they held the
tribe captive. The village was absolutely unlike anything else in the
form of habitations found in the island. Three of the buildings were
large structures, built in three of the well-known types of
architecture, and the other parts of the village were laid off
regularly.

Surrounding the village was a strong embankment, as though originally
used as a fortification, and the village itself was located on the side
of a hill, betokening sanitary considerations.

"But I do not see," observed George, "what the copper in the cave had to
do with the town?"

"Nor do I," responded Harry. "Suppose we see John at the first
opportunity. There are other things besides the copper I would like to
know. John has asked every one that he has come into contact with about
the different wrecks that have come ashore within the past two years,
and no one seems to have any idea that more than two of the
_Investigator's_ boats came ashore."

"Well, if they did it isn't at all likely that they could come to the
southern shore, when the wrecked vessel was to the north of the island."

"It is just for that reason," responded George, "that I believe we shall
find other islands in the vicinity, and who knows but some of the boats
reached those islands?"

"I am with you," said Harry. "Shall we talk to John about it?"

"By all means. But stop! Why not have a talk with the Professor first?"

"Good idea. We owe everything to him."

CHAPTER II

A MYSTERIOUS MESSAGE

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 bui