Sucking thoughtfully at his pipe, he checked and
rechecked them.

Harry Wilson regarded him through squinted eyes.

"What the hell is going to happen now?" he asked.

"We'll have to wait and see," Russ answered. "We know what we want to
happen, what we hope will happen, but we never can be sure. We are
working with conditions that are entirely new."

Sitting beside a table littered with papers, staring at the gigantic
machine before him, Gregory Manning said slowly: "That thing simply has
to adapt itself to spaceship drive. There's everything there that's
needed for space propulsion. Unlimited power from a minimum of fuel.
Split-second efficiency. Entire independence of any set condition,
because the stuff creates its own conditions."

He slowly wagged his head.

"The secret is some place along the line," he declared. "I feel that we
must be getting close to it."

Russ walked from the control board to the table, picked up a sheaf of
papers and leafed through them. He selected a handful and shook them in
his fist.

"I thought I had it here," he said. "My math must have been wrong, some
factor that I didn't include in the equation."

"You'll keep finding factors for some time yet," Greg prophesied.

"Repulsion would have been the answer," said Russ bitterly. "And the
Lord knows we have it. Plenty of it."

"Too much," observed Wilson, smoke drooling from his nostrils.

"Not too much," corrected Greg. "Inefficient control. You jump at
conclusions, Wilson."

"The math didn't show that progressive action," said Russ. "It showed
repulsion, negative gravity that could be built up until it would shoot
the ship outside the Solar System within an hour's time. Faster than
light. We don't know how many times faster."

"Forget it," advised Greg. "The way it stands, it's useless. You get
repulsion by progressive steps. A series of squares with one constant
factor. It wouldn't be any good for space travel. Imagine trying to use
it on a spaceship. You'd start with a terrific jolt. The acceleration
would fade and just when you were recovering from the first jolt, you'd
get a second one and that second one would iron you out. A spaceship
couldn't take it, let alone a human body."

* * * * *

"Maybe this will do it," said Wilson hopefully.

"Maybe," agreed Russ. "Anyhow we'll try it. Equation 578."

"It might do the trick," said Greg. "It's a new approach to the gravity
angle. The equat