1 88 REFERENCE TO ROGET AND FARADAY. 



demands the annihilation of force is necessarily erroneous." 

 In this Joule not only concedes to Roget and Faraday priority 

 in holding the view that force, as he conceives it, is indes- 

 tructible, but concedes it in such a manner as to imply that 

 their views were so well known that references to their 

 works were unnecessary. He apparently brings their views 

 forward as affording authority for his own. In his first 

 statement of his views as to the indestructibility of "force" — 

 written ten months previously — "being satisfied that the 

 grand agents of nature are, by the Creator's fiat, indestructible, 

 and that whenever mechanical force is expended an exact 

 equivalent of heat is always obtained," he cites no human 

 authority whatever, and as it cannot be doubted that Joule 

 would then gladly have adduced such authority, it must 

 be inferred that he had in the meantime become aware of 

 some expressions by both Faraday and Roget, which were • 

 not previously known to him, and which he conceived to be 

 evidence of views in accordance with his own. What these 

 expressions were it is of course impossible to say, but it is 

 important to notice, that previous to June, 1844, and for at 

 least some years after, there appears to be nothing written by 

 Roget or Faraday that contains even a suggestion that they 

 conceived or used " force " in any but the then usual sense 

 as available energy, or that from which available powers could 

 be obtained ; nor does it appear that they in any way fell into 

 the error of conceiving this "force" to be indestructible, but, 

 on the contrary, they both emphatically and explicitly 

 express their conviction (of the truth) namely, that where- 

 ever mechanical effect is produced " force " is expended, 

 which nothing will revive but an act of creation. These 

 views are expressed clearly in paragraphs 2071 and 2073 °f 

 Faraday's "Experimental Researches," to which also Faraday 



