246 SCIENCE SRETCHES. 
heels “well placed” on some projecting shelf of 
rock. 
At times in dur descent we felt the force of 
the tourment, a wind peculiar to the high moun- 
tains, —a sort of snow-laden whirlwind, or “ wind 
made visible.” This wind goes furiously over the 
mountain-side, tearing off loose rocks, starting 
avalanches, and tossing about the banks of snow. 
Whenever one of these struck us, we lay flat and 
clung to the rocks, lest we should be literally blown 
off the mountain. One of our company, I remem- 
ber, wore a narrow brimmed hat drawn down tight- 
ly over his ears; the tourment took it and whirled 
it high into the air. The learned professor fell flat 
on the ground, while every hair of his head caught 
the rotary motion and stood straight out. 
As we went farther, we noticed more and more 
the treacherous character of the stones on the 
mountain side. The whole outer coat of the 
mountain is loose, scarcely a rock anywhere on 
the Swiss side being firmly attached. Into all 
the joints of the strata the water from the melting 
snow finds its way, and by the freezing of this 
water the joints are widened and the blocks of 
hornblende are daily pushed nearer and nearer to 
the edge. Thus nothing is firm; nothing is stable, 
and each year the mountain offers a new face to 
the weather. 
Going down the mountain is more difficult than 
going up. This is not only on account of the men- 
tal strain of constantly looking over precipices, but 
because of the looseness of the rocks. Stepping 
down on a stone, one is more apt to detach it than 
