266 PEOrESSOE TYNDALL’S OBSEEVATIONS ON THE MEE DE GLACE. 
The stakes along the line are marked thus, 0. The firing of them co^enced at 
the Echellets or eastern side of the ralley, and they were numbered>m to side ; the 
measurement, on the contrary, commenced at the “Pont." Hence ^ 1'* 
stake was the first encountered in the measurement. This stake stood at ^ 
.326 links, or nearly 72 yards from the edge of the glacier. Stake ^o. 1 at the other 
end of the line stood close beside the lateral morame at the eastern side of the gla . 
Eeferring to the notes, it will he seen that the place of marimum morement occurs 
between the stakes 12 and 13, the former at a distance of 1544 links, and the Htter 
distance of 1260 links from the western side of the glacier. The mean of these is d i 
links; consequently, as the entire width is 3926 links, the point of maximum motion is 
here 1131 links nearer to the western than to the eastern side of the ^ er e ace.^ 
dirt also which marks the junction of the portion of the ice denied from t e o u 
Geaiit, with that derived from the other tributaries, is crossed at the distance 2.01 ; nence 
the place of maximum motion occurs at a point 854 links zvest of the dirt, w e on e 
lines set out lower down the point of maximum motion was far in upon the chrt, eas - 
ward from the junction. The position of the point of maximum motion changes, there- 
fore, in exact accordance with the explanation given above. 
But the question is capable of still closer examination. The notes enable us to com- 
pare a number of points at the eastern side of the glacier with others, situated at t e 
same respective distances from the western side. Let us call every pan of points, one o 
which is situated as far from the eastern boundary as the other is froni the western. 
corresponding points. The corresponding points along our fourth line may t en e lange 
as follows ; — „ w- e v 
S. V. S. V. S. V. S. ^ . S. N . 
y^est . . . . 17— 15 ; 16— ITT: 15—224; 13—231- 
East 
3—121 ; 
- 171 ; 
4—151; 
^4 ’ 
,151; 7-181; 9-191] 
12-2311... (A) 
The numbers under the letter S ar-e those of the stakes, those under V are the corre- 
sponding yelocities. It will be seen that in each case the point on the western poition 
of the glacier moves quicker than the corresponding point on the eastern side - s a 
whole, therefore, the western side moves more speedily than the eastern, w ic i is u 
reverse of what was observed lower down, but quite demonstrative of t le exp ana lo 
Avhich refers the effect to the curvature of the valley. 
An inspection of the notes also shows, that at the place where the fourth line crosse 
the glacier, the crevasses ai-e found chiefly upon the portion derived from 
du Geant. The dirt which amiounces the position of the other tributaries o mi 
de Glace is crossed at the distance 2251 ; and after this distance we find t le 
“crevasse nearly closed,” “closed crevasse;” so that not only is the eastern side of he 
glacier here less crevassed than the western, but crevasses previously formed aie pai la ), 
or wholly closed up. The shifting of the place of strain consequent on the change o 
curvature, carried naturally along with it the shifting of the crevasses. It may be inteiied 
from the notes that the measurement of such a line is not without its difficulties. 
