THE ESKERS OF NOVA SCOTIA. PREST. 389 



The evidence elsewhere is much the same as here. Nansen 

 tells that in Norway eskers are rare, but that in Sweden they 

 are both numerous and prominent, and this is in accordance 

 with conditions as the slopes are steeper and more moun- 

 tainous in Norway than in Sweden, and eskers if formed, 

 would be more easilj" swept away. 



The fact that most of the esker ridges of Nova Scotia 

 and Eastern United States have been but slightly disturbed 

 by eroding influences where they were supposed to have been 

 most exposed to them, shows that neither marine nor flluvia- 

 tile agencies were active. 



No Marine Action. — On the coast of Maine, where a post- 

 glacial elevation took place, there is no evidence of marine 

 action on the eskers; therefore they must have retained their 

 protective covering of ice until after the sea had retired. 



A Natural Conclusion. — The natural conclusion is that 

 eskers could be formed in glacier crevasses, but could not by 

 any possibility be formed in subglacial streams; and being 

 confined between these walls of ice, the contents could not 

 be eroded to any extent until the disappearance, or partial 

 disappearance, of the ice in the next interglacial age exposed 

 them to view. Thus protected, they have preserved their 

 special characters. When an increasing temperature began 

 to melt the ice, subglacial streams and leakage w'ould carry 

 off without doubt much of the excess of w^ater from the 

 crevasses, thus preventing erosion and transportation of the 

 elevated portions of transverse eskers. The proof of this 

 is that these uneroded ridges are .still to be seen in their 

 original positions; so when the last fragments of the ice shed 

 disappeared it left the gravel ridges reposing in almost their 

 present form, except where since denuded by brooks or 

 rivers. 



Potholes and Gaps. Potholes, gaps and small kames 

 could be, and probably were, formed by surface streams 



