128 



HOBBS— CHARACTERISTICS OF THE 



[April 22, 



stantly and consist of larger or smaller fragments which separate 

 along the crevasses and fall into the sea. Only twice were calvings 

 of the second class observed, namely, in late October and in early 

 November. Of one of these von Drygalski says : 



I heard a thundering noise, but at first neither I nor the Greenlanders 

 who were with me saw anything. Suddenly a great distance away from 

 the margin of the glacier, an ice berg emerged from the sea, rose out of the 

 water, though not to the height of the cliff, and then moved away accom- 

 panied by a continuous loud tumult and by a rise in the level of the water, 

 through the agency of which it moved away from the cliff quite rapidly. It 

 did not come from the cliff, but certainly emerged from below. The Green- 

 landers, whom I afterwards questioned about it, gave me the same impres- 

 sion. . . . The margin of the glacier was unchanged. 



fiu ^ *S;J 



Fig. 43. A large berg floating in Melville Bay and surrounded by sea ice. 



Here it was noticed that the berg was long though not as high as 

 the ice clifif which terminated the glacier. It is the opinion of von 

 Drygalski that bergs of this class come from the lowest layers of the 

 glacier. Because of the pack-ice which in winter forms in front of 

 the glacier, the ice cliff is at that time not cut away so fast, and it 

 was, in fact, observed in the winter farther out than during the sum- 

 mer. This explanation in the main is in agreement with that of 

 Russell. 



Bergs of von Drygalski's first class, which are the most massive 

 of all, separate from the entire thickness of the ice front. Two 



