By agreement a course was marked out farther south than was taken on their previous trips, because they had never explored the country immediately north of the South River, except beyond the falls, and it was their aim to learn every foot of the territory.

On their way they pa.s.sed the mysterious hole where George had his experience, and the route was also close to the spot where Harry found him when he was lost. Both places were again visited, so that samples of rock might be taken from one of the places, and the Professor hoped the clay bed on the small creek might indicate the proximity of other metals than they had been able to find previously.

Late that evening they reached the edge of the main forest, and a camp made for the night. Red Angel was with them. He was as happy at the sight of the forest as an orang well could be. It was his delight to exhibit his skill as a climber on these occasions, and where the woods were dense he would spring from limb to limb with surprising agility.

During the night, as on several previous trips, Angel exhibited his nervousness, which was attributed to the presence of some animal that alarmed him, but otherwise nothing disturbed the camp.

"How far do you think we are from the falls?" asked Harry.

The Professor made a mental calculation as he replied: "We cannot be far east of it; possibly five or ten miles at most, and it is very likely several miles south. Since you suggest it, we might deviate from our route and take it in, as to do so will not take up more than two hours of our time. It interests me because I have not examined the place from which our boat was taken. That is one of the mysteries I am most interested in."

George was anxious to get a solution of that singular occurrence and jumped at the opportunity to go there. A southwesterly course was at once marked out, and after traveling about three hours George's alert ear caught a sound, as he was at that time leading the advance. Running back he called out: "Do you hear that peculiar sound?"

The wagon stopped. In the stillness around them they could hear a faint murmuring sound.

"Do you know what that is?" The boys looked at each other. "I think,"

continued the Professor, "that must be the falls."

"Then why not turn to the left and go directly to the river?"

They did so, and within fifteen minutes the river was in sight. A further trip of ten minutes brought them to the foot of the falls, where the boat had been deposited nearly five months before and which had so mysteriously disappeared, only to be recovered by them and again lost by accident, as detailed.

A search along the river bank failed to reveal any trace of the tree overhanging the stream, where the oars had been placed, and instead the river washed out a small bay. All along the banks were evidences of washouts which piled up driftwood every place along the sh.o.r.e where there was a root or snag which would hold the acc.u.mulations. The Professor wandered down the stream, pulling out and examining pieces of the limbs, to find, if possible, whether there were any evidences of the drift having been cut by human agencies.

So far as could be seen, the limbs had all been broken, not cut, and this was a relief, in a sense. The South River drained a large part of the island, and it might rightly be inferred that the driftwood in a stream of this kind, if it flowed through a region inhabited by man, would show some signs which they might interpret.

As they were returning George pointed across the river at a peculiarly shaped log, or what appeared to be portion of a large tree. The river at this point was about seventy-five feet wide. The Professor was silent for some time. "My eyesight is not of the best, but it does not look to me like a tree."

"I can easily swim the stream," and Harry had his clothing off in short order, and plunged in. Gaining the other side, he drew himself up, and without touching a thing in and about the debris, called out excitedly: "It is a boat, something like our life-boat! Yes; it is exactly like our boat!"

"Can you dislodge it? If not, I'll come over."

"Never mind, I can manage it, I think."

The interior of the boat was filled with acc.u.mulated material of all sorts, princ.i.p.ally leaves and bark, and when it had been lightened of all that weight Harry put his shoulder against the stern, and soon succeeded in dislodging it from its seat against the tree which held it a prisoner.

Just before he had it in a position to launch the Professor called out: "Don't put it in the water until you have found something which will serve as a paddle." The stream at this point, being less than a half mile below the falls, had a fairly good current, so that without an oar of some kind he would not be able readily to get it across.

"I can't find any signs of oars, so I will take a piece of this wood."

He ferried it across, and landed a hundred feet below. As he neared the sh.o.r.e George sprang toward it excitedly, and cried out: "Look at that!

See the name, 'Investigator'!"

Harry stopped rowing, and bent over the side of the craft; there, plainly, near the stern, was the word "Investigator" followed by the letter "L." The s.p.a.ce beyond the letter L was broken, and if anything else had originally been in that s.p.a.ce it had been brushed off by contact with some outside object.

This was, undoubtedly, one of the companion lifeboats of their ill-fated ship.

"How do you suppose this boat ever got here?"

"It undoubtedly came over the falls, and if so, it must have come from the interior of the island. My only solution is, that our companions in this boat were also, like us, cast ash.o.r.e, or, at any rate, the boat itself was, and if they reached land safely probably used this boat on the river."

"Isn't it singular that this boat has been treated just as our boat was, since they removed the lockers? Why should they do that?"

"The interesting thing to me is," answered the Professor, "why the boat was lost by them, if it ever was in the possession of our friends on the island?"

"Possibly the natives may have captured or killed them."

"That is a plausible explanation, but there may be a reason which is entirely different from anything which now occurs to us. I believe a search of the island will show that we are not the only white people living here, and that the loss of the boat indicates that they are not on friendly terms with the natives."

All thoughts of hunting were now dissipated. It did not interest them in the least.

They sat down and debated the discovery. Undoubtedly, it had drifted down South River and gone over the falls, as the indented sides and bottom of the boat plainly showed. How far had the river carried it before the falls were reached? It was a matter of regret now that they had pa.s.sed up the river before the animal trail in their path had caused them to leave it, instead of trying to discover its source.

Something must be done. Their companions must be in peril. That was a situation hinted at by the Professor. They had a duty to perform, if such should turn out to be the case. With many misgivings they decided that they must follow up the stream, cost what it might. No provision had been made for a lengthy trip, but, fortunately, they had plenty of ammunition, and as to food, they could supplement what they had by forage along the way, as they had often done before.

"What shall we do with the boat?"

"Let us find a place for it far enough from the sh.o.r.e to be beyond reach of the river, and hide it, so there will be no further danger of its disappearance."

"We are so used to have things get away from us that it has become a habit," said Harry, laughing.

While they were engaged in the task of drawing the boat up, Red Angel appeared, excitedly chattering and endeavoring to attract their attention, and frequently running back in the direction of the wagon.

"What is the matter with him? I never saw him with such antics before."

George, who had the greatest control over him, ran up and tried to catch him, but the little fellow avoided capture, and whenever George would get near he would spring toward the wagon, keeping up his excited gesticulations all the while.

The Professor now ran forward without another word, and Harry stood there wondering what had happened, or was about to happen. As he ran past George, who was still trying to get Angel, the Professor merely said: "He is trying to get you to go to the wagon."

The boys understood, and both started on a run. Harry was the first to get there. The team had disappeared!

Their further adventures on the island are related in the next book, ent.i.tled "The Mysteries of the Caverns."

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