In one of the domes we had only one candle, and the bearer of this after a time contrived to let it fall, leaving us standing with our heads in perfect darkness; while the indistinct light which strayed about our feet showed faintly a circle of icicles, hanging from the lower part of the dome, the fringe, as it were, of our rocky petticoats.
In one of the lower parts of the cave, where darkness prevailed, and locomotion was only possible on the lowest reptile principles, M.
announced that she could see clear through the ice-floor, as if there were nothing between her and the rock below.

I ventured to doubt this, for there was an air of immense thickness about the whole ice; and as soon as A.and I had succeeded in grovelling across the intervening space, and converged upon her, we found that the appearance she had observed was due to a most perfect reflection of the roof, as shown by the candles we carried, which may give some idea of the character of the ice.

We did not care to study this effect for any very prolonged time, inasmuch as we were obliged meanwhile to stow away the length of our legs on a part of the ice which was thinly covered with water,--one result of its proximity to the arch communicating with the smallest pit.
It has been said that the whole ice-floor sloped slightly towards one side of the cave, the slope becoming rather more steep near the edge.[52] Clearly, ever so slight a slope would be sufficiently embarrassing, when the surface was so perfectly smooth and slippery; and this added much to the difficulty of walking in a bent attitude.

On coming out of one of the domes, I tried progression on all-fours--threes, rather, for the candle occupied one hand,--and I cannot recommend that method, owing to the impossibility of putting on the break.

The pace ultimately acquired is greater than is pleasant, and the roof is too near the floor to allow of any successful attempt to bring things to an end by the reassumption of a biped character.
We placed a thermometer in the line of greatest current, and another in a still part of the cave.