The Forms of Water in Clouds and Rivers, Ice and Glaciers

IN CLOUDS AND RIVERS, ICE AND GLACIERS.

§ 1. Clouds, Rains, and Rivers.

1. Every occurrence in Nature is preceded by other occurrences which are its causes, and succeeded by others which are its effects. The human mind is not satisfied with observing and studying any natural occurrence alone, but takes pleasure in connecting every natural fact with what has gone before it, and with what is to come after it.

2. Thus, when we enter upon the study of rivers and glaciers, our interest will be greatly augmented by taking into account not only their actual appearances, but also their causes and effects.

3. Let us trace a river to its source. Beginning where it empties itself into the sea, and following it backwards, we find it from time to time joined by tributaries which swell its waters. The river of course becomes smaller as these tributaries are passed. It shrinks first to a brook, then to a stream; this again divides itself into a number of smaller streamlets, ending in mere threads of water. These constitute the source of the river, and are usually found among hills.

4. Thus the Severn has its source in the Welsh Mountains; the Thames in the Cotswold Hills; the Danube in the hills of the Black Forest; the Rhine and the Rhone in the Alps; the Ganges in the Himalaya Mountains; the Euphrates near Mount Ararat; the Garonne in the Pyrenees; the Elbe in the Giant Mountains of Bohemia; the Missouri in the Rocky Mountains, and the Amazon in the Andes of Peru.

225. The winter chosen is an inclement one. There is snow in London, snow in Paris, snow in Geneva; snow near Chamouni so deep that the road fences are entirely effaced. On Christmas night—nearly at mid-night—1859, your deputy reaches Chamouni.

226. The snow fell heavily on December 26; but on the 27th, during a lull in the storm, we turn out. There are with me four good guides and a porter. They tie planks to their feet to prevent them from sinking in the snow; I neglect this precaution and sink often to the waist. Four or five times during our ascent the slope cracks with an explosive sound, and the snow threatens to come down in avalanches.[D]

[D] Four years later, viz. in the spring of 1863, a mighty climber and noble guide and companion of mine, named Johann Joseph Bennen, was lost, through the cracking and subsequent slipping of snow on such a slope.

The freshly-fallen snow was in that particular condition which causes its granules to adhere, and hence every flake falling on the trees had been retained there. The laden pines presented beautiful and often fantastic forms.

227. After five hours and a half of arduous work the Montanvert was attained. We unlocked the forsaken auberge, round which the snow was reared in buttresses. I have already spoken of the complex play of crystallising forces. The frost figures on the window-panes of the auberge were wonderful: mimic shrubs and ferns wrought by the building power while hampered by the adhesion between the glass and the film in which it worked.

§ 36. Birth of a Crevasse: Reflections.

249. Preserving the notion that we are working together, we will now enter upon a new field of enquiry. We have wrapped up our chain, and are turning homewards after a hard day's work upon the Glacier du Géant, when under our feet, as if coming from the body of the glacier, an explosion is heard. Somewhat startled, we look enquiringly over the ice. The sound is repeated, several shots being fired in quick succession. They seem sometimes to our right, sometimes to our left, giving the impression that the glacier is breaking all round us. Still nothing is to be seen.

250. We closely scan the ice, and after an hour's strict search we discover the cause of the reports. They announce the birth of a crevasse. Through a pool upon the glacier we notice air bubbles ascending, and find the bottom of the pool crossed by a narrow crack, from which the bubbles issue. Eight and left from this pool we trace the young fissure through long distances. It is sometimes almost too feeble to be seen, and at no place is it wide enough to admit a knife-blade.

251. It is difficult to believe that the formidable fissures among which you and I have so often trodden with awe, could commence in this small way. Such, however, is the case. The great and gaping chasms on and above the ice-falls of the Géant and the Talèfre begin as narrow cracks, which open gradually to crevasses.

349. But low down to our right, and surrounded by the sheltering mountains, is an object the beauty of which startles those who are unprepared for it. Yonder we see the naked side of the glacier, exposing glistening ice-cliffs sixty or seventy feet high. It would seem as if the Aletsch here were engaged in the vain attempt to thrust an arm through a lateral valley. It once did so; but the arm is now incessantly broken off close to the body of the glacier, a great space formerly covered by the ice being occupied by its water of liquefaction. A lake of the loveliest blue is thus formed, which reaches quite to the base of the ice-cliffs, saps them, as the Arctic waves sap the Greenland glaciers, and receives from them the broken masses which it has undermined. As we look down upon the lake, small icebergs sail over the tranquil surface, each resembling a snowy swan accompanied by its shadow.

350. This is the beautiful little lake of Märgelin, or, as the Swiss here call it, the Märgelin See. You see that splash, and immediately afterwards hear the sound of the plunging ice. The glacier has broken before our eyes, and dropped an iceberg into the lake. All over the lake the water is set in commotion, thus illustrating on a small scale the swamping waves produced by the descent of vast islands of ice from the Arctic glaciers. Look to the end of the lake.