Not that he had ever lacked it, but his was a restful life, compared to theirs, and he seldom had need to show what he could do in a strenuous way. Though once, when Jerry had been in danger from a wild animal on one of their trips, the professor, armed only with a light gun which he used to bring down birds without injuring their plumage, rushed up and fired in the animal’s face, delaying the attack long enough for Ned to kill the beast.

“They watched me pretty closely,” went on the scientist. “But when I began collecting bugs and spiders, of which there is a wonderful variety in the valley, they began to think I was a bit out of my head,” he said with a chuckle. “Then, thinking me harmless and simple, they did not keep such a close espionage over me, and——”

“You fooled ’em good and proper!” exclaimed Bob, admiringly. “We couldn’t have done it half as well.”

“Not much!” declared Jerry. “We’d have probably tried to concoct some elaborate scheme to escape, and they’d have found it out right away. But the professor’s simple trick worked.”

“I didn’t exactly intend it for a trick,” said the scientist, who was the soul of honesty and fair-dealing. “I really did make a good collection while I was held a prisoner in the valley.”

“And have you really learned the secret of the mysterious ravine and just how the cattle rustlers work?” asked Ned.

“I think I have. Of course I haven’t seen the actual secret door, but I believe I can show you how to find it.”

“And the reason the marks of the cattle always stopped before the end of the gorge was reached was because they put the beasts on the stone-boat and dragged them over the remaining distance,” said Jerry. “It was a clever trick, but it’s been found out.”

“But not by us,” put in Ned, gloomily. “We have fallen down all along on this job.”