Rollo in Switzerland

by Jacob Abbott

A glacier, when really understood, is one of the most astonishing and impressive spectacles which the whole face of Nature exhibits. Mr. George and Rollo explored quite a number of them in the course of their travels in Switzerland; and Rollo would have liked to have explored a great many more.

A glacier is a river of ice,—really and truly a river of ice,—sometimes two or three miles wide, and fifteen or twenty miles long, with many branches coming into it. Its bed is a steep valley, commencing far up among the mountains in a region of everlasting ice and snow, and ending in some warm and pleasant valley far below, where the warm sun beats upon the terminus of it and melts the ice away as fast as it comes down. It flows very slowly, not usually more than an inch in an hour. The warm summer sun beams upon the upper surface of it, melting it slowly away, and forming vast fissures and clefts in it, down which you can look to the bottom, if you only have courage to go near enough to the slippery edge. If you do not dare to do this, you can get a large stone and throw it in; and then, if you stand still and listen, you hear it thumping and thundering against the sides of the crevasse until it gets too deep to be any longer heard. You cannot hear it strike the bottom; for it is sometimes seven or eight hundred feet through the thickness of the glacier to the ground below.

THE CREVASSE.

The surface of the glacier above is not smooth and glassy like the ice of a freshly-frozen river or pond; but is white, like a field of snow. This appearance is produced in part by the snow which falls upon the glacier, and in part by the melting of the surface of the ice by the sun. From this latter cause, too, the surface of the glacier is covered, in a summer's day, with streams of water, which flow, like little brooks, in long and winding channels which they themselves have worn, until at length they reach some fissure, or crevasse, into which they fall and disappear. The waters of these brooks—many thousands in all—form a large stream, which flows along on the surface of the ground under the glacier, and comes out at last, in a wild, and roaring, and turbid torrent, from an immense archway in the ice at the lower end, where the glacier terminates among the green fields and blooming flowers of the lower valley.

The glaciers are formed from the avalanches which fall into the upper valleys in cases where the valleys are so deep and narrow and so secluded from the sun that the snows which slide into them cannot melt. In such case, the immense accumulations which gather there harden and solidify, and become ice; and, what is very astonishing, the whole mass, solid as it is, moves slowly onward down the valley, following all the turns and indentations of its bed, until finally it comes down into the warm regions of the lower valleys, where the end of it is melted away by the sun as fast as the mass behind crowds it forward. It is certainly very astonishing that a substance so solid as ice can flow in this way, along a rocky and tortuous bed, as if it were semi-fluid; and it was a long time before men would believe that such a thing could be possible. It was, however, at length proved beyond all question that this motion exists; and the rate of it in different glaciers at different periods of the day or of the year has been accurately measured.

If you go to the end of the glacier, where it comes out into the lower valley, and look up to the icy cliffs which form the termination of it, and watch there for a few minutes, you soon see masses of ice breaking off from the brink and falling down with a thundering sound to the rocks below. This is because the ice at the extremity is all the time pressed forward by the mass behind it; and, as it comes to the brink, it breaks over and falls down. This is one evidence that the glaciers move.

But there is another proof that the ice of the glaciers is continually moving onward which is still more direct and decisive. Certain philosophers, who wished to ascertain positively what the truth was, went to a glacier, and, selecting a large rock which lay upon the surface of it near the middle of the ice, they made a red mark with paint upon the rock, and two other marks on the rocks which formed the shore of the glacier. They made these three marks exactly in a line with each other, expecting that, if the glacier moved, the rock in the centre of it would be carried forward, and the three marks would be no longer in a line.

This proved to be the case. In a very short time the central rock was found to have moved forward very perceptibly. This was several years ago. This rock is still on the glacier; and the red mark on it, as well as those on the shores, still remains. All the travellers who visit the glacier look at these marks and observe how the great rock on the ice moves forward. It is now at a long distance below the place where it was when its position was first recorded.

Then, besides, you can actually hear the glaciers moving when you stand upon them. It is sometimes very difficult to get upon them; for at the sides where the ice rubs against the rocks, immense chasms and fissures are formed, and vast blocks both of rock and ice are tumbled confusedly together in such a manner as to make the way almost impracticable. When, however, you fairly get upon the ice, if you stand still a moment and listen, you hear a peculiar groaning sound in the moraines. To understand this, however, I must first explain what a moraine is. On each side of the glacier, quite near the shore, there is usually found a ridge of rocks and stones extending up and down the glacier for the whole length of it, as if an immense wall formed of blocks of granite of prodigious magnitude had been built by giants to fence the glacier in, and had afterwards been shaken down by an earthquake, so as to leave only a confused and shapeless ridge of rocks and stones. These long lines of wall-like ruins may be traced along the borders of the glacier as far as the eye can reach. They lie just on the edge of the ice, and follow all the bends and sinuosities of the shore. It is a mystery how they are formed. All that is known, or rather all that can be here explained, is, that they are composed of the rocks which cleave off from the sides of the precipices and mountains that border the glacier, and that, when they have fallen down, the gradual movement of the ice draws them out into the long, ridge-like lines in which they now appear. Some of these moraines are of colossal magnitude, being in several places a hundred feet broad and fifty or sixty feet high; and, as you cannot get upon the glacier without crossing them, they are often greatly in the traveller's way. In fact, they sometimes form a barrier which is all but impassable.