dropped lazily down to the zero mark. Our ears didn't sting, no glass went dusting into crystalline powder, and a quick peek through the door showed no ring of fire surrounding the lab.

"We may just have done it!" I said, hopefully, as the silver-nosed machine began to float upward (We hadn't had to mount the parabolic reflector in the position of a nose-cone, but it made the thing look neater, somehow.)

It seemed a little torpid in its ascent, but that could be credited to the extra weight of the reflector and cornflakes, not to mention the fact that the helices had to suck all their air in under the lip of the silvery nose-cone before they could thrust properly. But its rise was steady. Six inches, ten inches—

Then, at precisely one foot in height, something unexpected happened. Under the base of the machine, where the sound-heated air was at its most torrid, a shimmering disc-like thing began to materialize, and warp, and hollow out slightly, and beside it, a glinting metal rod-thing flattened at one end, then the flat end went concave in the center and kind of oval about the perimeter, and something brownish and shreddy plopped and hissed into the now-very-concave disc-like thing.

"Artie—!" I said, uneasily, but by then, he, too, had recognized the objects for what they were.

"Burt—" he said excitedly. "Do you realize what we've done? We've invented a syntheticizer!"

Even as he was saying it, the objects completed their mid-air materialization (time: five seconds, start to finish), and clattered and clinked onto the scale. We stood and looked down at them: A bowl of cornflakes and a silver spoon.

"How—?" I said, but Artie was already figuring it out, aloud.

"It's the soundwaves," he said. "At ultrasonic, molecule-disrupting vibrations, they're doing just what that Philosopher's Stone was supposed to: Transmuting. Somehow, we didn't clean out the reflector sufficiently, and some of the traces of our other trial insulations remained inside. The ceramics formed the bowl, the metals formed the spoon, the cornflakes formed the cornflakes!"

"But," I said logically (or as logically as could be expected under the circumstances), "what about the rubber, or the fabrics?"

Artie's face lit up, and he nodded toward the machine, still hovering at one foot above the scale. In its wake, amid the distorting turbulence of the sound-tortured air, two more objects were materializing: a neatly folded damask napkin, and a small rubber toothpick. As they dropped down to join their predecessors, the machine gave a satisfied shake, and rose steadily to the two-foot level. I was scribbling frantically in my notebook: Bowl + cereal + spoon: 5 seconds. Lag: 10 seconds. Napkin + toothpick: 3 seconds. Total synthesizing time: 18 seconds. Allowance for rise of machine per foot: 2 seconds.

"Burt—!" Artie yelled joyously, just as I completed the last item, "Look at that, will you?!"

I looked, and had my first presentiment of disaster. At two feet, the machine was busily fabricating—out of the air molecules themselves, for all I knew—two bowls, two spoons, and two bowlfuls of cereal.

"Hey, Artie—" I began, but he was too busy figuring out this latest development.

"It's the altimeter," he said. "We had it gauged by the foot, but it's taking the numerical calibrations as a kind of output-quota, instead!"

"Look, Artie," I interrupted, as twin napkins and toothpicks dropped down beside the new bowls on the table where the scale lay. "We're going to have a little problem—"

"You're telling me!" he sighed, unhappily. "All those damned random factors! How many times did the machine have to be repaired after each faulty test! What thickness of ceramics, or fabric, or rubber, or metal remained! What was the precise distribution and dampness of each of those soggy cornflakes! Hell, Burt, we may be forever trying to make a duplicate of this!"

"Artie—" I said, as three toothpick-napkin combinations joined the shattered remains of triple bowl-cereal-spoon disasters from the one-yard mark over the scale, "that is not the problem I had in mind."

"Oh?" he said, as four shimmering discs began to coalesce and shape themselves. "What, then?"

"It's not that I don't appreciate the side-effect benefits of free cornflake dinners," I said, speaking carefully and somberly, to hold his attention. "But isn't it going to put a crimp in our anti-gravity machine sales? Even at a mere mile in height, it means that the spot beneath it is due for a deluge of five-thousand-two-hundred-eighty bowls of cornflakes. Not to mention all those toothpicks, napkins and spoons!"

Artie's face went grave. "Not to mention the five-thousand-two-hundred-seventy-nine of the same that the spot beneath would get from the gadget when it was just one foot short of the mile!"

"Of course," I said, calculating rapidly as the five-foot mark produced a neat quintet of everything, a quintet which crashed noisily onto the ten lookalikes below it as the machine bobbed silently to the six-foot mark, "we have one interesting thing in our favor: the time element."

"How so?" said Artie, craning over my shoulder to try and read my lousy calligraphics on the pad.

"Well," I said, pointing to each notation in turn, "the first batch, bowl-to-toothpick, took twenty seconds, if we include the time-lapse while the machine was ascending to the one-foot mark."

"Uh-huh," he nodded. "I see. So?"

"So the second batch took double. Forty seconds. Not only did it require thirty-six seconds for the formation of the stuff, it took the machine twice as many seconds to reach the two-foot mark."

"I get it," he said. "So I suppose it took three times the base number for the third batch?"

"Right. A full minute. And the materialization of the objects is—Boy, that's noisy!" I interrupted myself as batch number six came smashing down. "—always at a point where the objects fit into a theoretical conical section below the machine."

"How's that again?" said Artie.

"Well, bowl number one formed just below the exhaust vent of the central cylinder. Bowls two and three, or—if you prefer—bowl-batch two, formed about six inches lower, edge to edge, at the cross-section of an imaginary cone (whose rather truncated apex is the exhaust vent) that seems to form a vertical angle of thirty degrees."

"In other words," said Artie, "each new formation comes in a spot beneath this cone where it's possible for the new formations to materialize side-by-side, right?" When I nodded, he said, "Fine. But so what?"

"It means that each new materialization occurs at a steadily increasing height, but one which—" I calculated briefly on the pad "—is never greater than two-thirds the height of the machine itself."

Artie looked blank. "Thank you very kindly for the math lesson," he said finally, "but I still don't see what you are driving at, Burt. How does this present a problem?"

I pointed toward the un-repaired hole in the lab ceiling, where the machine, after dutifully disgorging the number-seven load, was slowly heading. "It means that unless we grab that thing before it gets too much higher, the whole damn planet'll be up to its ears in cornflakes. And the one-third machine-height gap between artifacts and machine means that we can't even use the mounding products to climb on and get it. We'd always be too low, and an increasing too-low at that!"

"Are you trying to say, in your roundabout mathematical way, let's grab that thing, fast?"

"Right," I said, glad I had gotten through to him. "I would've said as much sooner, only you never listen until somebody supplies you with all the pertinent data on a crisis first."