( 440 ) 

 proper places. It is, in general, to be 

 remarked, that a clear idea of variations 

 in condu(fl correfponding with thofe of foil, 

 is a matter of much importance, and fhould 

 be attended to with care. 



The reader, I hope, will excufe any 

 fmall inaccuracies which may have crept 

 into this long feries of calculations : As a 

 minute certainty in each fum is not of confe- 

 quence to the general aim of the work, 

 fuch accuracy may be the better difpenfed 

 with. 



The 



