THE EARTH. 299 



moved, the air returns to fill up the former vacui- 

 ty. Such is the usual method of accounting for 

 this phenomenon ; but, unfortunately, the sea and 

 land breezes are visitants that come at all hours. 

 On the coast of Malabar, * the land breezes begin 

 at midnight and continue till noon ; then the sea 

 breezes take their turn and continue till midnight. 

 While, again, at Congo, the land breezes begin 

 at five and continue till nine the next day. 



But, if the cause of those be so inscrutable 

 that are, as we see, tolerably regular in their vi- 

 sitations, what shall we say to the winds of our 

 own climate, that are continually shifting, and 

 incapable of rest ? Some general causes may be 

 assigned, which nothing but particular experi- 

 ence can apply. And, in the first place, it may 

 be observed, that clouds and heat, and, in short, 

 whatever either increases the density or the elas- 

 ticity of the air in any one place, will produce a 

 wind there ; for the increased activity of the air 

 thus pressing more powerfully on the parts of it 

 that are adjacent, will drive them forward ; and 

 thus go on, in a current, till the whole comes to 

 an equality. 



In this manner, as a denser air produces a 

 wind, on one hand, so will any accident that 

 contributes to lighten the air, produce it on the 

 other ; for a lighter air may be considered as a 

 vacuity into which the neighbouring air will rush : 

 and hence it happens, that when the barometer 



Buffon, vol. ii. p. 252. 



