Telegraph system. Historical artwork of an operator using a Baudot telegraph system. He is using a keyboard with five keys to enter a message to be transmitted as a series of electric pulses. The system was invented by French engineer Emile Baudot (1845-1903) in 1870, and was the first truly digital code. Incoming messages were decoded by the receiver (centre), and printed onto a length of ticker tape (spool at centre). Skilled operators could send 180 letters per minute on the Baudot system. Published in La Telegraphie Historique (History of Telegraphy) by Alexis Belloc in 1888.