Part 2 (1/2)

It is filled by the robbed waters of countless smaller rivers, one by one drawn within its drainage area by the action of side-streams cutting through intervening ridges. All these rivers and their tributaries go on cutting their way back with ever-increasing vigour as the trunk outlet is lowered by their united volume. This is the process whereby an original plateau is sculptured into a maze of ridges and valleys. The towering heights we behold were never elevated in isolated magnificence.

A different thrust did not send up the Matterhorn, the Weisshorn, and Monte Rosa, but all the neighbourhood was elevated by one great heaving.

To begin with, some lines of elevation were a little higher than others, and they determined the position of princ.i.p.al peaks and ridges; but as the ma.s.s was elevated the hollows were engraved by the _burin_ of flowing water. The higher the ma.s.s was raised the deeper the hollows were impressed and the wider became their opening, for the self-same forces operate on every slope and continually eat it away and open side-valleys and subsidiary side-valleys into them. These forces operating on both sides of every ridge rapidly pull down its crest and ultimately round it off and reduce it lower and lower continually, so that it is only a question of time for the biggest mountain ma.s.s to be lowered to the level of the plains around it.

Running water is not the only agent that has to be considered. Even more energetic agents act in the higher regions of frost. There the snow that is melted by the sun (whose dissolving power is as operative in the regions so-called of perpetual snow as it is below) percolates into the crevices of the rocks and finds out all their weak places. At night this water freezes, and in freezing expands, thus acting like a wedge and splitting the rock it has penetrated. Next time the sun s.h.i.+nes the pieces thus split off may fall. Sooner or later, after repeated operations of the wedge, they must fall, and a new surface of rock will be uncovered to be split and s.h.i.+vered in its turn. The rocks that fall tumble ultimately on to the snow-fields that spread over the high open s.p.a.ces, where they are taken charge of by the great carrying agents of the heights--the glaciers. The higher a peak is, relatively to its neighbours, the more rapidly will frost attack it, and the more energetic will be the destruction wrought upon it. I have heard it estimated, or perhaps only guessed, that 1000 tons of rock fall daily from the upper portion of the Matterhorn's rock-pyramid. The great peaks of the Himalaya are falling yet more rapidly to pieces.

But what in this relation is the action of the glaciers? At one time they were regarded as a great abrading agency. It was thought that the high valleys were fas.h.i.+oned out by them. Later it was concluded that their hollowing action was a negligible quant.i.ty. The general belief now is that it is not considerable. Whatever may be the action of glaciers upon their beds, it is at all events a small matter compared with their action as transporting agents. Glaciers are not h.o.a.ry acc.u.mulations of snow, collected in hollow places since the beginning of the world, as our forefathers supposed, but flowing streams of ice, whose rate of movement varies with the slope, the lat.i.tude, the mean temperature, and other factors of their situation. The snow that falls at high elevations lies in great ma.s.ses where it finds lodgment, or falls to such places from the steep rocks which are unable to give it steady support. By these means it falls and drifts together into those great upper reservoirs we call the snow-fields--resplendent areas of purest white, so toilsome to cross when the sun s.h.i.+nes hotly upon them, and so incomparably beautiful to look upon. Here by melting of the surface, percolation into the body of the snow-field, and freezing there, and by the pressure of the ever-increasing acc.u.mulation of snow, the substance is gradually changed into granulated ice, and the ice thus formed slowly moves down-hill. The various neighbouring streams of ice flow and unite together, and thus, reaching lower and lower levels and continually melting, they come to a line where the annual increment of snow is equal in amount to the depth of snow annually melted. This is called the snow-line. Still downward flows the ma.s.s, and now the amount melted becomes greater than the amount annually received. The thickness of the ice steadily diminishes till at last the total arrival melts and the glacier ends in a so-called snout.

[Ill.u.s.tration: 18. THE FALLS OF TOSA, VAL FORMAZZA. Said to be the grandest in the Alps, 470 feet high. The Tosa falls in three cascades.

The first only is shown in the picture.]

The great importance of glaciers in mountain formation is the part they play as carrying agents. There is practically no limit to the weight of rock they will bear down with them in their steady uninterrupted flow. Whatever falls upon the glacier at any part of its course is carried down by it and ultimately dumped off its sides or end.

