4i8 



ILLUSTRATIONS OF THE 



adion of the gulf-flream. In the North Sea, 

 the current which fets out of the Baltic, has evi- 

 dently determined the ihape of the fand-banks 

 oppofite to the coaft of Norway, and produced 

 a circular fweep in them, of which it is impoffi- 

 ble to miftake the caufe. 



In proof of the adion here afcribe(J to the 

 waters of the fea, in tranfporting materials to an 

 unlimited extent, we may add the well-known 

 obfervation, that the ftones brought up by the 



r 



lead from the bottom of the fea, are generally 

 round and polifhed, hardly ever fiiarp and an- 



gular. 



This could never happen to ftones that 



were not fubjed to perpetual attrition. 



372. Currents are no doubt the great agents in 

 diffufing the detritus of the land over the bottom 

 of the fea. Thefe have been long known to ex- 

 ift • but it is only ftnce the later improvements 

 in navigation, that they have been underftood to 

 conftitute a fyftem of great permanence. 



larity 



;, regu 

 d extent, conneded with the trade 



ds. and other circumft 



in the natural 



hiftory of the globe. The gulf-ftream was ma 



ny years fince obferved to 



fport the 



and the temperature of the tropical regions into 

 the climates of the north ; and we are indebted to 

 the refearches of Major Rennel, for the know- 

 ledge of a great fyftem of currents, of which it is 



only a part. That geographer, who is fo eminent 



for 



