Part 17 (1/2)

”You'll see,” promised the alien. He fumbled in the back of the machine, drew forth a cord, and plugged it into a wall socket. A small tube in the heart of the machine glowed cherry red and the pistons began to move, first slowly, then more rapidly. After a while, it was humming away at an even, steady clip, pistons barreling back and forth in purposeless but inexorable motion.

Kemridge bent and peered as close to the workings of the gadget as he dared. ”It's an engine. What of it?”

”It's a special kind of engine,” Plorvash said. ”Suppose you take the plug out.”

The Earthman worked the plug from its socket and looked at the machine. Then the plug dropped from his limp hand and skittered to the floor.

”It -- doesn't stop going, does it?” Kemridge asked quietly. ”The pistons keep on moving.”

”This is our power source,” Plorvash said smugly. ”We use them in vehicles and other such things. It's the third problem.”

”We'll give it a try,” Marner tried to say casually.

”I'll be most interested in the results,” Plorvash said, ”And now I must bid you a good day.”

”Sure,” Marner said weakly. ”Cheers.”

They watched the broadbeamed alien waddle gravely out of the laboratory, waited till the door was closed, and glanced at the machine.

It was still moving.

Marner licked his lips and looked pleadingly at Kemridge. ”Dave, can we build a perpetual-motion machine?”

The Domerangi machine worked just as well plugged in or unplugged, once it had tapped some power source to begin with. The pistons threaded ceaselessly up and down. The basic components of the thing seemed simple enough.

”The first step to take,” Marner said, ”is to shut the d.a.m.ned thing off so we can get a look at its innards.”

”How do we do that?”

”By reversing the power source, I suppose. Feed a negative pulse through that power input and that ought to do it. We'll have to reverse the polarity of the signal.”

Half an hour's hard work with the tools and solder had done that. They plugged the scrambled cord into the socket and the machine coughed twice and subsided.

”Okay,” Marner said, rubbing his hands with an enthusiasm he did not feel. ”Let's dig this baby apart and find out what makes it tick.” He turned and stared meaningfully at Kemridge. ”And let's adopt this as a working credo, Dave: inasmuch as the Domerangi have already built this thing, it's not impossible. Okay?”

”That seems to be the only basis we can approach it on,” Kemridge agreed.

They huddled around the device, staring at the workings. Marner reached down and pointed at a part. ”This thing is something like a tuned-plate feedback oscillator,” he observed. ”And I'll bet we've almost got a thyratron tube over here. Their technology's a good approximation of ours. In fact, the whole thing's within our grasp, technically.”

”Hmm. And the result is a closed regenerative system with positive feedback,” Kemridge said dizzily. ”Infinite energy, going round and round the cycle. If you draw off a hundred watts or so -- well, infinity minus a hundred is still infinity!”

”True enough.” Marner wiped a gleaming bead of perspiration from his forehead. ”Dave, we're going to have to puzzle this thing out from scratch. And we don't dare fail.”

He reached doggedly for a screwdriver. ”Remember our motto. We'll use our natural savvy and a little perspiration, and we ought to do it.”

Three weeks later, they had come up with their first trial model -- which wobbled along for half an hour, then gave up.

And a month after that, they had a machine that didn't give up.

Hesitantly, they sent for Plorvash. ”There it is,” Marner said, pointing to the bizarre thing that stood next to the original model. Both machines were humming blithely, plugs dangling from the sockets.

”It works?” Plorvash whispered, paling. ”It hasn't stopped yet,” Marner said. There were heavy rings under his eyes and his usually plump face was drawn, with the skin tight over his cheekbones. It had been two months of almost constant strain and both Earthmen showed it.

”It works, eh?” Plorvash asked. ”_How_?”

”A rather complex hypers.p.a.ce function,” Kemridge said. ”I don't want to bother explaining it now -- you'll find it all in our report -- but it was quite a stunt in topology. We couldn't actually duplicate your model, but we achieved the same effect, which fulfills the terms of the agreement.”

”All as a matter of response to challenge,” said Marner. ”We didn't think we could do it until we _had_ to -- so we did.”

”I didn't think you could do it, either,” Plorvash said hoa.r.s.ely. He walked over and examined the machine closely. ”It works, you say? Honestly, now?” His voice was strained.

”Of course,” Marner said indignantly. ”We have just one question.” Kemridge pointed to a small black rectangular box buried deep in a maze of circuitry in the original model. ”That thing down there -- it nearly threw us. We couldn't get it open and so we had to bypa.s.s it and subst.i.tute a new system for it. What in blazes is it?”

Plorvash wheeled solidly around to face them. ”That,” he said in a strangled voice, ”is the power source. It's a miniature photoelectric amplifier that should keep the model running for -- oh, another two weeks or so. Then the jig would have been up.”

”How's that?” Marner was startled.

”It's time to explain something to you,” the alien said wearily. ”_We don't have any perpetual-motion machines._ You've been cruelly hoaxed into inventing one for us. It's dastardly, but we didn't really think you were going to do it. It took some of our best minds to rig up the model we gave you, you know.”

Marner drew up a lab stool and sat down limply, white-faced. Kemridge remained standing, his features blank with disbelief.

Marner said, ”You mean we invented the thing and you didn't -- you -- ”

Plorvash nodded. ”I'm just as astonished as you are,” he said. He reached for a lab stool himself and sat down. It groaned under his weight.

Kemridge recovered first. ”Well,” he said after a moment of silence, ”now that it's all over, we'll take our machine and go back to Earth. This invalidates the contest, of course.”

”I'm afraid you can't do that,” Plorvash said. ”By a statute enacted some seven hundred years ago, any research done in a Domerangi government lab is automatically government property. Which means, of course, that we'll have to confiscate your -- ahem -- project.”

”That's out of the question!” Marner said hotly.

”And, furthermore, we intend to confiscate _you_, too. We'd like you to stay and show us how to build our machines.”

”This is cause for war,” Kemridge said. ”Earth won't let you get away with this -- this kidnapping!”

”Possibly not. But in view of the way things have turned out, it's the sanest thing we can do. And I _don't_ think Earth will go to war over you.”

”We demand to see our Consul,” said Marner.

”Very well,” Plorvash agreed. ”It's within your rights, I suppose.”

The Earth Consul was a white-haired, st.u.r.dy gentleman named Culbertson, who arrived on the scene later that day.