Phoch Avalanches. 145- 



them. When the chill of evening made itself felt, and the drop- 

 ping water and the indefinite murmurs from the glacier below 

 were stilled, the silence became oppressive. The stillness was 

 so profound that it seemed as though the footsteps of the advanc- 

 ing shadows should be audible. 



On warm sunny days, however, there are noises enough amid 

 the mountains. The snow, partially melted and softened by the 

 heat, falls from the cliffs in avalanches that make the mountains 

 tremble and, with a roar like thunder, awaken the echoes far 

 and near. -During our stay at Camp 15 the avalanches were 

 sometimes so frequent on the steep mountain faces toward the 

 north that the roar of one falling mass of snow and rocks was 

 scarcely hushed before it was succeeded by another. 



On the southward-facing cliffs of Mount Augusta, composed of 

 schist which disintegrates rapidly, there are frequent rock ava- 

 lanches. A rock or a mass of comminuted schist sometimes 

 breaks away even in midday, although these avalanches occur 

 most frequently when the moisture in the rocks freezes. The 

 midday avalanches, I fancy, may be started by the expansion of 

 the rocks owing to the sun's heat. A few stones dislodged high 

 up on the cliffs fall, and, loosening others in their descent, soon 

 set in motion a train of dirt and stones, which flows down the 

 steep ravines with a long rumbling roar, at the same time send- 

 ing clouds of dust into the air. If the wind is blowing up the 

 cliffs, as frequently happens on warm days, the dust is carried 

 far above the mountains, and hangs in the air like clouds of 

 smoke. 



It has been frequently stated that St. Elias is a volcano, and 

 sea captains sailing on the Pacific have seen what they supposd 

 to be smoke issuing from its summit. As its southern face is 

 composed of the same kind of rocks and is of the same precipi- 

 tous nature as the southern slope of Mount Augusta, it appears 

 probable that what was supposed to be volcanic smoke was in 

 reality avalanche dust blown upward by ascending air currents. 



The disintegration of the mountain summits all through the 

 St. Elia? region is so great that one constantly wonders that any- 

 thing is left ; yet, except late in the fall, the snow surfaces at the 

 bases of even the steepest cliffs are mostly bare of debris. The 

 absence of earth and stones on the surfaces of the neve fields is 

 mainly due, of course, to the fact that these are regions of accu- 

 mulation where the winter's snow exceeds the summer's melting. 



