THE SNOW 47 



residual glaciers are. In general the south sides are 

 convex and irregular, while the north sides are con 

 cave both in their vertical and horizontal sections; 

 the wind in ascending these curves converges to 

 ward the summits, carrying the snow in concentrat 

 ing currents with it, shooting it almost straight up 

 into the air above the peaks, from which it is then 

 carried away in a horizontal direction. 



This difference in form between the north and 

 south sides of the peaks was almost wholly pro 

 duced by the difference in the kind and quantity 

 of the glaciation to which they have been sub 

 jected, the north sides having been hollowed by 

 residual shadow-glaciers of a form that never 

 existed on the sun-beaten sides. 



It appears, therefore, that shadows in great part 

 determine not only the forms of lofty icy moun 

 tains, but also those of the snow-banners that the 

 wild winds hang on them. 



