Part 13
In descending we went straight down upon a bergschrund, which had compelled us to make a circuit in coming up. This particular kind of fissure is formed by the lower portion of a snow-slope falling away from the upper, a crevasse being thus formed between both, which often surrounds the mountain as a fosse of terrible depth. Walter was the first of our party, and Jenni was the last. It was quite evident that the leader hesitated to cross the chasm; but Jenni came forward, and half by expostulation, half by command, caused him to sit down on the snow at some height above the fissure. I think, moreover, he helped him with a shove. At all events, the slope was so steep that the guide shot down it with an impetus sufficient to carry him clear over the schrund. We all afterwards shot the chasm in this pleasant way. Jenni was behind. Deviating from our track, he deliberately chose the widest part of the chasm, and shot over it, lumbering like behemoth down the snow-slope at the other side. It was an illustration of that practical knowledge which long residence among the mountains can alone impart, and in the possession of which our best English climbers fall far behind their guides.
The remaining steep slopes were also descended by glissade, and we afterwards marched cheerily over the gentler inclines. We had ascended by the Rosegg glacier, and now we wished to descend upon the Morteratsch glacier and make it our highway home.
We reached the point at which it was necessary to quit our morning’s track, and immediately afterwards got upon some steep rocks, rendered slippery here and there by the water which trickled over them. To our right was a broad couloir, filled with snow, which had been melted and refrozen, so as to expose a steeply sloping wall of ice. We were tied together in the following order: Jenni led, I came next, then Mr. Hutchinson, a practised mountaineer, then Mr. Lee-Warner, and last of all the guide Walter. Lee-Warner had had but little experience of the higher Alps, and he was placed in front of Walter, so that any false step on his part might be instantly checked.
After descending the rocks for a time Jenni turned and asked me whether I thought them or the ice-slope the better track. I pronounced without hesitation in favour of the rocks, but he seemed to misunderstand me, and turned towards the couloir. I stopped him at the edge of it, and said, ‘Jenni, you know where you are going; the slope is pure ice.’ He replied, ‘I know it; but the ice is quite bare for a few yards only. Across this exposed portion I will cut steps, and then the snow which covers the ice will give us a footing.’ He cut the steps, reached the snow, and descended carefully along it, all following him, apparently in good order. After some time he stopped, turned, and looked upwards at the last three men. ‘Keep carefully in the steps, gentlemen,’ he said; ‘a false step here might detach an avalanche.’ The word was scarcely uttered when I heard the sound of a fall behind me, then a rush, and in a moment my two friends and their guide, all apparently entangled together, whirred past me. I suddenly planted myself to resist their shock, but in an instant I was in their wake, for their impetus was irresistible. A moment afterwards Jenni was whirled away, and thus, in the twinkling of an eye, all five of us found ourselves riding downwards with uncontrollable speed on the back of an avalanche which a single slip had originated.
Previous to stepping on the slope, I had, according to habit, made clear to my mind what was to be done in case of mishap; and accordingly, when overthrown, I turned promptly on my face and drove my bâton through the moving snow, and into the ice underneath. No time, however, was allowed for the break’s action; for I had held it firmly thus for a few seconds only, when I came into collision with some obstacle and was rudely tossed through the air, Jenni at the same time being shot down upon me. Both of us here lost our bâtons. We had been carried over a crevasse, had hit its lower edge, and, instead of dropping into it, were pitched by our great velocity far beyond it. I was quite bewildered for a moment, but immediately righted myself, and could see the men in front of me half buried in the snow, and jolted from side to side by the ruts among which we were passing. Suddenly I saw them tumbled over by a lurch of the avalanche, and immediately afterwards found myself imitating their motion. This was caused by a second crevasse. Jenni knew of its existence and plunged, he told me, right into it--a brave act, but for the time unavailing. By jumping into the chasm he thought a strain might be put upon the rope sufficient to check the motion. But, though over thirteen stone in weight, he was violently jerked out of the fissure and almost squeezed to death by the pressure of the rope.
A long slope was below us, which led directly downwards to a brow where the glacier fell precipitously. At the base of the declivity the ice was cut by a series of profound chasms, towards which we were rapidly borne. The three foremost men rode upon the forehead of the avalanche, and were at times almost wholly immersed in the snow; but the moving layer was thinner behind, and Jenni rose incessantly and with desperate energy drove his feet into the firmer substance underneath. His voice, shouting ‘Halt! Herr Jesus, halt!’ was the only one heard during the descent. A kind of condensed memory, such as that described by people who have narrowly escaped drowning, took possession of me, and my power of reasoning remained intact. I thought of Bennen on the Haut de Cry, and muttered, ‘It is now my turn.’ Then I coolly scanned the men in front of me, and reflected that, if their _vis viva_ was the only thing to be neutralised, Jenni and myself could stop them; but to arrest both them and the mass of snow in which they were caught was hopeless. I experienced no intolerable dread. In fact, the start was too sudden and the excitement of the rush too great to permit of the development of terror.
