Chapter XIX. What Was Found Underground.

While Fremont was clambering down the eastern slope, studying the renegade Englishman whenever opportunity offered, and puzzling over the source of the fellow's information concerning the Cameron building and the Tolford estate papers, Ned Nestor and his companions were preparing to visit the interior of the strange shelter-place in which they found themselves.

The outer chamber, which, for convenience they marked "Chamber A" on the rough map they afterward made, was 30x40 feet in size, with the eastern side running parallel with the almost perpendicular face of rock which shot upward from the shelf which has before been alluded to. The opening faced directly east, and from it one could look miles over the desert of sand lying between the foot of the range and the Rio Grande del Norte, something like a hundred miles away.

To the north and south of this main chamber the boys found niches in the rock, evidently hewn there by man hundreds of years before. The rock was very hard here, and it seemed that work had ceased for that reason.

On the west side of the chamber there were two openings, perhaps four feet by six, each leading into a chamber 20x30 feet in size. Before entering these rooms, which held an odor of dampness and decay, the recently arrived Black Bears produced electric flashlights.

"We looked up Old Mexico," Harry Stevens said, turning on the flame, "and knew we'd be nosing around in caves and tunnels before we got back to God's country, so we brought our glims along with us."

"Well, don't burn them all at once," advised Nestor. "We shall need them for several days, probably, and there are no shops in the next block where dry batteries can be bought. Leave one out and put the rest away."

"We have a few extra batteries," said Harry. "We looked out for that."

"We shall doubtless need all you have, no matter how economically they are used," Nestor said. "Let me take the one you have, and I'll go on an exploring expedition into the south chamber."

"Me for the exploring expedition too!" cried Harry. "I want to see how it seems to go into a room ten thousand years old."

"Nixt ten thousand years!" observed Jimmie.

Harry nudged Peter Fenton and pointed to the west wall of the chamber, across which he threw the brilliant circle of the flashlight.

"There is the record," he said.

"Nix ten thousand years old!" insisted Jimmie.

No one knows how old," Fenton said. "No one has ever been able to translate the picture talk of the very early inhabitants. The man who carved those lines might have existed when the sandy desert out there was under water."

"Speaking of water, let's go on and see where they got their drinkings," put in Frank Shaw. "I'm nearly choked, and I'll bet there's a spring about here somewhere."

"Any old time you don't want something to eat or drink!" laughed Harry. "Well," he added, handing the flashlight to Nestor, "we may as well go in and see if there is a water system here."

"There surely is," Fenton said. "The people who dug this shelter out did not work where there was no water. If Nature did not supply it, they built aqueducts to convey it to locations where it was wanted. But Professor Agassiz says they lived ten thousand years ago, so, if they did put in a water system here, it may be out of commission now."

"How does he know how long ago they lived?" asked Jack.

"By their bones," was the reply. "Near New Orleans, under four successive forests, one on top of the other, and each showing traces of having been occupied by man, explorers recently discovered a human skeleton estimated to be fifty thousand years old. That fellow must have lived just after the last glacial epoch."

"I don't believe they know anything about how long ago he lived," observed Jimmie. "How can any one tell how long ago the last glacial epoch closed?"

"Figure out how far the melting line traveled from south to north," said Fenton, "then figure that the glaciers receded at the rate of only twelve feet every hundred years, and you'll know something about it."

"Come on!" cried Frank, "let's get in there and find their Croton system. I'm so thirsty my throat sizzles. Come on!"

Nestor, closely followed by the others, led the way into the south chamber, called, for convenience, "Chamber B" on the rough map made later on. The place was damp and cold, and a current of air came from the southwest corner, indicating an opening there.

After clearing away a heap of rocks and loose sand, which might once have been rock, the boys found an opening which had been, apparently, closed for a long period of time. When finally cleared, after an hour of hard work, the opening from which the current of air had come was discovered to be a door like arch in the west wall of the main chamber.

The electric flashlight, however, when introduced into the opening, showed a narrow passage beyond the opening instead of a square room. This tunnel-like passage was not far from six feet in width and about that in height. The walls showed that it had been cut through solid rock.

The boys listened for some indication of life or motion in the tunnel, but all was silent. Not even a bird or creeping thing disturbed the stillness of the place.

"Shall we go in now?" asked Nestor.

"Sure!" replied Shaw. "We may find a well in there!"

"Or a soda fountain, or a modern filter," grinned Jimmie. "How would they ever get a well down through this mountain?"

