Hughes printing telegraph, 1860.

UNITED STATES - APRIL 21: The British physicist David Edward Hughes (1831-1900) was born in Wales but emigrated to the United States, where he invented this successful telegraph in 1855. It was the first telegraph system which printed the text at the sending and receiving ends, thus abolishing the need for a special alphabetic code. The telegraph employs synchronised type-wheels at each end of the line. Pressing the keys raises pins opposite the required letters. When a pin makes contact, a hammer at the far end pushes the paper against the type-wheel there and prints the corresponding letter. An experienced operator could send messages of up to 30 words a minute using this telegraph. The system was mainly used on cable routes from Britain to Europe. (Photo by SSPL/Getty Images)