The Fourth-dimensional Demonstrator


	PETE DAVIDSON WAS engaged to Miss Daisy Manners of the Green Paradise floor show. He had just inherited all the properties of an uncle who had been an authority on the fourth dimension, and he was the custodian of an unusually amiable kangaroo named Arthur. But still he was not happy; it showed this morning.
	Inside his uncle’s laboratory, Pete scribbled on paper. He added, and ran his hands through his hair in desperation. Then he subtracted, divided, and multiplied. But the results were invariably problems as incapable of solution as his deceased relative’s fourth-dimensional equations. From time to time.a long, horselike, hopeful face peered in at him. That was Thomas, his uncle’s servant, whom Pete was afraid he had also inherited.
	“Beg pardon, sir,” said Thomas tentatively.
	Pete leaned harassedly back in his chair.
	“What is it, Thomas? What has Arthur been doing now?”
	“He is browsing in the dahlias, sir. I wished to ask about lunch, sir. What shall I prepare?”
	“Anything!” said Pete. “Anything at all! No. On second thought, trying to untangle Uncle Robert’s affairs calls for brains. Give me something rich in phosphorus and vitamins; I need them.”
	“Yes, sir,” said Thomas. “But the grocer, sir—”
	“Again?” demanded Pete hopelessly.
	“Yes, sir,” said Thomas, coming into the laboratory. “I hoped, sir, that matters might be looking better.”
	Pete shook his head, regarding his calculations depressedly.
	“They aren’t. Cash to pay the grocer’s bill is still a dim and misty hope. It is horrible, Thomas! I remembered my uncle as simply reeking with cash, and I thought the fourth dimension was mathematics, not debauchery. But Uncle, Robert must have had positive orgies with quanta and space-time continua! I shan’t break even on the heir business, let alone make a profit!”
	Thomas made a noise suggesting sympathy.
	“I could stand it for myself alone,” said Pete gloomily. “Even Arthur, in his simple kangaroo’s heart, bears up well. But Daisy! There’s the rub! Daisy!”
	“Daisy, sir?”
	“My fiancée,” said Pete. “She’s in the Green Paradise floor show. She is technically Arthur’s owner. I told Daisy, Thomas, that I had inherited a fortune. And she’s going to be disappointed.”
	“Too bad, sir,” said Thomas.
	“That statement is one of humorous underemphasis, Thomas. Daisy is not a person to take disappointments lightly. When I explain that my uncle’s fortune has flown off into the fourth dimension, Daisy is going to look absent-minded and stop listening. Did you ever try to make love to a girl who looked absent-minded?”
	“No, sir,” said Thomas. “But about lunch, sir—”
	“We’ll have to pay for it. Damn!” Pete said morbidly. “I’ve just forty cents in my clothes, Thomas, and Arthur at least mustn’t be allowed to starve. Daisy wouldn’t like it. Let’s see!”
	He moved away from the desk and surveyed the laboratory with a predatory air. It was not exactly a homy place. There was a skeltonlike thing of iron rods, some four feet high. Thomas had said it was a tesseract—a model of a cube existing in four dimensions instead of three.
	To Pete, it looked rather like a medieval instrument of torture-—something to be used in theological argument with a heretic. Pete could not imagine anybody but his uncle wanting it. There were other pieces of apparatus of all sizes, but largely dismantled. They looked like the product of someone putting vast amounts of money and patience into an effort to do something which would be unsatisfactory when accomplished.
	“There’s nothing here to pawn,” said Pete depressedly. “Not even anything I could use for a hand organ, with Arthur substituting for the monk!” 
	“There’s the demonstrator, sir,” said Thomas hopefully. “Your uncle finished it, sir, and it worked, and he had a stroke, sir.”
	“Cheerful!” said Pete. “What is this demonstrator? What’s it supposed to do?”
	“Why, sir, it demonstrates the fourth dimension,” said Thomas. “It’s your uncle’s life work, sir.”
	“Then let’s take a look at it,” said Pete. “Maybe we can support ourselves demonstrating the fourth dimension in shop windows for advertising purposes. But Idon’t think Daisy will care for the career.”
