THE AECTIC OB LABRADOR CURRENT. 435 



commonly prevails along the coast of the United States, in the direction 

 which is opposite to the Gulf Stream ? 



" I am aware that it is usually considered by seamen as an eddy current 

 derived from the Gulf Stream ; but from this view I am compelled to 

 dissent. For, in the first place, this current never assumes the gyrating 

 form of an eddy ; but continues its course, when unobstructed by gales, in 

 a direction which is generally parallel to the coast. But, secondly, in case 

 this current be derived from the Gulf Stream, it must necessarily partake 

 of the same elevated temperature ; whereas the reduction of temperature 

 which occurs on crossing the North- Western limit of the Gulf Stream is 

 most remarkable, and is almost without parallel in the Atlantic, except in 

 the immediate vicinity of ice. 



" It appears vain to allege the proximity of soundings or shallows as 

 explaining this extraordinary change of temperature, for this cannot avail 

 if the waters of the counter-current be derived from the Gulf Stream, to 

 say nothing of the erroneous character of the position here noticed. 



" From the evidence which is afforded by numerous facts and observa- 

 tions, it appears that the current in question is neither more nor less than 

 a mere sluggish prolongation of the Polar or Labrador Current, which 

 sweeps along the North-Eastern shore of this continent and the Island of 

 Newfoundland ; and this current, if I mistake not, may be traced in its 

 gradations of temperature, by the thermometer, from off the Southern 

 coasts of Newfoundland and Nova Scotia, through the entire distance, to 

 Cape Hatteras, if not to Florida. 



" An eddy current, off-setting to the Gulf Stream, would nowhere be so 

 likely to be met with as at the point of intersection of this Stream with 

 the extremity of the Grand Bank of Newfoundland, and sweeping from 

 thence upon the Southern shores of the island of that name ; and yet the 

 harbour of St. John's, in the Southern part of Newfoundland, is known to 

 have continued ice-bound, in 1831, so late as the month of June, although 

 in the latitude of Paris. This fact is a convincing proof of the unimpeded 

 continuation of the Polar Current to the Southward, in this region, not- 

 withstanding the near proximity of the Gulf Stream." 



H.M.S. Challenger proved the correctness of this theory. In May, 1873, 

 when 210 miles S.S.E. from Sandy Hook, proceeding to the Northward, 

 Sir "Wyville Thomson says,* " Although on the surface the influence of 

 the Gulf Stream was still felt to a certain extent, the contrast between the 

 observations of this day and the day before was most marked. We had 

 crossed the ' Cold Wall,' and the temperatures registered were almost 

 purely those of the Labrador return current. . . . The collection as 

 a whole had a decidedly Arctic character and recalled some of our 

 dredgings on the coast of Northern Europe, although it seemed that few 

 of the forms were absolutely identical." The temperature soundings 

 (p. 416) will give an idea of the way in which the cold water underlies the 

 warm in this region. 



(434.) The Velocity of the Arctic Current, over the Banks and to the 

 Southward of Newfoundland, is very variable, but at times is great. We can 



•' Voyage of the Challenger" vol. i., page 375. 



