"Hello!" he exclaimed suddenly, sitting bolt-upright.
What had attracted Dave's attention was a light. It had appeared suddenly on a ledge, almost at the top of the hill he was bent on climbing.
It was no fixed light, but a broad swaying jet of fire. Whoever held it was evidently swinging a lighted wisp of straw or something of that sort.
"I wonder what that means," mused Dave. "I wonder who it can be. Probably a native. But, native or otherwise, there is method in the way that light is moving. Yes, it certainly is a signal."
Such Dave decided it surely to be after watching the light for some minutes.
It described circular and other figures. It seemed directed at a point somewhere down the valley.
"I would like to know what is going on up there," said Dave, rousing up. "It would give me an inkling as to whom I have to deal with and where I really am."
After a further rest of a few minutes the young diver resumed the ascent of the hill.
CHAPTER XVII
A REMARKABLE SCENE