The town of Unity was located about ten miles from the sea, on a little stream, which had a waterfall, from which they derived the power for turning the machinery which had been put up.  This consisted of a saw mill, a small foundry, a machine shop, as well as grist mill and other mechanism suitable for a town.

All these enterprises were now being operated by the natives.  The leading commercial genius of the town was Blakely, who was one of the owners of the vessel on which John had sailed from San Francisco, and which was also wrecked by the same monsoon which sent the schoolship Investigator to the bottom.

It was Blakely’s idea that the work of the natives could be profitably turned to raising coffee, cocoa, and the different fibres which naturally grew all over the island, and in order to take advantage of the crops which could be grown there it would be necessary to open communication with the outside world.

To do this meant that they must build a ship, and thus reach civilization, and vessels could then bring such things to the islands as the natives could use, and take away the produce that the natives could turn out.

Such a plan was one which was heartily seconded by all the boys, who, although they had been engaged in the most wonderful experiences, were homesick, and longed to see their parents in the States, and thus relieve them of their anxiety, after an absence of more than two years.

It was with a will that all took a hand in the work, and the ship was nearing completion.  They had no facilities for making a large engine, so the vessel was a sailer, with a small propeller, and the largest size engine they could turn out was to be used as an auxiliary.

The next evening while the Professor, John and the boys were together, Harry brought up the subject of the talk of the previous evening.

“George and I have been talking about making a voyage of discovery.”

The Professor looked at Harry with that genial smile which the boys had learned to love.  Without answering for the moment, the old man turned to John, as the latter’s face lit up.

“I thought you boys were homesick?” he said.

“Well, yes,” answered George.  “But only for a little while.”

“Only homesick for a little while?” and the Professor’s hearty laugh followed.

“I mean we are homesick,-that is, we can be cured of it in a little while.”

Without relaxing that broad smile, the Professor continued:  “I suppose you want to be cured before you go on the voyage of discovery?  Is that it?”

“Yes.”

“But what do you expect to discover!” asked John, gravely.

“Just what you suggested on one occasion,” said Harry.

“We want to know where the treasures are on the islands,” remarked George.

“Then, there is another thing,” ventured Harry.  “I don’t think all the boats of our ship were lost, and it is likely that they found refuge on some other island.”

“But how do you know there are other islands near here?” asked the Professor.

“Well, I don’t know, only from what John has said.”

John looked at Harry for a moment quizzically, and then said:  “When did I say so?” he asked with a smile.

“When you told about the charts of the treasure caves.”

“But we have found them, haven’t we?”

“Yes; but not all of them.”

“That is true; and your argument is correct.  Unquestionably, there are other islands, probably not in the immediate vicinity, but near enough that they could have caught some of the boats.  I quite agree with you that we ought to make the attempt.  The Professor and I have just been talking of taking up the matter in order to relieve any who might have been so unfortunate as to be east away.”

“I am surprised,” said the Professor, “that you are not through with treasure hunting, and want some more of it.”

“But you know, Professor, that some of the most interesting times we had were during the investigations we made at the big cave at the Cataract on Wonder Island!”

“Quite true; but think of the immense riches you now have.  In the vault beneath the floor of the main shop you have the combined treasure of the two caves,” continued the Professor.

“Yes; and that shall be taken back by you to your homes in the States, and you will want to enjoy it,” and John said this with a most sincere air, as he looked at the boys.

“That would be nice,” said Harry reflectively.  “But if we are there the only thing we can do is to spend it, and there is no particular fun in doing that.”

“What?  No fun in spending the money?” exclaimed the Professor.

“Why, we haven’t spent a cent since we have been here, and we have enjoyed every hour of the time, except-except-” and George hung his head for a moment.

“I know,” said the dear old Professor; “I know what you mean.  Home still has a warm place in your heart.  That is right.  You must see your home, and then,-”

“Then we want to come back,” broke in Harry.

“It makes me happy to see that the lessons of the past while we have been together has impressed on your minds one thing; that it is not riches which give happiness.”

