468 CURRENTS AND WHALING. 



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 equator is crossed on the 

 return voyage, the better. These directions have sometimes been 

 ascribed wholly to the winds, which are represented as scant and un- 

 favourable in places other than those which the current would render 

 favourable for crossing the line. This may be in some degree true, 

 for the winds which in these parts of the ocean are always light, may 

 be affected and drawn along with so rapid a stream. The polar origin 

 of this Equatorial Stream will be rendered more probable from the 

 relative temperatures of the parts of the ocean whence it flows, and of 

 those where no current prevails. 



On the south coast of Brazil a current is found setting at first to the 

 southwest, and gradually changing its direction to south, until at the 

 mouth of the La Plata it ceases to be experienced, but appears then to 

 incline to the eastward, and spreads itself over the surface of the 

 Southern Atlantic. This is a phenomenon whose analogy to our Gulf 

 Stream cannot fail to be observed, and the resemblance becomes 

 stronger when it is seen that off the mouth of the La Plata it is met 

 by the Patagonian Current, a branch of the Great South Polar Stream, 

 that comes round Cape Horn, and sets along the'eoast of the country 

 whence it is named. This stream seems, like that of Labrador, to 

 throw a branch (that has been mistaken for an eddy) between the 

 southwest current and the coast. Such at least would appear to be 

 the case from the extent to which low temperatures prevail north- 

 wards, as was particularly noted off Cape Frio, and is exhibited in 

 the direction of the isothermal lines on the chart. 



The main body of this, or perhaps another southern polar stream 

 that enters the Atlantic, is often encountered on the surface to the 

 northward and eastward of the Falkland Islands. At times, icebergs 

 are borne along by it to the northeast, and in the neighbourhood of 

 those islands the whole sea has been described as occasionally covered 