	Thomas marched solemnly to a curtain just behind the desk. Pete had thought it hid a cupboard. He slid The cover back and displayed a huge contrivance which seemed to have the solitary virtue of completion. Pete could see a monstrous brass horseshoe all of seven feet high. It was apparently hollow and full of cryptic cogs and wheels. Beneath it there was a circular plate of inch-thick glass which seemed to be designed to revolve. Below that, in turn, there was a massive base to which ran certain copper tubes from a refrigerating unit out of an ice box.
	Thomas turned on a switch and the unit began to purr. Pete watched.
	“Your uncle talked to himself quite a bit about this, sir,” said Thomas. “I gathered that it’s quite a scientific triumph, sir You see, sir, the fourth dimension is time”
	“I’m glad to hear it explained so simply,” said Pete. 
	“Yes, sir. As I understand it, sir, if one were motoring and saw a pretty girl about to step on a banana pee1, sir, and if one wished to tip her off, so to speak, but didn’t quite realize for—say, two minutes, until one had gone en half a mile—” 
	“The pretty girl would have stepped on the banana peel and nature would have taken its course,” said Pete.
	“Except for this demonstrator, sir. You see, to tip off the young lady one would have to retrace the half mile and the time too, sir, or one would be too late. That is, one would have to go back next only the half mile but the two minutes. And so your uncle, sir, built this demonstrator—” 
	“So he could cope with such a situation when it arose,” finished Pete. “I see! But I’m afraid it won’t settle our financial troubles.”
	The refrigeration unit ceased to purr. Thomas solemnly struck a safety match.
	“If I may finish the demonstration, sir,” he said hopefully. “I blow out this match, and put it on the glass plate between the ends of the horseshoe. The temperature’s right, so it should work.”
	There were self-satisfied clucking sounds from the base of the machine. They went on for seconds. The huge glass plate suddenly revolved perhaps the eighth of a revolution. A humming noise began. It stopped. Suddenly there was another burnt safety match on the glass plate. The machine began to cluck triumphantly.
	“You see, sir?” said Thomas. “It’s produced another burnt match. Dragged it forward out of the past, sir. There was a burned match at that spot, until the glass plate moved a few seconds ago. Like the girl and the banana peel, sir. The machine went back to the place where the match had been, and then it went back in time to where the match was, and then it brought it forward.”
	The plate turned another eighth of a revolution. The machine clucked and hummed. The humming stopped. There was a third burnt match on the glass plate. The clucking clatter began once more.
	“It will keep that up indefinitely, sir,” said Thomas hopefully.
	“I begin, said Pete, “to see the true greatness of modern science. With only two tons of brass and steel, and at a cost of only a couple of hundred thousand dollars and a lifetime of effort, my Uncle Robert has left me a machine which will keep me supplied with burnt matches for years to come! Thomas, this machine is a scientific triumph!”
	Thomas beamed. 
	“Splendid, sir! I’m glad you approve. And what shall I do about lunch, sir?”
	The machine, having clucked and hummed appropriately, now produced a fourth burnt match and clucked more triumphantly still. It prepared to reach again into the hitherto unreachable past.
	Pete looked reproachfully at the servant he had apparently inherited.. He reached in his pocket and drew out his forty cents. Then the machine hummed. Pete jerked his head and stared at it.
	“Speaking of science, now,” he said an instant later. “I have a very commercial thought. I blush to contemplate it.” He looked at the monstrous, clucking demonstrator of the fourth dimension. “Clear out of here for ten minutes, Thomas. I’m going to be busy!”
	Thomas vanished. Pete turned off the demonstrator. He risked a nickel, placing it firmly on the inch-thick glasi plate. The machine went on again. It clucked, bummed, ceased to hum—and there were two nickels. Pete added a dime to the second nickel. At the end of another cycle he ran his hand rather desperately through his hair and added his entire remaining wealth—a quarter. Then, after incredulously watching what happened, he began to pyramid.
	Thomas tapped decorously some ten minutes later. “Beg pardon, sir,” he said hopefully. “About lunch,-sir—”
	Pete turned off the demonstrator. He gulped.
