936 



THE NATIONAL GEOGRAPHIC MAGAZINE 



AN 8-FOOT LIGNITE SEAM, NEAR GLENDIVE, MONTANA 



lignite, which are entirely useless for 

 steaming purposes and had previously 

 been considered practically worthless, 

 can be used most successfully in the gas 

 producer. 



REMARKABLE WORK OE THE GAS ENGINE 



Prof. Robert H. Fernald, late in 

 charge of the producer-gas tests of the 

 Geological Survey, made an estimate of 

 the cost and operation of a small gas en- 

 gine in comparison with that of a steam 

 engine of the same horse-power, and also 

 of two large engines, gas and steam, of 

 the same horse-power. The figures are 

 impressive. Professor Fernald gives the 

 cost of a 6oo-horse-power gas plant at 

 $48,000 and the steam plant at $40,000 — 

 $8,000 in favor of the steam plant. 

 Operating both plants 300 days, 24 

 hours a day, the total cost for coal in 

 the gas plant would be $3,680; in the 

 steam plant, $8,250. 



In a large plant, however, of 6,000 

 horse-power, he found no difference in 

 cost between steam and gas plants. But, 



running these two plants continuously 

 for one year, the gas plant would re- 

 quire but 21,000 tons of coal, which, at 

 say $2.50 a ton, would be $52,500, while 

 the steam plant would consume 42,000 

 tons of coal, at a cost of $105,000. The 

 total operating expense and fixed charges 

 of the 6,000-horse-power gas-producer 

 plant are given at $141,775, while those 

 of the 6,000-horse-power steam plant 

 would cost $219,535 — annual saving 

 of $77,580. 



In offering the estimates, Professor 

 Fernald declares that he has made the 

 best possible showing for the steam 

 engine, while that of the producer-gas 

 plant is but a fair figure. In conclusion, 

 he adds : "I believe that the producer- 

 gas plant can better the figure given, but 

 I doubt very much whether the steam- 

 plant figure can be excelled, even if it 

 can be reached." 



Surely such savings of cost as these 

 must appeal to the big manufacturers. 

 That they do is shown by the fact that 

 certain types of steam engines exhibited 



