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does it by caufing a greater Rarefadion of the Air 
in thofe Parts upon which its Rays falling perpen- 
dicularly, or nearly fo, produce a greater Degree of 
Heat there than in other Places ; by which means 
the Air there becoming fpecifically lighter than the 
reft round about, the cooler Air will by its greater 
Denfity and Gravity, remove it out of its Place to 
fucceed into it its felf, and make it rife upwards. 
But it feems, this Rarefadion will have no other 
Effed than to caufe the Air to rulh in from all Parts 
into the Part where ’tis moft rarefied, efpecialiy 
from the North and South, where the Air is cooleft, 
and not more from the Eaft than the Weft, as is 
commonly fuppofed : So that, fetting afide the di- 
urnal Motion of the Earth, the Tendency of the 
Air would be from every Side towards that Part 
where the Sun’s Adicn is moft'intenfe at the Time, 
and lb a N. W. Wind be produced in the Morning, 
and a N. E. in the Afternoon, by Turns, on this 
Side of the Parallel of the Sun’s Declination, and a 
S. W. and S. E. on the other. 
That the perpetual Motion of the Air towards 
the Weft, cannot be derived meerly from the Adion 
of the Sun upon it, appears more evidently from 
this : If the Earth be fuppoled at Reft, that Motion 
of the Air will be communicated to the fuperficial 
Parts, and by little and little produce a Revolution 
of the Whole the fame Way, except there be the 
fame Quantity of Motion given the Air in a con- 
trary Diredion in other Parts at the fame Time, 
which is hard to fuppofe. But if the Globe of the 
Earth had before a Revolution towards the Eaft, 
this by the fame means muft be continually retard- 
H 2 cd -• 
