They are lines of rupture consequent upon unequal motion. The glaciers below move quicker than the snow or ice which clings immediately to the mountains; hence these fissures result. The slower motion of that which is above can only be attributed to its having to sustain greater friction; for the rule is that the upper portion is set at a steeper angle than the lower. As that is the case, we should expect that the upper portion would move _quicker_ than the lower, and it would do so, doubtless, but for the retardation of the rocks over which, and through which, it passes.(170) We crossed the bergschrund of the Dent Blanche, I suppose, at a height of about 12,000 feet above the level of the sea. Our work may be said to have commenced at that point. The face, although not steep in its general inclination, was so cut up by little ridges and cliffs, and so seamed with incipient couloirs, that it had all the difficulty of a much more precipitous slope. The difficulties were never great, but they were numerous, and made a very respectable total when put together. We passed the bergschrund soon after nine in the morning, and during the next eleven hours halted only five-and-forty minutes. The whole of the remainder of the time was occupied in ascending and descending the 2400 feet which compose this south-western face; and inasmuch as 1000 feet per hour (taking the mean of ascent and descent) is an ordinary rate of progression, it is tolerably certain that the Dent Blanche is a mountain of exceptional difficulty. The hindrances opposed to us by the mountain itself were, however, as nothing compared with the atmospheric obstructions. It is true there was plenty of, “Are you fast, Almer?” “Yes.” “Go ahead, Biener.” Biener, made secure, cried, “Come on, sir,” and _Monsieur_ endeavoured. “No, no,” said Almer, “not there,—_here_,”—pointing with his bâton to the right place to clutch. Then ’twas Croz’s turn, and we all drew in the rope as the great man followed. “Forwards” once more—and so on. Five hundred feet of this kind of work had been accomplished when we were saluted (not entirely unexpectedly) by the first gust of a hurricane which was raging above. The day was a lovely one for dwellers in the valleys, but we had, long ago, noted some light, gossamer clouds, that were hovering round our summit, being drawn out in a suspicious manner into long, silky threads. Croz, indeed, prophesied before we had crossed the schrund, that we should be beaten by the wind, and had advised that we should return. But I had retorted, “No, my good Croz, you said just now ‘Dent Blanche is best’; we must go up the Dent Blanche.” I have a very lively and disagreeable recollection of this wind. Upon the outskirts of the disturbed region it was only felt occasionally. It then seemed to make rushes at one particular man, and when it had discomfited him, it whisked itself away to some far-off spot, only to return, presently, in greater force than before.