George O. Smith

“ Like the bird who was tossing baseballs out of the train—he quit when he ran out of them. Our gun will quit cold when we run out of electrons—or when the positive charge gets so high that the betatron can't overcome the electrostatic attraction."
"Venus Equilateral is a free grid," smiled Channing. "As soon as we shoot off electrons, Old Sol becomes a hot cathode and our Station collects 'em until the charge is equalized again." ”

“ The celestial globe of the meteor spotter blazed once in a blinding light and then went completely out of control. It danced with pin points of light, and the coupler that was used to direct the guns went crazy. Turrets tried to swivel, but the charge raised hob with the electronic controls, and the guns raised once and then fell, inert. One of them belched flame and fire, and the shell went wild. The carefully balanced potentials in the driver tubes was upset, and the ship lost headway. The heavy ion stream from the driving cathode bent and spread, touching the dynodes in the tube. ”

“ But in a spaceship that is trying to duck your shot, you'll need something that works with the speed of light. And, since we're going to be forced into something heavy and hard-hitting, its inertia will be even more so."
"Heavy and hard-hitting means exactly what?"
"Cyclotron or betatron. One of those dingusses that whirls electrons around like a stone on a string until the string breaks and sends the stone out at a terrific speed. We need a velocity that sounds like a congressional figure." ”

“ But the electrostatic stresses that filled the gaps between the accelerator and focusing anodes was no more visible than the electricity that runs a toy motor. Its appearance had not changed a bit, but from the meters, Walt Franks knew that megawatts of electronic power, in the shape of high-velocity electrons, was being poured from the cathode; accelerated by the ring anodes; and focused to a narrow beam by the focusing anodes. ”

“ We'll have to use electromagnetic deflection. From the constants of the electron stream out of our souped-up Suzy, we'll have to compute the necessary field to deflect such a beam. That'll be terrific, because the electrons are hitting it up at a velocity approaching that of light—maybe a hundred and seventy thousand miles per—and their mass will be something fierce. That again will help to murder Murdoch; increasing mass will help to keep the electrons from being deflected, since it takes more to turn a heavy mass—et cetera, see Newton's laws of inertia for complete statement. ”

“ Murdoch's radio was completely dead. His ship was yawing from side to side as the static charges raced through the driver tubes. The pilot gained control after a fashion, and decided that he had taken enough. He circled the Station warily and began to make a shaky landing at the South end.
Channing saw him coming, and with a glint in his eye, he pressed the lever for the fourth and last time.
Murdoch's ship touched the landing stage just after the charge had been driven out into space. The heavy negative charge on the Hippocrates met the heavy positive charge on Venus Equilateral. ”

“ As your current starts up from zero, the electron gun squirts a bouquet of electrons into a chamber built like a pair of pie plates set rim to rim. The magnet's field begins to build up at the same time, and the resulting increase in field strength accelerates the electrons and at the same time, its increasing field keeps the little devils running in the same orbit. Shoot it with two-hundred-cycle current, and in the half cycle your electrons are made to run around the center a few million times. That builds up a terrific velocity—measured in six figures, believe it or not. ”

“ We ram 'em with a bundle of electrons moving so fast that the charging effect can not work; before the space charge can build up to the level required for self-nullification of our beam, the damage is done."
"And all we need is a couple of trillion volts. Two times ten to the twelfth power. Grrr."
"I can see that you'll need a tablecloth," said Arden. "You birds can think better over at Joe's. Come along and feed the missus, Don."
Channing surveyed the instrument again, and then said: "Might as well, Walt. The inner man must be fed, and we can wrangle at the same time. ”

“ A voltage gradient will cause electrons to change their course like a lens, and with the usual trouble with inanimate things, it works the wrong way. In order to accelerate the electrons emitted from the cathode, they are subjected to the attraction of an anode which is operating at a high positive potential. The electrons leave the cathode, and as they are attracted by the positive anode, they begin to move. ”

“ Same way we make the electron gun work. Fire it off at a devilish voltage. Run your electron velocity up near the speed of light; the electrons at that speed will acquire considerable mass, in accordance with Lorenz's equation which shows that as the velocity of a mass reaches the speed of light, its mass becomes infinite. With a healthy mass built up by near-light velocities, the electrons will not be as easy to deflect. Then, too, we can do the damage we want before the charge can be built up that will deflect the stream. ”

“ The trip from Lincoln Head to Canalopsis was a fast one. Doug Thomas drove the little flier through the thin air of Mars at a breakneck speed and covered the twelve hundred miles in just shy of two hours. At the spaceport, Channing found that he was not denied the entrance as the reporter had been. He was ushered into the office of Keg Johnson in record time, and the manager of the Canalopsis Spaceport greeted Don with a worried expression on his face. ”

“ He was in no better shape than Don.
"They'd better be right," said Channing ominously. "We're asking for a kick in the teeth. The first bundle of stuff that leaves our gun will energize Murdoch's meteor spotter by shear electrostatic force. His gun mounts, which you tell me are coupled to the meteor detector for aiming, will swivel to cover the turret out here. Then he'll let us have it right in the betatron. If we don't get him first, he'll get us second."
"Don," said Walt in a worried voice, "How are we going to replace the charge on the Station? ”

