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See also:CAVE (See also:Lat. See also:cavea, from caves, hollow) , a hollow extending beneath the See also:surface of the See also:earth . The word " cavern " (See also:Lat. caverna) is practically a synonym, though a distinction is some-times See also:drawn between See also:sea caves and inland caverns, but the See also:term " See also:cave " is used here as a See also:general description . Caves have excited the See also:awe and wonder of mankind in all ages, and have been the centres See also:round which have clustered many legends and superstitions . They were the See also:abode of the sibyls and the See also:nymphs in See also:Roman See also:mythology, and in See also:Greece they were the temples of See also:Zeus, See also:Pan, See also:Dionysus, See also:Pluto and the See also:Moon, as well as the places where the oracles were delivered at See also:Delphi; See also:Corinth and See also:Mount See also:Cithaeron . In See also:Persia they were connected with the obscure See also:worship of See also:Mithras . Their names frequently are survivals of the superstitious ideas of antiquity, as, for example, the See also:Fairy, See also:Dragon's, or See also:Devil's Caves of See also:France and See also:Germany . See also:Long after . the Fairies and Little Men had forsaken the forests and glens of Germany, they dwelt in their palaces deep in the Harz Mountains, in the Dwarfholes, &c., whence they came from See also:time to time into the upper See also:air . The Seven Sleepers of See also:Ephesus slept their long See also:sleep in a cave . The hills of See also:Granada are still believed by the Moorish See also:children to contain the See also:great See also:Boabdil and his sleeping See also:host, who will awake, when an adventurous mortal invades their repose, to restore the See also:glory of the See also:Moors in See also:Spain . Caves have been used in all ages by mankind for habitation, See also:refuge and See also:burial . In the Old Testament we read that when See also:Lot went up out of Zoar he dwelt in a cave with his two daughters . The five See also:kings of the Canaanites took refuge from See also:Joshua, and See also:David from See also:Saul, in the caves of See also:Palestine, just as the Aquitani fled from See also:Caesar to those of See also:Auvergne, and the See also:Arabs of See also:Algeria to those of IDahra, where they were suffocated by See also:Marshal See also:Pelissier in 1845 . In Central See also:Africa David See also:Livingstone discovered vast caves in which whole tribes found See also:security with their See also:cattle and See also:household stuff . The cave of Machpelah may be quoted as an example of their use as sepulchres, and the See also:rock-hewn tombs of Palestine and of See also:Egypt and the Catacombs of See also:Rome probably owe their existence to the See also:ancient practice of burial in natural hollows in the rock . We might therefore expect to find in them most important See also:evidence as to the ancient See also:history of mankind, which would reach long beyond written See also:record; and since they have always 574 been used by See also:wild beasts as lairs we might reasonably believe also that their exploration would throw See also:light upon the animals which have in many cases disappeared from the countries-which they formerly inhabited . The labours of See also:Buckland, See also:Pengelly, See also:Falconer, Lartet and See also:Christy, and See also:Boyd See also:Dawkins have added an entirely new See also:chapter to the history of See also:man in See also:Europe, as well as established the changes that have taken See also:place in the See also:European See also:fauna . The See also:physical history of caves will be taken first, and we shall then pass on to the discoveries See also:relating to man and the See also:lower animals which have been made in them of See also:late years . Physical History.—The most obvious See also:agent in hollowing out caves is the sea . The set of the currents, the force of the breakers, the grinding of the See also:shingle inevitably discover the weak places in the cliff, and leave caves as one of the results of their See also:work, modified in each See also:case by the See also:local conditions of the rock . Those formed in this manner are easily recognized from their floors being rarely much out of the See also:horizontal; their entrances are all in the same See also:plane, or in a See also:succession of horizontal and parallel planes, if the See also:land has been elevated at successive times . From their inaccessible position they have been rarely occupied by man . Among them Fingal's Cave, on the See also:island of See also:Staffa, off the See also:south-See also:west See also:coast of See also:Scotland, hollowed out of columnar See also:basalt, is perhaps the most remarkable in Europe . In volcanic regions also there are caves formed by the passage of See also:lava to the surface of the ground, or by the expansion of See also:steam and gases in the lava while it was in a molten See also:state . They have been observed in the regions round See also:Vesuvius and See also:Etna, in See also:Iceland and See also:Teneriffe . We may take as an example the Grotto del See also:Cane (" cave of the See also:dog "), near See also:Pozzuoli, a few See also:miles to the south-west of See also:Naples, remark-able for the flow of carbonic See also:acid from crevices in the See also:floor, 'which fills the lower See also:part of the cave and suffocates any small See also:animal, such as a dog, immersed long enough in it . The most important class of caves, however, and that which immediately demands our See also:notice, is that composed of those which have been cut out of calcareous rocks by the See also:action of carbonic acid in the See also:rain-See also:water, combined with the