242 THE POPULAR SCIENCE MONTHLY. 



than one fourth the amount used twenty years ago. It may be that 

 the engines of Watt and Stephenson will yield in their turn to more 

 economical motors ; still, they have already expanded the wealth, re- 

 sources, and even the territories of England, more than all the battles 

 fought by her soldiers or all the treaties negotiated by her diplomatists. 



The coal which has hitherto been the chief source of power jjroba- 

 bly represents the product of five or six million years during which 

 the sun shone upon the plants of the carboniferous period, and stored 

 up its energy in this convenient form. But we are using this con- 

 served force wastefully and prodigally, for, although horse-j^ower in 

 steam-engines has so largely increased since 1864, two men only now 

 produce what three men did at that date. It is only three hundred 

 years since we became a manufacturing country. According to Pro- 

 fessor Dewar, in less than two hundred years more the coal of this 

 country will be wholly exhausted, and in half that time will be diflS- 

 cult to procure. Our not very distant descendants will have to face 

 the problem. What will be the condition of England without coal ? 

 The answer to that question depends upon the intellectual develop- 

 ment of the nation at that time. The value of the intellectual factor 

 of production is continually increasing, while the values of raw mate- 

 rial and fuel are lessening factors. It may be that, when the dreaded 

 time of exhausted fuel has arrived, its importation from other coal- 

 fields, such as those of New South Wales, will be so easy and cheap 

 that the increased technical education of our operatives may largely 

 overbalance the disadvantages of increased cost in fuel ; but this sup- 

 poses that future governments in England will have more enlightened 

 views as to the value of science than past governments have possessed. 



Industrial applications are but the overflowings of science welling 

 over from the fullness of its measure. Few would ask now, as was 

 constantly done a few years ago, " What is the use of an abstract dis- 

 covery in science ? " Faraday once answered this question by another, 

 " What is the use of a baby ? " Yet round that baby center all the 

 hopes and sentiments of its parents, and even the interests of the state, 

 which interferes in its upbringing so as to insure it being a capable 

 citizen. The processes of mind which produce a discovery or an 

 invention are rarely associated in the same person, for, while the dis- 

 coverer seeks to explain causes and the relations of phenomena, the 

 inventor aims at producing new effects, or at least of obtaining them 

 in a novel and efficient way. In this the inventor may sometimes suc- 

 ceed without much knowledge of science, though his labors are infi- 

 nitely more productive when he understands the causes of the effects 

 which he desires to produce. 



A nation in its industrial progress, when the competition of the 

 world is keen, can not stand still. Three conditions only are possible 

 for it. It may go forward, retrograde, or perish. Its extinction as a 

 great nation follows its neglect of higher education, for, as described 



