GEOLOGY. 643 



record is that which befell four hundred Austrian soldiers, 

 who, in the fifteenth century, were buried under one of 

 these falls of snow. 



Glaciers are met with most frequently in the valleys of 

 high mountains. From thence they are sometimes seen to 

 descend to a considerable depth, far below the line of eter- 

 nal snow, and display themselves in the midst of a luxuriant 

 vegetation, among the forests of conifers and the flowers of 

 the valleys which surround them. In the Arctic seas, as at 

 Spitzbergen, they even launch their gigantic crystalline 

 masses into the waves of ocean (Fig. 240). 



These icy plains, sometimes formed of obtuse and undu- 

 lated blocks, sometimes bristling with immense crystals, the 

 azure of which contrasts with the dead white of the snow, 

 when they are heaped up in the mountain gorges, appear 

 to our eyes like oceans, the waves of which have been solid- 

 ified by magic, in the midst of their most frightful commo- 

 tions, and destined to eternal immobility. They are really 

 seas of ice, six to eight leagues long, which climb the val- 

 leys and clear the elevated passes of mountains in order to 

 cross from one side of a mountain chain to the other. Fre- 

 quently vast blue and diaphanous grottoes open at their 

 bases, from which spring fountains, which soon become im- 

 petuous streams or rivers. 



During fine nights, when the silvery gleams of the moon 

 light up the glaciers which wind along the gorges of the 

 Alps, these resemble long and imposing opal shrouds spread 

 silently over the mountain sides, while their numerous crys- 

 tals here and there sparkle pale and luminous. 



Notwithstanding their apparent immobility, these seas of 



