fine columns which had already yielded to the advancing warmth: one of
these still remained, in the form of broken blocks of ice, in the
neighbourhood of the open hole in the roof, immediately below which hole
the stones of the floor were completely bare, and the thermometer stood
at 50°. At the far end of the cave, the thermometer gave something less
than 32°; a difference so remarkable, at the same horizontal level, that
I am inclined to doubt the accuracy of the figures, though they were
registered on the spot with due care. The uncovered hole, it must be
remembered, is so large, and so completely open, that the rain falls
freely on to the stones on the floor below.

By far the most striking part of this glacière is the north-west
wall, which is covered with a sheet of ice 70 feet long, and 22 feet
high at the highest part: in the neighbourhood of the ladders, this
turns the corner of the cave, and passes up for about 9 feet under the
second ladder. The general thickness of the sheet is from a foot to a
foot and a half; and this is the chief source from which the _fermier_
draws the ice, as it is much more easily quarried than the solid
floor. Some of my friends went to the cave a few weeks after my visit,
and found that the whole sheet had been pared off and carried away. On
some parts of the wall the sheet was not completely continuous, being
formed of broad and distinct cascades, connected by cross channels of
ice, and uniting at their upper and lower ends, thus presenting many
curious and ornamental groupings. On cutting through this ice, it was
found not to lie closely on the rock, a small intermediate space being
generally left, almost filled with minute limestone particles in a
very wet state; and the whole cavern showed signs of more or less
thaw.

[Illustration: THE GLACIÈRE OF S. GEORGES. VERTICAL SECTIONS OF THE