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Morse code system. 19th-century table of the Morse code system, showing letters and their corresponding telegraph signs (long and short dashes). Also shown are the signs for ciphers (numbers) and punctuation marks. This code was demonstrated in 1838 by US inventor Samuel Morse (1791-1872) and used in his 1840s telegraph system. This page is from 'History, Theory, and Practice of the Electric Telegraph' (1860) by US telegraph engineer George Bartlett Prescott (1830-1894). (KEYSTONE/SCIENCE PHOTO LIBRARY/KING'S COLLEGE LONDON/SCIENCE PHOTO LIBRARY)