THE VARIETIES OF CAVERNS.

Bruce Herald, Volume XIX, Issue 1933, 17 February 1888, Page 6

THE VARIETIES OF CAVERNS.

The cla^s of underground openings known as caverns have, in all countries and at all times, been specially captivating to lovers of the marvellous ; the strange architecture, beautiful ornamentation, aid peculiar inhabitants have combined to make them attractive. To men of science they have recently bpcome extremely interesting, because they throw light on the early conditions of savage man, and make same J startling contributions to the facts which bear on the so-called Darwinian theory. The oppn spaces of the underground may, at the outset of our inquiry, fir convenience, be divided into several distinct classes. First, we have the caverns or the channels excavated in limestone rocks by streams which find their way beneath the surface. These are by far the most extensive and the most interesting of the subterranean chamber?. Next, the channels and chambers hollowed out by the waters of hot springs on their way from the depths of the earth to the surface. Third comes the sea-caves, formed where the battering surras have worn away into the shore-cliflN along the line of some softer part of the rocks or of an incipient fusure. Fjurth, the cavities curiously formed where a lava-stream has f roz nor solidified on the surface, while the liquid rock below has flow 3d on or sunk back into the depths, leaving the arch standing, until the matter which originally supported it has disappeared. Lastly, we have the rifts formed in the rocks which have been rent by the mountain-building forces, where the walls on either side of the break — or, as it is termed by miners, the fault — have been pulled apart from each other, leaving a very deep aid long, but relatively narrow, fissure. la one or another of these groups we may place all the known cavities which occur beneath the earth's surface.— Scribner's Magazine.