378 T. C. CHAM BERLIN 



of the polar ice-field. It is therefore important to enter into some 

 detail respecting the essential features of this singular situation. 



A broad sea-arm branches off from the northwestern angle of 

 the Atlantic and gradually narrows northwardly until it forms 

 Davis Strait, although even here it has a width of 200 miles (see 

 map, Fig. i). This narrowing is due to a submerged ridge crossing 

 the sea-arm at this point and linking Greenland to Baffin Land. It 

 is a part of an intercontinental ridge to be described later. Beyond 

 this ridge the sea-arm broadens again and constitutes Bafhn Bay, 

 which attains a maximum breadth of about 480 miles, a depth at 

 several places of over 1,000 meters, and stretches onward to about 

 78° N. Lat. As the bay approaches this high latitude, the lands on 

 the east and west close about it and its bottom shelves up into rela- 

 tive shallowness. A rather narrow channel, Smith Sound, leads on 

 to the northward and connects, through Kennedy and Robson 

 channels, with the Polar Sea. The tide enters the poleward mouth 

 from the north, and the drift of the ice in these channels is southward 

 into the head of Bafhn Bay, but this drift is pressed to the right by 

 rotation and keeps mainly on the western side of the bay. Farther 

 south on this western side, Lancaster and Jones sounds join Baffin 

 Bay nearly opposite Melville Bay, into which they project their 

 cold waters. Both these sounds lead back through other narrow 

 channels westward and northwestward to the Polar Sea and are 

 fed by its icy waters, which press into them as though they were 

 outlets. With exceptions of this limited kind, Baffin Bay is land 

 girt. The great island, Greenland, confines it on the east and north; 

 the islands of the American Arctic Archipelago border it on the 

 west. The whole sea-arm takes the form of a long inlet into the 

 broken northeast angle of North America. From its mouth to the 

 head of Baffin Bay, this inlet has a length of about 1,500 miles. 

 Looked at comprehensively, the region is more largely land than sea, 

 although distinctly a combination of the two. 



Relations to ice-hearing currents. — The East Greenland ice-bear- 

 ing current is the greatest of all avenues of discharge of ice-floes 

 and melt-waters from the Polar Basin. Apparently, also, it is the 

 main line of ultimate discharge of the land waters that flow toward 

 the pole. The investigations of Nansen and his colleagues seem to 



