“The tree is caught fast!”

“I know it, Frank, but I don’t think it will stay caught for long!”

What the two chums said was true—the tree had caught in the boiling and foaming water, directly in the middle of the stream. The spray was flying all about them, so that they could scarcely make out what was ahead. But they heard a noise that could mean but one thing. A waterfall was there, dashing with a roar over the rocks and falling into a big pool below.

A minute went by. The tree was swinging around slowly. Now it began to grate along the rocks. Of a sudden an end bobbed up and then the tree was free, and on it rushed for the waterfall.

“We are going over!” shrieked Frank, and held fast, not knowing exactly why. Mark tried to answer, but the roar all around them drowned out every other sound.

On they went for a hundred yards, between rocks standing up higher than their heads. Then the brink of the waterfall was gained and here the tree seemed to pause for a moment. Over it went, carrying the boys with it, over and down, out of the sunlight into utter darkness.

By instinct more than reason both boys clung fast to the tree and that was their salvation. Down they went into the pool and the torrent of water came on top of them, sending them far beneath the surface. How long they remained under they could not tell, afterward, but it seemed an age. When they came up each was more dead than alive. But still they clung to the tree as it drifted away and lodged among the rocks a short distance further down the river.

“Frank, are you all right?” Mark asked the question, feebly, some ten minutes later.

“I—I guess so,” was the gasped out answer. “But, oh, Mark, wasn’t it an awful tumble?”

“That’s what it was, Frank. I didn’t think we’d come out of it alive.”

They left the tree and sat down on the rocks, and there rested for over an hour. The noise of the waterfall still thundered in their ears, but otherwise all was silent.

At last Mark arose and stretched himself. “If we are all right we may as well go on again,” he said.

“On the tree?”

“Yes. I don’t think there is any danger of another waterfall—at least not close by. We can watch the water and if the current gets too swift we can turn into shore before the tree gets beyond our control again.”

So it was agreed, and soon they were on the way once more. Below the falls the river was narrow for several miles but the current was not very swift, for much of the water was carried off by side streams flowing in various directions.

“We don’t seem to be getting to the Orinoco very fast,” observed Frank, after all of five miles had been covered. “I’ll wager we are at least twenty to thirty miles from camp.”

“Perhaps we are. But what do you advise? We can’t sit down here and suck our thumbs.”

“Hark! What was that? A gunshot?”

“It sounded more like a distant explosion,” cried Mark, leaping to his feet. “There it goes again. An explosion sure enough. What can it mean?”

“I think I know,” answered Frank. “It means that we are near some kind of a mine. That was the blasting of rocks.”

“I hope you are right, Frank. It came from down the river, didn’t it?”

“It did. Let us go on. There may be a regular miners’ camp below here.”

Once more they allowed their improvised craft to drift down the stream. The character of the country was changing, and presently they found themselves hemmed in by high rocky walls. Then came a bend eastward and they came in sight of a small settlement. There were a dozen houses built of timber covered with corrugated iron, and a small engine house with a tall iron smokestack. Back of the settlement were the openings to several gold and silver mines. As they approached another explosion rent the air and they saw a large section of a cliff give way and fall to the rocks below.

There were several boats tied up to a tiny dock running along the river, and the men on these gazed curiously at the boys as they drifted up and leaped aboard one of the craft.

“Where come you from?” demanded one of the men, in Spanish.

“We are American,” said Mark. “Can you speak English?”

“Americans, eh?” put in another man. “I’m an American myself. How did you get on that tree?”

“It’s a long story,” answered Mark. “We were with a party along the Orinoco but we went ashore and got lost. Are we far from that river?”

“Eight miles. You look pretty wet.”

“We came over the falls.”

“Gee whiz! It’s a wonder you are alive!” burst out the American, whose name was Simon Smither. “Come ashore, and I’ll take you to the boss. This place is Castroville. Maybe you’ve heard of it. We have here the Little Bolivar and the Moonlight Mines, two of the best payers in this section of the country.”

“Castroville!” ejaculated Frank. He remembered that Andy Hume had once mentioned the place to him. “Is there a newcomer here by the name of Andy Hume?”

“There is. He’s up to the office now. So you know him?”

“We do,” answered Mark, and then told their story while the whole party hurried from the river to where the offices of the mines were located, not far from the engine house.

Andy Hume saw them coming and leaped up from a stool to receive them. “I declare,” he cried. “Where did you come from? Thought you were hunting and fishing along the Orinoco.”

“We were,” answered Frank, and told of how they had become lost and of what had followed. “We must get back as soon as we can,” he added. “The professor and the others will be much worried over our absence.”

The matter was talked over, and by consulting one of the managers of the mines they obtained permission to use one of the boats, taking with them a native boatman who knew all the rivers of the vicinity thoroughly.

“He’ll get you back safe and sound,” said Andy Hume. “He’s a first rate fellow. He brought me here from Navaleno, forty miles away.”

“But how did you happen to come here?” questioned Mark. “I thought you were going prospecting?”

“So I was, but at Navaleno I met an old miner friend of mine, Captain Richards. He has an interest here and he wants me to look after it while he takes a trip to the States. So I’m booked here at a salary of two hundred dollars per month and found. Not so bad that, eh?” And the boys agreed that the arrangement was certainly very promising.

A comfortable meal and a chance to dry their clothing made both boys feel much better. While they were eating they asked a number of questions about the mines and when they had finished Andy Hume insisted upon showing them around.

“The output of these mines will be about six hundred thousand dollars this year,” he said. “To get out the gold and silver will cost the combined companies about two hundred thousand dollars, leaving a profit to the stockholders of four hundred thousand dollars. We have here all the latest machinery with the exception of a newly-patented quartz crusher which is now being built for us in the United States. At first the mining around here was what is commonly called cradling or placer mining,—that is, the miners would pick up what they could find on the surface or by ordinary digging—but that is past and all we get has to be blasted out of the mountains.”

An hour was spent in and around the mines, inspecting the shafts and the various machines for extracting the gold and silver. Then the boatman came up to announce that the boat was ready and they started to leave.

As they did so a strange boat, containing several passengers, arrived at the dock close at hand. As the passengers came toward where Frank and Mark were standing, the latter plucked the former hurriedly by the sleeve.

“See there, Frank,” he whispered.

Frank looked in the direction and gave a start.

“Why it’s that Dan Markel, the fellow who robbed Hockley!” he ejaculated.