10 



SCIENCE. 



[\. S. Vol. XXI. Xo. 523. 



sibility, and to indicate a point for study 

 and progress. 



It will n(;t be amiss for me to quote the 

 figures given me by the engineer in charge 

 of the Diesel engines which drove the 

 generators for power and light in the 

 'Tyrolean Alps' at the late world's fair in 

 St. Louis. 



These engines, three in number, of 225 

 horse power each, were the observed of 

 many observing engineers during the seven 

 months of the fair. The assistant engineer 

 in charge kept daily records of the work 

 done, and fuel used, and kindly gave me 

 a sample of his reports. The details are 

 extremely interesting. The work was 

 measured at the switchboard, no allowance 

 being made for loss of energy in the engine, 

 air pump and generator. The total work 

 of the three engines between noon and 

 midnight was 2,768.5 K.W.H. This is 

 equivalent to 3,711 II.P.H. 



Total fuel used (Indiana oil), 266 gal.s. 

 Fuel per 100 K.W. hours, 9.58 gals. 

 Fuel cost in car-tank lots, 3c. per gal. 

 Cost per 100 K.W.H., $0,287. 

 Cost of the day's fuel, $7.08 or 2.15 mills per 

 H.P.H. 



Thus one cent paid for the fuel for one ■ 

 horse power for four hours, forty minutes. 



The three engines worked luider about 

 two thirds of a full load and used three 

 gallons of lubricating oil during the day. 



The abo\'e figures seem to me little less 

 tliiUj remarkable. 



While still wasteful, as nature measures 

 energy, thf.so engines are several times as 

 efficient as the better styles of ordinary 

 steam-engines. Doubtless they lack sim- 

 plicity and the certainty of action which 

 comes from experience and close study ; 

 but I can not help feeling that the road 

 to the future 'prime mover' runs hard by 

 the construction shops of an internal-com- 

 bustion engine. Let students and pro- 

 fessors take warning. 



ARTIFICIAL CENTERS OF POWER. 



One of the most important openings for 

 future engineering enterprises is the estab- 

 lishment of large power centers, not only 

 where water power is available, but where 

 fuel is abundant as well. 



Take, for example, the vast coal mines 

 in the vicinity of the city of Philadelphia 

 and those in the vicinity of St. Louis. In 

 each case the power for industrial estab- 

 lishments and all kinds of moving ma- 

 chinery, large and small, in use in the 

 city, including the street cars and the 

 rolling stock on all roads, can well be 

 furnished by electrical currents from large 

 generating establishments near the mines. 

 Add to the above the establishment of gas 

 works sufficiently large to furnish all the 

 gas needed for illumination, for gas-en- 

 gines, for heating and cooking purposes in 

 a great city. In the case of St. Louis those 

 gas works should be near the extensive 

 coal mines of Belleville and other coal- 

 producing regions only a few miles from 

 U'c city. 



The effect of these two great steps for- 

 ward upon the physical and sociological 

 characteristics of a city can hardly be over- 

 estimated. The ultimate economy and con- 

 venience of such installations are enough to 

 justify them. We have yet to learn how 

 cheaply fuel gas and electric currents can 

 be furnished to large concentrated groups 

 of consumers. But omitting all questions 

 of mere financial economy, what a saving in 

 health, beauty and enjoyment! The Lon- 

 don fogs which we hear so much about ar(» 

 produced largely by London smoke, and the 

 prevention of smoke will to a very great 

 extent be the prevention of the fog. I look 

 forward to the day when, instead of a small 

 volcano of smoke from a brick crater above 

 every house, St. Louis will have all its 

 heating and cooking done by gas, and all 

 power will be furnished by electric cur- 

 rents, or by gas and combustion-engines, 



