CURRENTS AND WHALING. 497 



equator is crossed on the return voyage, the better. These directions 

 have sometimes been ascribed wholly to the winds, which are repre- 

 sented as scant and unfavourable 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 coast 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 

 with ice. This circumstance was remarked by Commodore Wads- 

 worth when commanding the Vincennes on a former cruise, and as I 

 learn from him, a French man-of-war was about the same time com- 

 pelled to go far to the eastward of the Falkland Islands in order to 

 avoid the ice, a necessity which he avoided by keeping close to the 

 Patagonian coast, which at such seasons is the safest route. That ice 

 is thus carried far north into the Atlantic, we had in our voyage a 

 sufficient proof; for every thing indicated our near approach to ice in 

 longitude 54° 30' W., and in latitude as low as 39° S. 



The great space in the middle of the South Atlantic is affected by 

 no more than temporary and partial currents. In particular, near the 



vol. v. 125 