	“Thomas,” he said in careful calm, “I shall let you, write the menu for lunch. Take a basketful of this small change and go shopping. And—Thomas, have you any item of currency larger than a quarter? A fifty-cent piece would be about right. I’d like to have something really impressive to show to Daisy when she comes.”

	Miss Daisy Manners of the Green Paradise floor show was just the person to accept the fourthdimensional demonstrator without question and to make full use of the results of modern scientific research. She greeted Pete abstractedly and uninterestedly asked just how much he’d inherited. And Pete took her to the laboratory. He unveiled the demonstrator.
	“These are my jewels,” said Pete impressively. “Darling, it’s going to be a shock, but—have you got a quarter?”
	“You’ve got nerve, asking me for money,” said Daisy. “And if you lied about inheriting some money.—”
	Pete smiled tenderly upon her. He produced a quarter of his own. 
	“Watch, my dear! I’m doing this for you!”
	He turned on the demonstrator and explained complacently as the first cluckings came from the base. The glass plate moved, a second quarter appeared, and Pete pyramided the two while he continued to explain. In the fraction of a minute, there were four quarters. Again Pete pyramided. There were eight quarters—sixteen, thirty-two, sixty-four, one hundred twenty-eight—-—At this point the stack collapsed and Pete shut off the switch.
	“You see, my dear? Out of the fourth dimension to you! Uncle invented it, I inherited it, and—shall I change your money for you?”
	Daisy did not look at all absent-minded now. Pete gave her a neat little sheaf of bank notes.
	“Aud from now on, darling,” he said cheerfully, “whenever you want money just come in here, start the machine—and there you are! Isn’t that nice?”
	“I want some more money now,” said Daisy. “I have to buy a trousseau.”		-
	“I hoped you’d feel that way!” said Pete enthusiastically. “Here goes! And we have a reunion while the pennies roll in.”
	The demonstrator began to cluck and clatter with bills instead of quarters on the plate. Once, to be sure, it suspended all operations and the refrigeration unit purred busily for a time. Then it resumed its self-satisfied delving into the immediate past.
	“I haven’t been making any definite plans,” explained Peie, “until I talked to you. Just getting things in line. But I’ve looked after Arthur carefully. You know bow he loves cigarettes. He eats them, and though it may be eccentric in a kangaroo, they seem to agree with him. I’ve used the demonstrator to lay up a huge supply of cigarettes for him—his favorite brand, too. And I’ve’ been trying to build up a bank account. I thought it would seem strange if we bought a house on Park Avenue and just casually offered a trunkful of bank notes in payment. It might look as if we’d been running a snatch racket.”
	“Stupid!” said Daisy. 
	“What?”
	“You could be pyramiding those bills like you did quarters,” said Daisy. “Then there’d be lots more them!”
	“Darling,” said Pete fondly, “does it matter bol much you have when I have so much?”
	“Yes,” said Daisy. “You might get angry with me.
	“Never!” protested Pete. Then he addeçl reminiscently, “Before we thought of the banknote idea, Thomas and I filled up the coal bin with quarters and half dollars. They’re still there.”
	“Gold pieces would be nice,” suggested Daisy, thinking hard, “if you could get hold of some. Maybe we could.”
	“Ah!” said Pete. “But Thomas had a gold filling in one tooth. We took it out and ran it up to half a pound or so. Then we melted that into a little brick and put it on the demonstrator. Darling, you’d really be surprised if you looked in the woodshed.”
	“And there’s jewelry,” said Daisy. “It would be fast still!”
	“If you feel in the mood for jewelry,” said Pete tenderly, “just look in the vegetable bin. We’d about run out of storage space when the idea occurred to us.”
	“I think,” said Daisy enthusiastically, “we’d better get married right away. Don’t you?”
	“Sure! Let’s go and do it now! I’ll get the car around!”
	“Do, darling,” said Daisy. “I’ll watch the demonstrator.”
	Beaming, Pete kissed her ecstatically and rushed from the laboratory. He rang for Thomas, and rang again. It was not until the third ring that Thomas appeared. And Thomas was very pale. He said agitatedly:
	“Beg pardon, sir, but shall I pack your bag?”
