Tom took Koku into his service, somewhat to the dismay of
Eradicate, who was desperately jealous. But poor Eradicate was
getting old, and could not do as much as he thought he could. So,
in a great measure, Koku replaced him, and Tom found much use for
the giant's strength.

Tom had begun his inventive work when, some years before this
story opens, he had bargained for Mr. Damon's motorcycle, after
that machine had shot its owner into a tree. Mr. Damon was,
naturally, perhaps, much disgusted, and sold the affair cheap.
Tom repaired it, made some improvements, and, in the first
volume of this series, entitled "Tom Swift and His Motorcycles,"
you may read of his rather thrilling adventures on his speedy
road-steed.

From then on Tom had passed a busy life, making many machines
and having some thrilling times with them. Just previous to the
opening of this story Tom had made a peculiar instrument,
described in the volume entitled "Tom Swift and His Photo-
Telephone." With that a person talking could not only see the
features of the person with whom he was conversing, but, by means
of a selenium plate and a sort of camera, a permanent picture
could be taken of the person at either end of the wire.

By means of this invention Tom had been able to make a picture
that had saved a fortune. But Tom did not stop there. With him to
invent was as natural and necessary as breathing. He simply could
not stop it. And so we find him now about to show to his chum,
Ned Newton, his latest patent, an aerial warship, which, however,
was not the success Tom had hoped for.