THE EARTH. 29 1 



mense ocean, that takes more than so many 

 months to return. Upon returning, the trade- 

 wind, which has been propitious, is then avoid- 

 ed ; the mariner is generally obliged to steer into 

 the northern latitudes, and to take the advantage 

 of every casual wind that offers, to assist him into 

 port. This wind, which blows with such con- 

 stancy one way, is known to prevail not only in 

 the Pacific Ocean, but also in the Atlantic, be- 

 tween the coasts of Guinea and Brasil, and 

 likewise in the ^Ethiopic Ocean. This seems to 

 be the great universal wind, blowing from the 

 east to the west, that prevails in all the extensive 

 oceans where the land does not frequently break 

 the general current. Were the whole surface of 

 the globe an ocean, there would probably be but 

 this one wind, for ever blowing from the east, 

 and pursuing the motions of the sun westward. 

 All the other winds seem subordinate to this ; 

 and many of them are made from the deviations 

 of its current. To form, therefore, any concep- 

 tion relative to the variations of the wind in 

 general, it is proper to begin with that which 

 never varies. 



There have been many theories to explain this 

 invariable motion of the winds ; among the rest, 

 we cannot omit that of Dr Lyster, for its strange- 

 ness : " The sea," says he, " in those latitudes, 

 is generally covered over with green weeds, for 

 a great extent ; and the air produced from the 

 vegetable perspiration of these, produces the trade- 

 wind." The theory of Cartesius was not quite so 

 absurd. He alleged, that the earth went round 



