45 



This vast ice sheet is slowly moving outward in all directions from 

 the elevated center, much as a pile of wax may be made to flow 

 outward by plac- 

 ing a heavy weight 

 upon the middle. 

 Moving t o w ar d 

 the north, east, 

 south and west, 

 this s'lacier must 

 of course come 

 to an end some- 

 where. In places, 

 usually at the heads 

 of bays, the end is 

 in tlie sea, as the 

 end of our glacier 

 must have been off 



99 



■ The e:\Cje of a part of the great Greenland ice sheet 

 {on the left) resting on the land, oxer which are strewn 

 many boulders brought by the ice and left there when it 

 melted. 



the shores of New^ England. From these sea-ends, icebergs con- 

 stantly break off; and, floating away toward the south, often reach, 



before they melt, as far as the 

 path followed by the steamers 

 from the United States to 

 Europe. Between the baj^s, 

 where the glacier ends in the sea, 

 the ice front rests jn the land 

 (Fig. 22), as it did over the 

 greater part of l\ew York and 

 i ^^ the States further west. There 

 it melts in the summer, supply- 

 ing streams with water and fill- 

 ing many small jDonds and lakes. 

 The front stands there year after 

 year, sometimes moving a little 

 ahead, again melting further 

 back so as to reveal the rocks on 

 83. — A scratched pebble taken from the which it formerly rested. 



ice of the Greenland glacier. Examining tins rock it is 



found to be polished, scratched and grooved just like the bed-rock 

 in New York ; and the scratches extend in the direction from which 



437 



