Part 6
The difference in texture exhibited by different clouds caused me to look a little more closely than I had previously done into the mechanism of cloud-formation. A certain expansion is necessary to bring down the cloud; the moment just before precipitation the cooling air and vapour may be regarded as divided into a number of polyhedra, the particles along the bounding surfaces of which move in opposite directions when precipitation actually sets in. Every cloud-particle has consumed a polyhedron of vapour in its formation; and it is manifest that the size of the particle must depend, not only on the size of the vapour polyhedron, but also 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; these considerations were found valid throughout the experiments; the case of toluol may be taken as representative of a great number of others. The specific gravity of this liquid is 0.85, that of water being unity; the specific gravity of its vapour is 3.26, that of aqueous vapour being 0.6. Now, as the size of the cloud-particle is directly proportional to the specific gravity of the vapour, and inversely proportional to the specific gravity of the liquid, an easy calculation proves that, assuming the size of the vapour polyhedra in both cases to be the same, the size of the particle of toluol cloud must be more than six times that of the particle of aqueous cloud. It is probably impossible to test this question with numerical accuracy; but the comparative coarseness of the toluol cloud is strikingly manifest to the naked eye. The case is, as I have said, representative.
In fact, aqueous vapour is without a parallel in these particulars; it is not only the lightest of all vapours, in the common acceptation of that term, but the lightest of all gases except hydrogen and ammonia. To this circumstance the soft and tender beauty of the clouds of our atmosphere is mainly to be ascribed.
The _sphericity_ of the cloud-particles may be immediately inferred from their deportment under the luminous beams. The light which they shed when spherical is _continuous_: but clouds may also be precipitated in solid flakes; and then the incessant sparkling of the cloud shows that its particles are _plates_, and not spheres. Some portions of the same cloud may be composed of spherical particles, others of flakes, the difference being at once manifested through the _calmness_ of the one portion of the cloud, and the _uneasiness_ of the other. The sparkling of such flakes reminded me of the plates of mica in the River Rhone at its entrance into the Lake of Geneva when shone upon by a strong sun.--_Proceedings of the Royal Society_, vol. xvii. p. 317.
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Clouds are so often referred to in these pages that I thought it might be of interest to note the latest remarks on their formation.
VIII.
_THE BEL ALP._
On Tuesday the 13th I accompanied a party of friends to the Märjelin See, skirted the lake, struck in upon the glacier, and having heard much of the position and the comfort of a new hotel upon the Bel Alp, I resolved to descend the glacier and pay the place a visit. The Valais range had been covered before we quitted the Æggischhorn; and, though the sun rode unimpeded in the higher heavens, vast masses of cloud continued to thrust themselves forth like tree-branches into the upper air.
The clouds extended, becoming ever blacker, until finally they were unlocked by thunder, and shook themselves down upon us in furious rain. The glacier is here cut up into oblique valleys of ice, subdivided by sharp-edged crevasses. We advanced swiftly along the ridges, but these finally abutted against the mountain, and we were compelled to cross from ridge to ridge. Hirst followed Bennen, and I trusted to my own devices. Joyously we struck our axes into the crumbling crests, and made our way rapidly between the chasms. The sunshine gushed down upon us, and partially dried our drenched clothes. At some distance to our left we observed upon the ice a group of persons, consisting of two men, a boy, and an old woman, engaged beside a crevasse; a thrill of horror shot through me, at the thought of a man being possibly between its jaws. We quickly joined them, and found an unfortunate cow firmly jammed between the frozen sides of the fissure, and groaning piteously. The men seemed very helpless; their means were inadequate, and their efforts ill-directed. ‘Give the brute space, cut away the ice which presses the ribs, and _you_ step upon that block which stops the chasm, and apply your shoulders to the creature’s buttocks.’ The ice splinters fly aloft, under the vigorous strokes of Bennen. Hirst suggests that a rope should be passed round the horns, so as to enable all hands to join in the pull. This is done. Another rope is passed between the hind legs. Bennen has loosened the ice which held the ribs in bondage, and now, like mariners heaving an anchor, we all join in a tug, timing our efforts by an appropriate exclamation. The weight moves, but extremely little; again the cry, and again the heave--it moves a little more. This is repeated several times till the fore-legs are extricated and thrown forward on the ice. We now lift the hinder parts, and succeed in placing the animal upon the glacier, panting and trembling all over. Folding our rope, we went onward. The day again darkened. Again the thunder rang, being now preceded by lightning, which was thrown into my eyes from the polished surface of my axe. Flash followed flash and peal succeeded peal with terrific grandeur, and the loaded clouds sent down from all their fringes dusky streamers of rain. They looked like waterspouts, so dense was their texture. Furious as was the descending shower, hard as we were hit by the mixed pellets of ice and water, I enjoyed the scene. Grandly the cloud-besom swept the mountains, their colossal outlines looming at intervals like overpowered Titans struggling against their doom.
