reaching to the very foot of
the cliff, and showed a disordered escarpment of drab and grayish rock,
lined here and there with banks and crevices of snow. This was perhaps a
dozen miles away, but at first no intervening atmosphere diminished in the
slightest the minutely detailed brilliancy with which these things glared
at us. They stood out clear and dazzling against a background of starry
blackness that seemed to our earthly eyes rather a gloriously spangled
velvet curtain than the spaciousness of the sky.

The eastward cliff was at first merely a starless selvedge to the starry
dome. No rosy flush, no creeping pallor, announced the commencing day.
Only the Corona, the Zodiacal light, a huge cone-shaped, luminous haze,
pointing up towards the splendour of the morning star, warned us of the
imminent nearness of the sun.

Whatever light was about us was reflected by the westward cliffs. It
showed a huge undulating plain, cold and gray, a gray that deepened
eastward into the absolute raven darkness of the cliff shadow. Innumerable
rounded gray summits, ghostly hummocks, billows of snowy substance,
stretching crest beyond crest into the remote obscurity, gave us our first
inkling of the distance of the crater wall. These hummocks looked like
snow. At the time I thought they were snow. But they were not--they were
mounds and masses of frozen air.

So it was at first; and then, sudden, swift, and amazing, came the lunar
day.

The sunlight had crept down the cliff, it touched the drifted masses at
its base and incontinently came striding with seven-leagued boots towards
us. The distant cliff seemed to shift and quiver, and at the touch of the
dawn a reek of gray vapour poured upward from the crater floor, whirls and
puffs and drifting wraiths of gray, thicker and broader and denser, until
at last the whole westward plain was steaming like a wet handkerchief held
before the fire, and the westward cliffs were no more than refracted glare
beyond.

"It is air," said Cavor. "It must be air--or it would not rise like
this--at the mere touch of a sun-beam. And at this pace...."

He peered upwards. "Look!" he said.

"What?" I asked.

"In the sky. Already. On the blackness--a little touch of blue. See! The
stars seem larger. And the little ones and all those dim nebulosities we
saw in empty space--they are hidden!"

Swiftly, steadily, the day approached us. Gray summit after gray summit
was overtaken by the blaze, and tur