"Nothing brilliant," said Jim. "We could use super-output voice amplifiers and yell halfway across the planet if we didn't have radio. We can radio far better than this cockeyed system of signaling." "We might cut the power." "Or spread out quite a bit. I still say, however, that this is no signaling system." "It works like one." "So can a clothesline be made to serve as a transmitter of intelligence. But its prime function is completely different." "S'pose we have a super-clothesline here?" asked Christine. "The way that hammer felt last night, I'm not too sure that this might not be some sort of tractor beam," said Jim. "Tractor beams are mathematically impossible." "Yeah, and they proved conclusively that a bird cannot fly," said Jim. "That was before they found the right kind of math. Up until Clerk Maxwell's time, radio was mathematically impossible. Then he discovered the electromagnetic equations, and we're squirting signals across the Inner System every day. And when math and fact do not agree, which changes?" "The math. Galileo proved that. Aristotle said that a heavy stone will fall faster. Then Galileo changed the math of that by heaving a couple of boulders off the Leaning Tower. But what have we here?" "Has anyone toyed with the transmission of power?" "Sure. A lot of science-fiction writers have their imaginary planets crisscrossed with transmitted power. Some broadcast it, some have it beamed to the consumer. When they use planes, they have the beam coupled to an object-finder so as to control the direction of the beam. I prefer the broadcasting, myself. It uncomplicates the structure of the tale." "I mean actually?" "Oh, yes. But the losses are terrific. Useful power transmission is a minute percentage of the total output of the gadget. Absolutely impractical, especially when copper and silver are so plentiful to string along the scenery on steel towers. No good." "But look at this cockeyed thing. Christine puts in a couple of hundred amps; I take them off my end. Believe it or not, the output meter at my end was getting a lot more soup than I was pouring in." "And my gadget was not taking anything to speak of," said Barney. "Supposing it was a means of transmitting power. How on Mars did they use a single tower there in the middle of the Red Desert? We know there was a Martian city at Canalopsis, and another one not many miles from Lincoln Head. Scribbled on the outer cover of this book is the legend: 'Tower Station, Red Desert,' and though the Martians didn't call this the 'Red Desert, the terminology will suffice for nomenclature." "Well?" asked Jim. "You notice they did not say: 'Station No. 1,' or '3' or '7.' That means to me that there was but one." "Holy Smoke! Fifteen hundred miles with only one station? On Mars the curvature of ground would put such a station below the electrical horizon--" Jim thought that one over for a minute and then said: "Don't tell me they bent the beam?"