[ 



I 



cr 



t3 



jff, Helmholtz on the hiter action of Natural Forces. 191 



Leads of all centuries have followed in the most diverse ways, 

 namely, to fabricate money out of nothing, invited solution. 

 The similarity with the philosopher's stone sought by the an- 

 cient chemists was complete. That also was thought to contain 

 the quintessence of organic life, and to be capable o£ producin 

 gold. 



The spur which drove men to inquiry was sharp, and the 

 talent of some of the seekers must not be estimated as small. 

 The nature of the problem was quite calculated to entice poring 

 brainSj to lead them round a circle for years, deceiving ever with 

 new expectations which vanished upon nearer approach, and 

 finally reducing these dupes of hope to open insanity. The 

 phantom could not be grasped. It would be impossible to give 

 a history of these efforts, as the clearer heads, among whom the 



elder Droz must be ranked, convinced themselves of the futilit 



WA ineir experiments, ana were naturaiiy not mcnnea to spea 

 much aboat them. Bewildered intellects, however, proclaimed 

 often enough that they had discovered the grand secret ; and as 

 the incorrectness of their proceedings was always speedily mani- 

 fest, the matter fell into bad repute, and the opinion strengthened 

 itself more and more, that the problem was not capable of solu- 

 tion; one difficulty after another was brought under the domin- 

 ion of mathematical mechanics, and finally a point was reached 

 where it could be proved, that at least by the use of pure me- 

 chanical forces no perpetual motion could be generated. 



We have here arrived at the idea of the driving force or 

 power of a machine, and shall have much to do with it in future. 



I must therefore give an explanation of it. The idea of work 

 is evidently transferred to machines by comparing their arrange- 

 ments with those of men and animals, to replace which they 

 ^ere applied. We still reckon the work of steam-en^iiies ac- 

 cording to horse power. The value of manual labor is deter- 

 i^ined partly by the force which is expended in it (a strong la- 

 borer is valued more highly than a weak one), partly, however, 

 by the skill which is brought into action. A machine, on the 

 contrary, which executes work skilfully, can always be multi- 

 '^ied to any extent ; hence its skill has not the high value of 

 uman skill in domains where the latter cannot be supplied by 

 machines. Thus the idea of the quantity of work in the case of 

 machines has been limited to the consideration of the expendi- 

 ture of force; this was the more important, as indeed most ma- 

 chines are constructed for the express purpose of exceeding, by 

 t^e magnitude of their effects, the powers of men and animals. 

 Hence, in a mechanical sense, the idea of work is become identi- 

 cal with that of the expenditure of force, and in this way I will 

 ^Pply it in the following pages. 



1 