	“I’m going to be——— Pack my bag? What for?”
	“We’re going to be arrested, sir,” said Thomas. He gulped. “I thought you might want it, sir. An acquaintance in the village, sir, believes we are among the lower-numbered public enemies, sir, and respects us accordingly. He telephoned me the news.”
	“Thomas, have you been drinking?”
	“No, sir,” said Thomas pallidly. “Not yet, sir. But it is a splendid suggestion, thank you, sir.” Then he said desperately: “It’s the money, sir—the bank notes. If you recall, we never changed but one lot of silver into notes, sir. We got a one, a five, a ten and so on, sir.”
	“Of course,” said Pete. “That was all we needed. Why not?” -
	“It’s the serial number, sir! All the one-dollar bills the demonstrator turned out have the same serial number—and all the fives and tens and the rest, sir. Some person with a hobby for looking for kidnap bills, sir, found he had several with the same number. The secret service has traced them back. They’re coming for us, sir. The penalty for counterfeiting is twenty years, sir. My—my friend in the village asked if we intended to shoot it out with them, sir, because if so he’d like to watch.”
	Thomas wrung his hands. Pete stared at him.
	“Come to think of it,” he said meditatively, “they are counterfeits. It hadn’t occurred to me before. We’ll have to plead guilty, Thomas. And perhaps Daisy won’t want to marry me if I’m going to prison. I’ll go tell her the news.”
	Then he started. He heard Daisy’s voice, speaking very angrily. An instant later the sound grew louder. It became a continuous, shrill, soprano babble. It grew louder yet. Pete ran.
	He burst into the laboratory and was stunned. The demonstrator was still running. Daisy had seen him piling up the bills as they were turned out, pyramiding to make the next pile larger. She had evidently essayed the same feat. But the pile was a bit unwieldy, now, and Daisy had climbed on the glass plate. She had come into the scope of the demonstrator’s action.
	There were three of her in the laboratory when Pete first entered. As he froze in horror, the three became four. The demonstrator clucked and hummed what was almost a hoot of triumph. Then it produced a fifth Daisy. Pete dashed frantically forward and turned off the switch just too late to prevent the appearance of a sixth copy of Miss Daisy Manners of the Green Paradise floor show. She made a splendid sister act, but Pete gazed in paralyzed horror at this plethora of his heart’s desire.
	Because all of Daisy was identical, with not only the same exterior and—so to speak—the same serial number, but with the same opinions and convictions. And all six of Daisy were convinced that they, individually, owned the heap of bank notes now on the glass plate. All six of her were trying to get it. And Daisy was quarreling furiously with herself. She was telling herself what she thought of herself, in fact, and on the whole her opinion was not flattering.

	Arthur, like Daisy, possessed a fortunate disposition. He was not one of those kangaroos who go around looking for things to be upset about. He browsed peacefully upon the lawn, eating up the dahlias and now and again hopping over the six-foot hedge in hopes that there might be a dog come along the lane to bark at him. Or, failing to see a dog, that somebody might have come by who would drop a cigarette butt that he might salvage.
	At his first coming to this place, both pleasing events had been frequent. The average unwarned passer-by, on seeing a five-foot kangaroo soaring toward him in this part of the world, did have a tendency to throw down everything and run. Sometimes, among the things he threw down was a cigarette.
	There had been a good supply of dogs, too, but they didn’t seem to care to play with Arthur any more. Arthur’s idea of playfulness with a strange dog—especially one that barked at him—was to grab him with both front paws and then kick the living daylights out of him.
	Arthur browsed, and was somewhat bored. Because of his boredom he was likely to take a hand in almost anything that turned up. There was a riot going on in the laboratory, but Arthur did not care for family quarrels. He was interested, however, in the government officers’ when they arrived. There were two of them and they came in a roadster. They stopped at the gate and marched truculently up to the front door.
	Arthur came hopping around from the back just as they knocked thunderously. He’d been back there digging up a few incipient cabbages of Thomas’ planting, to see why they didn’t grow faster. He soared at least an easy thirty feet, and propped himself on his tail to look interestedly at the visitors.
