“It’s the only way, I guess,” agreed the miner.

“And there’s no more use digging here,” came from Jim Nestor, as he took up the pick and shovel and started toward the airship. “It’ll fool those fellows,” and he chuckled as he waved his hand toward the group on the cliff above them.

“They seem some put out,” observed Ned, who was looking at Noddy and his cronies through the glasses. “They’re holding a conference, I guess.”

“What about the professor?” asked Mr. Brill, as they all left the big rock. “If we’re going to the other end of the valley do we want to leave him near here?”

“No, we’d better pick him up,” agreed Jerry.

“Let’s have dinner first,” suggested Bob. “I’ve got it almost ready.”

“That’s right, Chunky; don’t let anything interfere with the meals,” laughed Jerry.

Another look at the place on the cliff where the spies had been, showed that they had vanished. Probably they had observed that they were being looked at with glasses, and did not want to betray their movements too much.

“I wonder what they’re up to?” said Ned.