102 CA USES which affca the ACC URACY 



19. THE amount of the terms which are thus rejected comes 

 now to be considered ; and it will be afcertained with fufficient 

 accuracy, if we compute the fecond term of the feries, or that 

 which involves in it m * . Now ; 



*+rf+ i 



2 





ffj* 



and = %.(i = m-\ --- SsV. 



fo that ,f* = 



Therefore, by fubftitution, H * 



4 2 12 



THIS is the coefficient of phg., which gives 0, corrected 

 both for the temperature of the air and the firft inequality of 

 expanfion, ( 5). The term ( -- A m, is M. DE Luc's cor- 



\ 2 / 



redlion, as has been already obferved, the third term, viz. 



i r H+h r *r(H+b) H*+AHb+b\ 



( --- ^ -- v T ' H -- 3J: 3--]z% contains not only 



\ 2 4 2 12 / 



a part which depends on the equable decreafe of heat as we 

 afcend in the atmofphere, but alfo one which arifes from the 

 above mentioned inequality of expanfion. 



2-0. THE 



