We next proceeded farther up, and tested the contrary curvature of the glacier, opposite to Trélaporte. The station chosen for this purpose was on a grassy platform of the promontory, whence, on the 28th of July, a row of stakes was fixed at right angles to the axis of the glacier. Their motions, measured on the 31st, gave the following results:—

Fifth Line.[B]—Daily Motion.

No. of stake. Inches.
West 1moved111/4
2"131/2
3"123/4
4"15
5"151/4
6"16
7"171/4
8"191/4
9moved193/4
10"19
11"191/2
12"171/2
13"16
14"143/4
15"10 East.

This line was set out and numbered from the Trélaporte side of the valley, and was also measured by Mr. Hirst, over boulders, ice-ridges, chasms, and moraines. The entire width of the glacier here was found to be 893 yards, or somewhat wider than it is at the Ponts. It will also be observed that its motion is somewhat slower.

An inspection of the notes of this line showed me that stakes 3 and 14, 4 and 12, 7 and 10, were "corresponding points;" the first of each pair standing as far from the western side, as the second stood from the eastern. In the following table these points and their velocities are arranged exactly as in the case of the fourth line.

Numbers and Velocities of the Corresponding Points on the Fifth Line.

No. Vel.No. Vel.No. Vel.
West3 123/44 157 171/4
East14 143/412 171/210 19

EASTERN HALF MOVES QUICKEST.

In each case we find that the stake on the eastern side moves more quickly than the corresponding one upon the western side: so that where the fifth line crosses the glacier the eastern half of the Mer de Glace moves more quickly than the western half. This is the reverse of the result obtained at our fourth line, but it agrees with that obtained on our first three lines, where the curvature of the valley is similar. The analogy between a river and a glacier moving through a sinuous valley is therefore complete.