PHYSICAL AND LITERARY. 93 



evident from the following experiment, 

 That fuppofing the drynefs of the air 

 and its denfity to continue the fame, more 

 water is evaporated in w^arm weather than 

 in cold. At the fame time, we find eva- 

 poration njuch increafed in froft, which 

 is owing to two caufes, altogether agree - 

 . able to the theory of folution ; the firft 

 is, that the air being condenfed by cold, 

 ^ttrads more water than formerly ; the 

 next is, that the dry winds from the 

 north and eaft, which generally accom- 

 • pany froft, attra(5t water more powerful- 

 ly than can be done by moift air. 



These obfervations fuggeft the follow- 

 ing refledlion. That an attempt to reduce 

 fummer and winter evaporation to any 

 . flandardof proportion, which is under- 

 taken by DocSlor Hale, refolves into an 

 attempt to give a ftandard for the heat, 

 the denfity, and the drynefs of the air in 

 J fummer and in winter. DocStor Hale 

 found pofhbly in his experiments the 

 fummer and winter evaporation to be e- 

 qual i but he certainly was in the wrong, 



from 



