well as he was able, Allen put out his hands before him, to ward off the shock of a sudden contact of any sort, for he did not know but that he might be dashed upon a jagged rock at any instant. Then he prayed earnestly for deliverance.
On and on he swept, the stream several times making turns, first to one side and then to the other. Once his hand came brushing up to a series of rocks, but before he could grasp them he was hurled onward in an awful blackness.
A quarter of an hour went by – a time that to the young man seemed like an age – and during that period he surmised that he must have traveled a mile or more.
Then the current appeared to slacken up, and he had a feeling come over him as if the space overhead had become larger.
"This must be an underground lake," he thought. "Now if I – Ah, bottom!"
His thought came to a sudden termination, for his feet had touched upon a sloping rock but a few feet below the surface of the stream. The rock sloped to his right, and, moving in that direction, Allen, to his great joy, soon emerged upon a stony shore.
He took several cautious steps in as many different directions and felt nothing. He was truly high and dry at last.
This fact was a cheering one, but there was still a dismal enough outlook. Where was he and how would he ever be able to gain the outer world once more?
CHAPTER VII.
The Cave in the Mountain
Allen was too exhausted to do more than move about cautiously. He felt for the edge of the stream, and then moved away from it for several yards.
His hand came in contact with a dried bush and several sticks of wood, all of which had probably floated in at one time on the stream, and these at once made him think of a fire. What a relief a bit of light would be!
In his life on the long range, Allen had found a watertight matchbox very useful. He felt in his pocket and found the article still safe. He opened it with fingers that trembled a little; but the matches were still dry, and in a trice one was struck and lit.
He held the match under some of the driest of the brush, and had the satisfaction of seeing it blaze up. He piled the stuff up, and on top placed several heavy sticks. Soon he had a fire which blazed merrily.
The light illumined the cavern, casting a ruddy glare on the rocks and the rippling water. It was a weird and uncanny scene, and he shivered involuntarily. He would have given a good deal to have been in the outer world once more.
Allen saw that the river had simply widened at the spot, and that a hundred yards further on it flowed into a narrow channel, as before. Only on the side which he occupied was there anything in the shape of a shore. Opposite the rocks stood straight up, and were covered with moss and slime.
"If I am to get out, it must be from this shore upward," Allen thought as he surveyed the situation. "I can never get back on the river. One could never row even a boat against that current."
The shore was not more than thirty or forty feet wide. It was backed up by rocks, but Allen was glad to see that they did not present an unbroken surface. There were numerous fissures, and in one place the opening was a dozen feet in width.
Selecting the brightest of the firebrands Allen, left the vicinity of the stream and started to explore this opening. He was in great hopes that it would lead upward and that he would thus be enabled to climb out of his prison – for to him that damp, dark place was nothing less.
The opening was filled with loose stones, and Allen had to be careful for fear of spraining an ankle, or worse. He moved along slowly, halting every few steps to survey the scene ahead.
Twenty yards distant from the entrance to the fissure Allen came to a turn to the left. Here was a narrow opening just large enough for him to pass through. Beyond was another cavern-like spot not over ten yards in width and height and of interminable length.
Fearful of losing his way, Allen hesitated about advancing. But presently he plucked up courage, and, holding down his firebrand, he allowed it to burn up again and then proceeded along the chamber.
The flooring was uneven and covered with loose rocks and stones. Huge stalactites hung down from overhead, and in several spots the moisture dripped down with weird hollow sounds.
"I would like to know how far underground I really am," was Allen's earnest mental speculation as he came to a halt beside a tiny stream which flowed from one side of the cavern to the other. "If there was only some slope which led upward it would be more encouraging. But it's about as flat as a bit of prairie land."
Allen hopped over the stream, and, assured that he could easily retrace his steps if necessary, continued on his search, his firebrand held over his head.
It was a discouraging journey when the end was reached. Before him arose a solid wall not less than twenty feet in height, at which elevation the cavern appeared to continue. Allen gazed up at the wall with a hopeless look on his face.
"Humph! How in the name of creation am I to climb up there?" he muttered. "It's as steep as the side of a house and twice as slippery. If I can't find some sort of stepping places I reckon I'm beaten and booked to go back to where I started from."
Waving the firebrand to make it burn the brighter, Allen began to scrutinize the face of the wall before him. He started at one end, resolved that not a foot of the surface should escape him.
He had traveled along some fifteen feet when he came to something that made him start back in astonishment.
"Great Caesar!"
Before him were a number of letters, cut in smooth rock, which was apparently quite soft. The letters read:
Barnaby Winthrop's Mine.
Allen stared at the letters on the rock as if he had not spelled out the words aright. But there was no mistake. They really read "Barnaby Winthrop's Mine."
"Well, if this isn't the most wonderful discovery ever made!" ejaculated the young man, finally. "So this is the place that Uncle Barnaby talked of as being the richest claim in Idaho. I wonder how he ever found it?"
While Allen stood close to the rocky wall he reached the conclusion that his uncle must have come there by the river, but whether a voluntary or involuntary passenger he could not decide. He knew Uncle Barnaby was exceedingly fearless, but was there any human being who would take the awful risk of a journey on that underground river, not knowing to where it led?
"He must have been caught, just as I was," said Allen to himself, at last. "And that being so, the question is, how did he manage, after he was once here, to get out?"
While Allen was debating this question he cast his eyes about for some means of scaling the wall. He walked along its face until the very end was reached, and there, to his joy, discovered a dozen rudely cut niches, some of them were close together and others nearly a yard apart, but, with the end of the firebrand between his teeth, he had no great difficulty in pulling himself up to the level of the flooring of the cavern above.
Allen now found himself in an opening not over fifty yards square. The roofing was hardly out of reach, and the young man saw at a glance that the quartz rock was full of virgin gold and silver. It was a veritable bonanza.
"A million dollars or more!" he cried, enthusiastically. "Uncle Barnaby struck it rich for once. I wonder why he don't come back and begin operations. It's queer I didn't get word from him."
Allen could not help but spend some time in looking around, so fascinating was the sight of the precious metal as it shimmered here and there in the ruddy glare of the torch. His uncle would be rich indeed, and he knew that he and his brothers would not be forgotten by their generous guardian.
But soon the thought of escape came back to him. Was there an opening to the outer world, or was he entombed alive?
At the far end of the chamber, after a long search, Allen came to a narrow passageway, which he was compelled to enter on hands and knees. It led upward and he had great hopes that ere long he would emerge into the outer air once more.
But he was doomed