It remains therefore to fubftitute fome other caufe, ca- 
pable of producing a like conftant effeft, not liable to the 
lame Objeftions , but agreable to the known properties of 
the Elements of Air aiid Water, and the laws of the Motion 
of fluid Bodies. Such an one is, I conceive, the Action of the 
Suns Beams upon the Air and Water, as he pa lies every day- 
over the Oceans, confidered together with the Nature of the 
Soyl, and Scituation of the adjoyning Continents: I. lay 
therefore, firfl: that according to the Laws of Staticks , the 
Air which is lels rarlfied or expanded by heat, and conle- 
quently more ponderous, muft have a Motion towards thofe 
parts thereof, which are more rarified, and left ponderous, to 
bring it to an Mquilihrium \ and Iccondly, that the pre- 
fence of the Sun continually fbifting to the Weftwards, that 
part towards which the Air tends, by reafonof the Rari- 
ladion made by his greatefl: Aff riii.^;^ Heat, is with him car- 
ried Weft ward, and confequently tiie tendency of the whole 
Body of the lower Air is that way. 
Thus a general Eafterly Wind is formed, which being 
impreffed upon all the Air of a vaft Ocean, the parts impel 
one the other, and fo keep rocking til! the next return of the 
Sun, whereby lb much of the Motion as was loft, is again 
reftorfd, and thus the Eafterly wind is made perpetual. 
Fr TTi the fame Principle it follov/s, that this Eafterly 
Wind fhouid on the North Sjde of the Equator, be to the 
North Vi ardi of the £aft, and in South Latitudes to the 
Scutawa^Tis thereof; for near thcLi^e, the Air is much 
more rariiied; than at a greater diftance from it ; becaule 
of the Sun twice m a year Vertical, and at no time diftant 
above ^'^dg. and a half, at which diftance the heat, being as 
the Sine of the Angle of Incidence, is but little fliort of tfiat 
of the perpendicular Ray, Whereas under the Tropicks, 
though theSonftay long Vertical^ yet he is as long47dg.off; 
which is a kind of Winter, Avherein the Air lb cools, as that 
the Summer Heat cannot warm it to the lame Degree with 
that under the Equator. Wherefore the Air to the North- 
wards 
