Julius Wilhelm Gintl was an Austrian physicist. He was notable as the developer of an early form of duplex electrical telegraph

Electrical telegraph

An electrical telegraph is a telegraph that uses electrical signals, usually conveyed via telecommunication lines or radio. The electromagnetic telegraph is a device for human-to-human transmission of coded text messages....

, which allowed two messages to be transmitted on a single wire, in opposite directions. This "duplex" communication was an early specific case of the general practice of multiplexing.

Gintl's method would be developed to economic viability by J. B. Stearns, and the refined method used in Edison's implementation of a quadruplex telegraph

Quadruplex telegraph

The Quadruplex telegraph is a type of electrical telegraph which allows a total of four separate signals to be transmitted and received on a single wire at the same time Quadruplex telegraphy thus implements a form of multiplexing.The technology was invented by American inventor Thomas Edison, who...

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