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YEARBOOK, PUBLIC MUSEUM, MILWAUKEE 



[Vol. II. 



the amount of snowfall occurring at its upper limits and along its lower 

 course; second, the steepness of the slope down which it extends; and 

 third, the rate of melting at the lower end of the ice. The upper parts 

 do not melt to any appreciable extent even on the warmest summer 

 days, but at the lower end the rate of melting keeps pace with the move- 

 ment of the ice down the slope and a delicate balance of these two 



Fig. 32. — Narada Falls of Paradise river. 



forces determines the position of the end of the ice. Nearly all glaciers 

 at the present time are retreating, that is, from year to year their lower 

 end is retiring to a higher and higher altitude. In the case of the 

 glaciers of Mt. Rainier, this action has been going on for a long time, 

 as can be seen from a study of the various moraines abandoned by the 

 glaciers in their retreat. This retreat of the Nisqually Glacier has 

 amounted to about a thousand feet in the last twenty-five years, and as 



