GLACIERS.[1]
A glacier is a field or immense mass of ice formed in the deep valleys of high mountain ranges upon which snow seems to be eternal. The snow, however, is not so lasting. Indeed, it is constantly evaporating, returning to the clouds from which it descended; or, remaining exposed to the rays of the sun, or to the influence of a hot southerly wind, it melts and trickles down until it is seized by the cold and congealed into ice. Thus, by means of the millions of drops which melt only to freeze and melt again, and again grow solid, the mass is constantly transformed, and, little by little, the snow so lately fallen upon the summit of the mountain is found to have descended the slopes. Even in the summer these enormous quantities of ice and snow produce a local winter, all the more curious from the contrast, for side by side with the gloomy glacier, with its great gaping crevices, its collection of stones, its terrible silence, flowers are blooming, birds are singing, and fruit ripens. It is like death and life.
The glacier, however, has a life of its own. Though difficult to discover its secret progress, it is in constant motion. Like the avalanche, its work is to carry the rubbish of the crumbling mountains into the plains, not by violence, but by the patient labor of every moment. It is true that glaciers have ages, almost endless, in which to do their work, but slowly as they move, their destination is the sea, where they must one day be swallowed up. Always immovable in appearance, they are really ice rivers flowing in a rocky bed. On its course the solid river behaves very much as would one of running water. It has its windings, its depths and shallows, its rapids and cascades.
A GLACIER AND CREVASSE.
But the ice, not possessing the suppleness or fluidity of water, accomplishes, somewhat awkwardly, the movements forced upon it by the nature of the ground. It can not at its cataracts fall in one level sheet as does the water current; but, according to the inequalities of the bottom, and the cohesion of the ice crystals, it fractures, splits, gets cut up into blocks inclining various ways, falling over one another, becoming cemented together again in curious obelisks, towers, fantastic groups. Even in that part where the bottom of the immense groove inclines with tolerable regularity, the surface of the glacier does not in the least resemble the even surface of the water of a river. The friction of the ice against its edges does not ripple it with tiny waves similar to those of the shore, but fractures and refractures it with crevices intersecting one another in a multitude of fissures or cracks, which, widening out into chasms, become what are known as crevasses, and which make travel upon a glacier so dangerous.
Looking down from the edges of these chasms we see layer upon layer of bluish ice separated by blackish bands, the remains of rubbish carried down from the surface, or at other times the ice may be as clear and perfect as one single crystal. What is the depth? We do not know. A jutting crag of ice, combined with the darkness, prevents our glance descending to the lowest rocks; yet we sometimes hear a mysterious noise ascending from the abyss: it is the water rippling, a stone becoming loosened, a bit of ice splitting off and falling down. Explorers have descended these chasms to measure their density and to study the temperature and composition of the deep ice. Sometimes they have been able to do it, without any great risk, by penetrating laterally into the clefts from the rocks which serve as banks to the rivers of ice. Frequently, too, they are let down by ropes. But for one scientific discoverer who carefully and with proper precaution thus explores the holes of the glaciers, how many unhappy shepherds have been ingulfed by these chasms! Yet it is known that mountaineers having fallen to the bottom of a crevasse, though wounded and bleeding and dazed by the darkness, have yet preserved their courage and managed to save their lives. There was one who followed the course of a subglacial stream, and thus made a veritable journey below the enormous vault of ice.
Without descending into the depths of a glacier to study its air-bubbles and crystals, praiseworthy as the courageous effort may be, we can find much to interest us upon its surface.
In this apparent confusion everything is regulated by law. Why should a fissure always be produced in the frozen mass opposite one point of the steep bank? Why at a certain depth below should the crevasse, which has gradually become enlarged, again bring its edges nearer each other, and the glacier be re-cemented? Why should the surface regularly bulge out in one part to become fissured elsewhere? On seeing all these phenomena, which roughly reproduce the ripples, wavelets, and eddies on the smooth sheets of the water of a river, we better understand the unity which presides over everything in nature.
When, by long exploration, we have become familiar with the glacier, and we know how to account to ourselves for all the little changes which take place upon it, it is a delight to roam about it on a fine summer's day. The heat of the sun has given it voice and motion. Tiny veins of water, almost imperceptible at first, are formed here and there; these unite in sparkling streamlets which wind at the bottom of miniature river-beds, hollowed out by themselves, and then suddenly disappear in a crack in the ice, giving forth a low plaint in a silvery voice. They swell or fall according to the variations of the temperature. Should a cloud pass before the sun and cool the atmosphere, they barely continue to flow; when the heat becomes greater, the rivulets assume the pace of torrents; they sweep away with them sand and pebbles, which, meeting little drifts of earth, form banks and islands; then toward evening they calm down, and soon the cold of the night congeals them afresh.