THE FOSSIL BONE CAVE, THE SPARKLING ROCK, AND THE CRYSTAL ROCK.
About 20 yards north from the ladder to the underground river is the entrance to the Fossil Bone Cave. Here is a stratum of coffee-coloured slatey substance in layers like those of the Wianamatta shale. It is so soft that a gentle touch is sufficient to pulverise it. It is slightly honeycombed, and its outer surface is covered with imitations of delicate lichens. In this cave there is not anything in the shape of a stalagmite, except an empty brandy bottle on a little shelving rock, and that would be generally regarded as a bad substitute. For æsthetic as well as for other reasons, it would be better to keep such "stalagmites" out of the caves. On the top of a large rock is a mass of "washdirt," 14 inches deep, with "headings" of about the same dimensions. Some experienced diggers say they never saw more promising stuff. During the yellow fever from which so many suffered a few years ago, companies were floated on the strength of "claims" equally delusive. Proverbially, "auriferous ground" is deceitful, and this "washdirt," which looks rich enough to make a prospector's eyes sparkle with delight, has proved to be as worthless as a lying prospectus. A portion of it was washed, but did not show the colour of gold. It remains, however, an object of interest, and may serve to teach a useful lesson.
There are in this cave solid limestone rocks above and below. The roof is about 500 feet beneath the surface of the mountain. In the bed of the cavern are many fossil bones. Some appear to be remains of native dogs. In various rocks are clusters of bat bones. A very noticeable osseous object is the vertebra of a bird with one side-bone. There is no trace of the other. There are also many large bones, the cylindrical cavities of which are filled up with formation. Some of these bones are deposited about eight feet from the bottom of the cave. On one ledge is a heap of bones, large and small. Some of them are very fine specimens. The height of this cave is about 15 feet, and its breadth from 8 to 15 feet.
Travelling from the passage leading to the Fossil Bone Cave N.N.W. about 40 yards, and passing through a cutting N.W. about 30 yards, the visitor comes to "The Sparkling Rock." A cutting, five feet by two feet, forms the entrance to a spacious hall, where is seen the Sparkling Rock, large and shelving. The principal portion of it is slightly coloured, but the lower part is beautifully white. It is hung with large stalactites and fleecy pendants. Some of the formation resembles sheepskins, with the woolly side outwards, thrown negligently over the ledges. From this point the course runs west about 30 yards through a hall from 20 to 25 feet high, and from 15 to 20 feet wide, and thence north about 40 yards to the Crystal Rock.
About 14 yards west from the Sparkling Rock, and by a road wide enough for a coach and four, there is a large upward shaft of about 100 feet to the Grotto Cave, which, as previously stated, is between the Helena and the Lucinda caves in the left-hand branch. Here the tourist gets a good idea of the way in which the two branches of the Imperial Cave are situated with regard to each other. The right-hand branch is the lower series. The left-hand branch is higher up in the interior of the mountain, and to the south-east, with the exception of the Grotto Cave, which is immediately overhead, and about 100 feet from the Sparkling Rock.
On the left-hand side of the passage, and about 25 yards from the Crystal Rock, is a very pretty grotto of formation, with an overhanging ornamental mass like a canopy. Up above, about 40 feet, is the opening to an unexplored cave, the mouth of which is composed of solid shining rock, with white stalactites. There are also, round about, coloured stalactites varying in length from an inch to a couple of feet. The remainder of the passage is lofty and rugged.
Not far from the entrance to the Crystal Rock is the bottom of the shaft down which the curator was lowered from the Coral Cave (a sub-cavern of the Elder Cave) into the Imperial, and on the wall this memorable event is duly recorded. Here we read:—"These caves were discovered by Jeremiah Wilson." Then follows a list of the names of persons who lowered the fearless curator down the black hole: "Alfred Whalan, Thomas A. Gread, Jeremiah F. Cashin, Joseph Read, Nicholas Delaney, Ralph T. Wilson, Thomas Pearson, Heinrich Neilzet, and William Read." They were named "Wilson's Imperial Caves" on February 16, 1879. From this spot the Sparkling Rock is about 15 yards N.N.E. It is about 25 feet wide and about 18 feet high. Stalactitic formation descends from an angle in the roof, and rests on four or five finely coloured terraces which glitter all over as though they were covered with spangles. To the left of these terraces is a large basin with coral sides and a rim composed of three or four layers of shell-shaped pattern overlapping like fish scales, the rows being a little way apart from each other, and the intervening spaces filled with formation. The bottom of the basin is covered with very delicate ornamentation, deposited by water which has soaked through to a lower level. In the background is another rock, covered with similar formation, fringed with stalactites, and stalactites also descend to it from the roof.