Mr. Redfield on the Currents of the Atlantic. 297 
Having noticed that portion of the Gulf Stream which, on 
passing the bank of Newfoundland, moves towards the Azores 
and the African coast, we will now follow that considerable por- 
tion of the Stream which is found to pass towards the western 
coast of the British islands and along the coast of Norway, till 
it enters the polar basin. From this frozen region it again emer- 
ges in the great polar current, covered with floating ice, which, 
skirting the coasts of Labrador and Newfoundland, falls in with 
the Gulf Stream at the southern extremity of the Grand Bank, 
and now becomes, mainly, a subaqueous current, the deeper por- 
tion of which can be traced only by its propelling effect on the 
deeply immersed icebergs, which it forces athwart the warm 
tropical stream, till they become dissolved by the higher tempe- 
rature of the latter. 
Observations of the temperature made in sounding at various 
depths in the Gulf Stream, and particularly in the region where it 
overruns or crosses the polar current, would be of high interest, and 
of great value in estimating the dynamics of the ocean currents. 
As connected with the foregoing outline of the main system 
of superficial currents in the North Atlantic, I propose now a par- 
ticular inquiry, relating to a single branch of this system of ocean 
streams, which perhaps may serve to show the origin or charac- 
ter of some currents which pursue opposite directions in other 
oceans. From what source, then, is that southwesterly current 
derived which commonly prevails along the coast of the United 
States, in the direction which is opposite to the Gulf Stream ? 
Iam aware that this is usually considered by seamen as an 
eddy current, derived from the Gulf Stream; but from this view 
Iam 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 gen- 
erally 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 tem- 
perature which occurs on crossing the northwestern limit of the 
Gulf Stream is most remarkable, and is almost without a par- 
allel in the Atlantic, except in the immediate vicinity of ice. 
It appears vain to allege the proximity of soundings or shal- 
lows as explaining this extraordinary change of temperature, for 
this cannot avail if the waters of the counter current be derived 
Vol. xiv, No. 2.—July-Sept. 1843. 38 
