Artificial Gravity - first mention
Procuring gravitational forces without a suitably large mass.

Asteroid From Outside Solar System
An asteroid or similar body that comes from outside the solar system; an interstellar body.

Eavesdropping Ray - hears through walls
A device that allows others to hear from outside ordinary locked rooms.

Glassite
A transparent material of great strength.

Gravity Assist - very early use
Using the gravity and orbital speed of a celestial body to change speed and course of a spacecraft.

Invisible Cloak -long before Harry Potter
A cloak that renders the wearer invisible.

Low-scale Detectors
Magnifies even the smallest sound.

Lunar Mining - moon mining camp
Very early (first?) reference to mining operations on the moon.

Moon Dome - first reference
A permanent domed structure for living on the Moon.

Moon Walk - presages Apollo
Very early realistic depiction of walking on the moon in low gravity.

Oxygen Space Flare
A flare that burns inside a glass bulb with oxygen.

Paralyzing Ray - early use
Stops body motions.

Pencil Heat Ray - narrow beam
An offensive, man-portable heat ray.