See also:mechanical See also:friction of the See also:sand and stones set in See also:motion by the streams which have, at one time or another, flowed through them . They occur at various levels, and are to be met with wherever the strata are sufficiently compact to support a roof . Those of See also:Brixham and See also:Torquay and of the See also:Eifel are in the Devonian See also:limestone; those of See also:Wales, See also:Somerset, the Pennine See also:chain, See also:Ireland, the central and See also:northern counties of See also:Belgium, See also:Saxony, and See also:Westphalia, of See also:Maine and See also:Anjou, of See also:Virginia and See also:Kentucky, are in that of the Carboniferous See also:age . The cave of Kirkdale in See also:York-See also:shire, and most of those in See also:Franconia and See also:Bavaria, penetrate See also:Jurassic limestones . The Neocomian and Cretaceous limestones contain most of the caverns of France, rendered famous by the See also:discovery of the remains of the cave-men along with the animals which they hunted; as well as those of the See also:Pyrenees, the See also:Alps, See also:Sicily, Greece, See also:Dalmatia, See also:Carniola and Palestine . The cave of Lunelviel near See also:Montpellier is the most important of those which have been hollowed in limestones of the See also:Tertiary age . They are also met with in rocks composed of See also:gypsum; in Thuringia, for example, they occur in the saliferous and gypseous strata of the Zechstein, and in the gypseous Tertiary rocks of the See also:neighbour-See also:hood of See also:Paris, as, for example, at See also:Montmorency . Caves formed by the action of carbonic acid and the action of water are distinguished from others by the following characters . They open on the abrupt sides of valleys and ravines at various levels, and are arranged round the See also:main axes of erosion, just as the branches are arranged round the See also:trunk of a See also:tree . In a great many cases the relation of the valley to the See also:ravine, and of the ravine to the cave, is so intimate that it is impossible to deny that all three have been produced by the same causes . The caves themselves ramify in the same irregular See also:fashion as the valleys, and are to be viewed merely as the capillaries in the general valley See also:system through which the rain passes to join the main channels . Some-times, as in the famous caves of See also:Adelsberg, Kentucky, Wookey Hole in See also:Somersetshire, the See also:Peak in See also:Derbyshire, and in many in the See also:Jura, they are still the passages of subterranean streams; but very frequently the drainage has found an outlet at a lowerlevel, and the ancient watercourses have been deserted . These in every case See also:present unmistakable See also:proof that they have been traversed by water in the sand, See also:gravel and See also:clay which they contain, as well as in the worn surfaces of the sides and bottom . In all districts where there are caves there are See also:funnel-shaped depressions of various sizes called pot-holes or See also:swallow-holes, or betoires, " chaldrons du diable," " marmites See also:des geants," or " katavothra," in which the rain is collected before it disappears into the subterranean passages . They are to be seen in all stages, some being See also:mere hollows which only contain water after excessive rain, while others are profound See also:vertical shafts into which the water is continually falling . Gaping Ghyl, 33o ft., and Helln Pot in See also:Yorkshire, 300 ft. deep, are examples of the latter class . The cirques described by M . See also:Desnoyers belong to the same class as the swallow-holes . The history of swallow-holes, caves, ravines and valleys in calcareous strata may be summed up as follows:--The calcareous rocks are invariably traversed by See also:joints or lines of shrinkage, which are lines of weakness by which the direction of the drainage is determined; and they are composed to a large extent of carbonate of See also:lime, which is readily exchanged into soluble bicarbonate by the addition of carbonic acid . The rain in its passage through the air takes up carbonic acid, and it is still further charged with it in percolating through the surface See also:soil in which there is decomposing See also:vegetable See also:matter . As the raindrops converge towards some one point, determined by some local See also:accident on the surface, and always in a See also:line of See also:joint, the carbonic acid attacks the carbonate of lime with which it comes into contact, and thus a funnel is gradually formed ending in the vertical joint below . Both funnel and vertical joint below are being continually enlarged by this See also:process . This chemical action goes on until the See also:free carbonic acid is used up . The subterranean passages are enlarged in this manner, and what was originally an insignificant network of fissures is See also:developed into a See also:series of halls, sometimes as much as from 8o to See also:ioo ft. high . These results are considerably furthered by the mechanical friction of the pebbles and sand hurried along by the current, and by falls of rock from the roof produced by the removal of the underlying strata . In many cases the results of this action have produced a See also:regular subterranean See also:river system . The thick limestones of Kentucky, for example, are traversed by subterranean See also:waters which collect in large See also:rivers, and ultimately appear at the surface in full See also:power . The river See also:Axe, near See also:Wells, the stream flowing out of the Peak Cavern at See also:Castleton, Derbyshire, that at Adelsberg in Carniola, flow out of caverns in full See also:volume . The river See also:Styx and the waters of See also:Acheron disappear in a series of