bearded head, so perfect that you could have thought it the work of a sculptor; and further on, toward the end of our walk, the figure of a warrior with a helmet and coat of mail, and his arms crossed, of the illusion of which, with all my efforts, I could not possibly divest my mind. Two stalactites, descending close to each other, are called, in a German inscription over them, with sentimentality truly German, the union of two hearts. The resemblance is certainly very striking. After passing The Hearts,' we came to the Ball Room.' It is customary for the inhabitants of Adelsberg, and the surrounding country, to come on Whit-Monday to this grotto, which is brilliantly illuminated; and the part called the ball room is actually employed for that purpose by the peasantry. A gallery, very appositely formed by nature, serves the musicians for an orchestra; and wooden chandeliers are suspended from the vaulted roof. It is impossible for me to describe minutely all the wonderful varieties; the 'Fountains' seeming, as they fall, to be frozen into stone; the 'Graves,' with weeping willows waving over them; the 'Picture,' the 'Cannon,' the 'Confessional,' the Pulpit,' the 'Sausage-maker's Shop,' and the 'Prisons.' I must not omit mentioning one part, which, though less grand than many others, is extremely curious. The stalactites have here formed themselves like folds of linen, and are so thin as to be transparent. Some are like shirt-ruffles, having a hem, and looking as if they were embroidered; and there is one, called the 'Curtain,' which hangs exactly in natural folds like a white and pendent sheet. Every where you hear the dripping as of a continual shower, showing that the mighty work is still going on, though the several stages of its progress are imperceptible. Our attention was so excited, that we had walked two hours without feeling the least fatigue, or being sensible of the passage of time. We had gone beyond the point where most travellers had stopped, and had been rewarded for it by seeing stalactites of undiminished whiteness, and crystals glittering, as the light shone upon them, like unnumbered diamonds."

Stalactical depositions vary in colour according to the nature of the surrounding rocks, and Humboldt remarks in general that the formations occur more beautifully and completely in proportion as the caves are narrow and enclosed, since the deposition of crystals is less disturbed by the circulation of the surrounding air. On this account those of the wide open cavern of Caripe, which he explored, were far inferior to the stalactites of Adelsberg. In our own country the spot most remarkable for these formations is the Blue John mine, another of the celebrated places of the Peak, near its great cavern. This is a natural cavity, worked as a mine for the sake of obtaining the elegant fluor spar which gives its name to the site, and which is here found in small detached pieces in the limestone rock. Rude steps, leading downwards about sixty yards, conduct to a series of caverns and passages encrusted with depositions of lime, which have assumed a variety of interesting forms. In our illustrated instance, stalactites, of a delicate pearly yellow colour, of fine texture, and fantastically varied one from the other, have grown downwards until they rested upon some shelf of a lower stratum, probably of earthy matter. Arriving at such a plane, the waters in future spread more widely around, forming a deposit, and connecting the former stems with an inferior tablet of similar composition. The earthy or mineral stratum having been by some chance removed, the fairy columns attached to their kindred floor now remain suspended in middle space. These are graphically termed "the Organ." It is much to be regretted that a Continental reproach against us, that of an Englishman's eyes being in his fingers, here receives an illustration of its truth. Some unprincipled and vagabond sight-seers have wantonly mutilated this rarity, and deprived it of its earlier proportions, for which cause the relics are now upbraidingly exhibited in a rude wooden cage. Here, as at Antiparos, the principal subterranean apartment is termed the "Hall," a wide and lofty cavity, such as imagination conceives

would be a fitting home for the romantic outlaws pictured by Salvator Rosa, or described in the pages of Schiller. In this spot, not a long time ago, a popular

nobleman, who prosecuted adventurous researches in the most dangerous recesses of the mine, feasted a multitude of his friends, and made the wet rock resound to the toasts and sentiments imported from a more fashionable atmosphere. In a certain direction from this grand focus the visiter is led to a narrower and more irregular space, presenting a towering cupola, the grandeur of whose shivered sides can only be exhibited by drawing upwards, with cord and pulley, a round of lighted candles supplied by the conductor: these illuminate successively the varied and peculiar stages of the internal surface. The perpetual waters which trickle down have left a residuum of lime, which has been moulded, by accident, and by industrious and gentle operation, into a thousand free tresses and waving bands. The whole is fashioned by Nature with less of the abrupt form which characterises the congelation of fountain streams by cold, and presents a grotesque enamel of exquisite polish and gracefulness, giving to the artificial plain or coloured lights, uplifted within the conical abyss, beautiful reflections from its unrivalled crystallised surfaces. Frequently, while attention is riveted to the precinct of gloom and awful solitude, a chaunt of voices is heard from the summit of the dome, accessible by hidden performers from other avenues of the mine. The fleeting and distant expression of sound, with the mournful intervals of the strain, seems like a song of captive spirits, obedient to the rigid discipline of some invincible gnome.

