292 UNIVERSAL ERUDTTIOIT. 



mention this once for all. This fcience begins 

 by examining the properties of the atmofphere that 

 furrounds this globe, the air that we breathe, and 

 the clouds that pafs over our heads , the cauies 

 of rain, fnow, dews* tempefts, but efpccially of 

 the winds, as well thofe called variable, as the 

 trade winds , as alfo of whirlwinds and other 

 meteors. It mows that an air charged with va- 

 pours is heavier than a clear air*, and confe- 

 quently more elaftic ;. that it prefles more, and 

 that from thence arifes that agitation, that mo- 

 tion in the air which is called wind : and that 

 the fwiftefl wind does not pafs over more than 

 fifty feet in a fecond. It inquires likewife into 

 the caufes of the variation of the weather, and- 

 the different temperature of each- climate. 



VII. Geography then proceeds to the con- 

 templation of the earth itfelf. It examines its 

 mountains and vallies : it confiders that chain of 

 mountains of 188 geographic leagues in length, 

 which the Greek and Latin authors call the Alps, 

 and which feparate Italy from Germany, and Swit- 

 zerland from France ; thofe celebrated moun- 

 tains in South America called the Cordeliers, the 

 higheft in the known world, and of which the 

 greateft, named ChimborafTo, is j 9320 feet above 

 the furface of the fea. It defcribes the vlocanos 



* The more general opinion iy> that the clrieft air is the 

 heavieft ; and the obfervations on the barometer feem to con- 

 firm this opinion. 



