miles in length, by a maximum of half a mile in width. Immediately to the south the limestone dyke is covered, but it crops up again about seven miles distant, and continues on the surface for 15 to 20 miles, in the direction of Goulburn. Near to what is called the Gallery (the approach to the bridge over the arch) is an old gum tree, growing right over the centre of the Devil's Coach House, and 500 feet above the gullies, which can be seen by looking over the precipice. If it were a blue gum tree, "and nothing more," it would be as uninteresting as the "yellow primrose by a river's brim" was to Peter Bell. As a specimen of its kind this tree is a failure; but it happens to be in the centre of the cave reserve, and the "blaze" on it bears the mark, "F 69." From this point the reserve extends two and a half miles east and west by five miles north and south, and is certainly one of the most wonderful areas dedicated to the public. In the rocks near to the Centre Tree is an orifice called "The Devil's Hole." It pierces the mountain obliquely, but without much deviation from a straight line, and a stone thrown down it takes, according to its weight, from nine to twelve seconds to find a resting-place on the floor of the Devil's Coach House! This is an experiment which should not be tried without precaution, and then only under official sanction, otherwise some serious accident may occur. It would be well to erect notice-boards at this and several adjacent places, warning persons not to cast stones into the caverns, for the whole mountain is full of holes and caves and drives. A piece of rock cast heedlessly into a crevice or perforation in one cave might mean death to a tourist in lower cavernous regions, and there is neither medical man nor coroner within convenient distance. From the bridge (which is guarded by wire ropes) on the western side, the visitor looks down on the Elder Cave; the Zigzag is in front, and below is the sylvan valley from which the "ermin'd frost" has been thawed, and which now "laughs back the sun." To the eastward are in view of the spectator the Nettle and Arch Caves gate, the south entrance to the Devil's Coach House, and the waterfall to the Cave River. In the distance can be discerned a place known as Oaky Camp, or McEwan's Camp, which is of interest in connection with bushranging episodes of the olden time. From the highest point of the hill over the Grand Archway the cave-house can be seen nestling in the valley 500 feet below. Perched upon this pinnacle, with terrible depths on each side and awe-inspiring grandeur at every turn, the beholder is apt to realise how very small is the space he fills in the economy of Nature, how inadequate is language to express deep emotions of the mind, and how marvellous are the works of the Creator! CHAPTER IX. THE ELDER CAVE.