the south lunar pole, they attain a depth where the rays of the sun
never reach. Nothing more frightful than the spectacle which many of
these terrible chasms present can be pictured by the imagination. As
the lazy lunar day slowly advances, the sunshine, unmitigated by
clouds or atmospheric veil of any kind, creeps across their rims and
begins to descend the opposite walls. Presently it strikes the ragged
crest of a ridge which had lain hidden in such darkness as we never
know on the earth, and runs along it like a line of kindling fire.
Rocky pinnacles and needles shoot up into the sunlight out of the
black depths. Down sinks the line of light, mile after mile, and
continually new precipices and cliffs are brought into view, until at
last the vast floor is attained and begins to be illuminated. In the
meanwhile the sun's rays, darting across the gulf, have touched the
summits of the central peaks, twenty or thirty miles from the crater's
inmost edge, and they immediately kindle and blaze like huge stars
amid the darkness. So profound are some of these awful craters that
days pass before the sun has risen high enough above them to chase the
last shadows from their depths.

Although several long ranges of mountains resembling those of the
earth exist on the moon, the great majority of its elevations assume
the crateriform aspect. Sometimes, instead of a crater, we find an
immense mountain ring whose form and aspect hardly suggest volcanic
action. But everywhere the true craters are in evidence, even on the
sea-beds, although they attain their greatest number and size on those
parts of the moon -- covering sixty per cent of its visible surface --
which are distinctly mountainous in character and which constitute its
most brilliant portions. Broadly speaking, the southwestern half of
the moon is the most mountainous and broken, and the northeastern half
the least so. Right down through the center, from pole to pole, runs a