A stone that falls on the highest rim of the snowfield will presently be covered up by newly-fallen snow and will be carried down at, or close to, the floor of the glacier, where it will either be ground to powder or will not emerge till it is melted out at the end of the glacier's snout. A stone that plunges in a creva.s.se to the bottom of the glacier will have similar experiences. Stones that tumble on to the glacier surface further down will not be so deeply covered by annual acc.u.mulations of snow, and will therefore sooner emerge again on to the surface by the melting away of the acc.u.mulation above them. Stones that fall on to the glacier below the snow-line will not be covered up at all, but will simply be carried down on the surface.

The visible collections of stone rubbish carried by a glacier are called its moraines. As the surface of a glacier tends to become convex the moraine-stuff tends to be rolled off towards the sides, where it forms the right and left lateral moraines. Where two glaciers flow together and unite, the right lateral moraine of the one and the left of the other will join and be carried down as a medial moraine on the surface of the united glacier. Such medial moraines may be observed in considerable numbers flowing down, side by side, on glaciers formed by the union of a number of higher tributaries. First comers to the Alps, beholding them from a distance, or seeing them in photographs, sometimes have thought they were cart-ruts, thus showing how false a scale of size their unaccustomed vision applies to mountain views.

A given kind of rock subjected to the action of frost and the other disintegrating forces operative at high levels, usually breaks up into debris of a roughly uniform average size. There will, of course, be some large ma.s.ses and a lot of dust and gravel, but the average lump will be fairly uniform. A climber in a given district comes to know what to expect on a moraine, and he will immediately notice if the average size of the debris is much larger or smaller than usual. Thus, when he sees a debris-slope or a moraine from a distance, he is instinctively conscious that its granulated aspect represents great blocks of rock. That gives him a roughly correct scale for the view. The lowlander, who has never been in contact with a moraine, has no such sense, and can imagine that the brown streak he sees a few miles away is, as it looks to be, a mere line of dust. It was through the aspect of the moraines and debris-slopes that I first obtained an approach to a direct visual understanding of the vaster scale of the Himalayas than that of the Alps.

A cliff below the snowy regions, if it does not rise out of the sea, is protected at its base by the debris fallen from it. What tumbles from above piles up below, and keeps the foot of the cliff from being eaten away. But a cliff or slope of rock rising out of a glacier or snow-field is deprived of such protection. All the stones that fall from it are carried away by the ice, so that the surface of the whole cliff keeps on peeling off, and that face of the mountain is gradually planed away.

Where a great glacier bay reaches into the mountains this action may be very energetic. The whole surrounding cirque is constantly eaten at and continually extends its inner circ.u.mference. In some regions this action is more rapid than in others. Where, as in the tropics, the heat is great by day and the frost at high alt.i.tudes bitter by night, destruction goes quickly forward, and the mountains are vigorously reduced. Weak points in the rocky structure are soon found out. The range itself will be penetrated. A pa.s.s thus formed tends to be continuously lowered. In the neighbourhood of the greatest alt.i.tudes the destruction is of course most vigorous. This is the reason why, in so many places, alike in the Himalayas and the Andes, cross-cutting rivers find their way through a range by a gorge that pa.s.ses quite near a culminating peak. The great Indus gorge below Nanga Parbat is the most notable instance I can recall.

We have thus, in the briefest possible manner, sketched out how some of the chief sculpturing forces operate to form mountains. I have not attempted to go into detail or to explain the various corrections and modifications that have to be applied to make the simple outline correspond with facts. Some valleys are actual depressions formed by the caving in of the earth along a line of weakness. Every mountain region contains examples of such hollows. Now and again by some complication or intersection of the wrinkling process a small area may be forced up considerably higher than the surrounding elevation and thus the ma.s.s provided for an exceptionally high peak. Volcanic peaks also remain to be considered, and have been excluded from the foregoing brief survey.

In the main, however, the statement is correct that the mountains of a region are produced by the sculpturing into ridges and subsidiary ridges of a great and slowly elevated ma.s.s. What begins as a growing plateau, pa.s.ses through the stage of rocky and snowy ranges, becomes later on an area of undulating country, and if time sufficed would ultimately flatten out once more into a plain. Between the first stage and the last the sculpturing operations of nature pa.s.s through many phases. In the beginning, when the area has only just begun to rise from the level, those forces operate gently. Slopes are slight and streams flow easily down them. When the mountains have been roughly blocked out and the valleys precipitously deepened, the region enters into the dramatic stage of its history. The peaks are at their highest, the valleys at their deepest relatively to the heights. Cliffs are boldest, needles sharpest, torrents most voluminous and rapid. Now is the time when great mountain-falls most frequently occur. The rocks do not merely crumble away stone by stone, but huge ma.s.ses are undermined and fall with gigantic crash and violence into the valleys, temporarily damming them across and forming lakes, which presently burst, and pour an incredible volume of water in destructive flood down the narrow and winding valley below. The flood transports and grinds up great quant.i.ties of rock and carries the material afar, for hundreds of miles perhaps, before the plain is reached and the mud deposited upon it.

