George Edward Mannering

“ Snow avalanches are most frequent after fresh falls of snow followed immediately by warm weather, and after a little experience amongst the mountains one soon learns to detect their customary tracks. Ice avalanches are mainly caused through the overhanging portion of ice at the terminals of secondary glaciers—that is, glaciers which break off before descending to the valley or to the parent glacier below. The tracks of ice avalanches are almost invariably unmistakable and are swept night and day without cessation, and very frequently at regular intervals. ”

“ All around us is snow, either freshly fallen or merging into névé. We begin to walk down, and at first, upon the steeper slopes, cross a few large crevasses and bergschrunds by means of snow bridges; then, as the incline becomes less steep, we walk for six miles or so upon a smooth surface of névé, or perchance knee-deep in fresh snow, and scarcely a crevasse exists. At the beginning of the great turn we gradually leave the névé and find ourselves upon hard, white ice, and soon transverse crevasses appear ”

“ But some snow avalanches almost crawl down the couloirs, and make a strange and ever-continued hissing as they move. These are composed of heavy and sodden snow, and begin after the sun has been up for some hours, continuing until nightfall. These are not so dangerous on a gentle slope, and one can often waddle or half glissade down in the midst of one with perfect safety, though they make one uncomfortably wet. ”

“ It is well-known in physics that water at 39° Fahr. is at its heaviest, and as soon as the warm stone—the dark colour of the stone having absorbed more heat than the surrounding ice—begins to sink the warmer water follows it, whilst that in the neighbouring temperature of 32° Fahr. rises to the surface and becomes in its turn re-warmed, and so on. ”

“ The motion of glaciers is yet another bone of contention, but it is generally admitted that the cause of it is to be found mainly in gravitation, and is also partially accounted for by the strange property of 'viscosity' in what appears to the casual observer to be nothing more or less than a rigid solid. ”

“ If one happens to be below then it is a case of sauve qui peut and a rush for the nearest protection, for there is no saying how many tons, or indeed how many hundreds of tons, of loose rocks or stone may start in a wild and dusty rattle down the hillside. ”