exposed to heat equal to that of a summer's day, did 

 from a circular surface, eight inchhes in diameter, eva- 

 porate six ounces in 24 hours. If so, the thickness of 

 <i skin of water, evaporated in two hours, is the 53d 

 part of an inch. But were it only a ftOth, it would ex- 

 hale the tenth of an inch in two hours. And on this 

 principle every ten square inches of the surface of 

 water, yield in vapour a square inch of water daily: 

 each square foot half a pint : every space of four 

 feet square, a gallon: a mile square 6$14 tons: a 

 quantity abundantly sufficient to furnish, both dews, 

 rains, springs, and rivers. So that we need not have 

 recourse for supplies to the great abyss, whose surface, 

 at high water, is surmounted several hundred feet, even 

 by ordinary hills : and some thousands, by those vast 

 mountains, from whence the largest rivers take their 

 course. 



Nevertheless we may allow a different rise to those 

 springs, which ebb and flow with the sea : as likewise to 

 those lakes whose water is salt, and which have sea-tish 

 in them,- although they have no communication with 

 any sea, by any visible passage. 



To explain this a little more at large. It is evident 

 from experience, that a vapour is perpetcmlly rising 

 from the sea, rivers, and lakes. The winds carry this 

 vapour through the atmosphere, in the form of a cloud 

 or mist. When it meets with a colder air, or is stopt 

 by mountains, it condenses, and falls to the earth. As 

 it falls, it finds several chinks and crannies, through 

 which it insinuates into the mountains, and lodges there, 

 till increasing its store, it bursts out and takes the name 

 of a fountain. 



That this is really the case, will easily be allowed, by 

 all who seriously consider, 1. That the vapours' rising 

 from the sea, are more than sufficient to supply both the 

 surface of the earth, and the rivers with water. 2. That 

 the mountains, by their particular structure, arrest the 

 vapours that float in the atmosphere, and having col- 

 lected them in their reservoirs, dismiss them again 



VOL, III, C 



