"Not a speck of anything that even remotely corresponds with the black sand that Zeb brought East with him," said the man of science, dejectedly.
"It isn't possible that we have been fooled," said Zeb.
"Or landed on the wrong island," struck in Jack.
"It must be the right island," declared Zeb.
"How do you make that out?" asked Jack.
"Well, it's got every mark on it that the map gives, for one thing," said Zeb.
"That's so," agreed the professor, and then he added hopefully: "However, I haven't covered half the ground yet."
Tom and Dick came tramping back at that juncture. They carried some canned goods and Dick bore the rusty shovel that they had seen the day before sticking up in the black barren.
"It was sticky and moist out there," he said, "but I figured we could always use this shovel, so I went out and brought it along."
He flung himself down full length in the shade for it was hot and there was not a breath of wind to fan the canyon. The professor, who sat facing Dick, concentrated his attention for an instant on the soles of the youngster's boots. Then he leaped up with a yell that startled them.