plains known as "seas" is a
dark gray dashed with green and brown,--a color presented also by a few
of the great craters.

This opinion of Schmidt's, shared by Beer and Maedler, Barbican's
observations now convinced him to be far better founded than that of
certain astronomers who admit of no color at all being visible on the
Moon's surface but gray. In certain spots the greenish tint was quite
decided, particularly in _Mare Serenitatis_ and _Mare Humorum,_ the very
localities where Schmidt had most noticed it. Barbican also remarked
that several large craters, of the class that had no interior cones,
reflected a kind of bluish tinge, somewhat like that given forth by a
freshly polished steel plate. These tints, he now saw enough to convince
him, proceeded really from the lunar surface, and were not due, as
certain astronomers asserted, either to the imperfections of the
spy-glasses, or to the interference of the terrestrial atmosphere. His
singular opportunity for correct observation allowed him to entertain no
doubt whatever on the subject. Hampered by no atmosphere, he was free
from all liability to optical illusion. Satisfied therefore as to the
reality of these tints, he considered such knowledge a positive gain to
science. But that greenish tint--to what was it due? To a dense tropical
vegetation maintained by a low atmosphere, a mile or so in thickness?
Possibly. But this was another question that could not be answered at
present.

Further on he could detect here and there traces of a decidedly ruddy
tint. Such a shade he knew had been already detected in the _Palus
Somnii_, near _Mare Crisium_, and in the circular area of _Lichtenberg_,
near the _Hercynian Mountains_, on the eastern edge of the Moon. To what
cause was this tint to be attributed? To the actual color of the surface
itself? Or to that of the lava covering it here and there? Or to the
color resulting from the mixture of other colors seen at a distance too
great to allow of their being distinguished separately? Impossible to
tell.

Barbican and his companions succeeded no better at a new problem that
soon engaged their undivided attention. It deserves some detail.

Having passed _Lambert_, being just over _Timocharis_, all were
attentively gazing at the magnificent crater of _Archimedes_ with a
diameter of 52 miles across and ramparts more than 5000 feet in height,
when Ardan startled his companions by suddenly exclaiming:

"Hello! Cultivated