Returning up the dale, we closed the mouth of the artificial level, and went back to the Ricklow Cavern. Although the portal is so majestic, the passage becomes anything but commodious at the end of a few paces. Once more we had to crawl over hard, water-worn rock, deeply fissured and thrown out of the horizontal; our galled knees and elbows could scarcely be induced to go at all, and the pace was miserably slow. Then the roof came down so close in a horizontal fissure of huge extent, that there was nothing for it but to wriggle. My friends had ascertained that 280 feet of this work leads into a lofty chamber. It is one of those long, vertical fissures, not wide but enormously high, that are common in the Castleton caves. There were indications of galleries overhead, but we were too much exhausted to attempt climbing without a ladder. Only one exit was practicable, which led in 20 feet into just such another hollow, but still wider and uglier of aspect. Filling the cavity to a height of 30 feet was a mountain of shattered rocks, flung together pell-mell and wedged loosely. When we climbed it, the light of our candles showed that the structure was hollow, and hardly more durable in appearance than a house of cards. Some of the rocks were held by points and corners, swinging on their long axes; a touch sent others clattering down, as we crept with the utmost caution up the adjoining wall. It was as if the interior of the hill had been rent apart by an earthquake, and the headlong stream of rocks caught suddenly and held by the closing in of the fracture. We clambered to the summit of this hollow mass of ruin, and lit some magnesium wire. The formless walls went up into a dark void above us, their ledges fringed with glistening spikes and tendrils of transparent stalactite, revealed by the glare. There had been visitors here before. Scratched on the walls, but partially coated over by a crystalline enamel, were the initials "H. B.--R. A.," and the date 1817; other scrawls were indecipherable. No doubt this was the cave whose legendary renown had reached our ears. Getting down our shattered staircase was a more formidable job than the ascent. One stone, as big as a table, rocked like a see-saw when we set foot on it. Stalactites were not numerous in these caves, which are not only very humid, but continually swept by water. Animal remains were plentiful, all recent, bones being carried in by beasts of prey and deposited by floods. As this process must have been going on for ages, the two Cales Dale caverns would probably yield good results to palæontological research.