Looking in advance, I noticed that the slope, for a short distance, became less steep, and then fell as before. ‘Now or never we must be brought to rest.’ The speed visibly slackened, and I thought we were saved. But the momentum had been too great: the avalanche crossed the brow and in part regained its motion. Here Hutchinson threw his arm round his friend, all hope being extinguished, while I grasped my belt and struggled to free myself. Finding this difficult, from the tossing, I sullenly resumed the strain upon the rope. Destiny had so related the downward impetus to Jenni’s pull as to give the latter a slight advantage, and the whole question was whether the opposing force would have sufficient time to act. This was also arranged in our favour, for we came to rest so near the brow that two or three seconds of our average motion of descent must have carried us over. Had this occurred, we should have fallen into the chasms, and been covered up by the tail of the avalanche. Hutchinson emerged from the snow with his forehead bleeding, but the wound was superficial; Jenni had a bit of flesh removed from his hand by collision against a stone; the pressure of the rope had left black welts on my arms; and we all experienced a tingling sensation over the hands, like that produced by incipient frostbite, which continued for several days. This was all. I found a portion of my watch-chain hanging round my neck, another portion in my pocket; the watch was gone.
This happened on the 30th of July. Two days afterwards I went to Italy, and remained there for ten or twelve days. On the 16th of August, being again at Pontresina, I made on that day an expedition in search of the lost watch. Both the guides and myself thought the sun’s heat might melt the snow above it, and I inferred that if its back should happen to be uppermost the slight absorbent power of gold for the solar rays would prevent the watch from sinking as a stone sinks under like circumstances. The watch would thus be brought quite to the surface; and, although a small object, it might possibly be seen from some distance. Five friends accompanied me up the Morteratsch glacier. One of them was the late Mr. North, member for Hastings, a most lovable man. He was then sixty-four years of age, but he exhibited a courage and collectedness, and indeed a delight, in the wild savagery of the crevasses which were perfectly admirable.
Two only of the party, both competent mountaineers, accompanied me to the track of our glissade, but none of us ventured on the ice where it originated. Just before stepping upon the snow, a stone some tons in weight, detached by the sun from the heights above us, came rushing down the line of our descent. Its leaps became more and more impetuous, and on reaching the brow near which we had been brought to rest it bounded through the air, and with a single spring reached the lower glacier, raising a cloud of ice-dust. Some fragments of rope found upon the snow assured us that we were upon the exact track of the avalanche, and then the search commenced. It had not continued twenty minutes when a cheer from one of the guides--Christian Michel of Grindelwald--announced the discovery of the watch. It had been brought to the surface in the manner surmised, and on examination seemed to be dry and uninjured. I noticed, moreover, that the position of the hands indicated that it had only run down beneath the snow. I wound it up, hardly hoping, however, to find it capable of responding. But it showed instant signs of animation. It had remained eighteen days in the avalanche, but the application of its key at once restored it to action, and it has gone with unvarying regularity ever since.
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Mr. Hutchinson has published the following note of the accident in the ‘Alpine Journal’:
‘As one of the party concerned in the accident on the Piz Morteratsch last July, I trust I shall not be thought presumptuous in bearing my testimony to the entire accuracy of Professor Tyndall’s account. I can add no facts of any importance to those there mentioned, unless it be that we estimated the distance down which we were carried at fully 1,000 feet--a conclusion which, Mr. Tyndall tells me, was confirmed by his subsequent visit to the spot. The angle of the slope we did not measure, nor can I give the time of our descent with any accuracy; it seemed to me a lifetime. From the moment that the snow cracked, Jenni behaved with the greatest coolness and courage. But he ought not to have taken us down the ice-slope so late in the day--it was then nearly half-past two o’clock--and that after a warning word from Professor Tyndall and myself. Of Walter’s conduct the less said the better; our opinion of his courage was not raised by this trial of it.’
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[Until Mr. Gossett’s letter reached me a few days ago I was not aware of the singular likeness between the loss of Bennen’s watch and of my own.--April 1871.]
XX.
_ALPINE SCULPTURE._
To the physical geologist the conformation of the Alps, and of mountain-regions generally, constitutes one of the most interesting problems of the present day. To account for this conformation, two hypotheses have been advanced, which may be respectively named the hypothesis of _fracture_ and the hypothesis of _erosion_. Those who adopt the former maintain that the forces by which the Alps were elevated produced fissures in the earth’s crust, and that the valleys of the Alps are the tracks of these fissures. Those who hold the latter hypothesis maintain that the valleys have been cut out by the action of ice and water, the mountains themselves being the residual forms of this grand sculpture. To the erosive action here indicated must be added that due to the atmosphere (the severance and detachment of rocks by rain and frost), as affecting the forms of the more exposed and elevated peaks.
