The entrance to the glacière itself is elliptical in shape, 43 feet broad at the base, and the cave increases in size as it extends farther into the rock, the floor descending gently till a horizontal esplanade of ice is reached. This esplanade was 66 feet by 30 at the time of Pictet's visit, deeper in the middle than at the sides, and mounting the rock at the farther side of the cave; there was a small stalagmite at one side, but that would seem to have been the only ornamentation displayed. The temperature was 34°·7, a foot above the ice, and 58° in the external air. Timothée had been in the glacière in the previous April, and had found no ice,--nothing but a pool of water of considerable depth. M. Thury, in August 1859, found two sheets of ice in the lowest part of the cave: one, nearly 50 feet long, was partially covered with water; the other, presenting an area of about 14 square yards, showed more water still. There were no stalactites and columns such as M. Morin had found in August 1828, nor even the low stalagmite which Pictet saw in 1822. The summers of 1828 and 1859 were exceptionally hot, and this fact has been held to account for the smaller quantity of ice seen in those years. M. Thury found the cold due to evaporation to be considerably less than 1° F.,[78] and he and M. Morin both fixed the general temperature of the cave at 36°.5; they also found a current of air entering by a fissure in the lowest part of the cave, but it did not disturb the whole of the interior, for in one part the air was in perfect equilibrium. M. Gampert,[79] in the summer of 1823, found a strong and very cold current of air descending by this fissure, along with water which ran from it over the ice; he believed that this was refrigerated by evaporation, in passing through the thickness of the moist rock. Two peasants visited this cave three times in the winter season, viz. on October 22, November 26, and on Christmas Day; and one of them, by name Chavan, drew up an account of their experiences, which was read by M. Colladon before the _Société de Physique et d'Histoire Nat. de Genève_ in 1824.[80] The peasants found very little ice in columns at the time of the October visit, and there were signs of commencing thaw. The thaw was much more pronounced in November, when the ice had nearly disappeared even from the lowest parts of the cave, and they found the air within quite warm. On Christmas Day they had great difficulty in reaching the glacière, and narrowly escaped destruction by an avalanche, which for a time deterred them from prosecuting the adventure: they persisted, however, and were rewarded by finding only water where in summer all was ice, and a temperate warmth in the cave. They observed that the roof had fissures like chimneys.