“The derivation of the German name for glacier, =gletscher=, is suggested as coming not from their icy material, but their perpetual motion, from =glitschen=, to glide; more probably, however, from the idea of gliding upon their surface. These glaciers come down from the air, down out of heaven, a perpetual frozen motion, ever changing and gliding, from the first fall of snow in the atmosphere, through the state of consolidated grinding blocks of ice, and then into musical streams that water the valleys. First it is a powdery, feathery snow, then granulated like hail, and denominated _firn_, forming vast beds and sheets around the highest mountain summits, then frozen into masses, by which time it has traveled down to within seven thousand feet above the level of the sea, where commences the great ice-ocean that fills the uninhabitable Alpine valleys, unceasingly freezing, melting and moving down. It has been estimated by Saussure and others, that these seas of ice, at their greatest thickness, are six or eight hundred feet deep. They are traversed by deep fissures, and as they approach the great precipices, over which they plunge like a cataract into the vales, they are split in all directions, and heaved up into waves, reefs, peaks, pinnacles and minarets. Underneath they are traversed by as many galleries and caverns, through which run the rills and torrents constantly gathering from the melting masses above. These innumerable streams, gathering in one as they approach the termination of the glacier, rush out from beneath it, under a great vault of ice, and thus are born into the breathing world, full-grown roaring rivers, from night, frost and chaos.