caverns which were supposed to See also:lead down to the infernal regions . If the direction of the drainage in the rock has been altered, either by elevations such as those with which the geologist is See also:familiar, or by the opening out of new passages at a lower level, these watercourses become dry, and present us with the caves which have afforded shelter to man and the wild animals from the remotest ages, sometimes high up on the See also:side of a ravine, at other times See also:close to the level of the stream at the bottom . Caves, as a general See also:rule, are as little effected by disturbances of the rock as the ravines and valleys, which have been formed, in the main, irrespective of the lines of See also:fault or dislocation . We must now examine what happens to the bicarbonate of lime which has been formed by the action of the acid on the limestone . If a current of air See also:play upon the surface of the water, the carbonic acid, which floats up the lime, so to speak, is given off and the insoluble carbonate is deposited, and as a result of this action we have the elaborate and fantastic stony incrustations termed See also:stalactites and stalagmites . The water percolating through the rock covers the sides of the cavern with a stalactitic drapery, and if a line of drops persistently falls from the same point to the floor, the calcareous See also:deposit gradually descends from the roof, forming in some cases stony tassels, and in others long columns which are ultimately See also:united to the calcareous See also:boss formed by the plash of the water on the floor . The surface also of the pools is sometimes covered over with an See also:ice-like See also:sheet of stalagmite, which shoots from the sides, and sometimes forms a solid and See also:firm floor when the water on which it was supported has disappeared .
Sometimes the drops See also:form a little calcareous See also:basin, beautifully polished inside, which contains small See also:pearl-like particles of carbonate of lime, polished by friction one against the other
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The most beautiful stalactitic caves in Great See also:Britain are those of See also:Cheddar in Somerset, Caldy Island and See also:Poole's Cavern at See also:Buxton
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A portion only of the carbonate of lime is thus deposited in the hollows of the rock from which it was taken; the See also:rest is carried into the open air by the streams, in part deposited on the sides and bottom, forming tufa and the so-called petrifications, and partly being conveyed down to the sea to be ultimately secreted in the tissues of the See also:Mollusca, Echinodermata and Foraminif era
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Through these it is again collected in a solid form, and in the long course of ages it is again lifted up above the level of the water as limestone rock, and again undergoes the same series of changes
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Thus the See also:cycle of carbonate of lime is a never-ending one from the land to the ocean, from the ocean to the land, and so it has been ever since the first stratum of limestone was formed out of the remains of the animals and See also:plants of the sea
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The See also:rate of the See also:accumulation of stalagmite in caverns is necessarily variable, since it is determined by the presence of varying currents of air
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In the Ingleborough cavern a stalagmite, measured in 1839 and in 1873, is growing at the rate of •2946 in. per annum
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It is obvious, therefore, that the vast antiquity of deposits containing remains of man underneath layers of stalagmite cannot be inferred from a thickness of a few inches or even of a few feet
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The intimate relation which exists between caves and ravines renders it extremely probable that many of the latter have been originally subterranean watercourses, which have been unroofed by the degradation of the rock
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In all limestone districts ravines are to be found continued in the same direction as the caves, and the process of atmospheric erosion may be seen in the fallen blocks of See also:
A
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Martel. the intrepid explorer of most of the large European' caves, including those of Great Britain and Ireland
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The history of the Glacieres or Ice-caves will be found in See also: They were associated with the bones of the See also:reindeer, horse and bison, as well as with those of the great cave bear . These discoveries were of very great See also:interest, because they established the fact that the above animals had 'lived in Germany in ancient times . The first See also:bone cave systematically explored in See also:England was one at Oreston near See also:Plymouth in 1816, which proved that an See also:extinct species of rhinoceros (R. leptorhinus) lived in that district . Four years later the famous hyena den at Kirkdale in Yorkshire was explored by Buckland . He brought forward proof that it had been inhabited by hyenas, and that the broken and gnawed bones of the See also:mammoth, rhinoceros, stag, bison and horse belonged to animals which had been dragged in for See also:food . He pointed out that all these animals had lived in Yorkshire in ancient times, and that it was impossible for the carcases of the rhinoceros, hyena and mammoth to have been floated from tropical regions into the places where he found their bones . He subsequently investigated bone caves in Derbyshire, South Wales and Somerset, as well as