The temperature was half a degree lower than when there were three of us in the cave two days before. I deposited one of Casella’s registering thermometers, on wood, on a stone in that part of the floor which was free from ice, though there was ice all round it at some little distance. The thermometer was well above the surface of the ice, and was protected from chance drops of water from the roof.
The next morning I started early from Arzier, having an afternoon journey in prospect to the neighbourhood of another glaciere, and was accompanied by Captain Douglas Smith, of the 4th Regiment. On our way to La Genolliere, we came across the man who had served as guide the day before, and a short conversation respecting the glaciere ensued. He had only seen it once, many years before, and he held stoutly to the usual belief of the peasantry, that the ice is formed in summer, and melts in winter; a belief which everything I had then seen contradicted. His last words as we parted were, ‘Plus il fait chaud, plus ca gele;’ and, paradoxical as it may appear, I believe that some truth was concealed in what he said, though not as he meant it. Considering that his ideas were confined to his cattle and their requirements, and that water is often very difficult to find in that part of the Jura, a hot summer would probably mean with him a dry summer, that is, a summer which does not send down much water to thaw the columns in the cave. Extra heat in the air outside, at any season, does not, as experience of these caves proves abundantly, produce very considerable disturbance of their low temperature, and so summer