"Mine looks that way now," said Jim, "and we've only moved a couple of times. No, Barney, don't give 'em any ideas."

Jim picked up the hammer and tried to hit the table. Then, idly, he swung the hammer in the direction of the tube's end.

Barney gasped. In this direction there was no resistance. Jim's swing continued, and the look on Jim's face indicated that he was trying to brake the swing in time to keep from hitting the end of the tube. But it seemed as though he were trying to stop an avalanche. The swing continued on and on and finally ended when the hammer head contacted the end of the tube.

There was a burst of fire. Jim swung right on through, whirling around off balance and coming to a stop only when he fell to the floor. He landed in darkness again. The burst of fire emanated from the insulation as it flamed under the heat of extreme overload.

This time the lights were out all over Lincoln Head. The whole city was in complete blackout!

Candles were found, and they inspected the tube anxiously. It seemed whole. But the hammer head was missing. The handle was cut cleanly, on an optically perfect surface.

Where the hammer head went, they couldn't say. But on the opposite wall there was a fracture in the plaster that Jim swore hadn't been there before. It extended over quite an area, and after some thought, Barney calculated that if the force of Jim's hammer blow had been evenly distributed over that area on the wall, the fracturing would have been just about that bad.

"A weapon, all right," said Barney.

"Sure. All you have to do is to shoot your gun right in this end and the force is dissipated over quite an area out of that end. In the meantime you blow out all of the powerhouses on the planet. If a hammer blow can raise such merry h.e.l.l, what do you think the output of a sixteen-inch rifle would do? Probably stop the planet in its tracks. D'ye know what I think?"

"No, do you?"

"Barney, I think that we aren't even close as to the operation and use of this device."

"For that decision, Jim, you should be awarded the Interplanetary Award for Discovery and Invention-posthumously!"

"So what do we do now?"

"Dunno. How soon does this lighting situation get itself fixed?"

"You ask me... I don't know either."

"Well, let's see what we've found so far."

"That's easy," said Jim. "It might be a weapon, but it don't weap. We might use it for letting elevators down easy, except that it would be a shame to tie up a room full of equipment when the three-phase electric motor is so simple. We could toast a bit of bread, but the electric toaster has been refined to abeautiful piece of breakfast furniture that doesn't spray off and scorch the wallpaper. We could use it to transmit hammer blows, or to turn out electric lights, but both of those things have been done very simply; one by means of sending the hammerer to the spot, and the other by means of turning the switch. And then in the last couple of cases, there is little sense in turning out a light by short circuiting the socket and blowing all the fuses."

"That is the hard way," smiled Barney. "Like hitting a telephone pole to stop the car, or cutting the wings off a plane to return it to the ground."

"So we have a fairly lucid book that describes the entire hook-up of the thing except what it's for. It gives not only the use of this device, but also variations and replacements. Could we figure it out by sheer deduction?"

"I don't see how. The tower is in the midst of the Red Desert. There is nothing but sand that a.s.says high in iron oxide between Ca.n.a.lopsis, at the junction of the Grand Ca.n.a.l and Lincoln Head. Might be hid, of course, just as this one was, and we'll send out a crew of expert sub-sand explorers with under-surface detectors to cover the ground for a few hundred miles in any direction from the place where we found this. Somehow, I doubt that we'll find much."

"And how do you... ah, there's the lights again... deduce that?" asked Jim.

"This gadget is or was of importance to the Martians. Yet in the Temple of Science and Industry at Ca.n.a.lopsis, there is scant mention of the towers."

"Not very much, hey?"

"Very little, in fact. Of course the pictographs on the Temple at Ca.n.a.lopsis show one tower between what appeared to be two cities. Wavy lines run from one city to the tower and to the other city. Sayl I'll bet a cooky that this is some sort of signaling device!"

"A beam transmitter?" asked Jim skeptically. "Seems like a lot of junk for just signaling. Especially where such a swell job can be done with standard radio equipment. A good civilization-such as the Martians must have had -wouldn't piddle around with relay stations between two cities less than a couple of thousand miles apart. With all the juice this thing can suck, they'd be more than able to hang a straight broadcast station and cover halfway around the planet as ground-wave area. What price relay station?"

