“It’s queer I can’t pick out that landmark,” said Mr. Jenks after two days of weary searching, when their eyes were strained from long peering through telescopes.  “I’m sure it was around Indian Ridge, yet we’ve covered almost all the ground in this neighborhood, and I haven’t had a glimpse of it.”

“Perhaps it was destroyed in a landslide, or some cataclysm of nature,” suggested Mr. Parker.  “That is very possible.”

“If that’s the case we’re going to have a hard time to locate the cave of the diamond makers,” answered Mr. Jenks, “but I hope it isn’t so.”

They continued the search for another day, and then Tom, as they sat in the comfortable cabin of the airship that night, hovering almost motionless (for the motor had been shut down) made a proposition.

“Why not descend in some secluded place,” he suggested, “and wander around on foot, making inquiries of the miners.  They may know where the stone head is, or they may even know about Phantom Mountain.”

“Good idea,” spoke Mr. Jenks.  “We’ll do it.”

Accordingly, the next morning, the Red Cloud was lowered in a good but lonely landing place, and securely moored.  It was in a valley, well screened from observation, and the craft was not likely to be seen, but, to guard against any damage being done to it by passing hunters or miners, Mr. Parker and Mr. Damon agreed to remain on guard in it, while Tom and Mr. Jenks spent a day or two traveling around, making inquiries.

The young inventor and his companion proceeded on foot to a small settlement, where they hired horses on which to make their way about.  They were to be gone two days, and in that time they hoped to get on the right trail.

CHAPTER XII—­THE GREAT STONE HEAD

It was a wild and desolate country in which Tom Swift and Mr. Jenks were traveling.  Villages were far apart, and they were at best but small settlements.  In their journeys from place to place they met few travelers.

But of these few they made cautious inquiries as to the location of Phantom Mountain, or the landmark known as the great stone head.  Prospectors, miners and hunters, whom they asked, shook their heads.

“I’ve heard of Phantom Mountain,” said one grizzled miner, “but I couldn’t say where it is.  Maybe it’s only a fish story—­the place may not even exist.”

“Oh, it does, for I’ve been there!” exclaimed Mr. Jenks.

“Then why don’t you go back to it?” asked the miner.

“Because I can’t locate it again,” was the reply.

“Humph!  Mighty queer if you’ve seen a place once, and can’t get to it again,” and the man looked as if he thought there was something strange about Tom and his companion.  Mr. Jenks did not want to say that he had been taken to the mountain blindfolded, for that would have caused too much talk.

“I think if we spent to-night in a place where the miners congregate, listened to their talk, and put a few casual questions to them, more as if we were only asking out of idle curiosity, we might learn something,” suggested Tom.