From as early as 1836, there were various suggestions and inventions of dials for sending telegraph signals.
Unfortunately, the amplitude of the telegraph signal was only 70 volts.
This was in reality the first example of railroad trains moved by telegraph signals, a practice now so common and universal as to attract no comment.
It sent telegraph signals between unmanned stations, allowing almost anyone to translate code easily and precisely at one's own speed and convenience.
The term pen register originally referred to a device for recording telegraph signals on a strip of paper.
He also paid close attention to his work, and quickly learned to distinguish the differing sounds the incoming telegraph signals produced.
He often recounted Einstein's experience of reading a children's story about a child racing a telegraph signal going through a wire.
These used a moving pen attached to a galvanometer to record telegraph signals.
Relays originated with telegraphy as electromechanical devices used to regenerate telegraph signals.
Faster-than-light telegraph signals from another star.