496 Mr. Lubbock on the Heat of Vapours 



u as u" U. See p. 490. 



y c~ u " c u c- M " c u 



c I H, therefore 



y 



w = l 



H y-l 



If we take, as in p. 274, y = 1'5, 



H* 



i 



p=p* (lt 



. See p. 280, 9 =l) {I + ,' U -J- 



p' La. J q a. 



y-i 



r H. See vol. xvi., p. 440. 



1 



y 



~ 



In page 470 I found H -54378 (from the observations of M. 

 Gay Lussac) corresponding to the temperature 87'35 of Fahren- 

 heit, and to 30*145 inches of mercury in the barometer. As the 

 uncertainty with respect to the values of y and E appertaining to 

 the mean state of the atmosphere makes it useless to have recourse to 

 greater refinement, I shall now suppose that this value of H will be 

 sufficiently exact for the temperature 50 of Fahrenheit and for 30 

 inches of mercury in the barometer at the earth's surface ; the sequel 

 will show that this hypothesis is admissible, and the calculation of 

 i will stand thus : when y = 1 *5 



log -^jj = 4-2633392 log/3 = 9-522S787 



log M = 9-6377843 log H = 9'7354232 



log (1 + $') = 0-0159881 = 6-8041168 



3-9171116 6-0624187 



6-0624187 



log i = 7-8546929 i= -0071564 



u" - Nap. log riTff ~ '784-78. 



