"They occur most frequently along rocky shores of open seas, as in this case. Some of them are celebrated for their great extent, others for their gorgeous interiors, like this chamber. Some show the most beautiful draperies, or veils; in some cases portions of the ceiling have representations of magnificent inverted candelabra, and what appear to be carvings in the purest white."
"In what parts of the world are most of them found?"
"It does not seem that any portion of the world has a monopoly. The most celebrated are the grotto of Antiparas, in Greece; the Adelsberg caverns in Carniola, and the Mammoth in Kentucky. The latter is the largest in the world, the windings of which extend forty miles and through which is a subterranean river. In the river are eyeless fish, and fish with eyes, but sightless. Others are the Luray, in Virginia; the Wyandotte, in Indiana; Weir's, in Virginia; the Big Saltpeter, in Missouri, and Ball's, in New York. Of seashore caverns, the most famous and remarkable is Fingal's, on the coast of Scotland. Extensive caves are also found in the Azores, Canary Islands, in Iceland, in various portions of England, France and Belgium. Many of them are of immense value to the paleontologist."
"In what way are they of any use?"
"They have been of the greatest service, because in the early days of man, and before he knew enough to build his own habitation, he made the cave his home. You have heard of the 'cave man,' have you not? During the old stone period in England and other European countries, these caverns were the only abodes of man, and in them have been found layers from twenty to thirty feet thick, of successive accretions of bone, stalagmites and various articles of human manufacture."
This information added interest to the examination of the walls, and the eagerness of the boys to discover something new and startling was at its keenest edge. Before they had made a half circuit George announced that he could see a large opening, which turned to the right, and thus formed a bend to the general direction that the cavern had made.
A digression is necessary, in order to be able to understand all the elements in this remarkable voyage. The mouth of the cave was northeast of the Cataract home, and distant about a half mile, in a straight line. The opening for the first six hundred feet, which had been charted by them on the previous occasion, ran directly south, but from that point it turned toward the southwest, and this now, in a measure, explained the eagerness of the Professor to explore it, as he believed the cavern led to a point near their home.
"There is no water in the opening," was the further information from George, as they approached the contracted end of the chamber.
"Before we land let us see the other side of the chamber," was the Professor's suggestion.
The boat was veered around to the left, and before they had proceeded fifty feet it was apparent that a similar opening led out to the south, and a dry floor was visible, like in the other outlet. The boat was landed, and drawn up, two of the lamps taken out and the guns examined. The opening led into a second chamber, which looked like a canopied grotto of marble. Where they stood the chamber had the appearance of a huge letter A, the side walls of which ran together in the distance, but these walls were broken up by the most enchanting series of columns, and delicate entablatures, and the outlines of the figures were like blanched frescoes. It was such a weird and startling sight that the boys could not repress their amazement.