, it subsided.
But even in that brief time, the light aluminum screen had suddenly
become limp and slumped down, molten! The room was unbearably hot, and
the men were half blinded by the intensity of the light.

"It works!" yelled Wade. "It works! That sure was hot, too--it's
roasting in here." He flung open a window. "Let's have some air."

Arcot and Morey gripped hands with a broad grin. That display meant that
Earth and Venus would have space ships with which to fight space ships.
Reason enough for their joy.

Though they had made an unusual amount of progress already, there was
still a great deal of development work to be done. Fuller was needed,
Arcot decided, so he called the elder Morey and requested his services
if he could be spared from his present work. He could, and would arrive
later that day.

When Fuller appeared about mid-afternoon, he found the three friends
already at work on the development of a more compact apparatus than the
makeshift hookup used in making that first release mechanism.

"And so you can see," said Arcot as he finished his summary of their
work to that point, "we still have quite a job ahead of us. I'm now
trying to find some data for you to work on, but I can tell you this:
We'll need a ship that has plenty of strength and plenty of speed. There
will be the usual power plant, of course; the generators, the power-tube
board, and the electro-magnetic relays for the regular molecular motion
controls. Then, in addition, we must have controls for the ray
projector, though that must wait a while, for Dad is working on a method
of doubling our range.... Oh yes, the driving units will be inside the
ship now, for all our power will come from the energy of the
light-matter."

They spent the next hour in discussing the manifold details involved in
the design of their space ship: the mechanism involved in transferring
the light-energy to the drivers; a means of warming the ship in
interstellar space; a main horizontal drive for forward and backward
motion as well as braking; three smaller vertical power units to give
them freedom of direction in climb or descent; other smaller horizontal
power units for turning and moving sideways.

The ships, they decided, must be capable of six or seven thousand miles
a second. They would need three types of ships: a small single-man
speedster, without bunk or living quarters, simply a little power plant
and weapon. Designed for speed and mobility, it