JReport of the Besearches of M. Agassiz. 173 



one of its numbers, to refute the opinion of the German 

 philosopher, afresh substituting in its place the popular and 

 prevailing belief. He adduced facts— that at such a time 

 a particular field or meadow was invaded, trees were up- 

 rooted, and huts overturned ; and, as if these glaciers were 

 predestined to induce irritating discussions, we find that even 

 then the controversy assumed a very keen and angry tune. 

 M. Piouquet answered M. Kuhn's particles in a second me- 

 moir, in which he explained anew, and at more length, the 

 views and reasons which opposed his admitting that any, and 

 especially a rapid movement, took place ; and retreating 

 upon his scepticism, he demurred, as inadmissible, to all 

 proofs borrowed from the vague notions of the mountaineers. 

 He demanded precise facts, and especially measurements ; 

 and, as few of the savans had themselves made observations, 

 and mistrust now began to be entertained regarding the 

 recitals of the natives, all this made for the cause of M. 

 Piouquet. But De Saussure and Kuhn both had ocular 

 demonstration of the motion. The following is the state- 

 ment of the former. " In the month of July 1761, along 

 with my guide, Pierre Simon, I passed under a very high 

 glacier which is to the west of that of the Viler ins. There 

 I observed an immense block of granite, cubical in form, 

 and more than 40 feet long in all its dimensions, resting upon 

 the debris at the foot of the glacier, and deposited in its 

 place by this glacier. Let us be quick, said Pierre Simon to 

 me ; for the ice which presses upon the rock will soon force 

 it forward, and so overwhelm us. Scarcely had we safely 

 passed it, when it began to move ; at first it slid almost im- 

 perceptibly upon the debris lying under it ; it then tumbled 

 over upon its anterior face, then upon another ; it then began 

 to roll over, and the declivity increasing, it fell from spot to 

 spot, till it began to bound away, first to a small extent, and 

 then to great distances ; at each bound it shivered away 

 splinters, then great blocks, and finally the rocks on which it 

 fell ; all these fragments followed its wake down the slope of 

 the mountain, and it thus formed a torrent of rocks, great 

 and small, which overwhelmed a forest in which it was finally 



