846 



N: M. FENNEMAN 



the surface drainage. They reach apparently no great depths. 

 Many of them, which are several feet in depth and contain run- 

 ning water, are open less than half an inch at the top. Much of 



Fig. 6. — The Bergschrund,open about 15 feet. The columns at the right are ice ; 

 above them is snow. 



the surface drainage follows these narrow crevasses. That they 

 are primarily due to fracture and not to erosion is evident from 

 their absolute straightness for long distances. 



A most striking feature of this glacier is the prominent Berg- 



