212 WAVES OF SAND AND SNOW 



to drifting snow, but, as usually happens both in 

 travel and research, unlooked-for things forced 

 themselves upon the attention, and I shall deal 

 here with two of these. The first is the form 

 of snowcaps, determined, not by wind but by 

 gravity ; the second, the surface-waves on snow- 

 covered roads, which are made, not by wind but 

 by sledge traffic. 



Travelling by train westwards from Banff, in 

 the Rocky Mountains, I noticed that the snow was 

 of the clinging kind and collected in protuber- 

 ances around the base of trees and in mushroom - 

 shaped caps upon broken stumps. It was in the 

 Selkirk Mountains, west of the Rockies, however, 

 that the forms of clinging snow were most 

 strikingly exhibited. Near Glacier House, the 

 altitude of which is 4,000 feet above the sea, the 

 railway traverses a forest composed of tall, straight 

 pine-trees. Great numbers of these on either side 

 of the railway have been cut down to provide 

 timber for the long snow-sheds which protect the 

 trains from avalanches. The base of the trunk 

 being tough, the trees are not cut through at the 

 level of the ground but at a height of about 

 6 feet above. The result is that there are on both 

 sides of the railway -line hundreds of wooden pillars 

 about 6 feet high and of a nearly uniform diameter 



