Researches on Existing Glaciers. 273 



The movements of glaciers, and more especially those of 

 the lower glacier of the Aar, have for several years been the 

 object of my continued attention. In my Etudes (p. 150), 

 I have stated the progress of this glacier from 1827 to 1840, 

 which, after taking into account the corrections lately made by 

 M. Hugi, as to the distance of the hut from the Abschwung^VfO\x\& 

 amount to about 220 feet per annum. In August 1840, the 

 Hotel des Neuchatelois was 2457 feet from the angle of the 

 rock called the Ahschwung^ which separates the branch of the 

 Finsteraar from that of the Lauteraar. I took care to inscribe 

 this measurement on one of the walls of the block. The fol- 

 lowing year, on arriving at the Hotel des Neuchatelois, my 

 first proceeding was to measure the distance anew, and I then 

 found it to be 2623 feet. The block had therefore advanced 

 166 feet. This new measurement was likewise inscribed on 

 the block, and I am sure that on again visiting the glacier of 

 the Aar this year, I shall find that the block has advanced 

 about an equal distance. This is what any traveller may 

 ascertain who happens to be at the glacier before me. If 

 it be kept in mind that this annual progression takes place 

 at a point where the glacier is very little inclined, inasmuch 

 as its slope is scarcely 3°, and that at the same time the upper 

 masses, and especially the branch of the Lauteraar, are very 

 uniform, and do not present any trace of a rapid movement, 

 it will be understood that a sliding movement, such as is sup- 

 posed by many authors, is not at all probable. It suffices, more- 

 over, to have seen the localities, in order to be convinced 

 that at that point the glacier could never have advanced 

 otherwise than by a slow and continuous movement, caused 

 by infiltration and the daily congelation of the water which 

 penetrates the whole mass. 



These measurements ought further to establish,. in another 

 manner, the evidence of the movement by dilatation. It has 

 been reasonably said : If it be the infiltrated water which, by 

 becoming dilated, occasions the progression, it would not only 

 be necessary that the whole mass should advance, but that 

 the distance between two given points on the glacier itself 

 should also be augmented ; the same thing ought to occur 