"Nevertheless, I'm going to tinker up another one of these and see if it is some sort of signaling equipment."

The door opened and Christine Baler entered. She waved a newspaper before her brother's eyes and said: "Boy, have you been missing it!"

"What?" asked Barney.

"Pixies or gremlins loose in Lincoln Head."

"Huh-huh. Read it," said Jim.

"Just a bunch of flash headlines. Fire on Manley Avenue. Three planes had to make dead-tube landings in the center of the city; power went dead for no good reason for about ten minutes. Facade of the City Hall caved in.

Power plants running wild all over the place. Ten thousand dollars' worth of electrical equipment blown out. Automobiles stalled in rows for blocks."Jim looked at Barney. "Got a bear by the tail," he said.

"Could be," admitted Barney.

"Are you two blithering geniuses going to work all night?" asked Christine.

"Nope. We're about out of ideas. Except the one that Barney had about the gadget being some sort of signaling system."

"Why don't you fellows call Don Channing? He's the signaling wizard of the Solar System."

"Sure, call Channing. Every time someone gets an idea, everyone says, 'Call Channing!' He gets called for everything from Boy Scout wigwag ideas to super-cyclotronic-electron-stream beams to contact the outer planets. Based upon the supposition that people will eventually get there, of course."

"Well?"

"Well, I... we, I mean... found this thing and we're jolly well going to tinker it out. In spite of the fact that it seems to bollix up everything from electric lights to moving gears. I think we're guilty of sabotage.

f.a.gade of the City Hall, et cetera. Barney, how long do you think it will take to tinker up another one of these?"

"Few hours. They're doggoned simple things in spite of the fact that we can't understand them. In fact, I'm of the opinion that the real idea would be to make two; one with only the front end for reception, one for the rear end for transmission, and the one we found for relaying. That's the natural bent, I believe."

"Could be. Where are you going to cut them?"

"The transmitter will start just before the cathode and the receiver will end just after the... uh, cathode."

"Huh?"

"Obviously the cathode is the baby that makes with the end product. She seems to be a total intake from the intake end and a complete output from the opposite end. Right?"

"Right, but it certainly sounds like heresy."

"I know," said Barney thoughtfully, "but the thing is obviously different from anything that we know today. Who knows how she works?"

"I give up."

Christine, who had been listening in an interested manner, said: "You fellers are the guys responsible for the ruckus that's been going on all over Lincoln Head?"

"I'm afraid so."

"Well, brother warlocks, unless you keep your activities under cover until they're worth mentioning, you'll both be due for burning at the stake."

"O.K., Chris," said Jim. "We'll not let it out."

"But how are you going to tinker up that transmitter-relay-receiver system?"

"We'll take it from here to Barney's place across the avenue and into his garage. That should do it.""O.K., but now I'm going to bed."

"Shall we knock off, too?" asked Jim.

"Yup. Maybe we'll dream a good thought."

"So long then. We'll leave the mess as it is. No use cleaning up now, we'll only have to mess it up again tomorrow with the same junk."

"And I'll have that-or those-other systems tinkered together by tomorrow noon. That's a promise,"

said Barney. "And you," he said to Christine, "will operate the relay station."

Altas said to Than: "Now that your system is balanced properly, and we have proved the worth of this tube as a replacement, we shall take it to the roof and install it. The present tube is about due for retirement."

"I've done well, then?" asked Than.

"Considering all, you've done admirably. But balancing the device in the tower, and hooked into the circuit as an integral part is another thing. Come, Than. We shall close the line for an hour whilst replacing the tube."

"Is that permissible?"

"At this time of the night the requirements are small. No damage will be done; they can get along without us for an hour. In fact, at this time of night, only the people who are running the city will know that we are out of service. And it is necessary that the tube be maintained at full capability. We can not chance a weakened tube; it might fail when it is needed the most."

