telegraph, any device or system that allows the transmission of information by coded signal over distance.

How does the telegraph work simple?

Invention of the Telegraph

A part called the transmitter sent electric currents through the wires. At the other end, the currents moved needles on a part called the receiver. The receiver had a special plate with letters and numbers on it. The needles pointed to the letters and numbers to spell out messages.

What is a telegraph machine and what does it do?

Developed in the 1830s and 1840s by Samuel Morse (1791-1872) and other inventors, the telegraph revolutionized long-distance communication. It worked by transmitting electrical signals over a wire laid between stations.