas lamps 253

Gas lamps, diameter of the pipes for supplying them with gas 261

Gas mains 239

Gas mains, mode of proving them when laid 245

Gas mains, observations on 247

Gas mains, cost of a mile, laid under ground in London 252

Gas mains, of pewter, lead, and tin, why unfit for distributing gas 260

Gas mains, weight of different lengths, of a given bore 251

Gas metre, construction of 214

Gas metre, construction of, at the Royal Mint Gas Works 214

Gas metre, directions to workmen for fixing it 229

Gas metre, rule for calculating its power 220

Gas metre, at the Birmingham Gas Works, registering capacity of 220

Gas metre, at the Bristol Gas Works, registering capacity of 220

Gas metre, at the Chester Gas Works, registering capacity of 220

Gas pipes, directions to workmen for adapting them to the interior of houses 258

Gasometer house, of sheet iron, of a given size, cost of 178

Gasometer, tank of cast iron, of a given size, cost of 178

Gasometer, tank of brick work, of a given size, cost of 178

Gasometer, tank of wood, of a given size, cost of 178

Governor, or regulating guage 261

Governor, its application and efficacy 171

Governor, directions to workmen for fixing it 229

H.

Horizontal rotary retort. (See rotary retort horizontal) 110

L.

Lamps for burning coal gas 253

Lamps for burning coal gas, quantity of gas consumed by different kinds, in a given time 275

Lime machine originally employed, defects, and dangerous consequences to which it gave rise 141

Lime machine, lately adopted 149

Lime machine, at Birmingham gas works 149

Lime machine, at Chester gas works 149

Lime machine, at Royal Mint gas works 150

Lime machine, capacity requisite for purifying a given volume of gas in a given time 157

M.

Mains for conveying gas 245

Mains, average cost of a mile when laid in London 252

Mains, manner of proving them when laid 245

Mains, kind of, most economical for conveying gas 251

Mains, which do not supply branch pipes or lamps, observations on 250

Mains, faulty, how distinguished 240

Mercurial joint for pendent gas lamps 256

Muriate of ammonia, preparation of, from the ammoniacal liquor of coal 303

N.

Newcastle coal, maximum quantity of gas obtainable from different kinds 47

O.

Oven, for heating retorts, (See retort oven)

Oil, from coal tar 300

Oil gas 289

Oil gas, quantity obtainable from a given quantity of whale oil 296

Oven plan, of setting cast iron retorts 67

P.

Pendent gas lamp 257

Pipes, directions to workmen for adapting them to the interior of houses 258

Pitch from coal tar 302

Pitch, quantity obtainable from a given quantity of tar 302

Purifying apparatus, (See lime machine) 150

Q.

Quicklime, best method of preserving it for the purification of coal gas 160

Quicklime, quantity required for purifying a given volume of coal gas 162

R.

Reciprocating safety valve 196

Regulating guage, regulator, or governor 171 220

Regulating guage, at Birmingham Gas Works 177

Regulating guage, at Bristol Gas Works 177

Regulating guage, at Chester Gas Works 177

Retorts, cylindrical cast iron 52

Retorts, cylindrical, method of heating them by flues 59

Retorts, cylindrical, experiments on setting three to one fire place 61

Retorts, cylindrical, experiments on setting four to one fire place 53

Retorts, cylindrical, cost of erecting them 99

Retorts, cylindrical, best mode of working them 94

Retorts, cylindrical, minimum quantity of fuel required for working them 61

Retorts, cylindrical, temperature best adapted for working them 94

Retorts, cylindrical, conical 52

Retorts, cylindrical, conical, comparative power of 55

Retorts, cylindrical, ellipsoidal 53

Retorts, horizontal rotary 110

Retorts, horizontal rotary, at the Royal Mint Gas Works 112

Retorts, horizontal rotary, at Birmingham 111

Retorts, horizontal rotary, at Chester 111

Retorts, horizontal rotary, at Kidderminster 111

Retorts, horizontal rotary, action and management of 121

Retorts, horizontal rotary, advantages of 124

Retorts, horizontal rotary, directions to workmen with regard to working them 134

Retorts, parallelopipedal 52

Retorts, parallelopipedal, comparative power of 55

Retorts, parallelopipedal, best mode of working them 93

Retorts, semi-cylindrical 53

Retorts, oven, description of, at the Westminster and City of London Gas Works 69

Retorts, oven, experiments on 84

Revolving gas holder, at the Westminster Gas Works 181

Revolving gas holder, rule for calculating its capacity 185

S.

