Januaky 9, 1903.] 



SCIENCE. 



59 



this and other purposes the cost would be 

 correspondingly increased. 



A number of railroads contiguous to the 

 oil-producing centers have equipped their 

 locomotives to burn this fuel, and it is used 

 to some extent to fire marine boilers, and 

 with great satisfaction; since its displace- 

 ment for a given heating value is only 

 about one half that of coal, and the labor 

 cost is materially reduced. 



It is also used quite extensively in cer- 

 tain sections of the country as a steam 

 producer in power plants, but it is hardly 

 probable that liquid fuel will be a serious 

 competitor of coal, notwithstanding its 

 many advantages. At the present time, 

 as far. as power for manufacturing plants 

 is concerned, it is largely a question of 

 transportation, whether oil can be laid 

 down and handled at a given point more 

 cheaply than coal. It is probable, how- 

 ever, that oil fuel will supply a local de- 

 mand in certain sections where transpor- 

 tation charges, and possibly insurance, will 

 permit its use at a low cost, and it is in 

 this connection that it may become a com- 

 petitor of electrical transmission. 



One interesting phase of the power prob- 

 lem which forcibly presents itself to the 

 engineer at the present time is the vast 

 possibilities possessed by the modern com- 

 bustion engine, which includes the various 

 types of gas- and oil-engines. While its 

 use as a motor in industrial establishments 

 has been somewhat limited, yet there is a 

 marked tendency to employ the gas-engine 

 in manufacturing works, and a considera- 

 tion of its advantages and cost of opera- 

 tion, together with its high thermal effi- 

 ciency and possibility of still further im- 

 provement, indicates that, for a great many 

 purposes, both steam-engines and electric 

 motors may be ultimately replaced by gas- 

 engines. 



While the first cost of electric motors in 

 the smaller sizes is considerably less than 



the cost of well-made gas-engines for sim- 

 ilar capacities, the saving during the first 

 six months of service, due to the more 

 economical operation of the gas-engine, 

 will often more than compensate for the 

 difference in first cost. 



That the gas-engine in both large and 

 small sizes has reached a point in its de- 

 velopment where it can fairly rival the 

 steam-engine in reliability and satisfactory 

 running qualities there can be no question. 

 In point of fuel economy, a gas-engine of 

 moderate size is on a parity with the 

 largest triple-expansion steam-engines, and 

 will give a horse-power on less than one 

 pound of fuel. 



The high price of gas in this country 

 has contributed largely to those causes 

 which have prevented a more common use 

 of the gas-engine as a motor. For this 

 reason the gas-engine has generally been 

 used, not so much because of its high effi- 

 ciency as a thermodynamic machine, but 

 rather on account of its convenience and 

 saving in labor. It is true that natural 

 gas is cheap, but it is equally true that 

 natural gas is not generally available. 



It is to producer gas that we must look 

 for any marked increase in the use of the 

 gas-engine. Fortunately the manufacture 

 of producer gas has reached a high state 

 of development, and there are now in suc- 

 cessful use several processes by which 

 power gas can be made from cheap bitu- 

 minous coals as well as anthracite and 

 coke. The leanness of such gases renders 

 them less effective per cubic foot of gas, 

 as compared with the richer coal gas or 

 even water g^s ; but this difference is more 

 than compensated for by the low cost of 

 production. It is upon such power gas 

 that the commercial future of the gas- 

 engine as a general motor depends. 



A prominent factor in gas-engine prac- 

 tice which has attained a high degree of 

 development in European practice is the 



