18 M. Andre de Luc on the Glaciers of the Alps. 



1821, it destroyed an old forest, which had existed for two 

 centuries.* 



The progress of the Glacier des Bossons, and of the Grindel- 

 wald, so similar to that of the Glacier des Bois, proves that the 

 latter had never been so far advanced as it was in 1822, and 

 that Saussure w^is wrong in t<alving for moraines of this glacier 

 masses of stones situated at a much gi*eater distance from it 

 than the glacier reached on the year mentioned. M. Agassi z, 

 adopting the opinion of Saussure, reckons seven of these mo- 

 raines as far as the Bois des Tines : to these he adds ten or 

 eleven others, ascending towards the Col de Balme. It will 

 be seen, in a memoir which I have sent to the Geological 

 Society of France, for insertion in one of theii' bulletins, that 

 these supposed moraines are rolled boulders, as old as those 

 resting on Mont Saleve and on the .Tura. I examined them 

 in 1815, when on my way from Chamouni to Argeutiere. 



These are not the only ones which exist in this valley ; 

 others ai"e to be found near the Prieui-e, likewise near the tor- 

 rent of Taconay, and on the declivity of a mountain on the right 

 bank of the Arve, opposite the village of Ouches. These latter 

 ascend to the height of 400 or 500 feet above the bed of the 

 river. Huge collections of boulders or rolled blocks of stone 

 are found at certain distances, in all the valleys traversed by 

 the Arve, as far as Mont Saleve : they all date from the same 

 epoch. 



But let us retm'n to the subject of glaciers. M. Agassiz 

 supposes that the ice, when moving over a rocky ground, some- 

 times polishes it as perfectly as could be done by the hand of 

 a marble-cutter ; it rounds off the angles, scoops out furrows, 

 &c. I greatly ouestion the reality of these effects. M. Agas- 

 siz. cites as a proof the granites of the Grimsel. I have seen 

 th(. se granite rocks : they present convex and uniform masses ; 

 but I am convinced that no glacier ever passed over them. 

 The glacier of the Aar is distant from them more than a 

 league, at least from those in the vicinity of the Hospice. I 

 believe that M. Agassiz derives the facts which he adduces 

 from places where a glacier never passed. 



* Lettov of M. Alb. Hallev of Bvino, of November 1822, already cited. 



