or exhausted
through the forward tube, slowing their speed.

"Turn on the outside generator propellers," ordered Wichter. "I think
our batteries are getting low."

Joyce slipped the tiny, slim-bladed propellers into gear. They began
to turn, slowly at first in the almost non-existent atmosphere.

"Four hundred miles," announced Wichter. "How's the temperature?"

Joyce stepped to the thermometer that registered the heat of the outer
wall. "Nine hundred degrees," he said.

"Cut down to a thousand miles an hour," commanded Wichter. "Five
hundred as soon as the motor will catch that much. I'll keep our
course straight toward this crater. It's in wells like that, that
we'll find livable air--if we're right in believing there is such a
thing on Zeud."

* * * * *

Joyce glanced at the thermometer. It still registered hundreds of
degrees, though their speed had been materially reduced.

"I guess there's livable air, all right," he said. "It's pretty thick
outside already."

The professor smiled. "Another theory vindicated. I was sure that
Zeud, swinging on the outside of the Earth-moon-Zeud chain and hence
traveling at a faster rate, would pick up most of the moon's
atmosphere over a period of millions of years. Also it must have been
shielded by the moon, to some extent, against the constant small
atmospheric leakage most celestial globes are subject to. Just the
same, when we land, we'll test conditions with a rat or two."

At a signal from him, Joyce checked their speed to four hundred miles
an hour, then to two hundred, and then, as they descended below the
highest rim of the circular cliffs of the crater, almost to a full
stop. They floated toward the surface of Zeud, watching with
breathless interest the panorama that unfolded beneath them.

They were nosing toward a spot that was being favored with the Zeudian
sunrise. Sharp and clear the light rays slanted down, illuminating
about half the crater's floor and leaving the cliff protected half in
dim shadow.

The illuminated part of the giant pit was as bizarre as the landscape
of a nightmare. There were purplish trees, immense beyond belief.
There were broad, smooth pools of inky black fluid that was oily and
troubled in spots as though disturbed by some moving things under the
surface. There were bare, rocky patches where the stones, the long
drippings of ancient lava flow, were spread like bleaching gray
skeletons of monste