But, I say, you needn't carry that creel as well," he said.
"I don't want to; but suppose the candle goes out ?" "Oh, you'd better take it," said Mike eagerly.

"Ready ?" "Yes, if you are." Mike did not feel at all ready, but he held the lanthorn up high and took a step or two forward and downward, which left the sunlit part of the place behind, and then began cautiously to descend a long rugged slope, which was cumbered with stones of all sizes, these having evidently fallen from the roof and sides, the true floor of the tunnel-like grotto being worn smooth by the rushing water which must at one time have swept along, reaching in places nearly to the roof just above the boys' heads.
The way was very steep, and winding or rather shooting off here and there, after forming a deep, wonderfully rounded hollow, in which in several cases huge rounded stones lay as they had been left by the torrent, after grinding round and round as if in a mill, smoothing the walls of the hollow, and at the same time making themselves spherical through being kept in constant motion by the water.

These pot-holes, as a geologist would call them, are common enough in torrents, where a heavy stone is borne into a whirlpool-like eddy, and goes on grinding itself a deeper and deeper bed, the configuration of the rock-walls where it lies having prevented its being swept down at the first, while every year after it deepens its bed until escape becomes impossible.
Again and again, as they went on, places of this kind were met with; while twice over they had to pause at spots where the water must have sprung from a shelf ten or a dozen feet down into a basin which it had hollowed for itself in the course of time.
Upon the first of these sudden drops presenting itself Mike stopped with the lanthorn.
"Here's the end of it," he said.

"Goes down into a sort of bottomless pit, black as ink.

Let's go back." Vince stepped close to his side and gazed down into the black depths with a feeling of awe, the place looking the more terrible from the fact that the tunnel had narrowed until there was only just room for them to stand between the smooth granite walls.
"Looks rather horrid," said Vince.