Safety valve, reciprocating 196

Self-acting guage, (see governor) 171

Siphon 221

Sliding chandelier 257

South London Gas Works 69

Spigot and faucit pipes 241

Staffordshire coal 44

Swing bracket gas burner 257

T.

Tar, quantity obtainable from a given quantity of coal 130

Tar gas, quantity obtainable from a given quantity of coal tar 287

Tar gas, from vegetable tar 284

Tar, retort 285

Temperature for working cast iron retorts, remarks on 94

Test apparatus, for certifying the proper manner of working the lime machine 157

Theory of the production of gas lights 39

Towns lighted with gas 149

V.

Valve of gas holder 221

Valve, hydraulic 116

Valve, of horizontal rotary retort 116 124

Valve, lime machine 156

Valve, reciprocating 196

Ventilation of rooms lighted by gas 276

W.

Water reservoir, (See Siphon) 221

Wheel work, registering of gas metre 218

LONDON PRICE LIST

Of the most essential articles employed in the manufacture and application of Coal Gas; delivered free of expence at any Wharf between London and Vauxhall Bridge.

_Cast iron Spigot and Faucit Pipes._

DIAMETER. THICKNESS IN THE METAL. PRICE PER YARD. £. _s._ _d._ 1 and a half inch 5-sixths of an inch 2 6 2 inches 3-eighths 3 6 2 and a half ditto ditto 4 0 3 inches 7-sixteenths 4 6 4 ditto half an inch 6 6 5 ditto ditto 9 0 6 ditto ditto 10 0 7 ditto ditto 11 0 8 ditto 5-eighths 12 3 9 ditto ditto 16 6 10 ditto ditto 19 6

_Cast iron Flanch Pipes._

1 and a half inch 3 0 2 inches 4 0 2 and a half inch 4 10 3 inches 5 4 4 ditto 7 3 5 ditto 9 6 Quadrant flanch pipes 14 0 cwt. Bend pipes of different radii, branch pipes and accommodating pipes 13 0 cwt. From eight to six inches 13_s._ 6_d._ from 5 to 3 inches 14 0 Two, and 1 and a half inch 14 6 Siphon, water reservoir, or tar-well pipes, from 2 to 6 inches in diameter 15 0 cwt. Ditto, above 6 inches in diameter 14 0 Gas holder, or hydraulic valve pipes, with boxes 15 0 Wrought iron work and screws to ditto 0 7¹⁄₂ ℔ Retorts of best picked iron, from second process 13 0 cwt. Mouth pieces to ditto, ground and fitted 20 0 Wrought iron work and screws to ditto 0 7¹⁄₂ ℔ Connecting and stride pipes, ground 20 0 cwt. Hydraulic cylinders 15 0 Tapering pipes 15 0 Outer fire doors 15 0 Inner ditto 11 0 Fire back, bearers, dead plates 11 0 Top, register, and slide dampers 14 0 Pullies, and friction sectors, turned and fitted 22 0 Wrought iron gudgeons for ditto, turned and fitted 1 0 ℔. One inch bolts } Seven-eighths ditto } at 0 0 5¹⁄₂ ℔. Three-quarters ditto } Five-eighths 2 8 0 gross. Half-inch 1 18 0 gross. Tar receivers and purifying vessels 0 14 0 cwt. Condensing pipes, and inlet and outlet pipes for tanks 0 14 0 Cast iron tanks put together complete, with bolts, screws, cement, &c. 0 16 0 Gas holders, original construction, erected complete of sheet iron 0 60 0 Gas holder, collapsing ditto, complete, capacity 30,000 cubic feet 1000 0 0 Gas holder, collapsing ditto, complete, capacity 15,000 cubic feet 700 0 0 Gas holder, collapsing ditto, complete, capacity 22,000 cubic feet 800 0 0

