Ice-Caves of France and Switzerland

by G. F. Browne

As soon as the candle had mastered a portion of the darkness, we found that we were squatting on a steeply sloping descent of large blocks of stone, while in face of us was a magnificent wall of ice, evidently the continuation of the wall above, marked most plainly with horizontal lines. This wall passed down vertically to join the slope on which we were, at a depth below our feet which the light of the candle had not yet fathomed. The horizontal bands were so clear, that, if we had possessed climbing apparatus, we could have counted the number of layers with accuracy. Of course we scrambled down the stones, and found after a time that the angle formed by the ice-wall and the slope of stones was choked up at the bottom by large pieces of rock, one piled on another just as they had fallen from the higher parts. These blocks were so large, that we were able to get down among the interstices, in a spiral manner, for some little distance; and when we were finally stopped, still the ice-wall passed on below our feet, and there was no possible chance of determining to what depth it went. The atmosphere at this point was a sort of frozen vapour, most unpleasant in all respects, and the candles burned very dimly. The thermometer stood at 32°, half-way down the slope of stones.

We were able to stretch a string in a straight line from the lowest point we reached, through the interstices of the blocks of stone, and up to the entrance-hole, and this measurement gave 50 feet. Considering the inclination of the upper ice-floor, and the sharpness of the angle between the wall of ice and the line of our descent to this lowest point, I believe that 50 feet will fairly represent the height of the ice-wall from this point to the foot of the slope from the upper wall; so that 72 feet will be the whole depth of ice, from the top of the third ladder to the point where our further progress downwards was arrested. The correctness of this calculation depends upon the honesty of Mignot, who had charge of the farther end of the string, and was proud of the wonders of his cave.

SECTION OF THE LOWER GLACIÈRE OF THE PRÉ DE S. LIVRES.

A dishonest man might easily, under the circumstances, have pulled up a few feet more of string than was necessary, but 50 feet seemed in no way an improbable result of the measurement.

The ice was as solid and firm as can well be conceived. The horizontal bands would seem to prove conclusively that it was no coating of greater or less thickness on the face of a vertical wall of rock, an idea which might suggest itself to anyone who had not seen it, and I think it probable that the amount of ice represented in the section of the cave is not an exaggeration. We were unable to measure the whole length of the wall in the lower cave, from the large number of blocks of stone which had fallen at one end, and lay against its face. Probably, from the nature of the case, it was not so long as the 72 feet of wall above; but we measured 50 feet, and could see it still passing on to the right hand as we faced it. In trying to penetrate farther along the face, I found a wing of the brown fly we had seen in considerable abundance on the ice in La Genollière, frozen into the remains of a column.

There was so very much to be observed on all sides, and the measurements took up so much time, owing to the peculiar difficulties which attended them, that I did not examine with sufficient care the curious floor of ice through which we cut our way to the lower cavern. Neither did I notice the roof of the cavern thus reached, which may be very different from the shape of the upper surface of the floor composing it. If the ice-wall goes straight up, and the roof is formed of the ice-floor alone, then it is a very remarkable feature indeed. But, more probably, the lower wall leans over more and more towards the top, and so forms as it were a part of the roof. It is possible that, as the wall has grown, each successive annual layer has projected farther and farther, till at last some year very favourable to the increase of ice has carried the projection for that year nearly to the opposite stones, and then an unfavourable year or two would form the foot of the upper wall. This seems more probable, from the loose constitution of the floor at the point where it joins the stones, as if it were there only made up of drift and débris, while the part of the floor nearer the foot of the wall is solid ice. It has been suggested to me that possibly water accumulates in the time of greatest thaw to a very large extent in the lower parts of the cave, and the ice-floor is formed where the frost first takes hold of this water. But the slope of the ice-floor is against this theory, to a certain extent; and the amount of water necessary to fill the cavity would be so enormous, that it is contrary to all experience to imagine such a collection, especially as the cave showed no signs of present thaw. The appearance of the rocks, too, in the lower cave, and the surface of the ice-wall there, gave no indications of the action of water; and there was no trace of ice among the stones, as there certainly would have been if water had filled the cave, and gradually retired before the attacks of frost, or in consequence of the opening up of drainage. There were pieces of the trunks of trees, also, and large bones, lying about at different levels on the rocks. I never searched for bones in these caves, owing to the absence of the stalagmitic covering which preserves cavern-bones from decay; nor did I take any notice of such as presented themselves without search, for the bergers are in the habit of throwing the carcases of deceased cows into any deep hole in the neighbourhood of the place where the carcases may be found, in consequence of the general belief that living cows go mad if they find the grave of a companion; so that I should probably have made a laborious collection of the bones of the bos domesticus.

This belief of the bergers respecting the cows is supported by several circumstantial and apparently trustworthy accounts of fearful fights among herds of cattle over the grave of some of the herd. The sight of a companion's blood is said to have a similar effect upon them. Thus a small pasturage between Anzeindaz and the Col de Cheville, on the border of the cantons Vaud and Valais, is still called Boulaire from legendary times, when the herdsmen of Vaud (then Berne) won back from certain Valaisan thieves the cattle the latter were carrying off from La Varraz. Some of the cows were wounded in the battle, and the sight of their blood drove the others mad, so that they fought till almost all the herd was destroyed; whence the name Boulaire, from ébouëler, to disembowel,--a word formed from bouë, the patois for boyau.

When we left the lower darkness and ascended to the floor of ice once more, Mignot expressed a desire to see my attempt at a sketch of the glacière from that point, as he had been much struck during his negotiatory visit of the night before by the sketch of the entrance to the Glacière of S. Georges, chiefly because he had guessed what it was meant for. He was evidently disappointed with the representation of his own cave, for he could see nothing but a network of lines, with unintelligible words written here and there, and after some hesitation he confessed that it was not the least like it. A little explanation soon set that right, and then he began to plead vigorously for the wall which surrounded the trees at the mouth of the pit. Why was it not put in? He was told, because it could not be seen from below; but nevertheless he strongly urged its introduction, on the ground that he had built it himself, and it was such a well-built wall; facts which far more than balanced any little impossibility that might otherwise have prevented its appearance. After we had reached the grass of the outer world again, he made me sketch the entrance to the pit, pointing to the containing wall with parental pride, and standing over the sketch-book and the sketcher with an umbrella which speedily turned inside out under the combined pressure of wind, and rain, and years; a feat which it had already performed des fois, he said, in the course of his acquaintance with it.

Before finally leaving the glacière, I examined the structure of the great stream of ice, at different points near the top of the limiting wall. From its outward appearance it might have been expected to be rough, but it was not so; it was knotty to the eye, but perfectly smooth to the foot, and, when cut, showed itself perfectly clear and limpid. It did not separate under the axe into misshapen pieces, with faces of every possible variation from regularity, that is, with what is called vitreous fracture, but rather separated into a number of nuts of limpid ice, each being of a prismatic form, and of much regularity in shape and size. It was smooth, dark-grey, and clear; free from air, and free from surface lines; very hard, and suggesting the idea of coarse internal granulation. In the large ice-streams of some darker glacières, this ice assumed a rather lighter colour by candle-light, but always presented the same granular appearance, and cut up into the same prismatic nuts, and was evidently free from constitutional opacity.