The glacier becoming impracticable through crevasses, we retreated to its eastern shore, and got along the lateral moraine. It was rough work. The slope to our left was partially clothed with spectral pines. Storms had stripped the trunks of their branches, and the branches of their leaves, leaving the tree-wrecks behind, as if spirit-stricken and accursed. Our home is now in sight, perched upon the summit of a bluff opposite. We passed swiftly over the ridges towards our destination. Wet and thirsty, we reached the opposite side, and, striking into a beaten track, finally reached the pleasant auberge at which our journey ends.
From the hotel on the slope of Æggischhorn an hour’s ascent is required to place you in presence of the magnificent view from the summit. But the very windows of the hotel upon the Bel Alp command noble views, and you may sit upon the bilberry slopes adjacent before the grandest of mountain scenes. On the 14th I went down to the savage gorge in which the Aletsch glacier ends. A pine tree stood sheer over it; bending its trunk at a right angle near its root, and grasping a rock with its root, it supported itself above the chasm. Standing upon the horizontal part of the tree, I hugged its upright stem, and looked down into the gorge. It required several minutes to chase away my timidity, and as the wind blew more forcibly against me, I clung with greater fixity to the tree. In this wild spot, and alone, I watched the dying fires of the day, until the latest glow had vanished from the mountains.
Above the Bel Alp, and two hours distant, is the grey pinnacle of the Sparrenhorn. I went up there on the 15th. To the observer from the hotel it appears as an isolated peak; but it forms the lofty end of a narrow ridge, which is torn into ruins by the weather. At a distance in front of me was a rocky promontory like the Abschwung, right and left of which descended two streams of ice, which welded themselves to a common trunk glacier. The scene was perfectly unexpected and strikingly beautiful. Nowhere have I seen more perfect repose, nowhere more tender curves or finer structural lines. The stripes of the moraine bending along the glacier contribute to its beauty, and its deep seclusion gives it a peculiar charm. It seems a river so protected by its bounding mountains that no storm can ever reach it, and no billow disturb the perfect serenity of its rest. The sweep of the Aletsch glacier is also mighty as viewed from this point, and from no other could the Valais range seem more majestic. It is needless to say a word about the grandeur of the Dom, the Cervin, and the Weisshorn, all of which, and a great deal more, are commanded from the Sparrenhorn.
IX.
_THE WEISSHORN._
On Friday the 16th of August I rose at 4.30; the eastern heaven was hot with the glow of the rising sun, and against it were drawn the mountain outlines. At 5.30 I bade good-bye to the excellent little auberge of the Bel Alp,[9] and went straight down the mountain to Briegg, took the diligence to Visp, and engaged a porter immediately to Randa. I had sent Bennen thither to inspect the Weisshorn. On my arrival I learned that he had made the necessary reconnaissance, and entertained hopes of our being able to gain the top.
[9] Now a substantial hotel which merits encouragement.
This noble mountain, which is fourteen thousand eight hundred feet high, had been tried on various occasions and from different sides by brave and competent climbers, but all efforts had been hitherto unavailing.
Previous to quitting Randa to assail this formidable peak I had two pairs of rugs sewed together so as to form two sacks. These and other coverlets, together with our wine and provisions, were sent on in advance of us. At 1 P.M. on the 18th of August Bennen, Wenger, and myself quitted the hotel, and were soon zigzagging among the pines of the opposite mountain. Wenger had been the guide of my friend Forster, and had shown himself so active and handy on the Strahleck that I commissioned Bennen to engage him. During the previous night I had been very unwell, and as I climbed the slope I suffered from intense thirst. Water seemed powerless to quench the desire for drink. We reached a chalet, and at our request a smart young Senner caught up a pail, and soon returned with it full of delicious milk. The effect of the milk was astonishing. It seemed to lubricate every atom of my body, and to exhilarate with its fragrance my brain.
