On the banks of the lagoons they found abundant traces of the natives, and it was evidently a main camping-place on their way to and from their burial-place. Many of the trees were marked with triangles, a sign which considerably puzzled the elder travellers. The open country, the ample supply of water, and the relief from the gloomy surroundings of the scrub had restored the cheerful tone of the party, and imparted a sense of security to them.
But neither Brown nor Morton were men to neglect due precautions, now that their presence was known to the probably hostile inhabitants. So a watch was kept all night by the three whites in turn, Billy escaping the vigil, as blacks are not to be trusted to keep awake.
CHAPTER IV.
The Limestone Plain—The Devil's Tracks—A Strange Mark.
The morning found them early on the move, the night having passed without any alarm, false or real. They still followed the faint track leading straight toward the dark ridge they had seen beyond the blue expanse. This supposed dry lake had been visible from the camp before sunrise, but as the sun rose it disappeared, nor did they again sight it until nearly eight o'clock. At ten they were close to it, and all doubt as to its character was set at rest. They pulled up, not at the edge of a dry salt lake, but of an unbroken sheet of limestone rock. Nothing was visible ahead but this stony sea of bluish-gray, over which a heated haze was undulating. The dark line beyond, resembling a ridge, had vanished, and the wind that blew in their faces across the surface of this strange plain, was as hot as though it came from the open door of a furnace.
THEY FIND THE DEVIL'S TRACK ON THE ROCK-PLAIN.
Morton turned and rode along the edge of the rock to where the pad came in, for they had left the track for the last hundred yards. He whistled, and the others joined him. The track still continued right on across the rock, but its course was now indicated by other means. On the surface of the limestone had been scratched and chipped with infinite care, an imitation of human footsteps, or rather more than human footsteps, for the gigantic tracks were more than twice the size of a man's, and a stride to correspond was indicated. Side by side, about six feet apart, these two awful footsteps disappeared into the quivering mirage.