400 SECTION MECHANICS. 



into the middle of the fire-grate, so that the surface of the fire remains 

 always hot, and as the distillation of the gases from the raw coal goes 

 on continuously, the fire remains uniform in character and maybe readily 

 kept smokeless. The arrangement has been applied, in this country, 

 to boilers, flint glass furnaces, and puddling furnaces, and is said to 

 effect a decided economy in fuel and give altogether satisfactory results. 



The use of hydrogen and hydrocarbon gases, as furnace fuel, is 

 chiefly limited to the heating of small laboratory furnaces, or to work 

 on a scale but little greater ; as the cost of such gases, when artificially 

 produced, is too great to admit of their competing on a larger scale 

 with coal. In the comparatively few localities, however, in which 

 such gases have been found to flow naturally from bore holes, pene- 

 trating to beds of coal or shale, they form a valuable fuel, that is made 

 use of to a considerable extent. In some parts of Pennsylvania, 

 from bore holes put down for petroleum, a supply of gas, consisting 

 chiefly of marsh gas (CH 4 ), mixed with other hydrocarbons and with 

 hydrogen, has been found to rush steadily, for years, at a pressure 

 estimated at nearly one hundred pounds per square inch ;* and in the 

 case of at least one such "gas well," that at Leechburg, the gas has 

 been very effectively turned to account. There, according to a recent 

 number of the Enginnering and Mining Journal*; the gas is conveyed 

 from the well, through a distance of between one hundred and two hun- 

 dred yards, to adjoining sheet iron works, where it heats five puddling 

 furnaces, six heating furnaces, two annealing furnaces, and so on, and 

 furnishes in fact all the fuel required for turning out nearly thirteen 

 tons of sheet iron a day. Before the gas was brought to the works, the 

 daily consumption of coal had been seventy-five tons, and the make 

 per day of sheet iron did not then exceed ten tons ; so that the gas does 

 now as much work as would have required, on the former plan, ninety- 

 seven and a half tons of coal per day. 



Petroleum and other liquid fuels have also been used for heating 

 furnaces, both in England and in America, but on a scale only experi- 

 mental rather than really industrial. The results obtained are, how- 



* Engineering and Mining Journal (New York), March i8th, 1876, p. 269. 

 t Engineering and Mining Journal (New York), May 22nd, 1875, p. 367; and June 26th, 

 1875, p. 476. 





