ut of it here, and CO{2} froze solidly out of it
there, and on beyond it collected as restless, transparent liquid air.
At the same time, liquid air from another tank evaporated to maintain
the proper air pressure in the shack. Every so often Pop tapped the pipe
where the moisture froze, and lumps of water ice clattered out to be
returned to the humidifier. Less often he took out the CO{2} snow, and
measured it, and dumped an equivalent quantity of pale-blue liquid
oxygen into the liquid air that had been purified by cold. The oxygen
dissolved. Then the apparatus reversed itself and supplied fresh air
from the now-enriched fluid, while the depleted other tank began to fill
up with cold-purified liquid air.

Outside the shack, jagged stony pinnacles reared in the starlight, and
craters complained of the bombardment from space that had made them.
But, outside, nothing ever happened. Inside, it was quite different.

Working on his memories, one day Pop made a little sketch. It helped a
great deal. He grew deeply interested. Writing-material was scarce, but
he spent most of the time between two particular rocket-landings getting
down on paper exactly how a child had looked while sleeping, some
fifteen years before. He remembered with astonishment that the child had
really looked exactly like that! Later he began a sketch of his
partly-remembered wife. In time--he had plenty--it became a really
truthful likeness.

The sun rose, and baked the abomination of desolation which was the
moonscape. Pop Young meticulously touched up the glittering triangles
which were landing guides for the Lunar City ships. They glittered from
the thinnest conceivable layer of magnesium marking-powder. He checked
over the moondozer. He tended the air apparatus. He did everything that
his job and survival required. Ungrudgingly.

Then he made more sketches. The images to be drawn came back more
clearly when he thought of Sattell, so by keeping Sattell in mind he
recovered the memory of a chair that had been in his forgotten home.
Then he drew his wife sitting in it, reading. It felt very good to see
her again. And he speculated about whether Sattell ever thought of
millions of dollars' worth of new-mined diamonds knocking about
unguarded in the shack, and he suddenly recollected clearly the way one
of his children had looked while playing with her doll. He made a quick
sketch to keep from forgetting that.

There was no purpose in the sketching,