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tures inferior to that of ebullition. Now, by analogy, I apprehend 

 this latent heat in all inferior temperatures may thus be 

 determined : , , 



As the fenJ3>le heat of ebullition, when the barometer is at ^5 

 or below 25 is to the latent heat of the vapour at ebullition, fo is 

 the fenftble heat of water heated to any inferior degree above 

 31** to the latent heat of its vapour, multiplied by 5,222. Thus 

 the fenfible heat of water in ebuUition barometer 25 being I7i'',4 



(= 203°,+— 32") its fpecific heat is 987 (= 1^2^) the latent 



heat of the vapour of water at 22° above congelation (that is 

 52*^ on Fahr. fcale) is 657 for ^ I7l*',4- 987 :: 22°. 126 x 5^22 = 

 657. The latent heat of vapour infuch cafes cannot be determined 

 by experiment on account of the admixture of atmofpheric air, we 

 muft therefore refort to analogy, which in this cafe is perfed. 



The latent heat of pure vapour at greater heights is more 

 confiderable : thus at heights, at which the barometer ftands at 20 

 inches, the latent heat of vapour whofe temperature is 22° above 

 32*^, as in the lafl; cafe, is 730 ; for the heat of ebullition is 

 ig^^'S, per table, = 162'', 8 above 32'' ; and the latent heat of the 

 vapour at ebullition is 1039. Now ^ 162,8. 1039 •• ^'^ Ho and 

 140 X 5'22 = 730. 



T t 2 As 



