THICK ICE 



shore. When ice is thick and the wind 

 strong, especially toward spring when 

 there is apt to be free water along the 

 edge, you may stand by and see the 

 dredging effect at work, see the low, long 

 mound of gravel or sand slide backward 

 up the beach while the edge of the floe 

 crumples and grinds and crumbles, but 

 still moves irresistibly to its work. 



Over at Ponkapoag Pond, which is per- 

 haps a hundred thousand years older, the 

 effect of this pushing ice through the ages, 

 working at various levels, has been to 

 produce mounds and dikes almost beyond 

 belief. Moreover, these are placed in 

 such situations that it is plain to see that 

 the water was for the greater part of that 

 long time some feet higher than now. In 

 my first acquaintance with these ridges I 

 thought them dikes raised by modern 

 men, early farmers, perhaps, who thus 

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