_Wrought iron Gas Tubes screwed and fitted, warranted to bear a pressure equal to a column of water 300 feet high._

BORE. PENCE PER FOOT. 1 inch 10 7-eighths 8 3-quarters 7¹⁄₂ 5-eighths 7 Half an inch and 3-eighths 6¹⁄₂

_Copper Tubes._

BORE OF TUBE. PRICE PER FOOT. £ _s._ _d._ 3-eighths of an inch copper tubes 0 4¹⁄₂ Half ditto ditto 0 6 5-eighths ditto ditto 0 9 3-quarters ditto ditto 0 11¹⁄₂ 7-eighths ditto ditto 1 4 1 inch ditto 1 8 1 and a half ditto ditto 2 2

Union joints 3-eighths of an inch 8_s._ half an inch 9_s._ 5-eighths of an inch 10_s._ 6_d._ 3-quarters of an inch 0 14 0 per doz. Union T sockets, 3-quarters of an inch 20_s._ half inch 0 14 0 per doz. Three-quarters of an inch main cocks 0 4 6 each

_Brazed sheet iron Tubes._

BORE OF TUBE. PRICE PER FOOT. _s._ _d._ 3-eighths of an inch 0 3³⁄₄ Half an inch 0 4¹⁄₄ 5-eighths of an inch 0 5 3-quarters 0 6¹⁄₂ 1 inch 0 7¹⁄₂ 1 and a quarter 0 10 1 and a half 1 3

£. _s._ _d._ Ornamental gas lamp posts, and columns, fitted complete with York lamps glazed, tube, branches, cocks, and burners, ready for lighting £. 6 6 0 each Or castings for ditto 13 0 cwt. Wrought iron work for ditto 0 7¹⁄₂ ℔. Argand burners complete, from 2_s._ 6_d._ to 5 0 each Iron roofs for retort and gas holder houses, erected complete, at £. 6 6 0 per square of 100 feet, superficial measure.

_Cost of laying cast iron Gas mains in London. To take up the ground, to fill in, but not to re-pave the ground, and to drive two and a half inches of lead into the joints of the pipes._

DIAMETER OF MAINS. PER YARD. _s._ _d._ 3 inches 1 6 4 ditto 1 10 5 ditto 2 1 6 ditto 2 2 7 ditto 2 4 8 ditto 2 7 9 ditto 3 0 10 ditto 3 4

£. _s._ _d._ Tapping the mains and laying gun barrel, or branch pipes 0 1 0 per yrd. Governor complete to regulate every 24 hours 30,000 cubic feet of gas 60 0 0 A lime machine, new construction, to purify 30,000 cubic feet of gas every 24 hours 220 0 0 A gas metre, to register 30,000 cubic feet of gas every 24 hours 105 0 0 A gas light apparatus complete, capable of producing 48,000 cubic feet of gas every 24 hours, costs, if erected in London 8000 0 0

ESTIMATE OF ~A Gas Light Apparatus,~ Capable of producing every 24 hours, a light equal to 21,330 tallow candles, eight in the pound, burning for six hours.

£. _s._ _d._

Five horizontal rotary retorts, 12 feet 6 inches in diameter, complete for immediate use 2320 0 0 Two lime machines, ditto ditto 536 0 0 Two collapsing gas holders, 30,000 cubic feet capacity each 2000 0 0 A gas metre 200 0 0 A governor or regulating guage 100 0 0 Tar well 58 0 0 Pumps 67 0 0 Connecting pipes 265 0 0 Condensing pipes, between the retorts, tar well, and lime machines 219 16 0 Retort house, with iron roof 653 19 0 Lime machine house, with ditto ditto 230 0 0 Workmen’s tools and sundries 430 0 0 ---------------- £. 7079 15 0

This apparatus is capable of producing every 24 hours, 66,000 cubic feet of gas.

THE END.

C. Green, Printer, 15, Leicester Street, Leicester Square.

_In the Press_,

A DESCRIPTION OF THE CHEMICAL APPARATUS AND INSTRUMENTS,

WITH FIFTEEN QUARTO COPPER PLATES,

BY FREDRICK ACCUM.

WORKS

LATELY PUBLISHED BY FREDRICK ACCUM.

