CHAP, viii.] THE GULF-STREAM. 399 



these circumstances occur, however, in the confined 

 and contracted communication between the North 

 Atlantic and the Arctic Sea. Between Cape Eare- 

 well and North Cape there are only two channels 

 of any considerable depth, the one very narrow 

 along the east coast of Iceland, and the other 

 along the east coast of Greenland. The shallow 

 part of the sea is entirely occupied, at all events 

 during summer, by the warm water of the Gulf- 

 stream, except at one point, where a rapid current 

 of cold w^ater, very restricted and very shallow, 

 sweeps round the south of Spitzbergen and then 

 dips under the Gulf -stream water at the northern 

 entrance of the German Ocean. 



This cold flow, at first a current, finally a mere 

 indraught, aflPects greatly the temperature of the 

 German Ocean ; but it is entirely lost, for the slight 

 current which is again produced by the great con- 

 traction at the Strait of Dover, has a summer tem- 

 perature of 7 "5 C. The path of the cold indraught 

 from Spitzbergen may be readily traced on the map 

 by the depressions in the surface isothermal lines, and 

 in dredging by the abundance of gigantic amphi- 

 podous and isopodous crustaceans, and other well- 

 known Arctic animal forms. 



Prom its low initial velocity the Arctic return 

 current, or indraught, must doubtless tend slightly 

 in a westerly direction, and the higher specific gravity 

 of the cold water may probably even more power- 

 fully lead it into the deepest channels; or possibly 

 the two causes may combine, and in the course of 

 ages the currents may hollow out deep south- 

 westerly grooves. At all events, the main Arctic 



