Ice-Caves of France and Switzerland | Page 4

for all, that the ice in these caves is never found in a sheet on a pool of water; it is always solid, forming the floor of the cave, filling up the interstices of the loose stones, and rising above them, in this case with a surface perfectly level.
[Illustration: ICE-COLUMNS IN THE GLACI��RE OF LA GENOLLI��RE.]
We found four principal columns of ice, three of which, in the loftiest part of the cave, are represented in the accompanying engraving: I call them three, and not two, because the two which unite in a common base proceeded from different fissures. The line of light at the foot of the rock-wall is the only entrance to the glaci��re. The lowest column was 11-2/3 feet high and 1-2/3 feet broad, not more than 6 inches thick in the middle, half-way up, and flattened symmetrically so as to be comparatively sharp at the edges, like a huge double-edged sword. It stood clear of the rock through its whole height, but scarcely left room between itself and the wall of the cave for a candle to be passed up and down. The other two columns shown in the engraving poured out of fissures in the rock, streaming down as cascades, the one being 13-1/2 and the other 15 feet high; and when we tied a candle to the end of an alpenstock, and passed it into the fissures, we found that the bend of the fissures prevented our seeing the termination of the ice. An intermittent disturbance of the air in these fissures made the flame flicker at intervals, though generally the candle burned steadily in them, and we could detect no current in the cave. The fourth column was in the low part of the cave, and we were obliged to grovel on the ice to get its dimensions: it was 3-1/4 feet broad and 4-1/3 feet high, the roof of the cave being only 2-3/4 feet high; and it poured out of the vertical fissure like a smooth round fall of water, adhering lightly to the rock at its upper end like a fungus, and growing out suddenly in its full size. This column was dry, whereas on the others there were abundant symptoms of moisture, as if small quantities of water were trickling down them from their fissures, though the fissures themselves appeared to be perfectly dry.
In one of the fissures there was a patch of what is known as sweating-stone, [5] with globules of water oozing out, and standing roundly upon it: the globules were not frozen. This stone was exceedingly hard, and defied all our efforts to break off a specimen, but at last we got two small pieces, hard and heavy, and wrapped them in paper; ten weeks after, we found them of course quite dry, and broke them easily, small as they were, with our fingers. The fissure from which the shortest of the four columns came was full of gnats, as were also several crevices in the walls of the cave, especially in the lowest part; and we found a number of large red-brown flies, [6] nearly an inch long, running rapidly on the ice and stones, after the fashion of the flies with which trout love best to be taken. The central parts of the cave, where the roof is high, were in a state provincially known as 'sloppy,' and drops of water fell now and then from above, either splashing on wet stones, or hollowing out basins in the remaining ice, or, sometimes, shrewdly detecting the most sensitive spot in the back of the human neck. We placed one of Casella's thermometers on a piece of wood on one of the wet stones, clear of the ice, and it soon fell to 34��. Probably the temperature had been somewhat raised by the continued presence of three human beings and two lighted candles in the small cavern; and, at any rate, the cold of two degrees above freezing was something very real on a hot summer's day, and told considerably upon my sisters, so that we were compelled to beat a retreat,--not quite in time, for one of our party could not effect a thaw, even by stamping about violently in the full afternoon sun.
While we were in the cave, we noticed that the surfaces of the columns were covered by very irregular lines, marked somewhat deeply in the ice, and dividing the surface into areas of all shapes, a sort of network, with meshes of many different shapes and sizes. These areas were smaller towards the edges of the columns; the lines containing them were not, as a rule, straight lines, and almost baffled our efforts to count them, but, to the best of my belief, there were meshes with three, four, and up to eight