"Water in wells comes from elevations before it gravitates to the bottom of the holes from which we pump it," Shaw declared, in defense of his suggestion. "There may be a reservoir here somewhere."

"How far is this cavern floor from the surface above it?" asked Harry Stevens, with a judicial air.

"About four hundred feet," was the reply. "We must be about that distance from the highest point here."

"Then there is no reason why there should not be a reservoir above us," said Harry. "Water would filter through these rocks, all right."

The boys passed on in a southwesterly direction to the end of the tunnel, which was about fifty feet from the opening. Here they found a chamber about 10x16 feet in size. At the south side of this chamber was a trough-shaped place cut in the rock, and through this a small rivulet of water ran.

"I knew the people who built this shop wouldn't put in their time where no water could be procured," declared Fenton. "Why, this is simply fort, a mountain residence, where valley people came in time of war and secreted themselves. If we could read the hieroglyphics on the walls, we would be able to write a history of their troubles."

"Were they the real thing in cave-dwellers?" asked Jack, who was not noted for his studious habits, and who depended on his companions for a knowledge of the countries he visited as a member of the Black Bear Patrol.

"Earlier than some of the cave-men," replied Harry. "I wonder if this water is any good to drink?" he added, looking longingly at the crystal stream flowing under the round circle of the flashlight. "Who wants to try it?"

Frank Shaw did not wait to make many tests. Tormented with thirst, he felt of the water by rubbing it between his thumb and fingers, smelled of it, put it cautiously to his lips, and then, experiencing no bad effects from this contact, took a few drops into his mouth.

"It is fine!" he shouted, then. "Cold as ice and sweet as sugar! This beats a soda fountain, Jimmie!"

"Now, was this tunnel constructed on purpose to reach this spring?" asked Harry.

The lads examined the walls minutely, but there was no opening from the chamber, save the one by which they had entered.

"This must have been the milk house," laughed Frank, always ready to turn any subject under discussion into a joke. "I wonder if they kept their cows on the top of the peak? If they had tied their tails together and put one over each side, they never could have run away."

On their way back to Chamber B the boys discovered an opening in the north wall of the tunnel. This led to another tunnel, running in a northwesterly direction for about one hundred feet and ending in a chamber larger than any of the others. Nestor caught sight of a sparkle on the walls as he swung the flashlight about and pointed glittering sections out to the boys.

"Gold!" cried Frank.

"I'll bet a cooky we've found the hidden mine!" cried Jimmie.

"It is gold, all right," Harry Stevens said, "but there's no knowing whether it is here in quantities sufficient to pay the expense of mining and crushing the ore."

"Huh!" cried Jimmie, in a tone of reproach. "Don't you know that rock that will produce a dollar a tone is worth working? Well, then, look at this! There's ten dollars worth in the spot I cover with my hand! We've found somethin', boys!"

"So it wasn't to escape their enemies that the old chaps sequestered themselves here," said Fenton. "It was to dig out gold!"

"I never heard that there was gold in this part of Mexico," observed Jack. "I reckon we'll wake up when we get out into the sunlight."

"If you'll read up," Fenton replied, "you'll find that the state of Chihuahua abounds in niter and other salts, and is rich in mines of gold and silver. Do you really think we have come upon the deserted mine Jimmie talks about so much?" he added, turning to Nestor.

The latter took a folded paper from his pocket and examined it under the light of the electric torch.

"It seems that we have," was the reply. "I was not thinking much about the mine as I ascended the mountain, but now it strikes me that I unconsciously followed the directions given in this paper."

"That big lobster of an Englishman was looking for the mine," Jimmie said, "and so it was natural that he should lead you to it. I can't see how it belongs to any old estate, though," he added. "Looks like everybody's property to me."

"Perhaps it was the knowledge of the whereabouts of the mine that had value," suggested Nestor, "and not the fact of ownership. Anyway, we've found it."

The walls of the cavern appeared to blaze with gold, in flakes and in small nuggets. Here and there were empty pockets which appeared to have been stripped of their rich holdings. Upon inspection the floor of the chamber was found to be covered, in places, with crushed rock, where blocks cut from the walls had been broken up.

"There is no knowing how many million dollars worth of gold have been taken from here," Nestor said, "and there is no way of estimating, at this time, how far this rich rock extends into the mountain. The fact that the mine was abandoned may indicate that the ore became less valuable as the workers cut out from the center."

"It is rich enough now to pay for working, all right! cried Jimmie.

"There appears to be millions in sight," Nestor said, putting away his paper.