296 PEOFESSOK TTNDALIi ON THE VEINED STEUCTOtE OP GLA 
I afterwards traced the seams of white ice of “ du Ge^^o thei^m^ 
amid the ridges and hoUows at the base of the great ice-faU of Le Eognon. ^ . 
ris ie s"l opened out into two branches, which, after — ^ 
separate, would unite again so as to enclose a httle glacial rstod 
branches were thrown off from the principal seam. P" f 
Stream which had been fed by tributary branches. Fig. 17 the p 
Fig. 17. 
stream observed at the base of the iee-fall; fig. 18 is the plan of a seam of white ice 
Fig. 18. 
observed the same day lower down the glacier; their relationship is evident. I may 
remark that I have observed other seams produced by the gorging of orevmses with snou . 
and the subsequent closure of the fissures. 
clideringbhe place where they are formed, these channels cannot e.ape com 
nression • but let me remove all uncertainty on this point, by proving that not only at 
Le base of the seracs, but throughout almost its entire length, the Glacier du Gean. is 
Tht fct ploTlhlve to offL is that the transverse undulations of the glacmr, to which 
re “h! been so often made, become graduaUy sMHer as they escend. A senes 
of three of them, measured along the axis of the glacier on the 6th of Align t 185 „ 
r^he flowing respective lengths-955, 865, and 770 links, the shortest imdulahon 
Ling the furthest down the glacier. Now these undulations, as I shall subsequently sho . 
arTfue o a regularly recurrent action, and are doubtless originally of the same length , 
that LeToLr ones L shorter than the higher must therefore be due to comp— 
4e folllwing observation is, however, more conclusive. About 
•1 u fV. Tnpn1 and to the left as we ascend, theie is a gieen patci ij 
Taggy Tomtaln side.’ From this spot, as a station, I set out with a theodolite a hue 
(No. 1) transverse to the axis of the glacier. 
