“Our old friend, the professor!” exclaimed Ned. “How did you ever get there?” he called down the shaft.

“Never mind how I got here, my dear young friend,” expostulated the professor, “but please be so kind as to help me out. I came down a ladder, but the wood was rotten, and when I tried to climb out, the rungs broke. Have you a rope?”

“Run back to the machine and get one,” said Jerry to Bob. “We’ll have to pull him up, just as we did the day he fell over the cliff.”

In a few minutes Bob came back with the rope. A noose was made in one end and this was lowered to the professor.

“Put it around your chest, under your arms, and we will haul you up,” said Jerry.

“I can’t!” cried the professor.

“Why not?”

“Can’t use my hands.”

“Are your arms broken?” asked the boy, afraid lest his friend had met with an injury.