Page:Whymper - Scrambles amongst the Alps.djvu/491

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appendix.
MINGLED STRATA OF SNOW AND ICE.
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lumps could readily be compressed between the hands. This was also the case in some places below the depth of 15 feet. For example, at B B, on the section, the snow was not perceptibly denser than it was six or eight feet higher up. In other places, A A, it could not be termed snowy; it could not be readily compressed in the hands; and it looked and felt like an imperfect or wet and spongy form of ice. The colour at B B was perceptibly stronger than at A A, but it should be said that the colour here, and of the horizontal strata of ice, has been intentionally exaggerated upon the section for the sake of clearness.

The entire mass was pervaded with horizontal strata of pure ice. In the 22 feet that we penetrated there were 75 such layers, varying from one-tenth of an inch in thickness to 6¼ inches, which amounted in the aggregate to 25⅝ inches of solid ice. These strata were parallel to the surface of the snow, and to each other. Not perfectly so; sometimes they approached, and sometimes receded from each other. Neither was their substance (thickness) constant. In some places they were more, and in others less thick. For example, the stratum which is between the brackets marked 1863-4 ? and 1864-5 ? was in some places an inch and a half thick, but in others scarcely an eighth of an inch. Upon the whole, the stouter strata were continued completely round the sides of the pit, and were tolerably uniform in thickness. The finer strata, on the other hand, frequently died out in short distances, and seldom or never could be traced completely round the walls. The finer strata also were much more numerous towards the surface than towards the bottom of the pit, and they were readily obscured by the drifting snow. It was obvious, yet important to observe, that the strata or layers of pure ice became fewer in number as one descended, and that they constantly, although not regularly, became thicker.

I attempted to gain an idea of the temperature of the snow at different depths, but I do not care to quote my readings, as they were, without a doubt, falsified by the wind. I am not sure, moreover, that it is possible under any circumstances to obtain correct readings of snow temperature in the way that they were taken. The recorded temperatures, anyhow, must have been influenced by the surrounding air. If they were correct they proved that the lower strata were warmer than the upper ones.

We must now quit the region of facts, and descend to that of surmises and conjectures. The differences in the quality and in the tone of the snow of the first three feet below the surface were sufficiently marked to suggest that we saw in them snow belonging to three different years. The unanimous opinion of the four men was, that the uppermost 11 inches belonged to 1865-6, the next 10 inches to 1864-5, and the next 16 inches to 1863-4. In this matter they were not, perhaps, altogether incompetent judges. I am doubtful, however, whether their opinion was correct, and incline to the idea that the uppermost 11 inches had fallen during the summer of 1866, and that the succeeding 10 inches may have been all that remained of the preceding winter's snow. Whatever surprise may be felt at so small a depth being considered as representing a year's fall, must be modified when it is remembered that the position at which the pit was sunk could scarcely have been more exposed. We had evidence that a mere fraction only of the snow that