Than carried the tube to the top of the tower, and Altas remained to contact the necessary parties concerning the shut-off for replacement purposes. He followed Than to the top after a time and said: "Now disconnect the old tube and put it on the floor. We shall replace the tube immediately, but it will be an hour before it is properly balanced again."

It was not long before Than had the tube connected properly. "Now," said Altas, "turn it on one-tenth power and we shall align it."

"Shall I use the meters?"

"I think it best. This requires perfect alignment now. We've much power and considerable distance, and any losses will create great amounts of heat."

"All right," said Than. He left the tower top to get the meters.

Barney Carroll spoke into a conveniently placed microphone. "Are you ready?" he asked.

"Go ahead," said Christine.

"We're waiting," said Jim.

"You're the bird on the transmitter," said Barney to Jim. "You make with the juice."

Power rheostats were turned up gingerly, until Jim shouted to stop. His shout was blotted out by cries from the other two. They met in Barney's place to confer."What's cooking?" asked Jim.

"The meters are all going crazy in my end," said Barney. "I seem to be sucking power out of everything in line with my tube."

"The so-called relay station is firing away at full power and doing nothing but draining plenty of power from the line," complained Christine.

"And on my end, I was beginning to scorch the wallpaper again. I don't understand it. With no receiver-end, how can I scorch wallpaper?"

"Ask the Martians. They know."

"You ask 'em. What shall we do, invent a time machine and go back sixty centuries?"

"Wish we could," said Barney. "I'd like to ask the bird that left this textbook why they didn't clarify it more."

"Speaking of Don Channing again," said Jim, "I'll bet a hat that one of his tube-replacement manuals for the big transmitters out on Venus Equilateral do not even mention that the transmitter requires a receiver before it is any good. We think we're modern. We are, and we never think that some day some poor bird will try to decipher our technical works. Why, if Volta himself came back and saw the most perfect machine ever invented-the transformer-he'd shudder. Np connection between input and output, several kinds of shorted loops of wire; and instead of making a nice simple electromagnet, we short the lines of force and on top of that we use a lot of laminations piled on top of one another instead of a nice, soft iron core. We completely short the input, et cetera, but how do we make with a gadget like that?"

"I know. We go on expecting to advance. We forget the simple past. Remember the lines of that story: 'How does one chip the flint to make the best arrowhead?' I don't know who wrote it any more than I know how to skin a boar, but we do get on without making arrowheads or skinning boars or tr.i.m.m.i.n.g birch-bark canoes."

"All right, but there's still this problem."

"Remember how we managed to align this thing? I wonder it it might not take another alignment to make it work as a relay."

"Could be," said Jim. "I'll try it. Christine, you work these screws at the same time we do, and make the current come out as low as we can."

They returned to their stations and began to work on the alignment screws. Jim came out first on the receiver. Christine was second on the transmitter, while Barney fumbled for a long time with the relay tube.

Then Christine called: "Fellows, my meter readings are climbing up again. Shall I diddle?"

"Wait a minute," said Barney. "That means I'm probably taking power out of that gadget you have in there. Leave 'em alone."

He fiddled a bit more, and then Jim called: "Whoa, Nellie. Someone just lost me a millimeter. She wound up on the far end."

"Hm-m-m," said Barney, "so we're relaying.""Go ahead," said Jim. "I've got a ten-ampere meter on here now."

Barney adjusted his screws some more.

"Wait a minute," said Jim. "I'm going to shunt this meter up to a hundred amps."

"What?" yelled Barney.

"Must you yell?" asked Christine ruefully. "These phones are plenty uncomfortable without some loud-mouthed bird screaming."

"Sorry, but a hundred amps... whooshl What have we got here, anyway?"

"Yeah," said Christine. "I was about to say that my input meter is running wild again."

"Gone?"

"Completely. You shouldn't have hidden it behind that big box. I didn't notice it until just now, but she's completely gone."

"I'll be over. I think we've got something here."

An hour pa.s.sed, during which nothing of any great importance happened. By keying the transmitter tube, meters in the receiver tube were made to read in accordance. Then they had another conclave.