GASEOUS FUELS. IO~ 



As compared with coal, 57.25 pounds of coal or 63 pounds 

 of coke are about equal to 1000 cubic feet of the gas. The 

 actual equivalent in steaming or furnace work varies with the 

 furnace, and probably with the people using it. Equivalent 

 values of 14000 to 25000 cubic feet per ton of coal are 

 reported, and hardly any two users will give the same yield. 

 It seems to be especially adapted to glass-making, giving a 

 long, clean, ashless, smokeless flame, and hundreds of glass- 

 pots were set up in the neighborhood of the wells, especially 

 in Ohio. Each pot consumes from 58000 to 61000 cubic feet 

 per 24 hours in window-glass works and from 31000 to 49000 

 cubic feet in flint-glass works, the difference ' being of 

 course due to difference in burners and men, the gas being 

 the same. 



In all cases where this gas is used the chief claim made, in 

 addition to those of gases generally, has been cheapness, and 

 it has been sold without any regard to its actual value. A 

 comparison of its value with that of other gases is given by 

 McMillin in the Report of the Ohio Geological Survey, vol. 

 VI, page 544, as follows : 



1000 feet natural gas will evaporate .... 893 pounds of water. 



11 " coal " " " 591 



" " water " " " .... 262 " " 



11 " producer gas" " 115 " 



OIL GAS. 



There are several processes for producing gas from oil, 

 usually petroleum or its derivatives. Some of them decom- 

 pose the oil by means of heat alone, while others use steam, 

 or steam and air together. The most successful pure oil 

 process is the Pintsch ; this is used extensively in the large 

 cities of Europe and America to obtain a gas for illuminating 

 cars on railways. The gas is made by allowing the oil to fall 

 drop by drop on a strongly heated surface. Complete decom- 



