1892.] NATURAL SCIENCES OF PHILADELPHIA. 89 



of all known forces of the kind such as steam and electricity, were 

 never concealed and have always been knoAvn since the first pot 

 was boiled or the first savage was struck by lightning. 



AVhat has been discovered is not those, or any other " forces," if 

 we must continue to call them so, but practical and useful methods 

 of eliminating and applying them to our Avork ; and down to this 

 present time that can only be accomplished by the combustion of 

 fuel, without which we know of no way to produce any of them, on 

 a large and useful scale, and at times and places where they are 

 required. 



On the contrary there are certain weighty reasons for believing 

 that there can be no considerable unknown power lying concealed 

 anywhere in Nature. For any such poAver must be either useful or 

 useless in carrying on Nature's operations. If the latter, it must 

 long since have ceased to exist, for nothing that is useless 

 long survives without human protection. But if useful, then 

 it must be an active and perturbing agent, exerting a useful and 

 necessary function of some kind in Nature's laboratory and Avork- 

 shop. But while we can account for, explain and even predict, all 

 great natural phenomena from the smallest chemical reaction to 

 the most stupendous electrical, astronomical and meteorological 

 events, and can even calculate the movements of our earth and all 

 astronomical bodies, tracing every perturbation or eccentricity to its 

 cause, there is no evidence of the function or action of any mysteri- 

 ous or unknown force, no concealed perturber whose mysterious 

 existence and action disturbs our calculations and frustrates our 

 predictions. Then none exists ; and all that is left for us to con- 

 sider is how to reduce to our service those forces that are knoAvn, 

 Avithout the use of fuel or artificial heat. Steam and decomposed 

 Avater must be banished from the available category, for both are 

 simply results of heat, of AAhich, by terms of the supposition, there 

 would remain no useful supply except as it Avas obtained by the 

 first brain-deA'eloped anthropoids, directly from the sun. 



There remains for consideration electricity, AA'hich may be 

 obtained in minute quantity from chemical reactions, but its pro- 

 duction on a useful scale by such methods, is at present inconceiv- 

 able, unless by the prior production and handling of such vast 

 masses of expensive material as to rob the result of all economic 

 value. 



7 



