“pi 
Climate of the Candian West. 89 
across the Rocky Mountains to the plains. None of these 
three divisions is formed by a single line of elevations, but 
each consists of lines and groups of mountains almost 
untraceable in their confusion. They stand athwart 
prevailing winds, and hundreds of their peaks rise far into 
the chill regions of upper air, where winter is perennial. 
The highest are nearest the eastern border, and by the time 
the winds from the Pacific Coast have struggled between 
the crags, and swept across the wide snow-fields and ice-beds 
of the Selkirks and the Rockies, they are almost as dry as 
the dust ofa fiour-mill. Hence, of course, the rain-fall and 
snow-fall are far greater in the Gold and Selkirk ranges, first 
encountered, than in the Rockies; and the western side of 
each range is far more wet than the eastern. The snow-fall 
in the Selkirks amounts to about 30ft. in depth, yet winter 
,there is hardly three months long, and the weather, as a 
rule, is so mild that explorers and workmen find little 
inconvenience in tents and shanties, and are only comfort- 
able at work by taking off all their coats and laboring in 
their shirtsleeves. In the Rockies, on the contrary, the 
snow-fall is comparatively light, and what falls wastes 
rapidly, so that the railway is never incommoded in this 
range. ‘The cold, on the contrary, is often very severe, and 
the winter of longer duration than in the Selkirks. This 
contrast is easily explained: We have seen that the warm 
and damp currents of air from the Pacific Ocean are gradu- 
ally deprived of their moisture by condensation against the 
cold peaks of the Gold and the Selkirk ranges of mountains, 
so that they reach the Rockies almost dry. The very fact 
of its contact with the ice and snow must cool the air some- 
what, of course, but the philosophical explanation is behind 
this—the warm winds of the coast are cool winds in the 
tockies, because they have become dry winds. In giving 
up their moisture by condensation they have lost heat; and 
in their further rarification, due to their lofty flight over the 
high peaks, they have parted with still more heat, in exact 
proportion to the height ot their ascent. Everyone who has 
climbed a mountain or gone up in a balloon, has noted how 
ee SE - 
