Prior to the electrical telegraph, a widely used method of building national telegraph networks was the optical telegraph consisting of a chain of towers from which signals could be sent by semaphore or shutters fro… See more

Early printing telegraphs continued to use Morse code, but the operator no longer sent the dots and dashes directly with a single key. Instead they operated a piano keyboard with the characters to be sent marked on … See more

The teleprinter was invented in 1915. This is a printing telegraph with a typewriter-like keyboard on which the operator types the message. Nevertheless, telegrams continued to be sent in upper case only because th… See more