GLACIAL STUDIES IN GREENLAND. II. 



The Glaciers of Disco Island. 



Very much of the deep interest felt in the glaciation of 

 Greenland springs from the light it throws upon the former gla- 

 ciation of our own country and of Europe. In the region of 

 the old drift of the middle latitudes, the only glaciers that now 

 exist belong to the small mountain type. These very imper- 

 fectly represent the modes of action of continental glaciers. It is 

 natural therefore to turn for light to the polar ice-fields, which 

 alone approach continental dimensions. But this approach to 

 equality in dimensions and similarity in general habit is attended 

 by a possible, if not a probable, difference in the special effects 

 of latitude. If, to be sure, the ancient glaciations were caused by 

 changes of latitude, these differences might not exist. But this 

 hypothesis, like all other hypotheses relative to the origin of 

 ancient' glaciation, is at present open to very serious sources of 

 doubt. It is not safe, therefore, to assume like latitudes. The 

 peculiarities of glacial action due to latitude are therefore to be 

 sought out, and, if need be, taken account of in drawing com- 

 parisons between the ancient glaciation of low latitudes and the 

 present glaciation of high latitudes. 



It is not difficult to find a partial basis for the elimination of 

 these special effects. The great ice-field of Greenland ranges 

 through something more than twenty degrees of latitude, i. e., 

 it stretches from about Lat. 6o° N. to a limit but partially 

 known, somewhere beyond Lat. 82 N., according to Lieutenant 

 Peary. The former glaciation of the United States reached 

 somewhat south of Lat. 38 N. It hence appears that the old 

 glaciation stretched just about as far south of the southernmost 

 extremity of the present ice-field of Greenland, as this ice-field 

 now stretches north of that point. The difference between the 



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