ICE STREAMS IN THE UPPER GLACIÈRE OF ST. LIVRES.
In Upper Styria, the Frauenmauer Mountain, which overlooks the mining town of Eisenerz, contains a remarkable ice-chamber, consisting of a grotto from thirty to forty fathoms long, decked with ice-crystals, pillars of ice, and cascades of the same material, the floor being composed of ice as smooth as glass. In the summer pleasure parties assemble in the cave, and amuse themselves with sliding down its sloping ice-floors.
In his work on the Natural Wonders of the Austrian Empire, the naturalist Sartori describes his visit to an ice-cave on the Brandstein, a peak situated in the same district, which thus appears to be rich in glacières. He found crimpons necessary for descending the frozen snow, which led from the entrance to the floor of the cave, where he discovered pillars and capitals and pyramids of ice of every possible shape and variety, as if the cave had contained the ruins of a Gothic church or a fairy palace. At the further end, after passing large cascades of ice, his party reached a dark grey hole, which lighted up into blue and green under the influence of the torches; they could not discover the end of this hole, and the stones which they rolled down into it seemed to go on for ever.
Other natural glacières are also mentioned as occurring in Bohemia, Hungary, the Harz, in several places in North America, and probably there are few mountainous regions without them.
The Cave of Yermalik, already mentioned among the silent retreats of nature which have been rendered infamous by the cruelty of man, is likewise highly interesting as a natural glacière. After leaving the roomy dome in which they found the skeletons of the victims of Genghis Khan, Captain Burslem and Lieutenant Sturt proceeded through several low arches and smaller caves, and reached at length a vast hall, in the centre of which was an enormous mass of clear ice, smooth and polished as a mirror, and in the form of a gigantic beehive, with its dome-shaped top just touching the long icicles which depended from the jagged surface of the rock. A small aperture led to the interior of this wonderful congelation, which was divided into several compartments of every fantastic shape. In some the glittering icicles hung like curtains from the roof; in others, the vault was smooth as glass. Beautifully brilliant were the prismatic colours reflected from the varied surface of the ice when the torches flashed suddenly upon them as they passed from cave to cave. Around, above, beneath, everything was of solid ice, and being unable to stand on account of its slippery nature, they slid, or rather glided mysteriously, along the glassy surface of this hall of spells. In one of the largest compartments the icicles had reached the floor, and gave the idea of pillars supporting the roof.’[roof.’][[27]]
Rocks of volcanic formation seem to afford favourable opportunities for the congelation of water. Ice-caves are found in Mount Etna, on the Peak of Teneriffe, and among the lava-currents of Iceland.[[28]] Scrope visited one of these natural glacières near the village of Roth, in the neighbourhood of Andernach, on the Rhine. It formed the mouth of a deep fissure in a current of basalt derived from an ancient volcanic cone above it, and its floor was covered with a crust of ice at the time of his visit, about noon on a very hot day in August.
The phenomenon of wind-grottoes is analogous to that of ice-caves, and not seldom associated with it. Here cold currents of air, increasing in violence as the day is hotter, are found to blow from the interstices of rocks. One of the most celebrated of these Æolian caverns is found near Terni in Italy. The entrance is closed by an old gate, through the crevices of which the wind issues with a rustling noise, while in the grotto itself the current is sufficiently strong to extinguish a torch. The proprietors of some neighbouring villas have put the phenomenon to an ingenious use. Leaden pipes, branching out from the grotto, convey on sultry summer days an agreeable coolness through masks of gypsum with wide distended mouths, which are fixed in the walls of the apartments.
The small town of Roquefort in France has been renowned ever since the time of the Romans for the delicious flavour of its cheese, which is said to owe its excellence to the cool cellars in which it is matured. These are excavated on the northern slope of a great chalk plateau, and communicate with numerous fissures in the rock, from which air-currents stream forth of so low a temperature as to cause a thermometer marking +23° R. in the shade, and in the external atmosphere, to fall to +4° R. when exposed to their influence. The cellars are so valuable that one, which cost 12,000 francs in construction, sold for 215,000 francs.
In times of ignorance, superstition could not fail to attach its fables to the phenomenon of wind-grottoes. A cave near Eisenach was supposed to be the seat of purgatory, and popular credulity or terror willingly transformed the sounds produced by the rushing air-currents into the wailings of tormented souls.