Between Cape May and Madeira. 73 



character of an intermediate current, which extends from a 

 depth of 100 fathoms down to 800 and 900 fathoms from the 

 surface. The existence of this enormous mass of warm water, 

 nearly a mile thick, off the west coasts of Europe, is amply 

 proved by the temperature-soundings of H.M.S. "Porcupine" 

 between the Fseroe Islands and the Straits of Gibraltar. Its 

 depth necessarily decreases as the current proceeds northward, 

 but it still forms a layer 500 fathoms thick, of a temperature 

 from 10° C. to 8° C. in the channel between Rockall and 

 Scotland, and between the Hebrides and the Fseroe Islands. 

 It dwindles down to about 150 fathoms as it sweeps over the 

 area of Arctic water (below freezing-point) between the Fseroes 

 and Scotland discovered by H.M.S. "Lightning," then follows 

 the coast of Norway, and finally disappears in the seas of 

 Spitzbergen and Novaya Zemlya. In about lat. 65° N., near 

 the coast of Norway, it forms a surface-stratum about 200 

 fathoms thick of an average temperature of 7° C. In the 

 same latitude, the zero-point is reached at a depth of 300 and 

 400 fathoms. 



A comparison of the section between St. Thomas and 

 Halifax with the section between Cape May and the Azores 

 shows that the portion of the North Atlantic which they tra- 

 verse forms an area of nearly equal distribution of temperature, 

 and that this area coincides with what is known under the 

 name of the Sargasso Sea. It extends from Station 28 to 

 Station 52, or from lat. 25° to lat. 40° N. along the section 

 between St. Thomas and Halifax, and it occupies the whole 

 space between the edge of the Gulf Stream, near Station 41, and 

 Station 69, near the Azores, or between long. 70° and long. 38° W. 

 This area, about 1000 miles in diameter, may be fitly termed an 

 immense whirlpool in the middle of the North Atlantic, whose 

 waters revolve with the hands of the watch. It is covered 

 with a surface-stratum of warm water about 300 fathoms thick, 



F 



