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 Fare- 
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 water, 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, affects 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. 
From 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 
