ween these
centers a matter of ease and safety. Occasional destructive raids on the
waste lands were considered all that was necessary to keep the "wild"
Americans on the run within the shelter of their forests, and prevent
their becoming a menace to the Han civilization.

But nearly three hundred years of easily maintained security, the last
century of which had been nearly sterile in scientific, social and
economic progress, had softened and devitalized the Hans.

It had likewise developed, beneath the protecting foliage of the forest,
the growth of a vigorous new American civilization, remarkable in the
mobility and flexibility of its organization, in its conquest of almost
insuperable obstacles, in the development and guarding of its industrial
and scientific resources, all in anticipation of that "Day of Hope" to
which it had been looking forward for generations, when it would be
strong enough to burst from the green chrysalis of the forests, soar
into the upper air lanes and destroy the yellow incubus.

At the time I awoke, the "Day of Hope" was almost at hand. I shall not
attempt to set forth a detailed history of the Second War of
Independence, for that has been recorded already by better historians
than I am. Instead I shall confine myself largely to the part I was
fortunate enough to play in this struggle and in the events leading up
to it.

[Illustration: Seen upon the ultroscope viewplate, the battle looked as
though it were being fought in daylight, perhaps on a cloudy day, while
the explosions of the rockets appeared as flashes of extra brilliance.]

It all resulted from my interest in radioactive gases. During the latter
part of 1927 my company, the American Radioactive Gas Corporation, had
been keeping me busy investigating reports of unusual phenomena observed
in certain abandoned coal mines near the Wyoming Valley, in
Pennsylvania.

With two assistants and a complete equipment of scientific instruments,
I began the exploration of a deserted working in a mountainous district,
where several weeks before, a number of mining engineers had reported
traces of carnotite[1] and what they believed to be radioactive gases.
Their report was not without foundation, it was apparent from the
outset, for in our examination of the upper levels of the mine, our
instruments indicated a vigorous radioactivity.

[1] A hydrovanadate of uranium, and other metals; used as a source
of radium compounds.

On t