On the Gulf Stream and Currents of the Sea. 177 



difference in surface temperature only as the degree of heat ac- 

 cumulated there, it can be made to appear that the quantity of 

 specific heat daily discharged through the Gulf Stream, from those 

 regions, is sufficient to raise mountains of iron from zero to the 

 melting point, and to keep up from them a molten stream of metal 

 greater in volume than the waters daily discharged from the Mis- 

 sissippi river. Who, therefore, can calculate the benign influence 

 of this wonderful current upon the climate of the south ? 



At the depth of two hundred and forty fathoms, the temperature 

 of the currents setting into the Carribbean Sea has been found as 

 low as 48°, while that of the surface was 85°. Another cast, 

 with three hundred and eighty-six fathoms, gave 43° against 83° 

 at the surface. The hurricanes of those regions agitate the sea 

 to great depths : that of '80 tore rocks up from the bottom in 

 seven fathoms, and cast them on shore. They, therefore, cannot 

 fail to bring to the surface portions of the cooler water below. 



These cold waters, doubtless, come down from the north to 

 replace the warm water sent through the Gulf Stream, to moderate 

 the cold of Spitzbergen ; for, within the arctic circle, the temper- 

 ature at corresponding depths off the shores of that island is only 

 one degree colder than in the Carribbean Sea ; while, on the coasts 

 of Labrador, the temperature in depth is 25°, or 7° below the 

 freezing point of fresh water. Captain Scoresby relates that, on 

 the coast of Greenland, in latitude 72°, the temperature of the 

 air was 42°, of the water 34°, at the surface, and 29° at the 

 depth of one hundred and eighteen fathoms. He there found a 

 current setting to the south, and bearing with it this extremely 

 cold water, with vast numbers of ice-bergs, whose centres, per- 

 haps, were far below zero. It would be curious to ascertain the 

 routes of these under-currents, on their way to the tropical re- 

 gions, which they are intended to cool. One has been found at 

 the equator two hundred miles broad, and 23° colder than the 

 surface water. Unless the land, or shoals, intervene, it no doubt 

 comes down in a spiral curve. 



Perhaps the best indication as to these cold currents may be 

 derived from the fish of the sea. The whales first pointed out 

 the existence of the Gulf Stream by avoiding its warm waters. 

 Along our own coasts, all those delicate animals, and marine pro- 

 ductions, which delight in warmer waters, are wanting ; thus in- 

 dicating by their absence the cold current from the north now 



Vol. xLvii, No. 1.— April-June, 1844. 23 



