ix.] ALPINE TRAVELS, 1842. 2J<5 



but merely bands of a peculiar icy structure, which 

 retained and exhibited the dirt. This led me to a very 

 eaivful examination of the veined structure of the ice, 

 which I found to follow exactly these hyperbolic lines, 

 and to turn round their planes of cleavage very sharply 

 at the bottom of the bend, while a longitudinal section 

 of the glacier would show a dip inwards of 45. This 

 very important as furnishing the link between the 

 (tea/, jir<iIM, and cfamshctt stratification.' 1 

 A short, interval of bad weather obliged him to 

 descend to Chamounix. But soon after M. Studer and 

 sunshine arrived together, and it is easy to imagine 

 with what pleasure Forbes conducted his friend to the 

 scene of his labours, and explained to him their results. 

 ' Having conversed much/ he writes, 'with M. Studer on 

 the history of the glacier question, I made the following 

 memorandum of what I claim as original in my present 

 investigations, and submitted it to him. He considers 

 it historically accurate. The points 1 claim are these : 



* 1. The treatment of glacier motion as a problem of 

 mechanical forces, and its examination as such, from 

 exact data observed. 



* 2. Two experiments for distinguishing between the 

 theories of De Saussure and De Charpentier i.e. those 

 of gravitation and dilatation. One being the exact 

 measurement of a space along the ice, to be measured 



n after a certain time in order to asm-tain whether 

 any e.\j.;insion has occurred; the other, the determina- 

 tion of the lineal velocity of a number of points along 

 the in order to ascertain whether their motion is 



M remarkable bands are here represented as they occur on 

 the lower portion of the Mer !< (ilace. The photograph was taken 

 expressly for tins work fr .in tin- summit of the, Trelaporte, a bu:: 

 of the Aiguille li- ( harm"/, which Forbes used as one of his Mirve\in 

 utations (<i"i in 1*44. It rises to a height of nearly 2,0<in t 

 the glacier, and he tin of it as a point of view : 'The ascent 



Wi ' difficult, h>it the view jully repaid us. 1 1 c.miipands 



th. whole sweep Of the gla ; ,11 to the Col du < ll 



and to the foot of tin- (iiandi-t* JorafSes, 88 does no other point i 

 i it the . the ^lacier are beautifully 



1844. 



