352 On the Gulf Stream and contiguous currents. 



"joins" the Florida stream in no other manner than by passing un- 

 derneath the same, or yielding it a passage upon its bosom, the order 

 of superposition being mainly determined by the great diversity of 

 temperature. The icebergs being thus carried southward by the 

 deeper polar current, even after the latter has lost its influence at 

 the surface, their dissolution is speedily effected by the tepid water 

 of the Gulf Stream, and we are thus relieved from these dangerous 

 obstructions, which would otherwise be found in lower latitudes of 

 the Atlantic. These two streams of current, therefore, neither meet 

 nor coalesce in any proper sense ; but like other currents, both at- 

 mospheric and aqueous, pursue each its determinate course, the Gulf 

 Stream being thrown eastward by the greater rotative velocity which 

 it acquires in latitudes nearer the equator ; and the polar current be- 

 ing thrown westward along the shoals and soundings of the American 

 continent and its contiguous ocean depths, by the more tardy rota- 

 tion which it derived in higher latitudes. 



The writer in the Nautical Magazine above alluded to, supposes 

 the natural course of the polar current from Davis' Strait to be to- 

 wards the coast of Morocco, in North Africa ; but a little attention 

 to the effect of the earth's rotation on this current, will show that 

 both it and the ice-drifts which are borne on its surface, must tend 

 westwardly as above described, in despite of the powerful westerly 

 gales which prevail in these latitudes. Light articles, however, such 

 as bottles which are set afloat to determine the drift of currents, will 

 not only yield greatly to the influence of these winds, but on falling 

 into the surface current of the Gulf Stream will of course accompany 

 this current in its progress towards the coasts of Europe, where a 

 leading branch of this stream is found sweeping along the coast of 

 Norway towards the recesses of the Polar Sea, and which appears 

 to be ultimately resolved into the Labrador current. The south- 

 easterly branch of the stream, on leaving the Grand Bank, yields to 

 the centrifugal influence of the earth's rotation and consequently as- 

 sumes the shorter and more direct circuit of gravitation by the coast 

 of North Africa to the tropical latitudes, from whence it again merges 

 in the Florida stream. It is by this system of compensation, aided 

 by various subordinate gyrations, siich for instance as Rennell's cur- 

 are met with in the 'southern ocean in a lower latitude than that of Philadelphia. 

 But geologists do not seem to be fully aware of the permanent character and ex- 

 tent of the great polar currents, which, under successive changes of location, must 

 have prevailed from the beginning, in both hemispheres. 



