"Sure. As we know, the amount of energy radiated from the sun upon a spot the size of our solar tube is a matter of peanuts compared to the stuff we get out of it. Ergo, our beam must go to Sol and collect the power and draw it back down the beam. Measure the transit-time, and we'll know." "That's an idea. I've got a micro-clock in the lab. We can measure it to a thousandth of a second. Anyone like to get shook up?" "How?" asked Jim. "Snapping from zero to 1-G all to oncet-like isn't too gentle. She'll knock your eyes out." "Sounds like fun. I'm elected." "So am I," insisted Christine. "That's out," said Jim. "I know what he's talking about." "So do I," said Arden. "Don't do it." "Well, what better have you to offer?" "You and I are going down to the Mall." Channing groaned in mock anguish. "Here goes another closet full of female haberdashery. I'm going to close that corridor some day, or put a ceiling on the quantity of sales, or make it illegal to sell a woman anything unless she can prove that 'she has nothing to wear!'" "That, I'd like to see," said Walt. "You would," snorted Arden. "Come on, Chris. Better than the best of three worlds is available." "That sort of leaves me all alone," said Don. "I'm going to look up Wes Farrell and see if he's been able to make anything worth looking at for a driver detector." * * * * * Don found Wes in the laboratory, pouring over a complicated circuit. Farrell was muttering under his breath, and probing deep into the maze of haywire on the bench. "Wes, when you get to talking to yourself, it's time to take a jaunt to Joe's." "Not right now," objected Wes. "I haven't got that hollow leg that your gang seem to have developed. Besides, I'm on the trail of something." "Yes?" Channing forgot about Joe's, and was all interest. "I got a wiggle out of the meter there a few minutes ago. I'm trying to get another one." "What was it like?" "Wavered up and down like fierce for about a minute after I turned it on. Then it died quick, and has been dead ever since." "Could it have been anything cockeyed with the instruments?" "Nope. I've checked every part in this circuit, and everything is as good as it ever will be. No, something external caused that response." "You've tried the solar tube with a dynode of the same alloy as the driver cathodes?" "Uh-huh. Nothing at all. Oh, I'll take that back. I got a scratch. With a pre-meter gain of about four hundred decibels, I read three micromicroamperes. That was detected from a driver tube forty feet across the room, running at full output. I wondered for a minute whether the opposing driver was doing any cancellation, and so I took a chance and killed it for about a half second, but that wasn't it." "Nuts. Does the stuff attenuate with distance?"