Carroll adjusted knobs, brought the spot of sheer black into the center of the artificial plate and then expanded it. It was noticeable only because it—as a circle of utter no-response—was less energetic than the misty background.
"That," he said, "is it."
"The negative mass?"
He nodded. "Is the 'fence' ready?"
"Checked."
"Now's as good a time as any," he said laconically. He left the vantage-point and went to another panel in the laboratory and began to throw switches.
Five miles from Carroll's home a ten mile circle of wire came to life. Set on insulators mounted on trees in a rough circle, the area ten miles in diameter shimmered with a thin, misty film of energy—the same energy as that of the teleport.
It thickened as Carroll adjusted the driving gear, thickened and became more positive until it was as shiningly opaque as the teleport screen-mirror. Trees in the circle, cut clean at the surface of the mirror fell, impelled by gravity into the screen. Then above the perfect plane of energy was nothing.
The trimmed trees fell helter-skelter into a deep gorge from a smaller teleport plane twenty miles to the north.
Then the perfect plane bowed downward into a shallow paraboloid of revolution. As it went down the up-thrusting trees were trimmed off and the matter in them converted into energy. A minute but perfect sphere appeared atop a pillar of energy not far from the rim of the paraboloid.