THE VARIETIES OF CAVERNS.

Mataura Ensign, Volume 10, Issue 754, 9 March 1888, Page 2

THE VARIETIES OF CAVERNS.

The class 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 become extremely interesting, because they throw light on the early conditions of eavage man, and make some 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, for convenience, be divided into several dis-* tinct 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 chambers. 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 surges have worn away into the shore-cliff* along the line of some softer part of the rocks or of an incipient fissure. Fourth, the cavities curiously formed where a lava-stream has fvoz n or solidified on the surface, while the liquid rock below has flowed on or sunk back iuto the depths, leaving tha arcb 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 and long, but relatively narrow, fissure. In one or amtlier of thase groups wo may place all the known cavities which occur beneith the earth's Burface. — S^ribner's Mia/agine,