THE WHITE CYCLONE 119 



water. Slides need a slope for their coasting. On 

 a steep, smooth slope a comparatively small ac- 

 cumulation or weight of snow will slide off. But 

 if the slope is somewhat flattened or extremely 

 rough an enormous quantity may be required for the 

 starting, or if the weather be warm when the first 

 autumn snow falls it may partly melt and freeze fast. 

 This icy cement will probably endure until spring. 



Most slides follow the channels of water courses. 

 Slides may be ordinarily divided into storm, an- 

 nual, and century. A storm slide may run during 

 or shortly after the snowstorm. The annual slide 

 for the spring will carry most of the winter's ac- 

 cumulation of snow; the century, the accumula- 

 tion of scores of winters. The century snowslide 

 often does much damage by smashing its way down 

 through forests, making as it were a right-of-way 

 of its own. A storm slide, too, may be a danger- 

 ous and damaging one. If there is an unusual fall 

 of snow from an uncommon quarter, or if this snow 

 is drifted in an unusual place, it, like the century 

 slide, will smash down over a new track and leave 

 a line of wreckage behind it. 



The third slide was also started by the first slide 

 striking a mass of snow and stones in the upper 

 end of a shallow ravine. For more than a mile 

 this third slide ran on a course parallel with that of 

 the first in a weirdly spectacular race. Then slide 

 number three swerved and followed a crescent- 

 shaped course to the right. A succession of short- 



