1823.] Mr, Detoey on Gas Illumination, 405 



coal gas works at Glasgow, Liverpool, Sheffield, Leeds, Leices- 

 ter, Belfast, as well as London, and many other large commer- 

 cial and manufacturing towns, as well as small ones, in Great 

 Britain, will use coal gas, and some of them oil gas too, and the 

 people will be greatly benefited by them. I see no good reason 

 that they should not both do extremely well, though some 

 scientific, not practical men, may try to make us believe, that 

 one or the other is good for nothing. I see they are both good, 

 and there is plenty of room for both in this great manufacturing 

 country. I shall recommend to my employers to begin with 

 oil gas, because it is the best ; and oil being cheap, and coals 

 dear, it will be the cheapest, and will not cost nearly so much 

 to begin with as coal gas, and we shall require fewer hands 

 to carry it on. I can more easily manage it. When I can 

 get coals as cheaply as they do at Sheffield, and some other 

 places, I may make coal gas too. Besides, I need not lay 

 down pipes more than one-third as large as for coal gas, 

 and this is a great saving; so we shall all save by it. You ask 

 me to tell you how much oil gas costs, and how much profit may 

 be made by it. I cannot tell you any thing about that till I 

 have erected works, and made some oil gas, and see how many 

 people use it, and what they will pay for it. I have given you 

 more opinions already than some may think correct. If they 

 desire to possess more information, I would advise them to 

 travel as I have done, and inquire of every one they can find to 

 tell them ; and I am certain they will eventually acquire it. I 

 think the gas-lighting system in its infancy even in this country ; 

 and to learn all about it, you must see all engaged in it. I have 

 not seen half of them, but must go home and do the best I can. 

 You desire me to state what quantity of gas can be obtained 

 from different kinds of coal. This depends so much on the 

 manner in which it is worked, that if I give an opinion some will 

 say it is too high, and others too low. At Liverpool, I think, 

 Mr. King says he finds it good economy to obtain only about 

 7000 cubic feet from a ton. He uses the Wigan Orral coal. 

 At Glasgow, they obtain from their rich candle coal 12,000 feet. 

 This coal is called candle coal, because the people formerly 

 (and now too for what I know), used it instead of candles. 

 They make the best gas 1 have seen, always excepting that 

 procured from the decomposition of oil. Mr. Peckston 

 has given a very good table of the different kinds of coal 

 in the kingdom, and the quantity of gas to be obtained from 

 each ; and had he seen as much of oil gas as I have, 1 think he 

 would have given a better account of that than he has. To give 

 my opinion regarding retorts, I think those used by Mr. King, 

 and invented by him, the best I have seen for a large work. 

 They are large, wide, and flat, shaped something like a D, 

 turned half over to the left. They are made of rolled iron, and 

 rivetted. Those at Glasgow are much smaller, of cast-iron, and 

 nearly of the same shape. Mr. George Lowe^ manager of the 



