get along with a good deal less solar heat than it
receives, in proof of which I expect to find the poles themselves quite
comfortable. The reason the internal heat is so little taken into
account on earth is because, from the thickness of the crust, it cannot
make itself felt; for if the earth were as chilled through as ice, the
people on the surface would not feel the difference."

A Jovian week's explorations disclosed the fact that though the
island's general outlines were fairly regular, it had deep-water
harbours, great rivers, and land-locked gulfs and bays, some of which
penetrated many hundred miles into the interior. It also showed that
the island's length was about six thousand miles, and its breadth about
three thousand, and that it had therefore about the superficial area of
Asia. They found no trace of the great monsters that had been so
numerous on the mainland, though there were plenty of smaller and
gentle-looking creatures, among them animals whose build was much like
that of the prehistoric horse, with undeveloped toes on each side of
the hoof, which in the modern terrestrial horse have disappeared, the
hoof being in reality but a rounded-off middle finger.

"It is wonderful," said Bearwarden, "how comparatively narrow
a body of water can keep different species entirely separate. The
island of Sumatra, for instance, is inhabited by marsupials belonging
to the distinct Australian type, in which the female, as in the
kangaroo, carries the slightly developed young in a pouch; while the
Malay peninsula, joined to the mainland, has all the highly developed
animals of Asia and the connected land of the Eastern hemisphere, the
narrow Malacca Strait being all that has kept marsupials and mammals
apart, though the separating power has been increased by the rapid
current setting through. This has decreased the chance of creatures
carried to sea on drift-wood or uprooted trees getting safely over to
such a degree that apparently none have survived; for, had they done
so, we may be certain that the mammals, with the advantage their young
have over the marsupials, would soon have run them out, the marsupials
being the older and the less perfect form of life of the two."

Before leaving the beautiful sea-girt region beneath them, Cortlandt
proposed that it be named after their host, which Bearwarden seconded,
whereupon they entered it as Ayrault Island on the charts. After this
they rose to a great heigh