GLACIERS, Gletscher in German, is a name given extensive fields of ice and indurated snow, which occur in elevated mountainous districts, but particularly in the Alps of Switzerland and Savoy.
In all elevated countries, where the mountains rise above the line of perpetual congelatioD, their summits and flanks are covered with eternal snow. The snow which falls on these lofty regions at different seasons of the year, con tinues nearly in its original state, being converted into a substance of an intermediate character between snow and ice. On the sides of the mountainous declivities, there is more ice than on the summits ; but still these fields of in durated, or of half-congealed snow, are by no means en titled to the name of glaciers, although they have been very improperly called the Upper Glaciers by an intelli gent traveller.
The real glaciers are those accumulations of ice and snow which occupy the high vallies between individual mountains, generally far below the line of perpetual con gelation, and extend themselves into the cultivated vallies which border upon the great chain. These glaciers are commonly encircled with lofty mountains ; they stretch from north to south, and very few have an easterly or a westerly direction.
The general character of a glacier depends upon the nature and state of the valley in which it lies. When the sides of the valley are smooth, and its inclination small, there is little variety in the appearance of the glacier. It presents a tolerably smooth surface, and is intersected with few rents or ravines. When the sides of the valley are rough and unequal, and its general inclination considera ble, the surface is divided by deep chasms, and covered with numerous elevations, sometimes 50 or 100 feet high. If the declivity is more than 30° or 40°, the large cliffs and masses of ice arc forced against each other with great violence, and are accumulated in the most varied and sin gular forms. These general remarks will be better un der stood from a particular description of the two celebrat ed glaciers of De Boisson and De I3ois, in the valley of Chamouni, as they were seen by the writer of this article in the autumn of 1814.
After crossing the Arve, above Servoz, by the wooden bridge of St Pelissier, and ascending a steep and rugged road, the sides of which are every where marked by the scoops and rents which Sir James Hall has observed on the whinstone and sandstone rocks in Scotland, we ap proach the village of Chavanon, and obtain a fine view of the different peaks of Montblanc. The village of Les Ouches is seen in front, and the Glacier de Boisson dis tinctly appears on the flank of Montblanc, stretching its frozen masses into the plain. We now leave the road, and after a little more than half an hour's walk through a fine meadow, and a gloomy forest of lofty pines, we reach the glacier. Its lower extremity and its lofty sides rise into high peaks and pyramids of ice, resembling regular crys tals, and having their hollows and crevices of a bright azure blue, which forms a fine contrast with the broken sunbeams diverging in every direction from the numerous surfaces by which they are reflected. On the hill, we reach the plateau or surface of the glacier, which does not present any thing remarkable. Its gently undu lating surface is crossed with numerous chasms, and cover ed with enormous masses of granite, which are gradually transported to a lower level, and accumulate in the plain below, forming what is called the moraines des glaciers. The Glacier de Boisson is bounded on the east side by lofty pines, many of which arc crushed to pieces by the irresistible pressure of the walls of ice ; and the ground in the neighbourhood is torn up, as if great convulsions were constantly accompanying the fall and descent of the icy cliffs. A few hundred yards only intervene between this region of sterility and desolation, and the rich and cul tivated fields in the valley.