Glacières; or, Freezing Caverns

by Edwin Swift Balch

Dr. Franz Sartori, in 1809, was a strong believer in the summer ice theory, and wrote of the flies and the gnats, the bats and the owls, and the foxes and the hares coming to Szilize to winter.

Alexander von Humboldt, in 1814, says about the Cueva del Hielo on the Peak of Teneriffe that so much snow and ice are stored up in winter that the summer heat cannot melt it all, and also adds that permanent snow in caves must depend more on the amount of winter snow, and the freedom from hot winds, than on the absolute altitude of the cave.

Dewey, in 1819, thought that the ice in the Snow Glen at Williamstown was a winter formation.

Professor M. A. Pictet visited Saint-Georges, Le Brezon and Montarquis and in 1822 endeavored to prove that they are cold current caves and that the ice in them is due entirely to draughts causing evaporation. He believed in the theory of the ice forming in summer more than in winter and that it could not be the residue of a winter deposit. He therefore argued that it must be due to descending currents of air which he thought would be most energetic in summer; that they would become at least as low as the mean annual temperature of the place and be still further cooled by evaporation. The strange thing about his theories is that he does not seem to have personally observed any draughts either at Saint-Georges or Le Brezon, but the fact that the ice was evidently not an accumulation of winter snow led him to try to reconcile what he had himself seen with de Saussure’s theories about windholes.

Jean André Deluc in 1822 published a paper discussing the theories of MM. de Cossigny, Prévost and Pictet. Deluc had never visited a glacière himself, but he explains clearly the impossibility of Professor Pictet’s cold current theory, on the simple ground that Professor Pictet himself did not find any cold currents. He takes up Professor Prévost’s theories warmly; using also the manuscript notes of Mons. Colladon who had visited the Grand Cave de Montarquis. Deluc says: “that the winter’s cold penetrates into these caves, freezes the water which collects there and that the ice thus formed has not the time to melt during the following summer.” He says further: “It seems that in the three glacières with which we have been occupied there is a flat or rather hollow bottom, where the waters can form a more or less deep pond, and whence they therefore cannot flow away; it is there they flow in winter; and as these are shut in places where the air cannot circulate, the heats of summer can only penetrate very feebly. The ice once formed in such cavities, only melts slowly; for one knows that ice in melting, absorbs 60° of heat; and where find this heat in an air always very cold and nearly still? During a great cold, the ice forms with great promptness, while it melts with much slowness, even when the temperature of the air is several degrees above zero; what must then not be this slowness when the temperature of the interior air only rises in summer one degree above freezing point. It would need several summers to melt this ice if it did not reform each winter.”

C. A. Lee, in 1825, wrote that the ice in the Wolfshollow near Salisbury was a winter formation.

G. Poulett Scrope, in 1826, accepted as the truth the statement that the cave of Roth was filled with ice in summer, but that it was warm during the winter. In 1827, he explained the presence of ice at Pontgibaud as follows: “The water is apparently frozen by means of the powerful evaporation produced by a current of very dry air issuing from some long fissures or arched galleries which communicate with the cave, and owing its dryness to the absorbent qualities of the lava through which it passes.”

F. Reich, in 1834, thought that there were two possible causes which might produce subterranean ice: 1, the difference in specific gravity between warm and cold air; 2, evaporation. He thought the cold air a sufficient cause in most caves, but he considered that evaporation also played a part not infrequently.

Professor Silliman, in 1839, gave the first hint, in the negative, about compressed air as a cause for subterranean ice. He said about Owego that if one could suppose that compressed gases or a compressed atmosphere were escaping from the water or near it, this would indicate a source of cold, but that as there is no indication of this in the water, the explanation is unavailable.

Professor A. Pleischl wrote in 1841 that he was told that ice formed on the Pleschiwetz and on the Steinberge in summer. Continuing, he says: "The author is therefore, as well as for other reasons, of the opinion, that the ice is not remaining winter ice, but a summer formation, and one formed by the cold of evaporation. * * * The basalt is, as a thick stone, a good conductor for the heat, and takes up therefore easily the sun’s warmth, but parts with it easily to other neighboring bodies. In the hollows, between the basalt blocks, is found, as I already mentioned, rotting moss, which forms a spongy mass, which is wet through with water. The basalt heated by the sun’s rays now causes a part of the water in the spongy mass to vaporize; for this evaporation the water needs heat, which it withdraws from the neighboring bodies and in part from water, and makes the water so cold, that it freezes into ice, as, under the bell of an air pump—Nature therefore makes here a physical experiment on the largest scale."