Beam-Powered Propulsion
Using a powerful energy source as motive power for a projectile.

Centrifugal Force Creates 'Artificial Gravity'
Using centrifugal force in a rotating cylinder as a substitute for gravity.

City of Space - rotating habitat
A very early reference to an enormous cylindrical space station.

Heliocar
Ground vehicle that can also lift off like a helicopter.

Motor Torpedo
A terrestrial torpedo, driven by ion beams.

Photograph of Earth from Space
An aerial photograph from outside the atmosphere.

Positive Ray Propulsion (Ion Drive)
An ion drive.

Robot Vending Machine
Machinery displaces news boys selling papers on street corners.

Satellite Photography for Surveillance
Use of pictures taken from near Earth orbit for reconnaissance in a military operation.

Self-Sustaining Space Craft
A spacecraft ecosystem.

Sunship
A space craft powered entirely by the sun.

Vitalium
A rare radioactive metal which enables solar power cells.