CHAPTER XI 
GLACIERS 
General Statement. — Among the mountains, and in 
the high latitudes of the earth, snow falls im the winter 
and accumulates on the ground. In most places this 
disappears With the coming of spring; but in the polar 
regions, and on many high mountains, the winter’s 
snowfall does not melt away in the summer. Each 
year a little more is added to the mass, until finally it 
must move from its place of accumulation. In the 
mountains it does this by slowly flowing down the 
valleys as valley glaciers ; but from such immense snow 
fields as that of the great Antarctic continent, or the 
one in Greenland, vast sheets of ice spread out in all 
directions from the centre of accumulation, forming 
great continental glaciers. 
In recent geological times, such an ice sheet moved 
down from the Labrador peninsula, over northeastern 
America, as far south as the latitude of New York 
(p. 475). Since its effects upon our country were so 
marked, the subject of glaciers becomes one of more 
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