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 the roof by the water filtering through.  The stalagmite was of the double-edged-sword shape, and the limestone deposit collected chiefly at one of its edges, the edge nearer to that part of the cave where thaw prevailed; so that the real edge was a ridge of deposit beyond the edge of the ice.[8] Patches of limestone paste lay on many parts of the ice-floor.

In the loftier part of the cave, water dropped from the roof to so large an extent, that ninety-six drops of water in a minute splashed on to a small stone immediately under the main fissure.  This stone was in the centre of a considerable area of the floor which was clear of ice; and it struck me that if the columns were formed by the freezing of water dropping from the roof, there ought to have been at some time a large column under this, the most plentiful source of water in the cave.  Accordingly, I found that the edge of the ice round this clear area was much thicker than the rest of the ice of the floor, and was evidently the remains of the swelling pedestal