[Fr., from L., glacies, ice.] Slow-moving rivers of ice, which derive their origin from the snow which falls on the higher slopes of lofty mountains. As the snow accumulates on the steep slopes, it acquires a tendency to descend under the influence of its own weight. In some cases it slides down slowly, and in others it breaks off in large sheets, which rush down rapidly, forming what is known as an avalanche. These snows, as they descend, gradually become compacted into ice and form glaciers, which extend along channels in the mountain sides to the valleys below. They are widely distributed, being met with in different parts of the American continent, and in Greenland; in Europe they occur in the Alps, in Norway, and in the Pyrenees; and in Asia in the Himalayas.

THE MER DE GLACE GLACIER.

THE MER-DE-GLACE GLACIER.