d to the bibliography at the end of this volume for a detailed
listing); they include _Einstein's Theory of Relativity_, which is a
companion work to the motion picture of the same name. He was also
editor-in-chief of Collier's sixteen-volume _Popular Science Library_.
It might be added that much of the editing and captioning of the
Einstein film was his work, and that he collaborated with Leon Barritt
in the invention of the Barritt-Serviss Star and Planet Finder, a device
still in use.

In comparison with his other writings his output of fiction is small:
five novels and a single short story. It is, however, characterized by
the same logic and interest, this time tossed aloft to soar on the wings
of romantic imagination. Two of these works deal in some detail with the
world of the future as he thought it might be--prophetic fiction, if you
will; another two give us a picture of life on neighboring planets; and
the final couple, although they maintain a terrestrial locale, show as
wide a scope of creative invention.

In only one of these does astronomy fail to play at least a supporting
role. That is _The Sky Pirate_ (1909), which is an adventure story laid
in the year 1936. Its plot revolves around an abduction for ransom in a
period which is visualized as rampant with piracy because of the general
adoption of air transportation. As usual, fact has outmoded prophecy,
for long before 1936 airplane speeds exceeded the 140 miles per hour
Serviss predicted. We still need, though, his invention which enables
badly damaged aircraft to drift slowly down to a safe landing.

_The Moon Metal_ (1900) deals with the problem of a strange, lunar metal
used as a monetary standard to replace gold when, in 1949, huge new
deposits of that metal rendered it common as iron. This is of short
story length, and amply demonstrates the author's mastery of that
medium.

From the prophetic as well as the entertainment standpoint, one of
Garrett Serviss' most interesting novels is _A Columbus of Space_. Here
he visualizes atomic energy liberated and harnessed to drive a rocket to
the planet Venus. His conception is uncannily close to truth; he names
uranium as the raw material from which is extracted the vital substance,
a "crystallized powder" which releases its energy on proper treatment.
No less intriguing is the description of the intelligent civilizations
on Venus which explorers from this world find.

Two later novels came from his pe