the mountain observatories as telescopes improve, and we should be
able to bring the moon within an apparent distance of about forty
miles, while the corresponding distance for Mars would be more than
seven thousand miles. But even with existing telescopic powers we can
see details on the moon no larger than some artificial constructions
on the earth. St Peter's at Rome, with the Vatican palace and the
great piazza, if existing on the moon, would unquestionably be
recognizable as something else than a freak of nature. Large cities,
with their radiating lines of communication, would at once betray
their real character. Cultivated tracts, and the changes produced by
the interference of intelligent beings, would be clearly recognizable.
The electric illumination of a large town at night would probably be
markedly visible. Gleams of reflected sunlight would come to us from
the surfaces of the lakes and oceans, and a huge ``liner'' traversing
a lunar sea could probably be followed by its trail of smoke. As to
communications by ``wireless'' signals, which certain enthusiasts have
thought of in connection with Mars, in the case of the moon they
should be a relatively simple matter, and the feat might actually be
accomplished. Think what a literature would grow up about the moon if
it were a living world! Its very differences from the earth would only
accentuate its interest for us. Night and day on the moon are each two
weeks in length; how interesting it would be to watch the manner in
which the lunarians dealt with such a situation as that. Lunar and
terrestrial history would keep step with each other, and we should
record them both. Truly one might well wish to have a neighbor world
to study; one would feel so much the less alone in space.

It is not impossible that the moon did at one time have inhabitants of
some kind. But, if so, they vanished with the disappearance of its
atmosphere and seas, or with the advent of its cataclysmic age. At the