d it do to charge fifty cents a pound?" asked McIlroy.

"The nickel, man, the tons of nickel worth a dollar and a half on Earth,
and not worth mining here; the low-grade ores of uranium and vanadium,
they need these things on Earth, but they can't get them as long as it
isn't worth the carrying of them. And then, of course, there's the water
we haven't got. We could afford to bring more water for more people, and
set up more distilling plants if we had the money from the nickel.

"Even though I say it who shouldn't, two-eighty a quart is too much to
pay for water."

Both men fell silent for a while. Then Jones spoke again:

"Have you seen our friend Evans lately? The price of chromium has gone
up, and I think he could ship some of his ore from Yellow Crater at a
profit."

"He's out prospecting again. I don't expect to see him until sun-down."

"I'll likely see him then. I won't be loaded for another week and a
half. Can't you get in touch with him by radio?"

"He isn't carrying one. Most of the prospectors don't. They claim that a
radio that won't carry beyond the horizon isn't any good, and one that
will bounce messages from Earth takes up too much room."

"Well, if I don't see him, you let him know about the chromium."

"Anything to help another Welshman, is that the idea?"

"Well, protection it is that a poor Welshman needs from all the English
and Scots. Speaking of which--"

"Oh, of course," McIlroy grinned as he refilled the glasses.

"_Slainte, McIlroy, bach._" [Health, McIlroy, man.]

"_Slainte mhor, bach._" [Great Health, man.]

* * * * *

The sun was halfway to the horizon, and Earth was a crescent in the sky
when Evans had quarried all the ice that was available in the cave. The
thought grew on him as he worked that this couldn't be the only such
cave in the area. There must be several more bubbles in the lava flow.

Part of his reasoning proved correct. That is, he found that by
chipping, he could locate small bubbles up to an inch in diameter, each
one with its droplet of water. The average was about one per cent of the
volume of each bubble filled with ice.

A quarter of a mile from the tractor, Evans found a promising looking
mound of lava. It was rounded on top, and it could easily be the dome of
a bubble. Suddenly, Evans noticed that the gauge on the oxygen tank of
his suit was reading dangerously near empty. He turned back to his
tractor, moving as slow