An Account of the Application of the Gas from Coal to economical Purposes. By Mr. WILLIAM MURDOCH. Communicated by the Right Hon. Sir JOSEPH BANKS, Bart. K. B. P. R. S. From the PHILOSOPHICAL TRANSACTIONS of the ROYAL SOCIETY of LONDON. THE facts and results intended to be communicated in this paper are founded upon observations made, during the present winter, at the cotton manufactory of Messrs. Philips and Lee at Manchester, where the light obtained by the combustion of the gas from coal is used upon a very large scale; the apparatus for its production and application having been prepared by me at the works of Messrs. Boulton, Watt, and Co. at Soho. The whole of the rooms of this cotton mill, which is, I believe, the most extensive in the United Kingdom, as well as its counting-houses and store-rooms, and the adjacent dwelling-house of Mr. Lee, are lighted with the gas from coal. The total quantity of light used during the hours of burning, has been ascertained, by a comparison of shadows, to be about equal to the light which 2500 mould candles of six in the pound would give; each of the candles, with which the comparison was made, consuming at the rate of 4-10ths of an ounce (175 grains) of tallow per hour. The quantity of light is necessarily liable to some variation, from the difficulty of adjusting all the flames, so as to be perfectly equal at all times; but the admirable precision and exactness with which the business of this mill is conducted, afforded as excellent an oppor→ tunity of making the comparative trials I had in view, as is perhaps likely to be ever obtained in general practice. And the experiments being made upon so large a scale, and for a considerable period of time, may, I think, be assumed as a sufficiently accurate standard for determining the advantages to be expected from the use of the gas lights under favourable circumstances. It is not my intention, in the present paper, to enter into a particular description of the apparatus employed for producing the gas; but I may observe generally, that the coal is distilled in large iron retorts, which during the winter season are kept constantly at work, except during the intervals of charging; and that the gas, as it rises from them, is conveyed by iron pipes into large reservoirs, or gazometers, where it is washed and purified, previous to its being conveyed through other pipes, called mains, to the mill. These mains branch off into a variety of ramifications (forming a total length of several miles), and diminish in size, as the quantity of gas required to be passed through them becomes less. The burners, where the gas is consumed, are connected with the above mains, by short tubes, each of which is furnished with a cock to regulate the admission of the gas to each burner, and to shut it totally off when requisite. This latter operation may likewise be instantaneously performed, throughout the whole of the burners in each room, by turning a cock, with which each main is provided, near its entrance into the room. The burners are of two kinds: the one is upon the principle of the Argand lamp, and resembles it in appearance; the other is a small curved tube with a coni cal cal end, having three circular apertures or perforations, of a thirtieth of an inch in diameter, one at the point of the cone, and two lateral ones, through which the gas issues, forming three divergent jets of flame, somewhat like a fleur-de-lis. The shape and general appearance of this tube, has procured it among the workmen, the name of the cockspur burner. The number of burners employed in all the buildings, amounts to 271 Argands, and 633 cockspurs; each of the former giving a light equal to that of four candles of the description abovementioned; and each of the latter, a light equal to two and a quarter of the same candles; making therefore the total of the gas light a little more than equal to that of 2500 candles. When thus regu lated, the whole of the above burners require an hourly supply of 1250 cubic feet of the gas produced from cannel coal; the superior quality and quantity of the gas produced from that material having given it a decided preference in this situation over every other coal, notwithstanding its higher price. The time during which the gas light is used, may, pon an average of the whole year, be stated at least at two hours per day of twenty-four hours. In some mills, where there is over work, it will be three hours; and in the few where night-work is still continued, nearly twelve hours. But taking two hours per day as the common average throughout the year, the consumption in Messrs. Philips' and Lee's mill, will be 1250 x 2 = 2500 cubic feet of gas per day; to produce which, seven hundred weight of cannel coal is required in the retort. The price of the best Wigan cannel (the sort used) is 131d. per cwt. (22s. 6d. per tou), delivered at the mill, or say about eight shillings for the seven hundred weight. Multiplying Multiplying by the number of working days in the year (313), the annual consumption of cannel will be 110 tons, and its cost £125. About one-third of the above quantity, or say forty tons of good common coal, value ten shillings per ton, is required for fuel to heat the retorts; the annual amount of which is £20. The 110 tons of cannel coal when distilled, produce about 70 tons of good coak, which is sold upon the spot at 1s. 4d. per cwt. and will therefore amount annually to the sum of £93. The quantity of tar produced from each ton of cannel coal is from eleven to twelve ale gallons, making a total annual produce of about 1250 ale gallous, which not having been yet sold, I cannot determine its value; but whenever it comes to be manufactured in large quantities, it cannot be such as materially to influence the economical statement, unless indeed new applica tions of it should be discovered. The quantity of aqueous fluid which came over in the course of the observations which I am now giving an account of, was not exactly ascertained, from some springs having got into the reservoir; and as it has not been yet applied to any useful purpose, I may omit further notice of it in this statement. The interest of the capital expended in the necessary apparatus and buildings, together with what is considered as an ample allowance for wear and tear, is stated by Mr. Lee at about £550. per annum: in which some allowance is made for this apparatus being made upon a scale adequate to the supply of a still greater quantity of light, than he occasion to make use of. VOL. XIII.-Second Series. has He is of opinion, that the cost of attendance upon candles would be as much, if not more, than upon the gas apparatus; so that in forming the comparison, no, thing need be stated upon that score, on either side. The economical statement for one year then stands thus: Cost of 110 tons of cannel coal £125. 20 145 Deduct the value of 70 tons of coak The annual expenditure in coal, after And the interest of capital, and wear and tear of apparatus 52 550 making the total expence of the gas apparatus, about £600. per annum. That of candles, to give the same light, would be about £2000. For each candle consuming at the rate of 4-10ths of an ounce of tallow per hour, the 2500 candles burning upon an average of the year two hours per day, would, at one shilling per pound, the present price, amount to nearly the sum of money abovemen tioned. If the comparison were made upon an average of three hours per day, the advantage would be still more in favour of the gas light; the interest of the capital, and wear and tear of the apparatus continuing nearly the same as in the former case; thus, 1250 + 3 = 3750 cubic feet of gas per day, which would be produced by 10 cwt. of cannel coals; this |