"Come on, Arnie! You're young and strong," came the voice of the mineralogist. "You should be able to lift as much of this stuff as I can. I understand you were lucky enough to get hold of Eileen—have you asked for the bonus yet?—but your work isn't done."

"It wasn't luck," Zaino retorted. Burkett, in spite of her voice, seemed much less of a schoolmistress when encased in a spacesuit and carrying a shovel, so he was able to talk back to her. "I was simply alert enough to make use of existing conditions, which I had to observe for myself in spite of all the scientists around. I'm charging the achievement to my regular salary. I saw—"



He stopped suddenly, both with tongue and shovel. Then, "Captain!"

"What is it?"

"The only reason we're starting this wall here is to keep well ahead of the flow so we can work as long as possible, isn't it?"

"Yes, I suppose so. I never thought of trying anywhere else. The valley would mean a much shorter dam, but if the flow isn't through it by now it would be before we could get there—oh! Wait a minute!"

"Yes, sir. You can put the main switch anywhere in a D. C. circuit. Where are the seismology stores we never had to use?"