nhabited part, and for several months had no idea that any human
beings lived there.

They had absolutely nothing but their clothing; not even a knife or
other tool, but despite this, set to work to make all the appliances
used in civilized life. The preceding volumes showed how this was done,
and what the successive steps were to obtain food and clothing, and to
make tools and machinery.

They built a home, and put up a water wheel, a workshop and laboratory;
captured a species of cattle, called the yak, and used the milk for
food, and trained the oxen to do the work of transportation; they found
ramie fiber and flax, built a loom and wove goods from which clothing
was made; they found various metals, in the form of ore and extracted
them; and finally made guns, electric batteries, and did other things,
as fast as they were able to carry on the work.

In the meantime several exploring trips were undertaken, and they
learned of the existence of savage tribes, and what was more startling
still, ascertained that other boats, belonging to the ill-fated
_Investigator_, had been cast ashore, and later on came in contact with
several tribes with whom they had a number of fights, and by chance
discovered a tribe, the Tuolos, who held two of the boys in captivity.

These they rescued, namely, Thomas Chambers and Ralph Wharton. Returning
from one of these expeditions they found a man at their home, who had
entirely lost his memory. This was John L. Varney, a highly educated
man, who had seen service in many lands, and later on was restored to
reason.

Prior to the present enterprise, which was related in the opening pages,
a chief, Uraso, of the Osagas, was wounded and captured by them, and
taken to their Cataract home, as they called it, and when healed, he had
left them, for the purpose of returning to his own tribe, so that he
might bring them to the Cataract as friends; but he was captured and
detained.

During this interim, the last expedition was organized, and after some
mishaps, they proceeded into the part of the country where the savages
lived, and on the way rescued the chief of the Saboros, and also a
former companion of John.

Two weeks before our story begins, the Professor was captured by a band
of Berees, and taken to their village, where he was instrumental in
healing the chief's favorite daughter, and in gratitude, placed his
warriors at the Professor's disposal to rescue his friends, who were
about to