"You cannot put everything out, can you?"
"Not quite, but pretty nearly, I'll leave a hole in the ether screen to pass visible light--no, I won't either. You folks can see just as well, even on the direct-vision wall plates, with light heterodyned on the fifth, so we'll close all ether bands, absolutely. All we'll have to leave open will be the one extremely narrow band upon which our projector is operating, and I'll protect that with a detector screen. Also, I'm going to send out all four courses, instead of only one--then I'll _know_ we're all right."
"Suppose they find our one band, narrow as it is? Of course, if that were shut off automatically by the detector, we'd be safe; but would we not be out of control?"
"Not necessarily--I see you didn't get quite all this stuff over the educator. The other projector worked that way, on one fixed band out of the nine thousand odd possible. But this one is an ultra-projector, an improvement invented at the last minute. Its carrier wave can be shifted at will from one band of the fifth order to any other one; and I'll bet a hat that's _one_ thing the Fenachrone haven't got! Any other suggestions?... all right, let's get busy!"
A single light, quick-acting detector was sent out ahead of four courses of five-ply screen, then Seaton's fingers again played over the keys, fabricating a detector screen so tenuous that it would react to nothing weaker than a copper power bar in full operation and with so nearly absolute zero resistance that it could be driven at the full velocity of his ultra-projector. Then, while Crane watched the instruments closely and while Dorothy and Margaret watched the faces of their husbands with only mild interest, Seaton drove home the plunger that sent that prodigious and ever-widening fan ahead of them with a velocity unthinkable millions of times that of light. For five minutes, until that far-flung screen had gone as far as it could be thrown by the utmost power of the uranium bar, the two men stared at the unresponsive instruments, then Seaton shrugged his shoulders.
"I had a hunch," he remarked with a grin. "They didn't wait for us a second. 'I don't care for some,' says they, 'I've already had any.' They're running in a straight line, with full power on, and don't intend to stop or slow down."