The Fourth-Dimensional Demonstrator
by Murray Leinster
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 fiancee,” 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 homey place. There was a skeletonlike 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 monkey!”
“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 I don’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 peel, 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 on 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 not 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 burnt 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
