d I
found the length of the side to be 30 feet. I had no means of
determining the height of the cave, and a guess might not be of much
value.

At first sight, the farther end of the cave was the most striking. The
water which comes from the melting snow down which we had passed in
reaching the glaciere, had cut itself deep channels in the floor, and
through these it coursed rapidly till it precipitated itself into a
large pit or _moulin_ in the ice, at the lowest point. This pit, a will
be seen by the section of the cave given on p. 174,[71] terminates the
glaciere; and the rock-wall at the farther edge falls away into a sort
of open fissure, down which magnificent cascades of ice stream
emulously, clothing that side of the pit, which would otherwise be solid
rock. We cut a few steps about the upper edge of this _moulin_, to make
all safe, and proceeded to let down a lighted candle, which descended
safely for 36 feet, showing nothing but ice on all sides; it then came
in contact with one of the falls of water, and the light was of course
extinguished. We next tied a stone to the string, and found that after
40 feet it struck on ice and turned inwards, under our feet, stopping
finally at the end of 51 feet; but whether it was really the bottom of
the pit that stopped it, or only some ledge or accidental impediment, we
could not determine. The diameter of this pit might be 3 yards, but we
took no measure of it.

At the extreme right of the cave we found another pit, a yard and a
half across, two-thirds of the circumference of which was formed by
the plateau of ice on which we stood, and the remaining third by a
fluting in the wall of rock. The maire said that, two years ago, this
hole was not visible, being concealed by a large ice-column which had
since fallen in. Here again I let down a lighted candle, with more
hopes of getting it to the bottom, as no part of the cave drained into
the pit. The candle descended steadily, the flame showing no signs of
atmospheric disturbance, and revealing the fact that the opposite side
of the pit, viz. the rock, which alone was visible from our position,
became more and more thickly covered with ice, of exquisite clearness,
and varied and most graceful forms. As foot after foot, and yard after
yard, ran out, and our heads craned farther and farther over the edge
of the pit to follow the descending light, (we lay flat on the ice,
for more safety,) the cries of the schoolmaster became