West 15 17-1/4 22-1/4 23-3/4 23-3/4
East 12-1/2 15-1/4 15-1/2 18-1/4 19-1/2
It is here seen that in each case the _western_ stake moved more
swiftly than its eastern fellow stake; thus proving, beyond a doubt,
that opposite the Ponts the western side of the Mer de Glace moves
swiftest--a result precisely the reverse of that observed where the
curvature of the valley was different.
But an additional test of the explanation is possible. Between the
Ponts and the promontory of Trélaporte the glacier passes another
point of contrary flexure, its convex curvature opposite to Trélaporte
being turned towards the base of the Aiguille du Moine, on the eastern
side. A series of stakes was placed across the glacier here; and the
velocities of those placed at certain distances from the western side
were compared, as before, with those of stakes placed at the same
distances from the eastern side. The following table shows the result
of these measurements; the numbers, as before, denote inches: