"Yes. I've got the range."
The coils hummed and heated with the current, and in a moment the
Benson curve-beam leaped from the projector.
The Benson curve-light was similar to an ordinary white searchlight
beam, except that its path, instead of being straight could be bent at
will into various curves--hyperbola, parabola, and for its extreme
curve, the segment of an ellipse--gradually straightening as it left
its source. It was effective for police work, with hand torches for
seeing around opaque obstructions. It had also another advantage,
especially when used at long range: the enemy, when gazing back at its
source, would under normal circumstances conceive it to be a straight
beam and thus be misled as to the location of its source. Or even
realizing it to be curved, one had no means of judging the angle of
the curve.
A narrow white stream of light, it flung through our window-oval,
forward under the dome and through the bow dome bullseye, into space.
I saw the men on the deck spring into sudden alertness with the
realization we were using it. The bow lookout on the forward
observation bridge crouched at his 'scope-finder to help us search.
From the control turret came an audiphone buzz, and Drac's voice: "Am
I headed right? The swing is almost completed."
"Finish the job and don't bother me now."
I bent over the field-mirror of the projector. On its glowing ten-inch
grid the shifting image of my range was visible, a curving, brilliant
limb of the Moon, with the sunlight on the jagged mountain peaks;
everywhere else was the black firmament and the blazing dots of stars.
Grantline crouched beside me. "I'll work the amplifiers. Going to
spread it much, Gregg?"
"Yes. A full spread first. We're in no mood for a detailed narrow
search."
I gradually widened the light. Three feet here at its source, it
spread in a great widening arc. With the naked eye we could see its
white radiance, fan-shaped as an edge of it fell upon the Moon. And
though optically it was not apparent, the elliptical curve of it was
rounding the Moon, disclosing the hidden starfield to our
instruments.
"Nothing yet?" I murmured.
"No."
"I'll try a narrower spread and less curve."
Grantline was searching the magnified images on the series of
amplifier grids. There was nothing. For an hour we worked; then
suddenly Grantline cried: "Gregg! Wait! Hold it!"