496 CURRENTS AND WHALING. 



wards alon<? the coasts of Labrador and Newfoundland ; and dividing 

 at the Banks, a branch of this follows the line of soundinos off Nova 

 Scotia and the United States, while another flows beneath the waters 

 of the Gulf Stream, passes southwards, and mingles with the waters 

 of the ocean, and affects the surface temperature where it comes in 

 contact with islands and banks. The uninterrupted flow of this vast 

 polar stream is along the coast of Portugal and Spain, and a small part 

 of it flows into the Bay of Biscay, caused by its striking upon Cape 

 Finesterre, and forms eventually the Rennell Current ; another part 

 flows into the Mediterranean, in consequence of the higher level of 

 the stream, when compared with the waters of that sea. The main 

 branch now pursues its course on the surface, until Madeira and 

 the Canaries are reached in its course, beyond which it is no longer 

 apparent. But below the surface, as shown by the low temperatures 

 of the deep-sea soundings, a submarine stream pursues its way to the 

 equator, where the waters again commence the same round as before. 



In the southern portion of the space included within the above 

 limits, is an expanse of water which presents remarkable phenomena. 

 This is called by the name of the Sargasso Sea, and is noted for the 

 quantity of the aquatic plant, known as the gulf-weed (Fucus natans), 

 that is found in it. The general impression seems to be, that this 

 space is occupied by a sort of eddy, in which is deposited all the 

 matter borne by the different currents of the ocean, and that to this 

 cause is due the accumulation of the gulf-weed. It would, however, 

 appear, that this idea cannot be correct ; for, in the first place, the 

 weed appears fresher there than when drifting in the Gulf Stream 

 and other currents, and is therefore nearer the place of its growth ; 

 then again, there is no evidence that any drift-wood, or other terrestrial 

 product, is found in the Sargasso Sea; and in the third place, the 

 currents that have already been spoken of, appear rather to set from 

 it, thus indicating that it has a higher level than other parts of the 

 ocean. That such difference of level has a physical cause, there can 

 be no reasonable question 



To connect the previous part of our subject with the currents of 

 the Southern Atlantic, we return to the Equatorial Stream. This 

 was met by us, as has been seen, in latitude 3° S. To avoid the 

 difficulties that this stream may cause, vessels outward-bound ought 

 so to shape their course as to avoid entering it too soon. Should 

 they neglect this, they may be set behind or to the westward of Cape 

 St. Roque. For the same reason, the further to the westward the 