“ Channing said to Walt: "That's going to be messy."
Inside of the Hippocrates, men were still frozen to their handholds. It was messy, and cleaning up the Hippocrates was a job not relished by those who did it.
But cleaning up Venus Equilateral was no small matter either.
Weeks went by before the snarled-up instruments were repaired. Weeks in which the captured Hippocrates was repaired, too, and used to transport material and special supplies from Terra, and Venus, and Mars. Weeks in which the service from planet to planet was interrupted and erratic. ”

“ The betatron is the ticket."
"But the cyclotron gives out with a lot more soup."
"If I had to increase the output of either one, I could do it a lot quicker with the betatron," said Channing. "In a cyclotron, the revolution of the electrons in their acceleration period is controlled by an oscillator, the voltage output of which is impressed on the D chambers. In order to speed up the electron stream, you'd have to do two things. One: Build a new oscillator that will dish out more power. Two: Increase the strength of the magnets. ”

“ It cures its own damage."
"Prevents," said Arden.
"All right, it acts as its own shield, electrostatically."
"About this mobility," said Walt, "I do not quite agree with that."
"You can't whirl a hunk of tube the size and weight of a good-sized telescope around fast enough to shoot holes in a racing spaceship," said Channing. "Especially one which is trying to dodge. We've got to rely upon something that can do the trick better. Your tube did all right following a meteor that runs in a course that can be predicted, because you can set up your meteor spotter to correct for the mechanical lag. ”

“ The higher the voltage difference between cathode and anode, the faster the electron will go.
"But the stream of electrons will be diverged if it falls through a field of increasing positive potential. In order to bring the stream to a focus, we must follow the first anode with another anode of a potential less than the first anode but still higher than the cathode. That bollixes up the works. It focuses the stream and slows it at the same time. ”

“ These anodes are shaped like rings so that their electrostatic effect will exist in the center of them; the beam passes through this center."
"In other words the ring-shaped electrodes are electrostatic lenses?"
"Nope. It is the space between them. The lens is either convex or concave depending upon whether the voltage gradient is from positive to less positive or if it is positive to more positive, respectively. In an electrostatic lens for electrons, the thing is not like a glass lens for light. ”

“ Well, stepping up the rig ten to one will dish us out just shy of a couple of thousand million volts, which, as brother Franks says, is not hay!"
Walt returned after a minute and said: "Warren's measuring the inductance of the betatron magnet. He'll calculate the value of C required to tune the thing to the right frequency and start to achieve that capacity by mazing up whatever high-voltage condensers we have on the Station. Now, Don, let's calculate how we're going to make the thing mobile." ”

“ Whether your lens is diverging or converging depends upon which way your electron stream is running through it. With light, a convex lens will converge the light no matter which direction the light is coming from. ”

“ Seems to me that it might be a little bit fatal."
"Didn't think of that," said Channing. "There's one thing, their personal charge doesn't add up to a large quantity of electricity. If we insulate 'em and put 'em in their spacesuits, they'll be all right as long as they don't try to grab anything. They'll be on the up and down for a bit, but the resistance of the spacesuit is high enough to keep 'em from draining all their electrons out at once. ”

“ That's because they are always ducking out of the way of loose meteorites and stuff, and that screws up their course. We can't see 'em, and must take their position on the basis of their expected course. We never know whether we hit 'em until they land.
"Now I've been trying to devise a space gun that will blast meteors directly instead of avoiding them by coupling the meteor detector to the autopilot." ”

“ What's necessary to make this dingbat tick?"
"I want to think out loud," said Channing.
"That's nothing unusual," said Arden. "Can't we get into Joe's? You can't think without a tablecloth, either."
"What I'm thinking is this, Walt. You've been trying to squirt electrons like a fireman runs a hose. Walt, how long do you suppose a sixteen-inch rifle would last if the explosives were constantly replaced and the fire burned constantly?"
"Not long," admitted Walt.
"A gun is an overloaded machine," said Don. "Even a little one. The life of a gun barrel is measured in seconds ”

“ Since the dingbat is to be used in space, we can leave the works of the gun open and project a healthy stream of electrons at the offending object without their being slowed and dispersed by an impending atmosphere. ”

“ It's a good thing that we don't have to swivel that mess of tube around a whole arc in actual use. It would take too long. But we'll put one in each upper quadrant of a spaceship and devise it so that its working arc will be small enough to make it work. Time enough to find that out after we know if it works."
"That's something that I've been wondering about," said Warren. "Why didn't we build a small one out here and evacuate the skin for a few hundred feet? We could set up a few chunks of iron and squirt electrons at 'em." ”

“ Meteor detectors are many and interconnected on a spaceship, as well as being alarmed and fused to the nth degree. Any trouble with them will bring a horde of ringing bells all through the ship which would bring the personnel a-running. They just don't go wrong for no reason at all. ”

“ Jeanne left, with Walt right behind her. Franks did not remain at the desk, however, but made his way from the office level to the outer skin of the Relay Station by way of a not-often-used stairway that permitted him to drop to the outer skin. ”

“ He saw the men looking quizzically at him as he turned away from the window, and with a smile that cost him an effort, he said: "All right, so Marconi didn't get WLW on his first try, either. Come on, fellows, and we'll clean up this mess." ”