5 MR. GREGORY ON MECHANIC POWER. 



It will not, I hope, be ex peeled thai I fliould point out ill 

 what inftances Mr. H's remarks appear to me completely ir- 

 relative lo the fubject in hand; or thofe in which he Teems to 

 have milunderftood the arguments of the late leared Profeflbr : 

 fuch a procedure would m\\y- lead into farther difcullinn, while 

 I feel folicitous to avoid it, from a confeioufnefs that it would 

 be very uninlerefting to moft of your readers. I {hall flrive 

 to confine myfelf, therefore, to fuch of Mr. H's enquiries as 

 bear upon the point in difpute, and for the fake of condenfing 

 my labour, fhall begin vyilh that in his poftfeript. 

 Arc animal Fhil then, I will endeavour to " (Jet Mr. H. right as lo the 



cxerti n and idenfiiy of animal exertion and mechanic power:" and to this 

 iacntical'/ ' en( * ll w '" ^e rfc q u dile to anfwer the queflion, — what is me- 

 chanic power? excluding, for the prefent, that acceptation 

 of the term in which it is underflood lo denote one of the fix 

 fimple machines, Now, it is pretty obvious, that the terms 

 power, force, &c. when ufed in mechanical fcience are 

 purely metaphorical ; for, as PiofefTor Dugald Steward re- 

 marks, (Elements <f the I'hilof phy of the Human Mind, ■ 

 p. 202 ) " All the languages which have hitherto exifted in 

 the world, have derived their origin from popular ufe; and 

 their application to philofophical purpofes was altogether out 

 fcife and ap- of the view of thofe men who firft employed them." Language 

 ?elms,°torc f ef e commenced amongft fimple men, who had little, if any ac- 

 power, &5, quaintance with what is now called fcience : and in the 

 gradual progrefs of moft nations, from the favage to the 

 fhepherd ftale, thence to the agricultural, and farther to the 

 commercial fiate, it would be very long before they would 

 think of attaching any other meaning to the terms in the dif- 

 ferent languages, correfponding to power, force, aclion,' re- 

 finance, repulfion, &c. than thofe which were manifeftly re- 

 ferable to the different kinds of human, or of animal exertion : 

 in fubfequent times when fcieniific men began to claflify, 

 arrange, and fyftematize the phenomena which they obferved 

 in the congrefs, motion, and mutual operation of bodies, they 

 found it much eafier to denote the circumftances they would 

 defcribe or treat of, by a figurative application of old terms, 

 to which fome analogous notions would neceflarily be attached 

 by every perfon, than to invent new ones, which would be 

 attended by no ideas independant of an arbitrary definition. 

 Nor, in this application, was there any danger of important 



error 



