FINAL DEDUCTIONS. 



87 



for him to solve her riddles and thus to obtain power 

 at a fraction of its present cost ; prolong the life of 

 the race indefinitely ; secure Hght, isolated from heat, 

 and in many times the quantity for a given amount of 

 labor now expended ; and produce electricity without 

 loss and directly, instead of, as at present, through the 

 intervention of heat-engines with their now enormous 

 wastes. Human progress depends upon the ability of 

 mankind to do more work, and to accompHsh greater 

 tasks, to supply the necessaries of life with less expen- 

 diture of time and strength, thus to secure leisure for 

 the production of the comforts and the luxuries that 

 give modern society its characteristics, and to insure 

 that leisure for thought, invention, intellectual de- 

 velopment of every kind, which still more strikingly 

 characterize the highest civihzation. In all this, only 

 the appHcation of the forces of nature without waste 

 and the complete subjection of all its energies can 

 give maximum result. 



It is now well known that the heat-engines, whether 

 steam, gas, hot air, or ether, only utilize a fraction of 

 the power latent in their fuel, and that this fraction, 

 as a maximum, in even an ideally perfect engine, is 

 measured by the division of the range of temperature 

 through which they expand their working fluids " by 

 the absolute " temperature of the fluid as supplied 

 to the engine ; that is, a temperature measured from 

 a point about 460°, on the Fahrenheit scale, below the 

 Fahrenheit zero. This fraction, we have learned, is, 

 in the case of the modern steam-engine, usually 

 between one fourth and one half ; while the actual 

 performance of our engines falls to one fourth or one 

 half this ideal maximum, in the ordinary and best 



