Cave

Cave, a hollow extending beneath the surface of the earth. Natural caves may originate in the expansive force of volcanic gases, as in the Grotto del Cane, near Pozznoli, in which carbon-dioxide still escapes from crevices in the floor; or in the erosive action of sea-waves and of the compression of air that they produce, as in Fingal's Cave, hollowed out of the columnar basalt of Staffa; or in the solvent action of water charged with carbon dioxide acting along joints in limestones. Some of these latter, such as the Mammoth Cave of Kentucky, and those of Adelsberg, extend for many miles, branching into innumerable chambers. Streams of water may still traverse them, or the subterranean drainage having been deflected, the floors of caves may be dry and suitable for occupation by man or animals. Caves have been used in all ages by man as dwellings, as refuges, or as tombs. In those in the Cretaceous limestones of Perigord the remains of an Esquimaux-like race, using rude (palaeolithic) flint-implements have been found, together with the bones of the animals they hunted, including the extinct mammoth, and cave-bear, and the reindeer, these bones being sometimes incised with graphic outline representations of the animals when alive. Many caves in Wales, France, and Spain yield remains of men of an Iberian or Basque race, who used polished stone (Neolithic) implements. The temporary sojourn of Lot and of David in caves, and the burial-cave of Machpelah are instances that may be cited from Holy Writ. Articles of the Bronze Age and others coming down to the fifth century have been found in caves in Britain, whilst in Arabia, China, and Central Africa many people still lead an underground life. The dark recesses of caverns and their use as refuges by conquered races have in most countries associated them with much legendary lore of oracles, sibyls, nymphs, fairies, sleeping heroes, and entrances to the nether world.