in Germany, and published his Reliquiae Diluvianae in 1822, a work which laid the See also:foundations of the new See also:science of cave-See also:hunting in this See also:country . The well-known cave of See also:Kent's Hole near Torquay furnished McEnery, between the years 1825 and 1841, with the first See also:flint implements discovered in intimate association with the bones of extinct animals . He recognized the fact that they proved the existence of man in See also:Devonshire while those animals were alive, but the See also:idea was too novel to be accepted by his contemporaries . His discoveries have since been verified by the subsequent investigations carried on by See also:Godwin See also:Austen, and ultimately by the See also:committee of the See also:British Association, which worked for several years under the guidance of Pengelly . There are four distinct strata in the cave . 1st, The surface is composed of dark earth, and contains See also:medieval remains, Roman pottery and articles which prove that it was in use during the See also:Iron, See also:Bronze and See also:Neolithic Ages . 2nd, Below this is a stalagmite floor, varying in thickness from r to 3 ft., and covering (3rd) the red earth, which contained bones of the hyena, lion, mammoth, rhinoceros and other animals, in association with flint implements and an engraved antler, which proved man to have been an inhabitant of the cavern during the time of its deposition . 4th, Filling the bottom of the cave is a hard See also:breccia, with the remains of bears and flint implements, in the main ruder than those found above; in some places it was no less than 12 ft. thick . The most remarkable animal found in Kent's Hole is the sabre-toothed carnivore, Machairodus latidens of See also:Owen . While the value of McEnery's discoveries was in dispute the France and See also:Switzerland . Classifica.lion.—The caves which have offered shelter to the See also:mammalia are classified according to their contents, and are of various ages, ranging from the Pliocene to the present See also:day . (1) Those containing the Pliocene mammalia belong to that age . (2) Those with the remains of the mammoth, woolly rhinoceros and other extinct species, or with paleolithic than (see See also:ARCHAEOLOGY), are termed Pleistocene . These are sometimes called See also:Quaternary, under the mistaken idea that they belong to an age succeeding the Tertiary period . (3) Those which contain the remains of the domestic animals in association with the remains of man either in the Neolithic, Bronze or Iron stages of See also:civilization are termed Prehistoric . (4) The See also:fourth See also:group consists of those which can be brought into relation with the historic period, and are therefore termed Historic . The Pliocene Caves.—It is a singular fact, only to be explained by the vast denudation of the earth's surface since the Pliocene Age, that only one cave referable to that age has as yet been discovered, that at Doveholes near Buxton, Derbyshire, described by Boyd Dawkins in 1903 (Quart . Journ . Geol . See also:Soc.) . The cave consists of a large horizontal chamber and a small passage, connected with a swallow-hole close by, and exposed in the working See also:face of a See also:quarry in 1901, at a depth of about 40 ft. from the surface . The locality is in the limestone See also:plateau, 1158 ft. high, which forms the See also:divide between the waters flowing into the See also:Mersey on the west and the See also:Humber on the east . Both swallow hole and cave were completely blocked up with debris, and the 576 exploration of the cave of Brixham near Torquay in 1858 proved that man was coeval with the extinct mammalia, and in the following See also:year additional proof was offered by the implements that were found in Wookey Hole . Similar remains have been met with in the caves explored since that time in Wales, and in England as far See also:north as Derbyshire (Creswell), proving that See also:palaeolithic man hunted the mammoth and rhinoceros and other extinct animals over the whole of southern and See also:middle England . The discoveries in Kent's Hole and in the Creswell caves prove further that palaeolithic man was in two stages of civilization—the ruder or riverdrift man, with implements of the type found in the river gravels (see ARCHAEOLOGY; and PALAEOLITHIC) being the older; and the more highly advanced, or the cave-man, mainly characterized by the better implements, and a singular facility in depicting animal See also:life (as shown by the figure of a horse incised on the fragment of a bone found in the Creswell caves), being the newer . We may also conclude from the See also:absence of palaeolithic implements from the glaciated regions in which most of these caves occur, that both riverdrift and cave-men dwelt in middle and northern Britain in the pre-glacial age, their remains being protected in the caverns from the denuding forces that removed all traces of their existence from the surface of the ground in glacial and See also:post-glacial times . The riverdrift man is, however, proved to be post-glacial in southern and eastern England, by the occurrence of his implements in the river gravels of that age . Both these peoples inhabited southern England and the See also:continent before and after the glacial period . The riverdrift man, whose implements occur in river deposits in middle and southern Europe, in Africa, Palestine and Hindustan, is everywhere in the same age of See also:primitive barbarism, and has not as yet been identified with any living See also:race . The cave-men are in a higher and more advanced stage, and led a life in Europe identical with that of the Eskimos in the See also:Arctic regions . The Pleistocene Caves of the European Continent.—The re-searches of See also:Mortillet have proved. that the same two See also: |