"Evans, man!" said Jones' voice in the intercom. "Alive you are!"
"A Welshman takes a lot of killing," Evans answered.
Later, in Evans' tractor, he was telling his story:
"... And I don't know how long I sat there after I found the water." He looked at the Goldburgian device he had made out of wire and tubing. "Finally I built this thing. These caves were made of lava. They must have been formed by steam some time, because there's a floor of ice in all of 'em.
"The idea didn't come all at once, it took a long time for me to remember that water is made out of oxygen and hydrogen. When I remembered that, of course, I remembered that it can be separated with electricity. So I built 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?"