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evaporation and of degelation, glaciers must necessarily be formed. 

 Before the glacier is born, we have immense snow-fields or neves. 

 Through accumulation the snow becomes compressed, and this process 

 continues until ice is formed. Ordinarily speaking, ice is a solid, hut in 

 reality it is not ; in fact, an absolute solid is unknown upon- the earth. 

 The behaviour of the ice is like that of a semi-plastic body. When by 

 motion the limit of elasticity in ice is reached and fracture occurs, 

 regelation in a great measure preserves the continuity of the mass. 

 Under the action of gravity and lying on the mountain sides or in depres- 

 sions, the ice mass flows, and in the same sense as water flows, only of 

 course very much slower. In a river we find the greatest current nea r 

 the middle, so it is with a glacier. As different rivers have different 

 velocities, depending upon the degree of slope, similarly do we find 

 the rate of flow in glaciers to differ widely, and for like reasons. 



Of the living glaciers of south-eastern Alaska, the Muir is the largest 

 and offers probably the best opportunity for measuring the rate of flow. 

 This glacier has an ice front of nearly two miles discharging into the 

 ocean. Its vertical ice-wall at the sea is over 200 feet in height, and its 

 area, including the neve and its ramifications, is approximately one 

 thousand square miles, or greater than the whole of the renowned Swiss 

 glaciers combined. 



By the pursuit of the study of astronomy one is led to contemplate 

 the utter material insignificance of man and his terrestrial domicile in 

 the grand macrocosm, and when one stands on this vast glacier, hears 

 its thundering echoes as it rends and breaks in its seaward journey, as 

 it grinds and scrapes the underlying rocks, as it changes mountains into 

 moraines, which in time become land, then again is he impressed with 

 the insignificance of man's powers when arrayed against the forces of 

 nature ; then is a new leaf of nature opened to his view, to read its 

 significant characters. 



Measurements have been made of the recession of the Muir glacier. 

 From them it appears that within the last few years, its average rate of 

 recession has been nearly a thousand feet per year. The flow or for- 

 ward motion of the glacier is scarcely appreciable at the sides, but in 

 the centre it is at the rate of about 2,500 feet per year. Prof. Wright 



