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July 24.
Yesterday morning we went to the source of the Arveiron. It is about a league from this village; the river rolls forth impetuously from an arch of ice, and spreads itself in many streams over a vast space of the valley, ravaged and laid bare by its inundations. The glacier by which its waters are nourished, overhangs this cavern and the plain, and the forests of pine which surround it, with terrible precipices of solid ice. On the other side rises the immense glacier of Montanvert, fifty miles in extent, occupying a chasm among mountains of inconceivable height, and of forms so pointed and abrupt, that they seem to pierce the sky. From this glacier we saw, as we sat on a rock close to one of the streams of the Arveiron, masses of ice detach themselves from on high, and rush with a loud dull noise into the vale. The violence of their fall turned them into powder, which flowed over the rocks in imitation of waterfalls, whose ravines they usurped and filled.
In the evening I went with Ducrée, my guide, the only tolerable person I have seen in this country, to visit the glacier of Boisson. This glacier, like that of Montanvert, comes close to the vale, overhanging the green meadows and the dark woods with the dazzling whiteness of its precipices and pinnacles, which are like spires of radiant crystal, covered with a net-work of frosted silver. These glaciers flow perpetually into the valley, ravaging in their slow but irresistible progress the pastures and the forests which surround them, performing a work of desolation in ages which a river of lava might accomplish in an hour, but far more irretrievably; for where the ice has once descended the hardiest plant refuses to grow; if even, as in some extraordinary instances, it should recede after its progress has once commenced. The glaciers perpetually move onward, at the rate of a foot each day, with a
