nd
found which side was heavy. They took metal off till it ran smoothly at
five hundred r.p.m. Then they spun it at a thousand. It vibrated. They
found imbalance that was too small to show up before. They fixed that.
They speeded it up. And so on. They tried to make the center of gravity
the center of the shaft by trimming off the weight that put the center
of gravity somewhere else. Right?"

The Chief said irritably: "No other way to do it! No other way!"

"I saw one," said Joe. "When they cleaned up the wreck at the airfield,
they heaved up the crates with a crane. The slings were twisted. Every
crate spun as it rose. But not one wobbled! They found their own centers
of gravity and spun around them!"

The Chief scowled, deep in thought. Then his face went blank.

"By the holy mud turtle!" he grunted. "I get it!"

Joe said, with very great pains not to seem triumphant, "Instead of
spinning the shaft and trimming the rotor, we'll spin the rotor and trim
the shaft. We'll form the shaft around the center of gravity, instead of
trying to move the center of gravity to the middle of the shaft. We'll
spin the rotors on a flexible bearing base. I think it'll work."

Surprisingly, it was Mike the midget who said warmly, "You got it! Yes,
sir, you got it!"

The Chief took a deep breath. "Yeah! And d'you know how I know? The
Plant built a high-speed centrifuge once. Remember?" He grinned with the
triumph Joe concealed. "It was just a plate with a shaft in the middle.
There were vanes on the plate. It fitted in a shaft hole that was much
too big. They blew compressed air up the shaft hole. It floated the
plate up, the air hit the vanes and spun the plate--and it ran as sweet
as honey! Balanced itself and didn't wobble a bit! We'll do something
like that! Sure!"

"Will you work on it with me?" asked Joe. "We'll need a sort of
crew--three or four altogether. Have to figure out the stuff we need. I
can ask for anybody I want. I'm asking for you. You pick the others."

The Chief grinned broadly. "Any objections, Haney? You and Mike and me
and Joe here? Look!"

He pulled a pencil out of his pocket. He started to draw on the plastic
table top, and then took a paper napkin instead.

"Something like this----"

The steaks came, sizzling on the platters they'd been cooked in. The
outside was seared, and the inside was hot and deliciously rare.
Intellectual exercises like the designing of a machine-tool operation
could not com