I must explain that we had pulled up a quantity of grass and strewed it over the sand, so as to make a snug soft sleeping-place for the night. While we were enjoying our dinner, the river, unobserved by us, had risen considerably, and was now flowing over that portion of the step whereon we had made up our beds. There had been no rain to account for this, so I suppose that the sun, blazing down on the rocks, causes a great evaporation of water during the day, and that, consequently, the volume of the stream is greater after sunset.
So we had now to put aside our pipes and grog for a few moments and undertake some necessary engineering operations: we cleared away a channel through the natural dam of grass, stones, and sand at the lower edge of the step, and so gave a free passage to the swollen stream. The flood subsided at once, and our beds were above water again. The doctor, then, acting in his medical capacity, suggested that damp mattresses were unhealthy; so we threw a few handfuls of grass on the top of the sodden mass, and our beds were what we were pleased to call dry again.
We lit a fire of the dead wood and kept it alight all night, so that we could occasionally warm ourselves by it; for a wind had sprung up at sunset, which swept up the ravine from the sea, making us feel uncomfortably chilly, thinly clad as we were and having no blankets to cover us.
We soon found that it would be impossible for us both to sleep at the same time, for the land-crabs had smelt us out and swarmed down upon us from all sides. We kept watch and watch; while one slept the other tended the fire and killed the land-crabs, as they approached, with sticks and stones. The other crabs, as usual, fed on the dead. I have, in the 'Cruise of the "Falcon,"' described the peculiarly uncanny way in which a land-crab eats his food. I saw this night, as I kept watch, at least twenty of them at a time devouring the carcasses of their slain friends. Each stood quite still, looking me straight in the face with his fixed outstarting eyes, and with an expression absolutely diabolical. He pulled the food to pieces with his two front claws, and then, with deliberate motion, brought the fragments of flesh to his mouth with one claw, and chewed them up with a slow automatic action, but still those horrible eyes never moved, but stared steadily into mine.
As we had no means of judging the time, it was difficult to divide the night into watches of even length, so we had to portion it out between us the best way we could.
CHAPTER XIII.
A NARROW ESCAPE.
We started early on the following morning, November 23, and reached the summit of the landslip before the sun had heated the black rocks, and the layer of close air immediately over them, to that high temperature which we had found so insupportable on the previous day.
We managed to ascend the cliff which hangs over the landslip without accident, but it was anxious work, and we experienced a sense of relief when we found ourselves safe once more on the upper plateau.