Second Line.—Daily Motion.
| No. of stake. | Inches. | |
| West 1 | moved | 71/2 |
| 2 | " | 103/4 |
| 3 | " | 121/4 |
| 4 | " | 141/2 |
| 5 | " | 16 |
| 6 | " | 163/4 |
| 7 | " | 171/2 |
| 8 | " | 19 |
| 9 | " | 191/2 |
| 10 | " | 21 |
| 11 | moved | 21 |
| 12 | " | 221/2 |
| 13 | " | 21 |
| 14 | " | 221/2 |
| 15 | " | 201/2 |
| 16 | " | 213/4 |
| 17 | " | 221/4 |
| 18 | " | 251/4 |
| 19 | " | ... |
| 20 | " | 253/4 East. |
CORROBORATIVE MEASUREMENTS.
As regards the retardation of the side, we observe here the same fact as that revealed by our first line—the motion gradually augments from the first stake to the last. The stake No. 20 stood upon the dirty portion of the ice, which was derived from the Talèfre tributary of the Mer de Glace, and far beyond the middle of the glacier. These measurements, therefore, corroborate that made lower down, as regards the non-coincidence of the point of swiftest motion with the centre of the glacier.
But it will be observed that the measurements do not show any retardation of the ice at the eastern extremity of the line of stakes—the motion goes on augmenting from the first stake to the last. The reason of this is, that in neither of the cases recorded were we able to get the line quite across the glacier; the crevasses and broken ice-ridges, which intercepted the vision, compelled us to halt before we came sufficiently close to the eastern side to make its retardation sensible. But on the 20th of July my friend Hirst sought out an elevated station on the Chapeau, or eastern side of the valley, whence he could command a view from side to side over all the humps and inequalities of the ice, the fixed point at the opposite side, upon which the telescope was directed, being the corner of a window of the Montanvert Hotel. Along this line were placed twelve stakes, the daily motions of which were found to be as follows:—
Third Line.—Daily Motion.
| No. of stake. | Inches. | |
| East 1 | moved | 191/2 |
| 2 | " | 223/4 |
| 3 | " | 283/4 |
| 4 | " | 301/4 |
| 5 | " | 333/4 |
| 6 | " | 281/4 |
| 7 | moved | 241/2 |
| 8 | " | 25 |
| 9 | " | 25 |
| 10 | " | 18 |
| 11 | " | ... |
| 12 | " | 81/2 West. |
The numbering of the stakes along this line commenced from the Chapeau-side of the glacier, and the retardation of that side is now manifest enough; the motion gradually augmenting from 191/2 to 331/2 inches. But, comparing the velocity of the two extreme stakes, we find that the retardation of stake 12 is much greater than that of stake 1. Stake 5, moreover, which moved with the maximum velocity, was not upon the centre of the glacier, but much nearer to the eastern than to the western side.
A NEW PECULIARITY OF GLACIER MOTION.