In the theatrical stage mud avalanches are likewise common. To produce them there must be a great supply of loose debris on steep rocks at a high level and much rapidly melting snow about them, whose water drains into gullies and unites in larger gullies, all with banks of rotten and crumbling rock. On a suitable day in early summer, when the sky is clear and the sun hot, the stones will fall in such numbers that they will plug some gully and dam back the water. It will collect and burst the dam, and a flow of stones, dust, and water will begin. At other neighbouring spots the same thing will happen, and the elements of the avalanche will flow together, block a larger gully, and presently burst that block also. So it will go on till a great ma.s.s of mud, water, and rocks collects somewhere and finally bursts loose in an avalanche which sweeps all before it.

Such an avalanche I saw from close at hand on 8th July 1892, in the mountains of Nagar. We were walking up the right bank of a great glacier river, and were forced at intervals to cross its tributaries which came rus.h.i.+ng down the hillside on our left. Approaching the mouth of one of these side gullies we heard a noise like thunder and beheld a vast black wave bulging down it. It pa.s.sed before we arrived and there was silence for a few minutes. Presently the sounds of another were heard aloft, and it soon heaved into view--a terrific sight. The weight of the mud rolled ma.s.ses of rock down the gully, turning them over and over like so many pebbles. They restrained the muddy torrent and kept it moving slowly with acc.u.mulating volume. Each big rock in the vanguard of the avalanche weighed many tons; some were about 10-foot cubes. The stuff behind them filled the gully some 15 feet deep by 40 wide. The thing travelled perhaps at the rate of seven miles an hour. Sometimes a bigger rock than usual barred the way till the mud, piling up behind it, swept it on. The avalanche ate into the sides of the gully and carried away huge undermined ma.s.ses that fell into it. We saw three enormous avalanches of this sort pa.s.s down the same gully in rapid succession, and, after we had gone by, others followed. All the neighbouring similar gullies discharged such groups of mud avalanches during that period of the year.

They are one of the chief agents used by nature to pull down mountains during this, the dramatic stage of their existence. The roaring torrential river below carries off the mud and receives the boulders in its bed, where they are rolled along and in time ground to powder.

Mud avalanches are rare now in the Alps, and are only caused by some exceptional event, such as the bursting of a glacier lake. Once they were common. Mountain-falls of any great size are also much rarer in the Alps now than they were formerly or than they are in some Himalayan regions. Alps and Andes have pa.s.sed beyond the culmination of their dramatic stage. The mountains of Hunza, Nagar, and North Kashmir generally, are in the midst of theirs.

A mountaineer who has acquired a knowledge of how mountains are made, who has seen in action the forces I have briefly described, who has climbed among mountains in suns.h.i.+ne and storm, in heat and frost, who has spent nights on their cold crests, who knows how and where avalanches of snow, ice, and rock are likely to fall and has a realising sense of their force, their frequency, and their ma.s.s: a mountaineer who has attained by long experience a knowledge of the ways and action of glaciers, who can as it were feel their weight and momentum, in whose mind, when he looks at them, they are felt to be moving and vigorous agents, who sees the lines of motion upon them, their swing round corners, their energy in mid course, their feebleness at the snout:--such a man can look abroad over a mountain panorama with an understanding, a sense of the significance of what he beholds, which, far from detracting from its aspect of beauty, adds greatly to it.

