xv.] FORBES 1 GLACIER DISCOVERIES. 519 



and brought up to the temperature of the freezing point, 

 and as the weight of the overlying snow mass increases 

 more a-nd more, it changes itself at last by firmer union 

 of its separate granules into a dense and hard mass of 



ice Thus, as the snow in the glaciers is pressed 



together into dense ice, so the already formed irregular 

 masses of ice are in many places united into dense clear ice. 

 This is most conspicuously visible at the foot of a glacier 

 cascade. There are glacier-falls, where an upper part of 

 the glacier ends at a steep rocky wall, and its blocks of 

 ice fall down like avalanches over the edge of this wall. 

 The heap of smashed blocks of ice which in consequence 

 piles itself up below, unites itself again at the foot of the 

 rocky wall into a continuous mass of dense ice, which 

 pursues its downward course as a glacier. . . . Thus you 

 see how, to the eye of the physicist, the glacier, with 

 its blocks of ice confusedly towering over one another, 

 its waste, stony, and discoloured surfaces, its destruction- 

 threatening crevasses, has become a majestic stream, 

 which flows down more peacefully and regularly than any 

 other ; which, according to fixed laws, contracts, spreads 



f out or, crashing and roaring, plunges down into the 

 abyss. If we follow it in conclusion, to its termination, 

 we find the water produced by its melting united into a 

 strong brook, breaking out and flowing down from the 

 icy gate of the glacier. No doubt such a brook, at first, 

 when it comes into view from below the glacier, looks 

 very dirty and muddy, for it brings down with it all th.-, 

 dust which the glacier has rubbed off from the rocks. 

 One feels disenchanted to see the wonderfully beautiful 

 and transparent ice changed to such muddy water ; but 

 in fact, the water of the glacier brook is itself just as 

 beautiful and clear as the ice, although for the time its 

 beauty is concealed. You must seek these brooks again, 



11 they have passed through a lake and there de- 

 posited their rockKlust. The lakes of Geneva, of Thun 

 &c., Lago Maggiore, the lakes of Como and Ganl-i, are 

 principally fed on glacier Water ; the clearness, and the 



.tiful blue or greenish blue colour, <>f their \\ater are 



