386 Drift Ice and Currents of the North Atlantic. 



in latitude than the southern extremity of the Grand Bank. The 

 other icebergs noticed by him, in like latitude, and longitude 

 67° 35^, probably passed near to Newfoundland, and their position 

 shows, in a more striking manner, the strong westwardly ten- 

 dency of the polar current. 



No impulsion but tbiat of a vast current, setting in a general 

 southwesterly direction and passing beneath the Gulf Stream, 

 could have carried these immense bodies to their observed posi- 

 tions, on routes which cross the gulf current in a region where 

 its average breadth has been found to be about two hundred and 

 fifty miles. 



The continued southwestern, and even more westwardly course 

 of that portion of the polar current which is found southward of 

 Newfoundland and Nova Scotia and west of the Gulf Stream, is 

 conclusively shown by the two icebergs met with by H. M. packet 

 Express, July 7, 1836, on the southern edge of the Sable Bank, 

 about seventy-five miles southwest from Sable Island. The 

 highest of these, estimated at 180 feet, was in latitude 43° 14', 

 longitude 61° 17', the other, 150 feet high, in latitude 43° 09', 

 longitude 61° 26'. Owing to the great depth of these ice islands, 

 they could not have passed through the Strait of Belle Isle, but 

 must have been carried by the main current eastward and south- 

 ward of Newfoundland to their observed position, which, by the 

 nearest course, is near 500 English miles from off Cape Race, the 

 southeast point of that island, in the direction S. 63° W., true 

 meridian, or W. S. W. i S. Of the further extension of this 

 portion of the polar current, in diminished force, along the coast 

 of the United States and the western border of the Gulf Stream, 

 as far as Cape Hatteras, if not to Florida, we have formerly 

 spoken, in another place.* 



The finding of a low temperature on the southern part of the 

 Grand Bank, or even to the southward of latitude 43°, is not suf- 

 ficient evidence of the entire absence of the Gulf Stream current : 

 for the recent presence or proximity of floating ice must neces- 

 sarily cause a great reduction in the surface temperature, and 

 there is no natural process by which the cold water of the sur- 

 face stream can be changed for warmer with a rapidity sufficient 

 to preserve a temperature at all corresponding to the warm por- 

 tions of the Gulf Stream. 



* This Journal, Vol. xxxii, p. 349. 