To him a mountain area is no confused labyrinth of valleys and tangle of ridges, but the orderly and logical expression of a number of forces, and of forces that are still operative. To him what he beholds is not a painting on the wall, finished and done once and for ever, but, as it were, a scene in a play--a scene to which others have led up, and after which others will follow, all linked together and arising one out of another in unavoidable and necessary sequence. He perceives the arrangement of the peaks to be as logical as that of the men in a regiment on parade. Each stands in its own proper place, b.u.t.tressed, and founded upon a broad and sufficient base. Its drapery of snow is not a kind of fortuitous whitewas.h.i.+ng, splashed on anyhow by the whim of a storm. It is a vital part of the peak to which it adheres, owing all its forms to the modelling of that peak--here lying in deep and almost level snow-fields where broad hollows exist beneath it; there breaking into a ma.s.s of towering seracs where it is forced to fall over a step in its bed; there again reuniting in a smoothly surfaced area where the bed is once more relatively smooth; yet again opening a system of creva.s.ses where its substance is torn asunder by unequal rates of flow.

[Ill.u.s.tration: 19. LOOKING OVER LUCERNE FROM THE DREI LINDEN. The Towers of the Musegg in the middle distance.]

To the instructed eye it is not mysterious why one peak should be a tower of rock and the next a dome of snow. All the forms a.s.sumed are the result of a few simple causes. They express the past history of the action of natural forces, not difficult of comprehension. Be a.s.sured that the understanding eye is well rewarded for the power of comprehension it has slowly and perhaps laboriously acquired. Such understanding comes not merely by familiarity with mountain regions, and is not to be attained by climbing alone, no matter for how many seasons or with what refinement of gymnastic ability. It comes indeed only to the climber, to the man who makes himself familiar with the fastnesses of the hills by actually going amongst them; but it only comes to him if he avails himself of his opportunities to watch the action of Nature's forces when he comes in contact with them. It is not enough merely to see, it is necessary also to look, to examine, to remember, and to love.

He that thus acquaints himself with the high places, will learn to know them as they can be known by no other. They will become to him a home, full of reminiscences, full of shared pleasures, full also of problems yet to be solved, and of hopes yet to be fulfilled. To such a mountain-lover weariness of mountains can never come. His climbing days may be ended, for whatever reason; he may cease to expect or even to desire to mount far aloft; but the mountains themselves, whencesoever seen, will remain to him a joy, permanent, indescribable, and of priceless worth, which he at least will hold to be superior to all other emotions aroused within him by the beauties of Nature.

CHAPTER IV

ALL SORTS AND CONDITIONS OF ALPS

Relatively few Alpine climbers of the present generation know the Alps. They know a district or two, perhaps, though even that amount of knowledge is not so common as might be expected. It were truer to say that the normal present-day climber knows a special kind of climbing and only cares to go where that is to be found. The popular kind of climbing to-day is rock-climbing. The new mountaineer is a specialist rock-climber. Having once fallen in love with rock-climbing, he devotes himself to it, becomes more and more skilful, hunts out harder and harder climbs, and only cares to go where those are to be had. He has discovered that England is not ill-provided with such scrambles, if you know where to look for them; and he knows. He may be found at Easter and Whitsuntide in recondite gullies in Wales, the Lakes, Derbys.h.i.+re, or Scotland. In the summer he is to be looked for among the Chamonix Aiguilles or in the Dolomites, or, if at other centres, then on the more difficult rock routes. Naturally a small area suffices him. It is not mountains he seeks but climbs. A single peak will afford him several, a small group might even occupy him for a lifetime of scrambling holidays.

[Ill.u.s.tration: 20. FRANcOIS DEVOUa.s.sOUD.]

He does not care for easy ways. He hates snow-pounding. A glacier route does not attract him unless it be difficult. Hence his knowledge even of his own particular district or districts is likely to be incomplete. He is not drawn to travel far afield. A wanderer by nature he cannot be; nor is the wandering instinct likely to be developed in him. He does not care for all sorts and conditions of Alps, but for one sort. Only where that kind is to be found is he attracted to go. All present-day mountaineers, of course, are not of this type; but this is the type that present-day mountaineering tends to develop; and of this type the output is considerable.

The old generation of climbers--the founders of the Alpine Club--men who were active in the sixties and seventies, were essentially wanderers. The craft of climbing was less an object of pursuit to them than the exploration of the Alps. Probably the reason was that they had the Alps to explore, and theirs was the pleasure of exploration which we have not. The Alps have all been explored before our coming. The old men had not even decent maps of the snowy regions to go by. No one knew what was round most upper corners, or whither pa.s.ses led, or how you could get by high-level routes from place to place. It was a great delight to solve such problems, and it led climbers to become geographers and to interest themselves in the general structure and topography of the Alps.