this thing.

"It runs an electric current through water, lets the oxygen loose in the room, and pipes the hydrogen outside. It doesn't work automatically, of course, so I run it about an hour a day. My oxygen level gauge shows how long."

"You're a genius, man!" Jones exclaimed.

"No," Evans answered, "a Welshman, nothing more."

"Well, then," said Jones, "are you ready to start back?"

"Back?"

"Well, it was to rescue you that I came."

"I don't need rescuing, man," Evans said.

Jones stared at him blankly.

"You might let me have some food," Evans continued. "I'm getting short of that. And you might have someone send out a mechanic with parts to fix my tractor. Then maybe you'll let me use your radio to file my claim."

"Claim?"

"Sure, man, I've thousands of tons of water here. It's the richest mine on the Moon!"

THE END