100 FORT CONFIDENCE. 



sun's rays at mid-day by innumerable canals, and 

 finally crumbles into a granular mass like the Jim 

 of the high Switz glaciers, that crackles under the 

 feet as soon as the sun sinks towards the horizon. 

 This firn is not universal; it is more common 

 within the arctic circle, and in situations where 

 there seems to have been originally a certain loose- 

 ness in the texture of the snow, and where its 

 surface is so much inclined that the sun's rays do 

 not fall on it obliquely about noon. I did not notice 

 it in any quantity on the level surface of a lake. 



The rapid evaporation of both snow and ice in 

 the winter and spring, long before the action of 

 the sun has produced the slightest thaw or appear- 

 ance of moisture, is made evident to residents in 

 the high latitudes by many facts of daily occur- 

 rence ; and I may mention that the drying of linen 

 furnishes a familiar one. When a shirt, after being 

 washed, is exposed in the open air to a tempe- 

 rature of 40° or 50° below zero, it is instantly 

 rigidly frozen, and may be broken if violently 

 bent. If agitated when in this condition by a 

 strong wind, it makes a rustling noise like thea- 

 trical thunder. In an hour or two, however, or 

 nearly as quickly as it would do if exposed to the 

 sun in the moist climate of England, it dries and 

 becomes limber. 



Mr. Kae mentioned to me another example of 



