Aliens Speak English
The skeleton men of Mercury speak English, but have a good reason for it.

The Mines of Haldar (1934)

Electro-Telescope
A device that could clearly image space battles and space ships, even from a great distance.

The Mines of Haldar (1934)

Golden Shuttles (Mechanical Mice) - tiny robots
Very small robots with an appetite for watch parts.

The Mechanical Mice (1941)

Psychophone
A device that allows the user to tune their mind to a future reality - a time-traveling device.

The Mechanical Mice (1941)

Robot Mother - self-reproducing automaton
A self-replicating robot, which creates a series of helper bots that adapt to conditions as needed.

The Mechanical Mice (1941)