ADVANCE AND RETREAT OF CANADIAN GLACIERS 737 



Great Glacier, of the Selkirks (Fig. 11). At a distance of only 

 two miles from the railroad, the glacier is easily reached by a good 

 trail. 



It is fed by a snow-field which forms a plateau at a level of about 

 7,000 feet. From this neve the glacier descends in a great ice cas- 

 cade to a level of 4,750 feet. Its surface is perfectly clean and much 



Fig. II. — Illecillewaet glacier. 



broken, seracs and crevasses being abundant. Its front is very 

 little steeper than the average slope of the glacier. 



In 1888 Dr. Green found that in twelve days the center of the 

 ice moved 20 feet; the side, 7 feet.^ Since 1887 Messrs. George and 

 William S. Vaux have made a special study of this glacier. The 

 general average of their observations shows a motion of from 6 to 2 

 inches daily in different parts of the ice. The great difference 

 between these figures and Dr. Green's may be due to some change 

 in conditions, or to the observations having been taken on different 

 parts of the ice. At all events, Dr. Green's figures seem too high 



I Among the Selkirk Glaciers (Macmillan, 1890). 