I had heard it stated that the Via Mala was a striking illustration of the fissure theory--that the profound chasm thus named, and through which the Hinter-Rhein now flows, could be nothing else than a crack in the earth’s crust. To the Via Mala I therefore went in 1864 to instruct myself by actual observation upon the point in question.
The gorge commences about a quarter of an hour above Tusis; and, on entering it, the first conclusion is that it must be a fissure. This conclusion in my case was modified as I advanced. Some distance up the gorge I found upon the slopes to my right quantities of rolled stones, evidently rounded by water-action. Still further up, and just before reaching the first bridge which spans the chasm, I found more rolled stones, associated with sand and gravel. Through this mass of detritus, fortunately, a vertical cutting had been made, which exhibited a section showing perfect stratification. There was no agency in the place to roll these stones, and to deposit these alternating layers of sand and pebbles, but the river which now rushes some hundreds of feet below them. At one period of the Via Mala’s history the river must have run at this high level. Other evidences of water-action soon revealed themselves. From the parapet of the first bridge I could see the solid rock 200 feet above the bed of the river scooped and eroded.
It is stated in the guide-books that the river, which usually runs along the bottom of the gorge, has been known almost to fill it during violent thunderstorms; and it may be urged that the marks of erosion which the sides of the chasm exhibit are due to those occasional floods. In reply to this, it may be stated that even the existence of such floods is not well authenticated, and that if the supposition were true, it would be an additional argument in favour of the cutting power of the river. For if floods operating at rare intervals could thus erode the rock, the same agency, acting without ceasing upon the river’s bed, must certainly be competent to excavate it.
I proceeded upwards, and from a point near another bridge (which of them I did not note) had a fine view of a portion of the gorge. The river here runs at the bottom of a cleft of profound depth, but so narrow that it might be leaped across. That this cleft must be a crack is the impression first produced; but a brief inspection suffices to prove that it has been cut by the river. From top to bottom we have the unmistakable marks of erosion. This cleft was best seen by looking downwards from a point near the bridge; but looking upwards from the bridge itself, the evidence of aqueous erosion was equally convincing.
The character of the erosion depends upon the rock as well as upon the river. The action of water upon some rocks is almost purely mechanical; they are simply ground away or detached in sensible masses. In other cases the action is chemical as well as mechanical. Water, in passing over limestone, charges itself with carbonate of lime without damage to its transparency; the rock is _dissolved_ in the water; and the gorges cut by water in such rocks often resemble those cut in the ice of glaciers by glacier streams. To the solubility of limestone is probably to be ascribed the fantastic forms which peaks of this rock usually assume, and also the grottos and caverns which interpenetrate limestone formations. A rock capable of being thus dissolved will expose a smooth surface after the water has quitted it; and in the case of the Via Mala it is the polish of the surfaces, and also the curved hollows scooped in the sides of the gorge, which assure us that the chasm has been the work of the river.
About four miles from Tusis, and not far from the little village of Zillis, the Via Mala opens into a plain bounded by high terraces, evidently cut by water. It occurred to me the moment I saw it that the plain had been the bed of an ancient lake; and a farmer, who was my temporary companion, immediately informed me that such was the tradition of the neighbourhood. This man conversed with intelligence, and as I drew his attention to the rolled stones, which rest not only above the river, but above the road, and inferred that the river must have been there to have rolled those stones, he saw the force of the evidence perfectly. In fact, in former times, and subsequent to the retreat of the great glaciers, a rocky barrier crossed the valley at this place, damming the river which came from the glaciers higher up. A lake was thus formed which poured its waters over the barrier. Two actions were here at work, both tending to obliterate the lake--the raising of its bed by the deposition of detritus, and the cutting of its dam by the river. In process of time the cut deepened into the Via Mala; the lake was drained, and the river now flows in a definite channel through the plain which its waters once totally covered.
From Tusis I crossed to Tiefenkasten by the Schien Pass, and thence over the Julier Pass to Pontresina. There are three or four ancient lake-beds between Tiefenkasten and the summit of the Julier. They are all of the same type--a more or less broad and level valley-bottom, with a barrier in front through which the river has cut a passage, the drainage of the lake being the consequence. These lakes are sometimes dammed by barriers of rock, sometimes by the moraines of ancient glaciers.
