[ igo'] 
The air in fultry weather, though riot cloudy, has 
a kind of hazinefs in it, which makes objeds at a 
dihance appear dull and indiftind. This hazinefs is 
occafioned by the great quantity of moifture equally 
diffufed in that air. When, by the cold wind blow- 
ing down among it, it is condenfed into clouds, and 
fills in rain, the 'air becomes purer and clearer. 
Hence, after gufts, diftant objeds appear diftind, 
their figures fliarply terminated. 
Extreme cold winds congeal the furface of the 
earth, by carrying off its fire. Warm winds after- 
wards blowing over that frozen furface will be chilled 
by it. Could that frozen furface be turned* under, 
and a warmer turned up from beneath it, thofe warm 
winds would not be chilled fo much. 
The furface of the earth is alfo fometimes much 
heated by the funj and fuch heated furface not being 
changed, heats the air that moves over it. 
Seas, lakes, and great bodies of water, agitated 
by the winds, continually change fur faces ; the cold- 
furface in winter is turned under, by the rolling of 
the waves, and a warmer turned up ; in. fummer, 
the warm is turned under, and colder turned up. 
Hence the more equal temper of fea-water, and the 
air over it. Hence in winter, winds from the fea 
feem warm, winds from the land cold. In fum- 
mer the contrary. 
Therefore the -lakes north-wefi: of us*, as they 
are not fo much frozen, nor fo apt to freeze as the 
earth, rather moderate than increafe the coldnefs of 
our winter winds. 
The air over the fea being warmer, and therefore 
lighter in winter than the air over the frozen land, 
^ In Penfilvania. 
may 