	“M-my heavens!” said the short, squat officer. He had been smoking a cigarette. He threw it down and grabbed his gun.
	That was his mistake. Arthur liked cigarettes. This one was a mere fifteen feet from him. He soared toward it. 
	The government maii squawked, seeing Arthur in mid-air and heading straight for him. Arthur looked rather alarming, just then. The officer fired recklessly, missing Arthur. And Arthur remained calm. To him, the shots were not threats. They were merely the noises made by an automobile whose carburetor needed adjustment. He landed blandly, almost on the officer’s toes—and the officer attacked him hysterically with fist and clubbed gun.
	Arthur was an amiable kangaroo, but he resented the attack, actively.
	The short, squat officer squawked again as Arthur grabbed him with his forepaws. His companion backed against the door, prepared to sell his life dearly. But then—and the two things happened at once-wbile Arthur proceeded to kick the living daylights out of the short, squat officer, Thomas resignedly opened the door behind the other and he fell backward suddenly and knocked himself cold against the doorstop.
	Some fifteen minutes later the short, squat officer said gloomily: “It was a bum steer. Thanks for pulling that critter off me, and Casey’s much obliged for the drinks. But we’re hunting a bunch of counterfeiters that have been turning out damn good phony bills. The line led straight to you. But if it had been you, you’d have shot us. You didn’t. So we got to dO the work all over.”
	“I’m afraid,” admitted Pete, “the trail would lead right back. Perhaps, as government officials, you can do something about the fourth-dimensional demonstrator. That’s the guilty party. I’ll show you.”
	He led the way to the laboratory. Arthur appeared, looking vengeful. The two officers looked apprehensive.
	“Better give him a cigarette,” said Pete. “He eats them. Then he’ll be your friend for life.”
	“Hell, no!” said the short, squat man. “You keep between him and me! Maybe Casey’ll want to get friendly.” -
	“No cigarettes,” said Casey apprehensively. “Would a cigar do?”
	“Rather heavy, for so early in the morning,” considered Pete, “but you might try.”
	Arthur soared. He landed within two feet of Casey. Casey thrust a cigar at him. Arthur sniffed at it and accepted it. He put one end in- his mouth and bit off the tip.
	“There!” said Pete cheerfully. “He likes it. Come on!
	They moved on to the laboratory. They entered— and tumult engulfed them. The demonstrator was running and Thomas—pale and despairing—supervised its action. The demonstrator was turning out currency by what was, approximately, wheelbarrow loads. As each load materialized from the fourth dimension, Thomas gathered it up and handed it to Daisy, who in theory was standing in line to receive it in equitable division. But Daisy was having a furious quarrel among herself, because some one or other of her had tried to cheat.
	“These,” said Pete calmly, “are my fiancée.”
	But the short, squat man saw loads of greenbacks appearing from nowhere. He drew out a short, squat revolver.
	“You got a press turning out the stuff behind that wall, huh?” he said shrewdly. “I’ll take a look!”
	He thrust forward masterfully. He pushed Thomas aside and mounted the inch-thick glass plate. Pete reached, horrified, for the switch. But it -was too late. The glass plate revolved one-eighth of a revolution. The demonstrator hummed gleefully; and the officer appeared in duplicate just as Pete’s nerveless fingers cut off everything.
	Both of the officers looked at each other in flat, incredulous stupefaction. Casey stared, and the hair rose from his head. Then Arthur put a front paw tentatively upon Casey’s shoulder. Arthur had liked the cigar. The door to the laboratory had been left open. He had come in to ask for another cigar. But Casey was hopelessly unnerved. He yelled and fled, imagining Arthur in hot pursuit. He crashed into the model of a tesseract and entangled himself hopelessly.
	Arthur was an amiable kangaroo, but he was sensitive. Casey’s squeal of horror upset him. He leaped blindly, knocking Pete over on the switch and turning it on, and landing between the two stupefied copies of the other officer. They, sharing memories of Arthur, moved in panic just before the glass plate turned.
