"There being no air," said Cortlandt, "it is safe to assume there
is no water, which helps to account for the great inequalities on
the body's surface, since the mountains will seem higher when
surrounded by dry ocean- bottom than they would if water came
halfway up their sides. Undoubtedly, however, the main cause of
their height is the slight effect of gravitation on an asteroid,
and the fact that the shrinking of the interior, and consequent
folding of the crust in ridges, may have continued for a time
after there was no longer water on the surface to cut them down.

"The temperature and condition of a body," continued Cortlandt,
"seem to depend entirely on its size. In the sun we have an
incandescent, gaseous star, though its spots and the colour of
its rays show that it is becoming aged, or, to be more accurate,
advanced in its evolutionary development. Then comes a great
jump, for Jupiter has but about one fourteen-hundredth of the
mass of the sun, and we expect to find on it a firm crust, and
that the planet itself is at about the fourth or fifth period of
development, described by Moses as days. Saturn is doubtless
somewhat more advanced. The earth we know has been habitable
many hundreds of thousands or millions of years, though three
fourths of its surface is still covered by water. In Mars we see
a further step, three fourths of its surface being land. In
Mercury, could we study it better, or in the larger satellites of
Jupiter or Saturn, we might find a stepping-stone from Mars to
the moon, perhaps with no water, but still having air, and being
habitable in all other respects. In our own satellite we see a
world that has died, though its death from an astronomical point
of view is comparatively recent, while this little Pallas has