but he added, alluding to your last attack on the mountain, "Wir waren fünf; der Professor und ich stimmten für Vorwärts; die drei andern stimmten dagegen."

'There is one circumstance in reference to my fall with the avalanche of the Haut de Cry that I am utterly unable to understand: I mean what physical phenomena took place when the avalanche stopped and froze. It stopped because in its progress downwards the broad couloir down which it was going got narrower, and the mass of snow could not pass. It froze because the successive portions of the body of the avalanche became compressed against the head, which latter had come to a stop. When the layer in which I was stopped, the pressure on my body was enormous-so great, in fact, that I expected I should be crushed flat. This pressure ceased suddenly: I know it, for the atrocious pains it was causing ceased suddenly too. What happened during that interval?'

[Bennen was well acquainted with winter snow; but no man of his temper, and in his position, would place himself in direct opposition to local guides, whose knowledge of the mountain must have been superior to his own.]

XIX.

ACCIDENT ON THE PIZ MORTERATSCH.

WHILE staying at Pontresina in 1864 I joined Mr. Hutchinson, and Mr. Lee-Warner, of Rugby, in a memorable expedition up the Piz Morteratsch. This is a very noble mountain, and, as we thought, safe and easy to ascend. The resolute Jenni, by far the boldest man in Pontresina, was my guide; while Walter, the official guide chef, was taken by my companions. With a dubious sky overhead, we started on the morning of July 30, a little after four A.M. There is rarely much talk at the beginning of a mountain excursion: you are either sleepy or solemn so early in the day. Silently we passed through the pine woods of the beautiful Rosegg valley, watching anxiously at intervals the play of the clouds around the adjacent heights. At one place a spring gushed from the valley-bottom, as clear and almost as copious as that which pours out the full-formed river Albula. The traces of ancient

glaciers were present everywhere, the valley being thickly covered with the rubbish which the ice had left behind. An ancient moraine, so large that in England it might take rank as a mountain, forms a barrier across the upper valley. Once probably it was the dam of a lake, but it is now cut through by the river which rushes from the Rosegg glacier. These works of the ancient ice are to the mind what a distant horizon is to the eye. They give to the imagination both pleasure and repose.

The morning, as I have said, looked threatening, but the wind was good; by degrees the cloud-scowl relaxed, and broader patches of blue became visible above us. We called at the Rosegg chalets, and had some milk. We afterwards wound round a shoulder of the hill, at times upon the moraine of the glacier, and at times upon the adjacent grass slope; then over shingly inclines, covered with the shot rubbish of the heights. Two ways were now open to us, the one easy but circuitous, the other stiff but short. Walter was for the former, and Jenni for the latter, their respective choices being characteristic of the two men. To my satisfaction Jenni prevailed, and we scaled the steep and slippery rocks. At the top of them we found ourselves upon the rim of an extended snow-field. Our rope was here exhibited, and we were bound by it to a common destiny. In those higher regions the snow-fields

show a beauty and a purity of which persons who linger low down have no notion. We crossed crevasses and bergschrunds, mounted vast snowbasses, and doubled round walls of ice with long stalactites pendent from their eaves. One by one the eminences were surmounted. The crowning rock was attained at half-past twelve. On it we uncorked a bottle of champagne; mixed with the pure snow of the mountain, it formed a beverage, and was enjoyed with a gusto, which the sybarite of the city could neither imitate nor share.

We spent about an hour upon the warm gneissblocks on the top. Veils of cloud screened us at intervals from the sun, and then we felt the keenness of the air; but in general we were cheered and comforted by the solar light and warmth. The shiftings of the atmosphere were wonderful. The white peaks were draped with opalescent clouds which never lingered for two consecutive minutes in the same position. Clouds differ widely from each other in point of beauty, but I had hardly seen them more beautiful than they appeared to-day, while the succession of surprises experienced through their changes were such as rarely fall to the lot even of an experienced mountaineer.

These clouds are for the most part produced by the chilling of the air through its own expansion. When thus chilled, the aqueous vapour diffused

through it, which is previously unseen, is precipitated in visible particles. Every particle of the cloud has consumed in its formation a little polyhedron of vapour, and a moment's reflection will make it clear that the size of the cloud-particles must depend, not only on the size of the vapour polyhedron, but on the relation of the density of the vapour to that of its liquid. If the vapour were light and the liquid heavy, other things being equal, the cloud-particle would be smaller than if the vapour were heavy and the liquid light. There would evidently be more shrinkage in the one case than in the other. Now there are various liquids whose weight is not greater than that of water, while the weight of their vapours, bulk for bulk, is five or six times that of aqueous vapour. When those heavy vapours are precipitated as clouds, which is easily done artificially, their particles are found to be far coarser than those of an aqueous cloud. Indeed water is without a parallel in this particular. Its vapour is the lightest of all vapours, and to this fact the soft and tender beauty of the clouds of our atmosphere is mainly due.'

After an hour's halt upon the summit the descent began. Jenni is the most daring man and powerful character among the guides of Pontresina. The manner in which he bears down all the others 1 Chapter V., p. 405, is devoted to Clouds.' See also note, p. 82.

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