312 ORIGIN OF A FLOE. 



6,000,000,000 of tons, its depth being about one hun- 

 dred and sixty feet. Around its border was thrown 

 up on all sides a sort of mountain chain of last year's 

 ice, the loftiest pinnacle of which was one hundred and 

 twenty feet above the level of the sea. This ice-hill, 

 as it might well be called, was made up of blocks of 

 ice of every shape and of various sizes, piled one 

 upon the other in the greatest confusion. Numerous 

 forms equally rugged, though not so lofty, rose from 

 the same ridge, and from every part of this desolate 

 area ; and if a thousand Lisbons w^ere crowded to- 

 gether and tumbled to pieces by the shock of an 

 earthquake, the scene could hardly be more rugged, 

 nor to cross the ruins a severer task. 



The origin of such a floe dates back to a very re- 

 mote period. That it was cradled in some deep recess 

 of the land, and there remained until it had grown 

 to such a thickness that no summer's sun or water's 

 washing could wdiolly obliterate it before the winter 

 cold came again, is most probable. After this it grows 

 as the glacier grows, from above, and is, like the gla- 

 cier, wholly composed of fresh ice, — that is, of frozen 

 snow. It will be thus seen that the accumulation of 

 ice upon the mountain tops is not different from the 

 accumulation which takes place upon these floating 

 fields, and each recurring year marks an addition to 

 their depth. Vast as they are to the sight, and dwarfs 

 as they are compared with the inland mer de glace, 

 yet they are, in all that concerns their growth, truly 

 glaciers — pigmy floating glaciers. That they can 

 only grow to such great depth in this manner will be 

 at once apparent, when it is borne in mind that ice 

 soon reaches a maximum thickness by direct freezing, 

 and that its growth is arrested by a natural law. 