A PRACTICAL ESSAY ON CHEMICAL RE-AGENTS OR TESTS,

Exhibiting the general nature of Chemical Re-Agents or Tests--the Effects which they produce upon different bodies--the Uses to which they may be applied, and the Art of applying them successfully.

THE SECOND EDITION,

_Illustrated by a Series of Experiments._ _Price 9s._

CHEMICAL AMUSEMENT,

Comprising a Series of curious and instructive Experiments in Chemistry, which are easily performed, and unattended by Danger.

_The Fourth Edition._ _Price 9s._

A PRACTICAL TREATISE ON GAS LIGHT,

WITH SEVEN COLOURED PLATES,

Exhibiting a summary description of the Apparatus and Machinery best calculated for illuminating Streets, Houses, and Manufactories, with Coal Gas; with Remarks on the general nature of this new branch of civil economy.

_The Fourth Edition._ _Price 12s._

ELEMENTS OF CRYSTALLOGRAPHY,

_After the Method of Haüy_,

WITH PLATES AND GRAPHIC DESIGNS,

Exhibiting the Forms of Crystals, their Geometrical Structure, and general Laws, according to which the immense variety of actually existing Crystals are produced.

_Price 15s._

A MANUAL OF ANALYTICAL MINERALOGY,

Intended to facilitate the Practical Analysis of Minerals, by pointing out to the Student concise directions for performing the Analysis of Metallic Ores, Earths, and other Minerals.

_Second Edition._ _2 Vols._ _Price 15s._

A SYSTEM OF THEORETICAL AND PRACTICAL CHEMISTRY,

IN TWO VOLS. WITH PLATES.

_Second Edition. Price 15s._

_Directions to the Binder._

Plate II, to face Title Page.

Plate III, IV, V, VI, and VII, at the end of the Book.

Transcriber’s Notes

Inconsistent, archaic and unusual language, punctuation and spelling have been retained, except as mentioned below. The book uses a comma for decimal point as well as for thousands separator.

The (minor) differences in wording between the Table of Contents and the actual text headings and the use of £ (with or without full stop and/or space) and _l._ have not been standardised.

Depending on the hard- and software used and their settings, not all elements may display as intended.

When relevant, texts have been removed from the plates and transcribed outside the plates.

Plate II, 'Accums’': as printed in original work.

Page xv, entry AMMONIACAL LIQUOR: there is no separate section for this material, but it is described in the first part of the section on Carbonate of Ammonia on page 303.

Page 43, 'Pont Tops': possibly Pontops.

Page 49, 'Tramsaren, near Kidwelly': possibly Trimsaran.

Page 79, table: the quantities given add up to 556 cubic feet.

Page 84, 'Enclosed are the result': as printed in the source document.

Page 86, Expenditure of Process A: the amounts given do not add up to the total.

Page 103/104, calculation: the numbers given do not add up to the first sub-total.

Page 196, example of capacity calculation: the dimensions given result in a capacity of 22,500 cubic feet.

Plate III, 'discription': as printed in the source document.

Changes:

Footnotes have been moved to under the paragraph where they are referenced.

Tables printed over multiple pages have been re-combined into single tables; where relevant, items such as Carried Over etc. have been removed. The lay-out of the tables with financial analyses has been standardised.

Several obvious minor typographical and punctuation errors have been corrected silently.

Page iii: 'as its little expresses' changed to 'as its title expresses'.

Page x: entries for pages 80 and 81 moved to their proper place.

Page xv: page number for entry AMMONIACAL LIQUOR changed to 303 (see above).

Page 42, 'principle coal mines' changed to 'principal coal mines'.

Page 43: 'Cowpers Main' changed to 'Cowper’s Main'.

Page 143: 'Melam' changed to 'Malam'.

Page 189, 'a fixed rigde point' changed to 'a fixed ridge point'.

Page 218, '10,00,000 revolutions' changed to '100,000 revolutions'.

Page 304: 'it will turn blue litmus, paper red' changed to 'it will turn blue litmus paper, red'.

Page 312: 'sal-ammonia' changed to 'sal-ammoniac'.

Index: Lines used as ditto marks and the word 'ditto' have been replaced with the dittoed words and phrases.