Two hours’ additional climbing brought us to our bivouac, a ledge of rock which jutted from the mountain-side, and formed an overhanging roof. On removing the stones from beneath the ledge, a space of comparatively dry clay was laid bare. This was to be my bed, and to soften it Wenger considerately stirred it up with his axe. The position was excellent, for lying upon my left side I commanded the whole range of Monte Rosa, from the Mischabel to the Breithorn. We were on the edge of an amphitheatre. Beyond the Schallenbach was the stately Mettelhorn. A row of eminences swept round to the right linked by lofty ridges of cliffs, which embraced the Schallenberg glacier. They formed, however, only a spur of the vaster Weisshorn, the cone of which was not visible from our dormitory. In company with Bennen I afterwards skirted the mountain until the whole colossal pyramid stood facing us. When I first looked at it my hopes sank, but both of us gathered confidence from a more lengthened gaze. The mountain is a pyramid with three faces, the intersections of which form three sharp edges or _arêtes_. The end of the eastern ridge was nearest to us, and on it our attention was principally fixed. We finally decided on the route to be pursued next morning, and with a chastened hope in both our breasts we returned to our shelter.
Water was our first necessity: it seemed everywhere, but there was none to drink. It was locked to solidity in the ice and snow. The sound of it came booming up from the Vispbach, as it broke into foam or rolled its boulders over its waterworn bed; and the swish of many a minor streamlet mingled with the muffled roar of the large one. Bennen set out in search of the precious liquid, and after a long absence returned with a jug and pan full. At our meal, Wenger, who is a man rich in small expedients, turned the section of a cheese towards the flame of our pine fire; it fizzed and blistered and turned viscous, and, the toasted surface being removed, was consumed with relish by us all. The sunset had been unspeakably grand, steeping the zenith in violet, and flooding the base of the heavens with crimson light. Immediately opposite to us rose the Mischabel, with its two great peaks, the Grubenhorn and the Täschhorn, each barely under 15,000 feet in height. Next came the Alphubel, with its flattened crown of snow; then the Allaleinhorn and Rympfischhorn; then the Cima di Jazzi; next the mass of Monte Rosa, flooded with light from bottom to top. The face of the Lyskamm turned towards us was for the most part shaded, but here and there its projecting portions jutted forth red hot as the light fell upon them. The ‘Twins’ were most singularly illuminated; across the waist of each of them was drawn a black bar, produced by the shadow of a corner of the Breithorn, while their bases and crowns were exposed to the crimson light. Over the rugged face of the Breithorn itself the light fell as if in splashes, igniting its glaciers and swathing its black crags in a layer of transparent red. The Mettelhorn was cold, so was the entire range governed by the Weisshorn, while the glaciers they embraced lay grey and ghastly in the twilight shade.
The sunlight lingered, while up the arch of the opposite heavens the moon, within one day of being full, seemed hastening to our aid. She finally appeared exactly behind the peak of the Rympfischhorn, the cone of the mountain being projected for a short time as a triangle on the lunar disc. Only for a short time, however; the silver sphere soon cleared the mountain, and bore away through the tinted sky. The motion was quite visible, and resembled that of a vast balloon. As the day approached its end the scene assumed the most sublime aspect. All the lower portions of the mountains were deeply shaded, while the loftiest peaks, ranged upon a semicircle, were fully exposed to the sinking sun. They seemed pyramids of solid fire, while here and there long stretches of crimson light drawn over the higher snow-fields linked the summits together. An intensely illuminated geranium flower seems to swim in its own colour, which apparently surrounds the petals like a layer, and defeats by its lustre any attempt of the eye to seize upon the sharp outline of the leaves. A similar effect was here observed upon the mountains; the glory did not seem to come from them alone, but seemed also effluent from the air around them. As the evening advanced, the eastern heavens low down assumed a deep purple hue, above which, and blending with it by infinitesimal gradations, was a belt of red, and over this again zones of orange and violet. I walked round the corner of the mountain at sunset, and found the western sky glowing with a more transparent crimson than that which overspread the east. The crown of the Weisshorn was imbedded in this magnificent light. After sunset the purple of the east changed to a deep neutral tint, and against the faded red which spread above it the sun-forsaken mountains laid their cold and ghastly heads. The ruddy colour vanished more and more; the stars strengthened in lustre, until finally the moon and they held undisputed possession of the sky.
My face was turned towards the moon until it became so chilled that I was forced to protect it by a light handkerchief. The power of blinding the eyes is ascribed to the moonbeams, but the real mischief is that produced by radiation from the eyes into clear space, and the inflammation consequent upon the chill. As the cold increased I was fain to squeeze myself more and more underneath the ledge, so as to lessen the space of sky against which my body could radiate. Nothing could be more solemn than the night. Up from the valley came the low thunder of the Vispbach. Over the Dom flashed in succession the stars of Orion, until finally the entire constellation hung aloft. Higher up in heaven was the moon, and her beams as they fell upon the snow-fields and pyramids were sent back in silvery lustre by some, while others remained a dead white. These, as the earth twirled round, came duly in for their share of the glory. The Twins caught it at length and retained it long, shining with a pure spiritual radiance, while the moon continued above the hills.
