It fell, as I have already explained, in a solid sheet, which made up the whole of the wall of the cave.

Higher than the roof of the cave I could not see what happened, except that it must be the open air, for the sun was shining on it.

The water was about three yards distant from the edge of the cave's floor, but it seemed to me that high up, level with the roof, this distance decreased to little more than a foot.
I could not see what the walls of the cave were like, but they looked smooth and difficult.

Supposing I managed to climb up to the level of the roof close to the water, how on earth was I to get outside on to the wall of the ravine?
I knew from my old days of rock-climbing what a complete obstacle the overhang of a cave is.
While I looked, however, I saw a thing which I had not noticed before.
On the left side of the fall the water sluiced down in a sheet to the extreme edge of the cave, almost sprinkling the floor with water.

But on the right side the force of water was obviously weaker, and a little short of the level of the cave roof there was a spike of rock which slightly broke the fall.