eas in 1861 we found it thick and dry (excepting a few
small basins containing water) and evidently permanent, in the middle
of a very hot August. The low part of the cave was so completely
protected from the current, that the candle burned there quite
steadily for an hour and a half: still, like the others, the column at
that end of the glaciere was broken down, and it therefore became
necessary to attribute its fall to some other agency than the current
of external air. There had been a very large amount of rain, and the
surface of the rock in the fissures was evidently wet; so I have no
doubt that the filtering through of the warm rain-water had thawed the
upper supports of the ice-cascades, and then, owing to their slightly
inclined position, the pedestal had not provided sufficient support,
and so they had fallen. One of them, perhaps, had brought down in its
fall the free column, which had stood two days before on its own base,
without any support from the rock. Very probably, too--indeed, almost
certainly,--the fall of the large mass of rock, which once formed the
bottom of the basin on the north side of the road, has affected the
old-established fissures, by which rain-water has been accustomed to
penetrate in small quantities to the glaciere, so that now a much
larger amount is admitted. On this account, there will probably be a
great diminution of the ice in the course of future summers, though
the amount formed each winter may be greater than it has hitherto
been. Constant examination of other columns and fissures has convinced
me, that, before the end of autumn, the majority of the glacieres will
have lost all the columns which depend upon the roof for a part of
their support, or spring from fissures in the wall; whereas those
which are true stalagmites, and are self-supporting, will have a much
better chance of remaining through the warm season, and lasting till
the winter, and so increasing in size from year to year. Free
stalagmites, however, which are formed under fissures capable of
pouring down a large amount of water on the occasion of a great flood
of rain, must succumb in time, though not so soon as the supported
columns.
A curious appearance was presented by a small free stalagmite in the
retired part of the cave. The surface of the stalagmite was wet, from
the drops proceeding from a fissure above, and was lightly covered in
many parts with a calcareous deposit, brought down from the fissures in
|