Instrument

Morse code

Telegraphy (from the Greek words tele (τηλε) = far and graphein (γραφειν) = write) is the long-distance transmission of written messages without physical transport of letters.

A telegraph sends electric pulses in a special code, composed from short and large marks. Usually, amateur radio operators use Morse code.

Claude Chappe's optical telegraph on the Litermont near Nalbach, Germany