“I know that,” said Harry.  “When I go out and see these poor people here, and I meet smiles on every face, and a welcome everywhere, the thought that we have tried to make them feel and know that wars were wrong, and that true happiness consists in trying to make others happy, it gives me more pleasure than all the gold which we took from the caves of the Buccaneers.”

“Yes, and there is another thing, that I have been thinking about,” said George.  “I really don’t think the people here are so bad, and never have thought so.”

“Well, they have been doing some pretty bad things,” remarked John.  “I would like to know what makes you think as you do.”

“I mean, that if it wasn’t for certain classes, like the Krishnos, say, the people would not be trying to sacrifice each other.  Those fellows are the ones who lie to the people, just as the fellows at the last cave told the people and the Chiefs that if they went into the cave the Great Spirit would destroy them.”

John and the Professor both laughed, while the boys looked on.  There did not seem to be anything amusing about that, and they wondered why they should laugh at George’s remark.

“Did it ever occur to you how like that is to the white man’s way of doing things?” asked John.

“I never thought of that!” said Harry.

“Do the white people act that way, too?” inquired George.  “I never knew that we had people who tried to deceive others so they could give them up as a sacrifice?”

“What do you think the Krishnos deceive the people for?” asked the Professor.

“So as to give them the power,” answered George.

“Quite true.  But what is the object of that power?”

“So they can rule?”

“Yes; but what gives them the power to rule?”

“Oh, I see now!  They get paid for it!  And that is why the Krishnos have all the best things, and are better cared for than even the chiefs are?”

“You have given the right answer.  The Krishnos don’t want to sacrifice human life because they love to do it, but because in the doing of it they inspire fear, and through fear they can get what they want.”

“But, Professor, you haven’t yet told us how that is like the white people do it.”

“In exactly the same way.  The Krishnos own the big gun factories, and they tell the chiefs that the people across the river, or on the other side of the mountain are going to rise up against them, and they must arm the people and attack them.  You see the white man’s Krishnos have a great cave, called a gun factory, and while he does not want to offer up any sacrifices for the love of it, he does so because it is his business to make guns, and ammunition, and shells which explode with terrific force, and destroy hundreds at every shot.”

“Well, after all, we are not much better than the savages here, are we?” said Harry, as he looked around, with a sad expression.

“We have advanced a little beyond them,” interpolated John.  “We have tried to systematize the killing.  The savage goes at it without regard.  But the white man has set rules to conduct the slaughter.  Of course, the rules do not say that they shall not kill but it does point out the impolite ways of killing.”

The Professor smiled at this homely way of putting it, but the boys looked doubtfully at John’s exposition, and then George ventured to remark:  “I can see the force of it, and it is my opinion that the savage way is, after all, the most reasonable.”

“If it is not the most reasonable,” answered the Professor, “it is certainly the most logical.  But we are getting away from our subject.  I understand from what John says that within the next week we shall be able to launch the vessel!”

“Yes,” answered Harry.  “Everything is now so far ahead that in two weeks more we can be ready to sail.”

“That is well.  I hear there is considerable rivalry among the men to go with you?”

“But aren’t you going with us?” asked George in a voice of alarm.

“No; my place is here.  I have no desire to go back.  I have induced John, much against his will, I know, to go with you, but I cannot leave my people here.  I will welcome you only the more gladly when you return.”

Harry was almost in tears, as he said:  “But we wanted you to go back with us so we could take you to our homes and let our people see you.  They would be so happy to see you and to hear you talk.”

“Thank you so much for the kind invitation.  Sometime in the future, when everything is properly settled here, and I can see my way clear, I will consider it an honor to visit your homes, and enjoy the friendship of your dear ones; but not now.”

The door opened quietly, and Angel stepped in, Angel being the Orang-outang to which we have alluded.  He was now nearly as tall as George.  He gravely shambled over to the Professor, and placed an envelope in his hand.

Angel was the most wonderful character in that community.  He was the pet and the playmate of all the children.  No one dared to harm him or offer an insult.  Such a thing would have caused an insurrection in that town.

While he could not speak, he could understand practically everything that was told him.  Daily he performed many extraordinary tasks, thanks to the training and care that George had bestowed upon him from the day he had become a captive.

