brought them to Arizona, where, in company with Jim Nestor, an old western miner, they had discovered a rich gold mine that had been lost for many years.

“There, my letter’s finished,” announced Jerry, about half an hour after the incident of the shooting.

“I had mine done an hour ago,” said Ned.

“Let’s run into town in the auto and mail them. We need some supplies, anyhow,” suggested Bob.

“All right,” assented the others.

The three boys went to the shed where their touring car, a big, red machine in which they had come West, was stored. Ned cranked up, and with a rattle, rumble and bang of the exhaust, the car started off, carrying the three lads to Rockyford, a town about ten miles from the gold diggings.

“I wonder if we’ll ever see Noddy Nixon or Jack Pender again?” asked Bob, when the auto had covered about three miles.

“And you might as well say Bill Berry and Tom Dalsett,” put in Jerry. “They all got away together. I don’t believe in looking on the dark side of things, but I’m afraid we’ll have trouble yet with that quartette.”

“They certainly got away in great shape,” said Bob. “I’ll give Noddy credit for that, if he is a mean bully.”

Noddy Nixon was an old enemy of the three chums. As has been told in the story of “The Motor Boys,” the first book of this series, Jerry, Ned and Bob, when at home in Massachusetts, had motor-cycles and used to go on long trips together, on several of which they met Noddy Nixon, Jack Pender and Bill Berry, a town ne’er-do-well, with no very pleasant results. The boys had been able to secure their motor-cycles through winning prizes at a bicycle race, in which Noddy was beaten. This made him more than ever an enemy of the Motor Boys.

The latter, after having many adventures on their small machines, entered a motor-cycle race. In this they were again successful, defeating some crack riders, and the prize this time was a big, red touring automobile, the same they were now using.

Once they had an auto they decided on a trip across the continent, and their doings on that journey are recorded in the second book of this series, entitled “The Motor Boys Overland.”

It was while out riding in their auto in Cresville one evening that they came across a wounded miner in a hut. He turned out to be Jim Nestor, who knew the secret of a lost mine in Arizona. While sick in the hut, Nestor was robbed of some gold he carried in a belt. Jack Pender was the thief, and got away, although the Motor Boys chased him.

With Nestor as a guide, the boys set out to find the lost mine. On the way they had many adventures with wild cowboys and stampeded cattle, while once the auto caught fire.

They made the acquaintance, on the prairies, of Professor Uriah Snodgrass, a collector of bugs, stones and all sorts of material for college museums, for he was a naturalist. They succeeded in rescuing the professor from a mob of cowboys, who, under the impression that the naturalist had stolen one of their horses, were about to hang him. The professor went with the boys and Nestor to the mine, and was still with them.

The gold claim was not easily won. Noddy Nixon, Pender, Berry and one Pud Stoneham, a gambler, aided by Tom Dalsett, who used to work for Nestor, attacked the Motor Boys and their friends and tried to get the mine away from them.

However, Jerry and his friends won out, the sheriff arrested Stoneham for several crimes committed, and the others fled in Noddy’s auto, which he had stolen from his father, for Noddy had left home because it was discovered that he had robbed the Cresville iron mill of one thousand dollars, which crime Jerry and his two chums had discovered and fastened on the bully.

So it was no small wonder, after all the trouble Noddy and his gang had caused, that Jerry felt he and his friends might hear more of their unpleasant acquaintances. Noddy, Jerry knew, was not one to give up an object easily.

In due time town was reached, the letters were mailed, and the supplies purchased. Then the auto was headed back toward camp. About five miles from the gold diggings, Ned, who sat on the front seat with Bob, who was steering, called out:

“Hark! Don’t you hear some one shouting?”

Bob shut off the power and, in the silence which ensued, the boys heard a faint call.

“Help! Help! Help!”

“It’s over to the left,” said Ned.

“No; it’s to the right, up on top of that hill,” announced Jerry.

They all listened intently, and it was evident that Jerry was correct. The cries could be heard a little more plainly now.

“Help! Hurry up and help!” called the voice. “I’m down in a hole!”

The boys jumped from the auto and ran to the top of the hill. At the summit they found an abandoned mine shaft. Leaning over this they heard groans issuing from it, and more cries for aid.

“Who’s there?” asked Jerry.

“Professor Uriah Snodgrass, A. M., Ph.D., F. R. G. S., B. A. and A. B. H.”

“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.

“No, my dear young friend, my arms are not broken. I am not hurt at all.”

“Then, why can’t you put the rope under your arms?”

“Because I have a very rare specimen of a big, red lizard in one hand, and a strange kind of a bat in the other. They are both alive, and if I let them go to fix the rope they’ll get away, and they’re worth five hundred dollars each. I’d rather stay here all my life than lose these specimens.”

“How will we ever get him up?” asked Bob.

CHAPTER II.
THE PROFESSOR’S STORY.

For a little while it did seem like a hard proposition. The professor could not, or rather would not, aid himself. Once the rope was around him it would be an easy matter for the boys to haul him out of the hole.

“If we could lasso him it would be the proper thing,” said Bob.

“I have it!” exclaimed Ned.

He began pulling up the rope from where it dangled down into the abandoned shaft.

“What are you going to do?” asked Jerry.

“I’ll show you,” replied Ned, adjusting the rope around his chest, under his arms. “Now if you two will lower me into the hole I’ll fasten this cable on the professor and you can haul him up. Then you can yank me out, and it will be killing two birds with one stone.”

“More like hanging two people with one rope,” laughed Bob.

But Ned’s plan was voted a good one. Jerry and Bob lowered him carefully down the shaft, until the slacking of the rope told that he was at the bottom. In a little while they