

339 On THE CHANGE of CLIMATE 



Let us transfer thefe trite and general reafonlngs to the 

 fituation of our middle colonies, with refpecl to land and 

 ■water. Our coaft runs nearly from North-Eaft to the 

 South-Weft, fo that if the land fhould at any time be 

 colder than the fea, and a current of cold air fhould fer 

 towards the fea, it muft pafs from the North-Weft to the 

 South-Eaft: But fuch winds we find generally take place 

 during cur winter feafon. For the Atlantic to the South- 

 Eaftward, is greatly heated during the furnmer feafon, 

 and will not foon lofe that heat when the fun goes to the 



Southward in the winter; add to this, a very notable cir- 

 cumftance, which is, that our coaft is conftantly wafiied 

 by a current of warm water, which being driven to the 



Weft 



Mexico 



winds near the equator 



!S 



the North-Eaftward, to give place to the fucceeding cur- 

 rent. But the furface of thefe, colonies foon grows cold 

 in the abfence of the Sun. Hence violent torrents of 

 winds pafs towards the Atlantic during the winter feafon ; 

 the colder the air is over the continent, the more violent 

 will thofe North- Wefters be. 



Can we difcover any change of circumftances, which mip-ht 



Wefte 



'lb 



or remove 



t^em entirely? It is very obvious that hard fmooth fur- 

 faces reflect heat better than thofe which are rough and un- 

 equal; the furface of a looking glafs, or any polifhed me- 

 tal, will refled more light and heat, than the rough fur- 

 face of a board. In the fame manner we obferve, that rocks 

 and fmooth beds of fand refled more heat, than a foft 

 broken furface of clay. A clear fmooth field alfo rcfleds 

 more heat, than the fame fpace would have done, when it 

 was covered with bullies and trees. 



If the furface of this continent were fo clear and fmooth, 

 that it would refled: fo much heat as might warm the in- 

 cumbent atmofphcrc, equal to the degree of heat produced 



by the neighbouring Atl 



an ecjuilibrium would be 



antic, 

 reftored) and we fliould have no ftated north- weft winds; 



But 