The temperature of caverns exhibits great diversities, dependent upon their extent and form, and that of the same cavern will greatly vary at different seasons. In those which are dry and deep, covered with a thick stony roof, and withdrawn from the influence of the alteration of the external air, by having only a limited opening, the temperature can vary but little, and will continue through the whole year at nearly the same degree of warmth which is peculiar to their geographical situation. Before the warmer air of summer has so penetrated the roof that the temperature of the cavern can be somewhat

raised, the cooler air of the autumn and of the winter begins to penetrate; but before this lower temperature can establish itself, it is again overtaken by the warmth of the following spring and summer. The consequence of all this is a temperature subject to little alteration, but lower than the mean temperature of the surrounding atmosphere. The ancient Romans, hence, according to Seneca, were accustomed to erect their country seats in the vicinity of those natural cavities which abound about the capital, for the purpose of enjoying their refreshing chilliness in the summer season. It was in one of these volcanic caverns that Tiberius was nearly destroyed while at supper; for, during the banquet, the roof suddenly gave way, and buried several of his attendants beneath its ruins, when Sejanus threw himself upon the emperor to preserve him from the falling

stones.

Many caverns, however, vary greatly in their temperature, and exhibit the apparently strange anomaly of being cold when the external air is warm, and warm when it is cold, in some instances carrying this contrast to the extreme, so as to be coated with ice amid the heat of summer, and affording a comfortable warmth amid the cold of winter. In the neighbourhood of Szelitze, a village of Hungary, there is a cave in the transition limestone of the Carpathians which displays this phenomenon. The country in the vicinity abounds with woods, and the air is sharp and cold. The entrance of the cavern, which fronts the north, is eighteen fathoms high, and eight broad; consequently, wide enough to receive a large supply of external air, which here generally blows with great violence; but the subterranean passages, which consist entirely of solid rock, winding round, stretch away farther to the north than has been yet discovered. In the midst of winter the air in this cavern is warm; but in summer, when the heat of the sun without is scarcely supportable, the cold within is not only very piercing, but so intense that the roof is covered with icicles of great size, which, spreading into ramifications, form very grotesque figures. When the snow melts, in spring, the inside of the cave, where its surface roof is exposed to the sun, emits a pellucid water, which immediately congeals as it drops, and thus forms the above icicles, and the very water that drops from them on the sandy ground freezes in an instant. It is even observed that the greater the heat is without, the more intense is the cold within, so that in the dog days all parts of this cavern are covered with ice, which the inhabitants use for cooling their liquors. The quantity of ice is so great that a narrator estimates that it would require six hundred waggons to remove it in a week. In autumn, when the nights grow cold and the heat of the day begins to abate, the ice in the cavern begins to dissolve, so that by winter no more ice is seen. The cavern then becomes perfectly dry, and has a mild warmth. At that season it is the haunt of swarms of flies, gnats, bats, owls, and even of hares and foxes that resort hither, as to their winter retreat, and remain till the return of spring. An instance almost as singular occurs at Besançon, in a grotto which extends 364 feet into the rock, the mouth of which, like that of Szelitze, is towards the north, and covered with vegetation. During the whole summer this cavern contains masses of ice, which melt away in October and November.

This apparently anomalous phenomenon is supposed to be capable of being explained by the relation which subsists between the moisture in these caverns and the external air. When it is hot and dry outside, as in summer, evaporation takes place, and by this means a considerable degree of warmth is withdrawn from the enclosed air, the vapours making their escape through the openings, and through fissures in the roofs. The greater the exterior temperature the more vigorously the evaporation is carried on, producing a degree of cold in the interior which may sink beneath the freezing point, just as in the greatest heat we can most readily freeze water if we surrround it with ether. It is upon this principle that travellers, in some regions, are accustomed to cool their drinks, which they bury in

