When we were sufficiently cool, we scrambled down the side of the pit opposite to that in which the archway lies, finding the rock extremely steep, and then came to a slope of 72 feet of snow, completely exposed to the weather, which landed us at the mouth of the glacière. The arch is so large, that we could detect the change of light in the cave, caused by the passage of clouds across the sun, and candles were not necessary, excepting in the pits shortly to be described. We saw at once that rapid thaw was going on somewhere or other; and when we stepped off the snow, we found ourselves in a couple of inches of soft green vegetable mud, like a _compote_ of dark-coloured duckweed--or, to use a more familiar simile, like a mass of overboiled and ill-strained spinach. To the grief of one of us, there was ice under this, of most persuasive slipperiness. The maire said that he had never seen these signs of thaw in his visits in previous years; and as we went farther and farther into the cave, he was more and more surprised at each step to find such a large quantity of running water, and so much less ice than he had expected. The shape of the glacière is a rough circle, 60 feet in diameter; and the floor, which is solid ice, slopes gradually down to the farther end. The immediate entrance is half-closed by a steep and very regular cone of snow, lying vertically under the small shaft we had seen in the rock above. The snow which forms the cone descends in winter by this shaft; and the formation must have been going on for a considerable time, since the lower part of the cone has become solid ice, under the combined influences of pressure and of _dégel_ and _regel_. I climbed up the side of this, by cutting steps in the lower part, and digging feet and hands deep into the snow higher up; and 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.