At twelve o’clock I looked at my watch, and a second time at 2 A.M. The moon was then just touching the crest of the Schallenberg, and we were threatened with the withdrawal of her light. This soon occurred. We rose at 2-1/4 A.M., consumed our coffee, and had to wait idly for the dawn. A faint illumination at length overspread the sky, and with this promise of the coming day we quitted our bivouac at 3-1/2 A.M. No cloud was to be seen; as far as the weather was concerned we were sure to have fair play. We rounded the shingly shoulder of the mountain to the edge of a snow-field, but before entering upon it I disburthened myself of my strong shooting jacket, leaving it on the mountain-side. The sunbeams and my own exertion would, I knew, keep me only too warm during the day. We crossed the snow, cut our way through a piece of entangled glacier, reached the Bergschrund, and passed it without a rope. We ascended the frozen snow of the couloir by steps, but soon diverged from it to the rocks at our right, and mounted them to the end of the eastern _arête_ of the mountain.
A snow saddle separated us from the higher rocks. With our staff-pikes at one side of the saddle, we pass by steps cut upon the other. We find the rocks hewn into fantastic turrets and obelisks, while the loose chips of this sculpture are strewn confusedly upon the ridge. Amid these we cautiously pick our way, winding round the towers or scaling them amain. The work was heavy from the first, the bending, twisting, reaching, and drawing up calling upon all the muscles of the frame. After two hours of this work we halted, and, looking back, saw two moving objects on the glacier below us. At first we took them to be chamois, but they were men. The leader carried an axe, and his companion a knapsack and an alpenstock. They followed our traces, losing them apparently now and then, and waiting to recover them. Our expedition had put Randa in a state of excitement, and some of its best climbers had urged Bennen to take them with him. This he did not deem necessary, and now here were two of them determined to try the thing on their own account, and perhaps to dispute with us the honour of the enterprise. On this point, however, our uneasiness was small.
Resuming our gymnastics, the rocky staircase led us to the flat summit of a tower, where we found ourselves cut off from a similar tower by a deep gap bitten into the mountain. The rope was here our refuge. Bennen coiled it round his waist; we let him down along the surface of the rock, until he fixed himself on a ledge, where he could lend me a helping hand. I followed him, and Wenger followed me. By a kind of screw motion we twisted ourselves round the opposite tower, and reached the ridge behind it. Work of this kind, however, is not to be performed by the day, and, with a view of sparing our strength, we quitted the ridge and endeavoured to get along the southern slope of the pyramid. The mountain was scarred by long couloirs, filled with clear hard ice. The cutting of steps across these couloirs proved to be so tedious and fatiguing that I urged Bennen to abandon them and try the ridge once more. We regained it and worked along it as before. Here and there upon the northern side the snow was folded over, and we worked slowly upward along the cornice snow. The ridge became gradually narrower, and the precipices on each side more sheer. We reached the end of one of its subdivisions, and found ourselves separated from the next rocks by a gap about twenty yards across. The ridge has here narrowed to a mere wall, which, however, as rock, would present no serious difficulty. But upon the wall of rock was placed a second wall of snow, which dwindled to a pure knife-edge at the top. It was white, of very fine grain, and a little moist. How to pass this snow catenary I knew not, for I did not think a human foot could trust itself upon so frail a support. Bennen’s practical sagacity, however, came into play. He tried the snow by squeezing it with his foot, and to my astonishment began to cross it. Even after the pressure of his feet the space he had to stand on did not exceed a hand-breadth. I followed him, exactly as a boy walking along a horizontal pole, with toes turned outwards. Right and left the precipices were appalling. We reached the opposite rock, and an earnest smile rippled over Bennen’s countenance as he turned towards me. He knew that he had done a daring thing, though not a presumptuous one. ’Had the snow,’ he said, ‘been less perfect, I should not have thought of attempting it; but I knew after I had set my foot upon the ridge that we might pass without fear.’
It is quite surprising what a number of things the simple observation made by Faraday in 1846 enables us to explain. Bennen’s instinctive act is justified by theory. The snow was fine in grain, pure, and moist. When pressed, the attachments of its granules were innumerable, and their perfect cleanness enabled them to freeze together with a maximum energy. It was this freezing which gave the mass its sustaining power.
Two fragments of ordinary table ice brought carefully together freeze and cement themselves at their place of junction; or if two pieces floating in water be brought together, they instantly freeze, and by laying hold of either of them gently you can drag the other after it through the water. Imagine such points of attachment distributed in great numbers through a mass of snow. The substance becomes thereby a semi-solid instead of a mass of powder. My guide, however, unaided by any theory, did a thing from which I should have shrunk, though backed by all the theories in the world.