36 FIFTH LETTER ON GLACIERS. [1844. 



during last summer, I may mention, that the state of my health 

 was so indifferent during the finer months of the year, and the 

 caution which it required so great, that I was quite unable to 

 prosecute, as I had hoped, the subject of my previous inquiries 

 in Switzerland. As, however, the journey was not quite unpro- 

 ductive, I will very shortly state the additional facts which I 

 was enabled to observe, claiming from you and from the Society 

 the indulgence which their scantiness requires. 



At Chamouni, the most obvious consideration was to deter- 

 mine the actual annual motion of the ice, the partial motions 

 of which during the summer months had been carefully ascer- 

 tained by me, as stated in my former communications. For 

 this purpose, I had two marks of a permanently distinguishable 

 kind, namely, blocks of stone lying on the surface of the ice ; 

 the one, formerly marked D 7, and referred to in my Travels 

 by that name, situated a little lower than the position of the 

 Montanvert ; the other, marked C, or " Pierre platte," on the 

 Glacier de Lechaud, near its junction with the Glacier du Geant. 

 It was the former of these masses which had been approximately 

 observed in position by my guide, Auguste Balmat, during the 

 winter of 1842-3, with great labour and fidelity observations 

 which first conclusively proved the fact which I had previously 

 suspected,* although opposed to the received opinions that the 

 glacier moves with considerable velocity even in winter. By 

 going to the spot with Balmat, and verifying the marks which 

 he had from time to time made, I ascertained that his measure- 

 ments, if not absolutely correct, did not admit of being 

 materially improved, owing to the great size and repeated turn- 

 ing over of the block in question. His measurements between 

 October 1842 and June 1843 have been published in the 

 volume already cited.f I had the mortification, however, to 

 find, on the llth September 1843, when I visited the block, 

 that though still upon the ice, it had got shoved so near the 

 moraine of the glacier near an angle of its course, as to be well 

 nigh stranded ; and that, in fact, since Balmat's last mark in 



* [See page 25.] f [Travels in the Alps, 1st edition, p. 151.] 



