stay in that cold
for a quarter of an hour. He had now the candle in his own possession,
and I was propped on a stone and an alpenstock in the lake, so he turned
to go, vowing that he would leave me alone in the dark if I did not come
out at once. There was no help for it, as the thermometer would have
been of no use without a candle, and a step in the dark is not pleasant
when all around is water, so I slowly drew up the thermometer and read
33 deg. F. In making final arrangements for departure, I let it lie in the
water for a few seconds longer, and it fell to 321/2 deg.; but Rosset would
not stay a moment longer, and I was obliged to be content with that
result. He made himself very easy about the matter, and said we must
call it zero; and in the evening I heard him telling the maire that the
greatest of the wonders he had missed, by his patriotic care for his
neck, was a lake of water which did not freeze, though its temperature
was zero (centigrade).

Among the stones at the bottom of this water, I saw here and there
patches of a furry sort of ice. I have often watched the freezing of a
rapid Scotch stream, where, in the swifter parts, the ice forms first at
the bottom and gradually creeps up the larger stones till it appears on
the surface, and becomes a nucleus, round which pieces of floating ice
collect; and the substance in the glaciere-lake had exactly the same
appearance as the Scotch ground-ice. But it could not be the same thing
in reality, for, as far as I understand the phenomenon of ground-ice,
some disturbed motion of the water is necessary, to drive down below the
surface the cold particles of water, which become ice the moment they
strike upon any solid substance shaped like fractured stone;[75] the
specific gravity of freezing water being so much less than that of water
at a somewhat higher temperature, that without some disturbing cause it
would not sink to the bottom.[76] So that it seems probable that the ice
at the bottom of the lake was the remains of a solid mass, of which the
greater part had been converted into water by some warm influence or
other. We noticed that a little water trickled down among the stones
which formed the slope of descent into the lowest gallery, so that
perhaps the lake was a collection of water from all parts of the various
ramifications of the fissure. Whence came the icy wind, it is impossible
to say, without further exploration. It was satisfactory to me to find
th