	Arthur bounced down again at the demonstrator’s hoot. The nearest copy of the short, squat man made a long, graceful leap and went flying out of the door. Pete struggled with the other, who waved his gun and demanded explanations, growing hoarse from his earnestness.
	Pete attempted to explain in terms of pretty girls stepping on banana peels, but it struck the officer as irrelevant. He shouted hoarsely while another Arthur hopped down from the glass plate—while a third, and fourth, and fifth, and sixth, and seventh Arthur appeared on the scene.
	He barked at Pete until screams from practically all of Daisy made him turn to see the laboratory overflowIng with five-foot Arthurs, all very pleasantly astonished and anxious to make friends with himself so he could play.
	Arthur was the only person who really approved the course events had taken. He had existed largely in his own society. But now his own company was numerous. From a solitary kangaroo, in fact, Arthur had become a good-sized herd. And in his happy excitement over the fact, Arthur forgot all decorum and began to play an hysterical form of disorganized leapfrog all about the laboratory.
	The officer went down and became a take-off spot for the game. Daisy shrieked furiously. And Arthur— all of him—chose new points of vantage for his leaps until one of him chose the driving motor of the demonstrator. That industrioua mechanism emitted bright sparks and bit him. And Arthur soared in terror through the window, followed by all the rest of himself, who still thought it part of the game.
	In seconds, the laboratory was empty of Arthurs. But the demonstrator was making weird, pained noises. Casey remained entangled in the bars of the tesseract, through which he gazed with much the expression of an inmate of a padded cell. Only one of the short, squat officers remained in the building. He had no breath left. And Daisy was too angry to make a sound—all six of her. Pete alone was sanely calm.
	“Well,” he said philosophically, “things seem to have settled down a bit. But something’s happened to the demonstrator.”
	“I’m sorry, sir,” said Thomas, pallidly, “I’m no hand at machinery.”
	One of Daisy said angrily to another of Daisy:
	“You’ve got a nerve! That money on the plate is mine!”
	Both advanced. Three more, protesting indignantly, joined in the rush. The sixth—and it seemed to Pete that she must have been the original Daisy—hastily began to sneak what she could frqm the several piles accumulated by the others.
	Meanwhile, the demonstrator made queer noises. And Pete despairingly investigated. He found where Arthur’s leap had disarranged a handle which evidently controlled the motor speed of the demonstrator. At random, he pushed the handle. The demonstrator clucked relievedly. Then Pete realized in sick terror that five of Daisy were on the glass plate. He tried to turn it off— but it was too late.
	He closed his eyes, struggling to retain calmness, but admitting despair. He had been extremely fond of one Daisy. But six Daisies had been too much. Now, looking forward to eleven and—
	A harsh voice grated in his ear.
	“Huh! That’s, where you keep the press and the queer, huh—and trick mirrors so I see double? I’m going through that trapdoor where those girls went! And if there’s any funny business on the other side, somebody gets hurt!” 
	The extra officer stepped up on the glass plate, inexplicably empty now. The demonstrator clucked. It hummed. The plate moved—backward! The officer vanished—at once, utterly. As he had come out of the past, he returned to it, intrepidly and equally by accident. Because one of Arthur had kicked the drive lever into neutral, and Pete had inadvertently shoved it into reverse. He saw the officer vanish and he knew where the supernumerary Daisies had gone—also where all embarrassing bank notes would go. He sighed in relief.
	But Casey—untangled from the tesseract—was not relieved. He tore loose from Thomas’s helpful fingers and fled to the car. There he found his companion, staring at nineteen Arthurs playing leapfrog over the garage. After explanations they would be more upset still. Pete saw the roadster drive away, wabbling.
	“I don’t think they’ll come back, sir,” said Thomas hopefully.
	“Neither do I,” said Pete in a fine, high calm. He turned to the remaining Daisy, scared but still acquisitive. “Darling,” he said tenderly, “all those bank notes are counterfeit, as it develops. We’ll have to put them all back and struggle along with the contents of the woodshed and the vegetable bin.”
	Daisy tried to look absent-minded, and failed.
	“I think you’ve got nerve!” said Daisy indignantly.