the earth, and light a quickly blazing fire over it, when the desired coolness is produced. On the contrary, the more the warmth and dryness of the external air are diminished, as in winter, the less will be its capability to promote evaporation in the cavern, the warmth contained in the air will no longer be absorbed, and the ice which has been produced must melt. The cooling in these caverns, however, so as to sink below the freezing point, can only occur where there is a certain relation, which but rarely subsists, between the openings and the evaporating surface of the interior. If the opening is too large, too much warm air is introduced, and the temperature of the interior is thereby much more increased than it can be diminished by evaporation. If it is too small, the vapours cannot withdraw themselves fast enough, and the evaporation is lessened, because the surrounding air is saturated with moisture. The ice-caverns, therefore, are comparatively rare; but, in addition to those named, there is a cave at Vesoul, in France, where a stream flowing through it is frozen over in summer, and clear of ice in winter. Sir Roderick Murchison, in the course of his geological surveys in Russia, met with a freezing cavern near the imperial salt-works at Iletski, to the south of the Ural mountains, situated at the southern base of a hillock of gypsum, one of a series of natural hollows used by the peasantry for cellars or stores. The cave in question is however the only one in the district which possesses the singular property of being partially filled with ice in summer, and of being destitute of it in winter. Standing on the heated ground and under a broiling sun, I shall never forget," he remarks," my astonishment when the woman to whom the cavern belonged unlocked a frail door, and a volume of air so piercingly keen struck the legs and feet, that we were glad to rush into a cold bath in front of us to equalise the effect." Three or four feet within the door, and on a level with the village street, beer and quash were half frozen. A little further the narrow chasm opened into a vault fifteen feet high, ten paces long, and from seven to eight feet wide, which seemed to send off irregular fissures into the body of the hillock. The whole of the roof and sides were hung with solid undripping icicles, and the floor was covered with hard snow, ice, or frozen earth. During the winter all these phenomena disappear; and when the external air is very cold, and all the country is frozen up, the temperature of the cave is such, that the Russians state they could sleep in it without their sheep-skins.

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There is another circumstance of high interest disclosed by the interior of many caverns, the occurrence of extinct animals of the ancient earth; on which account these receptacles have obtained the name of zoolithes or bone caverns. These sites are observed in almost every country of Europe and America, but the fact was not much known till the late Dr. Buckland published the result of his investigations. He made it the subject of his peculiar study, and with great felicity, illustrated the light which it throws upon the ancient condition of the earth, and the changes which the surface has undergone. His researches into the condition of a cave discovered in 1821 at Kirkdale in Yorkshire are highly valuable, and deserve a notice here. Its mouth had long been choked up with rubbish, and overgrown with grass and bushes, but was accidentally found by some workmen. The cave is situated on the older portion of the oolite formation (in the coral rag and Oxford clay) on the declivity of a valley. It extends as an irregular narrow passage 250 feet into the hill. There are a few expansions, but scarcely high enough to allow a man to stand upright. The sides and floor were found covered with a deposit of stalagmite, beneath which there was a bed of from two to three feet of fine sandy and micaceous loam, the lower portion of which in particular contained an innumerable quantity of bones, with which the floor was completely strewn. The greatest part of them were very well preserved, and still retained a great portion of their natural gluten, in consequence of the peculiar nature of their investiture. The animals

to which they belonged were the hyæna, bear, tiger, and lion, elephant, rhinoceros, hippopotamus, horse, ox, deer of three species, water-rat, and mouse, belonging wholly to extinct species, and the

same with those with which we are acquainted in the steppes of Asia. The most plentiful of all were the remains of the hyæna, and from the amount which he saw, Buckland estimated the number of the individuals interred here to be between two and three hundred. The animal must have been one half larger than the living species, in its structure resembling the hyæna of the Cape. The bears, which were less abundant, belonged to the

Kirkdale Cave.

large cavern species, which, according to Cuvier, was of the size of a large white horse and about eighteen feet in length. The elephants were the Siberian mammoth. Of the stags the largest was of the size of the moose deer. Of the ox two species were distinguished, and its bones were most frequent next to those of the hyæna. All these bones lay irregularly strewed one with another, but those of the largest animals were in the most remote and narrowest corners, into which they never could have penetrated while living. The teeth, and the hard marrowless bones of the extremities, as well as those of the fore and hind feet, were uninjured: these were so numerous that they must have belonged to a much greater number of individuals than could be estimated as belonging to the other bones. Many of the bones bore marks which exactly corresponded with the form of the incisor teeth of the hyæna, and the broken horns of the stag were evidently marked by gnawing. These facts warranted the conclusion, that the hyenas must have lived for a long time in this cave, and have dragged the bones of the larger animals, particularly the oxen, into this den, as their prey. The supposition was confirmed in the most striking manner by a variety of other facts. Dr. Buckland found that bones which he caused to be gnawed by living hyenas had exactly the same appearance as those found in the cavern, and the teeth and harder bones were thrown aside by them. He even found in great abundance excrements of the hyæna, which offered the closest resemblance to those of the living animal. From the facts described, it appears that the Kirkdale cave was for a long series of years a den inhabited by hyænas, who dragged into its recesses the other animal bodies whose remains are there commingled with their own,-some great catastrophe causing an inundation in this region which destroyed the whole race.

Similar zoolithic caverns occur in the following places in our own country: - 1. Kent's Cavern, in the limestone of North Devon, about a mile from Torquay. It is said to be nearly six hundred feet long, varying in width from two to seventy feet, and in height from one to six yards. The bones of extinct species of animals are found buried in a mass of mud, covered over with a crust of stalagmitic formation. From certain appear