206 ACCOUNT OF THE AUCTIC EEdlONS. 



can only give the relative motion of the superficial 

 water, as compared with that of the stratum of water 

 in which the kettle ^is suspended. In fact, this plan 

 for determining the course and velocity of currents, 

 goes on the supposition that currents are only su- 

 perficial, or that the waters below are always at rest, 

 which is not true. In a deep sea, therefore, where 

 no soundings can be obtained, the determination of 

 currents must always be a matter of difficulty ; and, 

 in some cases, of impracticability. 



By the effects of currents on vessels and other 

 floating bodies, the courses of many general and 

 some particular currents, have been determined in a 

 most satisfactory manner. That general and ex- 

 tensive current setting westward in tropical regions, 

 a branch of which, after doubling the Cape of Good 

 Hope, and extending considerably to the northv/ard 

 along the western coast of Africa, crosses the At- 

 lantic, accumulates in the Gulf of Mexico, passes 

 out by the Bahama Islands towards Newfoundland, 

 and constitutes what has been called the Gulf 

 Stream, — is too well known to need any proof or 

 particular description. On the great bank of New- 

 foundland, this stream meets with a current setting 

 southward from Baffin's Bay and the coasts of 

 Greenland ; and is deflected, perhaps, in two bran- 

 ches, towards the E. S. E. and E. N. E. By the 

 influence of these, plants, timber, fruits, &c. the 

 produce of America and the West Indies, are fre- 

 ojiently washed on shore on the coasts of Ireland, 



