"By its own weight made stedfast and immoveable."
The floor is very irregularly broken, consisting of vast heaps of the nitrous earth, and of the ruins of the hoppers or vats, composed of heavy planking, in which the miners were accustomed to leach it. The hall was, in fact, one of their chief factory rooms. Before their day, it was a cemetery; and here they disinterred many a mouldering skeleton, belonging it seems, to that gigantic eight or nine feet race of men of past days, whose jaw-bones so many vivacious persons have clapped over their own, like horse-collars, without laying by a single one to convince the soul of scepticism.
Such is the vestibule of the Mammoth Cave,--a hall which hundreds of visitors have passed through without being conscious of its existence. The path, leading into the Grand Gallery, hugs the wall on the left hand; and is, besides, in a hollow, flanked on the right hand by lofty mounds of earth, which the visitor, if he looks at them at all, which he will scarcely do, at so early a period after entering, will readily suppose to be the opposite walls. Those who enter the Great Bat Room, (Audubon Avenue,) into which flying visitors are seldom conducted, will indeed have some faint suspicion, for a moment, that they are passing through infinite space; but the walls of the Cave being so dark as to reflect not one single ray of light from the dim torches, and a greater number of them being necessary to disperse the gloom than are usually employed, they will still remain in ignorance of the grandeur around them.
Such is the vestibule of the Mammoth Cave, as described by the ingenious author of "Calavar," "Peter Pilgrim," &c.
From the vestibule we entered Audubon Avenue, which is more than a mile long, fifty or sixty feet wide and as many high. The roof or ceiling exhibits, as you walk along, the appearance of floating clouds--and such is observable in many other parts of the Cave. Near the termination of this avenue, a natural well, twenty-five feet deep, and containing the purest water, has been recently discovered; it is surrounded by stalagmite columns, extending from the floor to the roof, upon the incrustations of which, when lights are suspended, the reflection from the water below and the various objects above and around, gives to the whole scene an appearance equally rare and picturesque. This spot, however, being difficult of access, is but seldom visited.