Page:The fairy tales of science.djvu/303

Rh floor of this cavern is paved with polished marble of a delicate green colour, and the columns which appear to support the roof seem to be formed of a deep burning-red porphyry. But this cavern is merely the entrance-hall of the subterranean palaces; the principal apartment or throne-room is incomparably more gorgeous. At a depth of fifteen hundred feet below the surface of the earth, the traveller finds himself in a grotto whose height is one hundred feet, while it extends to a length of three hundred and forty feet. Here the pillars are of yellow marble; petrifactions resembling snakes, trees, and shrubs abound; and in some places icicles of pure white glistening marble depend from the roof, to a length of ten feet. The tales told of this awe-inspiring gnome palace have assumed the tone of the wildest romance; and its diamond-spangled caves and walls of ruby have been described with all the vividness of over-wrought imagination. Nevertheless, all this wondrous architecture—all these wild and fantastic forms, and every phenomenon attending the production of the roofs, sides, and floors of these caverns, can be accounted for, as we have said, by the percolation of water, clear as crystal, but charged with calcareous material.

In these caverns we discover stalactites in every stage of growth, and are thus enabled to conceive how a single specimen is formed. A drop of water holding a quantity of limestone in solution hangs from the roof, and as the fluid evaporates the