52 Kansas Academy of Science. 



than any other type of power plant during this period. Per- 

 haps the time for its development has not yet arrived. It may 

 be waiting for the notion of the great central power plant to 

 get more firmly fixed. Distributed over the country are enor- 

 mous deposits of lignite coal. This coal is worthless as an ordi- 

 nary fuel, but it may be burned in properly constructed pro- 

 ducers and give a fuel efficiency nearly as great as that of good 

 steam coals. Probably this type of plant will not be greatly 

 used until the railroads and scattered industrial plants give up 

 their own little wasteful units and learn to take their power 

 from great central plants located at the mines and distributed 

 through high-voltage transmission lines, as is now coming to 

 be the practice in water-power installations. In connection 

 with gas engines this decade has seen the invention of a new 

 type of unit that, so far, excels in efficiency anything previously 

 devised. This is the constant-pressure engine, known as the 

 Diesel motor. The thermal efficiency of this engine is over 30 

 per cent under actual working conditions. What this means 

 may be gathered from the fact that it has reduced fuel con- 

 sumption from one and a half to less than a half pound per 

 horsepower-hour. As a marine engine it has multiplied the 

 steaming radius of vessels by three, and the fact that its fuel is 

 liquid makes it possible to store and handle it with much 

 greater economy than is possible with coal. Engines of this 

 type have been in operation in Germany on the tarry by- 

 products of petroleum and asphaltum, heretofore wasted; so 

 that power has actually been produced, not only at no cost, but 

 its production has disposed of an otherwise inconvenient waste 

 material. Why should not the gas producer, using lignite fuel, 

 produce gas for the common gas engine, and at the same time 

 supply fuel for the Diesel motor in the form of the trouble- 

 some tarry products that now form one of the disadvantages of 

 the producer plant. We should then have our great central 

 station operating at an efficiency now unthought of, and using 

 a fuel which is at present almost useless. This development 

 remains, perhaps, for the next decade. 



