x.] ALPINE TRAVELS, 1846. 317 



is pleasant to exchange them for the quiet and comfort 

 of the Montanvert, where, as usual, everything is better 

 than at Chamounix : bread (most decidedly), butter 

 (most incomparably), mutton, honey, tea, cream, wine. 

 In short, I am in such good humour with my quarters 

 that I shall find it very difficult to descend again. 

 Auguste's eyes continue well, and he finds the railway 

 " f the greatest service to him/ 



Forbes's first care was directed to the examination of 



the .-}uces passed over by the blocks which he had 



Led on the surface of the glacier ; and he soon found 



that one of them (Block E, above ' 1' Angle ') had in two 



:-s moved something less than a quarter of a mile, 



while the ' Pierre Platte ' [c], in the neighbourhood of the 



Couverclc, had changed its position by about half that 



;ince. He then entered upon a course of investiga- 



tions on the ablation or melting of the ice at its surface, 



compared with the actual subsidence of the glacier in its 



bed. The former was easily ascertained by boring a 



horizontal hole in the wall of a crevasse, and observing 



from day to day the gradual diminution in thickness of 



the ice above it. The amount of the subsidence of the 



glacier, or the difference between the geometrical depres- 



sion of its surface and the ablation, was obtained by 



ring the level telescope of a theodolite on a measur- 



he extremity of which was pegged into the 



hole above mentioned, and then held vertically. When 



the height of the eye above the hole in question was thus 



. the level was then moved in the direction of 



a fixed object (a cross which had been cut on a stone), as 



a point of departure for the vertical height. The differ- 



ence in level of the eye above or below this fixed point 



iug been ascertained in a similar manner, the sum, or 



lie case might be) <f this measure and 



last, gave th<- dilferenee of level bet \\een the spot 



on which the theodolite, stood and the mark on the 



The n: ,ults of observations at t\\o 



<ns are given in the following table? : 