The Professor opened the envelope, and adjusted his glasses.  As he read his eyes opened wider and wider, while John and the boys drew closer.  While reading one of the sheets the Professor was slowly unfolding a scrap of dark colored material, smaller than the sheet he was reading.

“What is it?” asked Harry.

“The letter is from Blakely,” he said as he passed the papers to John.  “And what do you think it is about?”

All eagerly peered at the letter and then at the brown missive, whatever it was.

“Read it aloud,” said the Professor.

John handed it to George, and this is Blakely’s letter: 

                                                   “SOUTH MOUNTAIN,
                                                        Below Illya.

“My Dear Professor: 

  “I felt sure that my view as to the character of the mountain range

below the town was correct.  Copper outcroppings were found as far
south as the range can be seen, and there is also silver in abundance. 
This will surely be a profitable field for the natives.  Yesterday,
while prospecting on the southeastern side of the main ridge, I was
surprised to find a part of a metal pot, evidently of cast iron.  Quite
a number of articles, of no particular value were lying near, but
within the fragment of the pot, and protected by a shale of rock, was
the enclosed scrap, which I thought might interest you, as you have a
leaning in the direction of finding out hidden and abstruse things. 
Probably, you can decipher what it says.  All the men are well, and are
feeling jolly.  We may be ready to return in a week.  I hope the old
ship is coming along all right.

“Hurriedly, as ever,

“BLAKELY.”

“That is satisfactory.  Blakely is the right man for his job,” remarked John.

“Now, let us see what the scrap has to say,” said the Professor.

John held the scrap up to the light, and all peered at it.  “I think there are cross lines on it, although I am not quite sure,” he said, as he again held it up so the light could flash through it.

“What difference would that make whether it had or it hadn’t cross lines?” asked Harry.

“Simply this:  I wanted to satisfy myself whether or not it was taken from a ship’s pad, which is generally ruled both ways.”

“What is the object of having paper ruled both ways?”

“It is a convenient way of making calculations where measurements are necessary, as is the case in figuring out and placing the different celestial marks which guide the sailors.  I think this is a marine pad.  Now, let us see what it contains, before we go further.”

“See the name signed at the bottom,” cried out George.  “W-a-l-t.  That must be a ‘t’.  But the rest is blurred.”

“I wonder if that isn’t Walter?” said Harry.

“Who is Walter?” asked John.

“Walter?  Why he is the man who signed the note we found on the Investigator’s life boat N and from whom we have never heard.”

“I remember now,” said John, reflectively.  “He mentioned Wright who was one of my companions.  But I did not know Walter,-but what is this?” All craned forward now.  “Here is a line; it looks like a large V, pointing to the south;-that is if the upper part of the paper is the north.”

“There is some sort of tracing on it,” said George.

“Your eyesight is good, George, see if you can see any figures on the sheet that will explain the V, and the reason for the name below.”

“There is the slightest sign of a figure, or a word just below the point of the V. It looks like ‘30’.  This seems to be an arrow, which points to the right diagonally.”

“Now you boys have something to occupy your minds.  Yon have been interested in the Walter note for a year; now is the time to do some investigating.”

“I have an idea,” said Harry, jumping up.  “Where can we find the original Walter’s note?  We can compare the signature, and that will tell whether it is Walter or not.”

The Professor smiled as he noticed the eagerness of the boys.  They rushed out of the room and went over to the shop to reclaim the note that had given them so much concern fourteen months before.

When they had gone John said:  “I presume you have already guessed what the note contains?”

“Unquestionably it has reference to the location of the main ledge of copper or other ore which is measured from some point in that vicinity, and which may be determined later on by noting the place where the missive was found, or from some natural landmark.”

“That is my view, but I felt it would be better for the boys to dig it out for themselves,” replied John.

The wonderful nature of the instruction which the boys had obtained during their stay on the island, was characterized by this little incident.  Everything learned by one’s own exertions is not only more valuable because of that fact, but the facts thus gleaned will leave a stronger impress upon the mind.

The boys thus learned by doing things themselves, that they became strong and self reliant, and it made them happy to think that they were able to pick up the threads, however tangled, and weave them into a harmonious whole.  It is the secret of doing things well.