While I was occupied in making sketches and measurements, Mignot was engaged in chopping discontentedly at the floor, in two or three different places. At length he seemed to find a place to his mind, and chopped perseveringly till his axe went through, and then he suggested that we should follow. The hole was not tempting. It opened into the blackest possible darkness, and Mignot thrust his legs through, feeling for a foothold, which, by lowering himself almost to his armpits, he soon discovered: the foothold, however, proved to be a loose stone, which gave way under him and bounded down, apparently over an incline of like stones, to a distance which sounded very alarming. But he would not give in, and at length, descending still further by means of the snow in which the hole was made, he was rewarded by finding a solid block which bore his weight, and he speedily disappeared altogether, summoning me to follow. I proposed to light a candle first, not caring to go through such a hole, in such a floor, into no one knew what; but he was so very peremptory, evidently thinking that if he had gone through without a pioneering candle his monsieur might do the same, that there was nothing for it but to obey. The hole was very near the junction of the floor with the slope of stones where the floor terminated, and the space between the hole and the slope seemed to be filled up with a confused mass of snow and ice, in which the snow largely predominated; so that there was good hold for hands and feet in passing down to the stones, which might be about 7 feet below the upper surface of the floor. Here we crouched in the darkness, with our faces turned away from the presumed slope of stones, till a light was struck. The accomplice did not find it in the bond that he should go down, and he preferred to reserve his energies for his own peculiar glacière. [Illustration: LOWER GLACIÈRE OF THE PRÉ DE S. LIVRES.]