An example of this latter kind occurs in the Rosegg valley, about twenty minutes below the end of the Rosegg glacier, and about an hour from Pontresina. The valley here is crossed by a pine-covered moraine of the noblest dimensions: in the neighbourhood of London it might be called a mountain. That it is a moraine, the inspection of it from a point on the Surlei slopes above it will convince any person possessing an educated eye. Where, moreover, the interior of the mound is exposed, it exhibits moraine-matter--detritus pulverised by the ice, with boulders entangled in it. It stretched quite across the valley, and at one time dammed the river up. But now the barrier is cut through, the stream having about one-fourth of the moraine to its right, and the remaining three-fourths to its left. Other moraines of a more resisting character hold their ground as barriers to the present day. In the Val di Campo, for example, about three-quarters of an hour from Pisciadello, there is a moraine composed of large boulders, which interrupt the course of a river and compel the water to fall over them in cascades. They have in great part resisted its action since the retreat of the ancient glacier which formed the moraine. Behind the moraine is a lake-bed, now converted into a meadow, which is quite level, and rests on a deep layer of mould.
At Pontresina a very fine and instructive gorge is to be seen. The river from the Morteratsch glacier rushes through a deep and narrow chasm which is spanned at one place by a stone bridge. The rock is not of a character to preserve smooth polishing; but the larger features of water-action are perfectly evident from top to bottom. Those features are in part visible from the bridge, but still better from a point a little distance from the bridge in the direction of the upper village of Pontresina. The hollowing out of the rock by the eddies of the water is here quite manifest. A few minutes’ walk upwards brings us to the end of the gorge; and behind it we have the usual indications of an ancient lake, and terraces of distinct water origin.
From this position the genesis of the gorge is clearly revealed. After the retreat of the ancient glacier, a transverse ridge of comparatively resisting material crossed the valley at this place. Over the lowest part of this ridge the river flowed, rushing steeply down to join at the bottom of the slope the stream which issued from the Rosegg glacier. On this incline the water became a powerful eroding agent, and finally cut its channel to its present depth.
Geological writers of reputation assume at this place the existence of a fissure, the ‘washing out’ of which resulted in the formation of the gorge. Now no examination of the bed of the river ever proved the existence of this fissure; and it is certain that water can cut a channel through unfissured rock--that cases of deep cutting can be pointed out where the clean bed of the stream is exposed, the rock which forms the floor of the river not exhibiting a trace of fissure. An example of this kind occurs near the Bernina Gasthaus, about two hours from Pontresina. A little way below the junction of the two streams from the Bernina Pass and the Heuthal the river flows through a channel cut by itself, and 20 or 30 feet in depth. At some places the river-bed is covered with rolled stones; at other places it is bare, but shows no trace of fissure. The abstract power of water (if I may use the term) to cut through rock is demonstrated by such instances. But if water be competent to form a gorge without the aid of a fissure, why assume the existence of such in cases like that at Pontresina? It seems far more philosophical to accept the simple and impressive history written on the walls of those gorges by the agent which produced them.
Numerous cases might be pointed out, varying in magnitude, but all identical in kind, of barriers which crossed valleys and formed lakes having been cut through by rivers, narrow gorges being the consequence. One of the most famous examples of this kind is the Finsteraarschlucht in the valley of Hasli. Here the ridge called the Kirchet seems split across, and the river Aar rushes through the fissure. Behind the barrier we have the meadows and pastures of Imhof resting on the sediment of an ancient lake. Were this an isolated case, one might reasonably conclude that the Finsteraarschlucht was produced by an earthquake, as some suppose it to have been; but when we find it to be a single sample of actions which are frequent in the Alps--when probably a hundred cases of the same kind, though different in magnitude, can be pointed out--it seems quite unphilosophical to assume that in each particular case an earthquake was at hand to form a channel for the river. As in the case of the barrier at Pontresina, the Kirchet, after the retreat of the Aar glacier, dammed the waters flowing from it, thus forming a lake, on the bed of which now stands the village of Imhof. Over this barrier the Aar tumbled towards Meyringen, cutting, as the centuries passed, its bed ever deeper, until finally it became deep enough to drain the lake, leaving in its place the alluvial plain, through which the river now flows in a definite channel.[20]
[20] For further observations see p. 256.
But the broad view taken by the advocates of the fracture theory is, that the valleys are the tracks of primeval fissures produced by the upheaval of the land, and the cracks across the barriers to which I have referred are in reality portions of the great cracks which formed the valleys. Such an argument, however, would virtually concede the theory of erosion as applied to the _valleys_ of the Alps. The narrow gorges, often not more than twenty or thirty feet across, sometimes even narrower, frequently occur at the bottom of broad valleys. Such fissures might enter into the list of accidents which gave direction to the real erosive agents which scooped the valley out; but the formation of the valley, as it now exists, could no more be ascribed to it than the motion of a railway train could be ascribed to the finger of the engineer which turns on the steam.