similar assumption.

The influence of small accidents on the direction of rivers is
beautifully illustrated in glacier streams, which are made to cut
either straight or sinuous channels by causes apparently of the most
trivial character. In his interesting paper 'On the Lakes of
Switzerland,' M. Studer also refers to the bend of the Rhine at
Sargans in proof that the river must there follow a pre-existing
fissure. I made a special expedition to the place in 1864; and though
it was plain that M. Studer had good grounds for the selection of this
spot, I was unable to arrive at his conclusion as to the necessity of
a fissure.

Again, in the interesting volume recently published by the Swiss
Alpine Club, M. Desor informs us that the Swiss naturalists who met
last year at Samaden visited the end of the Morteratsch glacier, and
there convinced themselves that a glacier had no tendency whatever to
imbed itself in the soil. I scarcely think that the question of
glacier erosion, as applied either to lakes or valleys, is to be
disposed of so easily. Let me record here my experience of the
Morteratsch glacier.

I took with me in 1864 a theodolite to Pontresina, and while there had
to congratulate myself on the aid of my friend Mr. Hirst, who in 1857
did such good service upon the Mer de Glace and its tributaries. We
set out three lines across the Morteratsch glacier, one of which
crossed the ice-stream near the well-known hut of the painter Georgei,
while the two others were staked out, the one above the hut and the
other below it. Calling the highest line A, the line which crossed
the glacier at the hut B, and the lowest line C, the following are the
mean hourly motions of the three lines, deduced from observations
which extended over several days. On each line eleven stakes were
fixed, which are designated by the figures 1, 2, 3, &c. in the
Tables.

Morteratsch Glacier, Line A.

No. of Stake. Hourly Motion.

1 0.35 inch.

2 0.49 inch.

3 0.53 inch.

4 0.54 inch.

5 0.56 inch.

6 0.54 inch.

7 0.52 inch.

8 0.49 inch.

9 0.40 inch.

10 0.29 inch.

11 0.20 inch.

As in all other measurements of this kind, the retarding influence of
the sides of the glacier is manifest: the centre moves with the
greatest velocity.

Mortera