12 



ALASKA GLACIERS 



hibit their crowning banks of snow and ice in continuous 

 panorama. These ranges have been mapped in some de- 

 tail by the U. S. Coast Survey and the Canadian Inter- 

 national Boundary Commission, and it appears from a 

 comparison of the glaciers with contours of altitude that 

 the snow-line descends in both directions away from the 

 fiord. On the mountain slopes overlooking the water 

 glaciers do not form at a lower height than 4,500 feet, but 



FIG. 2. DAVIDSON GLACIER, FRONT VIEW, 1894. 



Showing the trench form of its valley.'the spreading of its end, and the two zones of the 

 fringing plain. Photograph by W. Ogilvie, from peninsula at left in fig. 3. See page 6. 



on the opposite slopes of the same ranges 3,500 feet seems 

 to be enough. 



Davidson Glacier, fed by a high snow-field lying several 

 miles back of the first mountain crest on the west, flows 

 to the fiord through a narrow trench and reaches sea- 

 level, though its ice does not actually touch the water of 

 the ocean. In its mountain trench it has a width of only 

 a half mile, but on escaping from the confining rock walls 

 and entering the fiord it immediately spreads into a semi- 

 circular fan with a radius (in 1894) of about three-fourths 

 of a mile. All about its frontal margin is a fringe of low- 

 land averaging three-fourths of a mile in breadth, consti- 

 tuted, at the surface, of rock waste brought by the glacier. 



