"We would have to stop soon, in any case," Wise replied, "for your available waste material is becoming scarce. It will take the substance of a fairly large planet to produce that which you require. You have, perhaps, a planet in mind which is to be used for the purpose?"

"Better than that. I have in mind the material of just such a planet, but already broken up into sizes convenient for handling."

"Oh, the asteroid belt!" Thorndyke exclaimed. "Fine! Kill two birds with one stone, huh? Build this thing and at the same time clear out the menaces to inert interplanetary navigation? But how about the miners?"

"All covered. The ones actually in development will be let alone. They're not menaces, anyway, as they all have broadcasters. The tramp miners we send—at Patrol expense and grubstake—to some other system to do their mining. But there's one more point before we flit. Are you sure that you can shift to the second stage without an accident?"

"Positive. Build another one around it, mount new Bergs, exciters, and screens on it, and let this one, machines and all, go in to feed the kitty—whatever it is," the technician finished.

"QX. Let's go, fellows!"


Two huge Tellurian freighters were at hand; and, holding the small framework between them in a net of tractors and pressors, they set off blithely toward Sol. They took a couple of hours for the journey—and there was no hurry, and in the handling of this particular freight caution was decidedly of the essence.

Arrived at destination, the crews tackled with zest and zeal this new game. Tractors lashed out, seizing chunks of iron—

"Pick out the little ones, men," cautioned Kinnison. "Nothing over about ten feet in section-dimension will go into this frame. Better wait for the second frame before you try to handle the big ones."