146 POPULAR SCIENCE MONTHLY. 



nearer accomplishment than at the end of the last quarter-century. 

 But the time will yet come, we at least may reasonably hope, if not pre- 

 dict, when a way will be found thus to increase the availability of the 

 stored energy of our fuel deposits, until they shall furnish ten times the 

 power and energy now obtainable from each ton of fuel; thus cor- 

 respondingly lengthening the period of human life and work in the 

 temperate regions of the earth. Were this to-day possible, the endur- 

 ance of the Pennsylvania coal-beds as sources of power would be length- 

 ened from the present anticipated century to a millennium, and the thir- 

 tieth century, instead of only the twentieth, would profit by them. Great 

 Britain might hope to continue a manufacturing nation for five cen- 

 turies to come, and the world might gain ten times as much permanent 

 wealth, by its use of the latent energy of fuel, as now seems possible. 



The mechanical engineer, the electrician and the chemist have here 

 an incentive to a most magnificent task and a noble rivalry. 



The second of our great triumvirate of inventors or discoverers is 

 more certainly coming. His advent is indicated by the electrical en- 

 gineer and the physicist in their use of electrical energy of enormously 

 high tension; while the biological chemist is now a close second in the 

 race, through his researches in the field of low-temperature combustion 

 and amongst the animal forms producing light and electricity without 

 heat — the animal machines in which the processes of nature are seen 

 already accomplishing the task. This being done, the engineer will be 

 able to reduce the cost of lighting, as measured in power, to one-twen- 

 tieth its present amount, and as measured in fuel, if he can combine 

 these two improvements effectively, to one-two-hundredth its amount 

 to-day, proportionally reducing the intimidating waste now going on in 

 our deposits of irreplaceable natural stores of power. 



The third inventor is also here with a crude beginning of his task, 

 and while, at the commencement of the nineteenth century, he was a 

 subject of unsparing ridicule, and even sometimes by able men within 

 the last decade, he would be a bold man who should to-day dare to 

 assert the improbability of the coming century seeing the problem 

 solved, so far as its engineering is concerned. The commercial problem 

 must be left to take care of itself — as it always has done hitherto. 



All these are evidently problems affecting vitally all progress in the 

 future of energy-production in the field of mechanical engineering. 

 AVhen complete conversion of energy is effected by any mechanism em- 

 ploying our natural sources of energy, the task of the builder of the 

 air-ship is rendered less diflficult, the cost of light-production is made 

 easier and the utilization of the latent energy of fuel through the heat- 

 engine is made comparatively insignificant in cost. 



This much is revealed to us through 'The Great Discovery of the 

 Age,' as some one has riglitly called it: the discovery and experimentally 



