"Let me step it off," said Harry. "I find it is just two and three-quarters inches."

"What was the distance, in feet from A to B?" asked John.

"I have the figures here," said George. "We found it was six hundred and ninety feet."

"If, now, you will multiply 690 by 2-3/4, we shall have the distance from this point A, and yonder point, or headland C."

[Ill.u.s.tration: _Fig. 6. The Second Limb._]

"I make it out to be just 1897.5," was Harry's conclusion.

The boys, together with John and a half dozen of the natives, went along the sh.o.r.e, and mounted the point C, and from that place selected another point in a southerly direction, and again made the same calculations.

The vessel in the meantime was put under sail and anch.o.r.ed a mile below, giving the surveying party time to make several triangulations, and late in the afternoon the party came on board, tired and ready to take a rest.

From the position taken up by the ship they could see a long stretch of sh.o.r.e line, practically straight, trending toward the southeast, and with their gla.s.s could see, miles away, a headland which afforded a p.r.o.nounced point for observation.

The next morning the same parties rowed to the sh.o.r.e, and Uraso was left with the party to guard the sh.o.r.e boat, while Muro accompanied John and the boys. On this occasion John issued the following instruction:

"The long point which you see in the distance is, probably, 15 miles beyond. It is not more than that, but this clear atmosphere is liable to deceive. I have instructed Sutoto to wait until one o'clock today, and if by that time there is no word from us Uraso will return to the ship, and you will take up anchor and steer for the headland beyond."

"So that you may understand our movements, we will strike into the interior, taking a course due east, for ten miles, or thereabout, and then turn to the south, and reach the sea near the place where the vessel will be located."

"I understand, now, how the distance can be measured by triangulation on land; but how to get the distances, on shipboard, is what puzzles me,"

said Harry.

John smiled as he replied: "I knew you would come to that sooner or later, so I prepared a little sketch (Fig. 7), which shows the bow of a vessel, and the tall mast. The lines from A to B give an angle with the vertical line of the mast, which will enable you to determine how far the ship is from any point."

"But I am still in the dark as to how, even if we have that distance, we can thereby tell by triangulation, on the vessel, how far one point is from another on the land."

[Ill.u.s.tration: _Fig. 7. Triangulation from a Vessel._]

"After the distance from the vessel to the point is determined, as I have shown, then the length of the ship itself is used as the two points to sight from, and the two lines thus projected, from the opposite ends of the vessel, together with the line lengthwise along the ship, form a triangle, the same as the triangle lines 1, 2, 3, in the sketch (Fig.

5)."

It might be well at this place to describe the equipment of the party as it left the boat. The natives carried a plentiful supply of provisions.

Each had a gun, the best kind of breech loaders, and also a spear.

The natives love to handle spears better than anything else in the way of a weapon, and each also had a knife, and some carried the inevitable bolo, that primitive form of hatchet which is known all over the world where steel or iron is available, and the people have arrived at such a state that they are able to make metal articles.

John and the boys also carried guns, but the boys had revolvers, seven shooters, not of large bore, but very convenient weapons, in close quarters. Each carried also a knife, and belt to contain the cartridges for the guns.

Harry carried a camera, which he had brought from the States, and George had the field gla.s.s strapped across the shoulders. John felt that they had a force large enough to make a fairly effective stand against a pretty strong force of natives, the entire party counting, in this instance, sixteen.

As they advanced into the interior, it was evident that they were gradually ascending, so that at about six miles from the landing place they reached the crest of the rising ground. Beyond, where the nature of the ground permitted they saw clearly that the distance beyond had a lower alt.i.tude than the place where they stood.

During this trip there was no evidence that the island was occupied, but they saw the most amazing evidences of tropical fruits and trees.

Magnificent trees were in evidence everywhere, and the woods, besides mahogany, and ebony, were of the most valuable character.

John noted all these things, but the boys were most interested in the birds and animals which roamed about. The latter were not large or vicious looking, but it was not permitted to shoot any of them lest it might alarm Uraso, who was at the landing.

Ahead could be seen several ridges, one of them heavily wooded. Reaching the summit they beheld a beautiful valley below, and opposite on a shelving rock, stood a type of mountain deer like a sentinel, while a dozen or more were feeding on the green slope beneath.

Frequently on the march the boys would take side trips, in the attempt to run down some of the curious animals, but they were careful to keep the main force in sight.

Thus they tramped on fully five miles beyond the crest of the ridge, and occasionally John would stop to examine some suspicious-looking indication of habitation.

"It would surprise me very much to find that the island is not inhabited," he said, as he examined what appeared to be a path.

At this juncture one of the native scouts came up and showed John a curious stone formation. John took it, and turned it over several times.

"That is part of a stone hatchet." The scout nodded a.s.sent with a smile.

All now became intent on searching. This finally resulted in bringing to light a well-formed spear, not unlike those originally used on Wonder Island among the native tribes.

Surely they were getting evidence pretty fast now. Then, while crossing a little rivulet, one of the scouts plainly saw the print of a native foot, which was unmistakable. True, it had been made days before, probably a month, but there it was, and now it was inc.u.mbent on them to find out where the people were.

The entire party scattered along the little stream, and searched both banks for a considerable distance, the boys taking an active part in the work. Usually the boys kept together, and entertained each other, but on this occasion all were so intent on discovering where, and in what direction the footprints would lead, that they quite forgot to watch each other.

John gave a customary whistle, as he was in the habit of doing, when it was desired to call the party together, and all of the scouts promptly returned, as well as Harry. George was nowhere to be seen. John questioned Harry. He had first missed him at the bend in the stream not two hundred feet to the north.

He rushed back in that direction, while John gave another blast on the whistle, and then listened intently for a reply. Harry came back without any intelligence, and almost frantic. John and the scouts then broke into a run, and Harry turned with them.

That instant a shot rang out. "That must be George," exclaimed John.

"Forward as quickly as possible."

The party turned the bend of the river. All along this part of the stream the banks were cut up by ridges and diminutive cliffs, and in many places were large shelving rocks which came up close to the stream.

Immediately after the shot John stopped, and listened for some sound, and the natives, usually so alert to recognize noises, did likewise.

"That shot means that George is in some danger," said John.

"But why does he not answer the whistle? Why should he shoot, and then not call to us, if there is any danger," said Harry in despair.

They turned the bend, and searched to and fro. The shot could not have been more than eight hundred feet away. The searchers spread out into a fan-shaped formation. One of the scouts ran up hurriedly and called to John, who went forward, and there, alongside of a huge rock, where there was little gra.s.s, he saw unmistakable evidence of a scuffle.

"These are the footprints of George's shoes," remarked Harry.

"Yes, and here are the prints of the native feet," said John, as one of the scouts distinctly pointed out two or three well defined marks.

"They are, undoubtedly, near at hand. We must now be on our guard," said John, as he pondered on the situation.

"I wonder why they didn't attack us?" asked Harry.

"The reason, no doubt, is that it is a small party. A larger body would not have attempted to capture one of us by stealth."

John turned to Hasmo, one of the fleetest runners, and instructed him to go back to the landing place at once, and advise Uraso to bring his men and provisions, as well as additional ammunition, and to hold the ship until additional word should be sent.

Hasmo was off in an instant, and then John issued additional instructions. "It is evident," he said, "that we must look for the people to the east or, more likely, toward the southeast. That is the reason why I had the boat held at the place where we have just landed.