NMSAT :: Networked Music & SoundArt Timeline

1844 __ Recording Telegraph
Samuel (Finley Breese) (1791-1872)
Comment : 1 May : Samuel F.B. Morse (d. 1872) publicly proves the viability of electric telegraph (with dots & dashes automatically written on a paper tape) by receiving in Washington a message from a distance of 25 miles, and 64 minutes ahead of the parallel message sent by train. 24 May : Samuel F.B. Morse uses his electric telegraph to send the message "What hath God wrought" on a completed 40 miles long line from Baltimore to Washington. The second message sent immediately after the first one was "Have you any news?". (Tom Standage)Samuel F.B. Morse invented his recording telegraph in October, 1832. « Mr. Morse went to work and got the machine built, and got it all ready to talk on the 24th day of last May. And then the folks in Washington all flocked round one end of the wires, and the folks in Baltimore flocked round t’other end of the wires to see the machine go. And then Mr. Morse called Anna [Miss Annie Ellsworth] and told her to get ready to speak to the floks at Baltimore; for she should have the first ‘say’, and say just what she’d a mind to. When they put the magnetism on to the wires, the first words the folks at Baltimore see coming out of their end of the wire , was, “What Hath God Wrought !”. And in less than two minutes the folks at baltimore spoke it back again to Washington, and the folks there see the same words coming out of ‘their’ end of the wires. ». (Major Downing, 22 Aug. 1844)With the exception of the original Wheatstone five-needle telegraph and the type-printing telegraphs of House and Hughes virtually all other public telegraphs, needle and acoustic, of the period transmitted code, actually cipher, in which movements or sounds are interpreted to represent characters, numbers and symbols. The original “Morse” code was devised by Alfred Vail in 1835 with 36 characters; there was also a different, extended Austro-German code, the “Hamburg Alphabet” that evolved into the “European Alphabet” in 1851 with 44 characters; and a particular Russian code that had 30 characters as well as numbers to suit an abbreviated Cyrillic alphabet. The “European Alphabet” or code was first used in British domestic circuits in June 1853. The China Submarine Telegraph Company solved the problem of telegraphing the 50,000 characters of the written Chinese language. It reduced its messages to several thousand common names and phrases and had each office provided with small numbered wooden printing blocks for each. The sender selected the appropriate phrases and the clerk transmitted their numbers. On receipt the appropriate numbered blocks were printed on to the outgoing message form. The Great Northern Telegraph Company compiled a “dictionary” giving numeric equivalents to Chinese characters for transmission in its China and Japan circuits in 1871; this caused some offence as its construction and the selection by clerks was arbitrary. (Steven Roberts, “Distant Writing - A History of the Telegraph Companies in Britain between 1838 and 1868”, 2010)
French comment : Le télégraphe Morse fut le premier télégraphe pratique et l'un des plus employés. Le principe des télégraphes enregistreurs est de sauvegarder une trace des dépêches transmises. Pour cela, Samuel Morse (1791-1872) qui était peintre et inventeur américain mis au point le télégraphe qui porte son nom et en 1832, l'alphabet correspondant. Ce système fût breveté en 1840. Le manipulateur se compose d'un socle de bois sur lequel sont fixées deux bornes P et M et un levier, muni de deux contacteurs, qui peut osciller verticalement. Dans sa position de repos, le ressort éloigne le levier de la borne P. Quand on veut envoyer un message, on appuie sur la poignée du levier afin de mettre en contact la borne P avec l'un des contacteurs du levier. Le courant passe et est interrompu dès que l'on relâche le levier qui retourne dans sa position de repos grâce au ressort de rappel. La manipulation de transmission est donc ainsi très simplifiée. Le récepteur fonctionne à l'aide d'un électro-aimant relié au fil de ligne et à la Terre. Quand un courant arrive la plaque de fer doux de l'électro-aimant est attirée et repoussée grâce au ressort de rappel suivant les ouvertures et fermetures du courant. Le levier est mis en mouvement et oscille. Il porte une pointe qui appuie sur une bande de papier. La longueur de la trace laissée sur le papier dépend de la durée du passage du courant. Un relais était utilisé pour suppléer à l'intensité du courant électrique de ligne qui était suffisant pour la transmission des signaux, mais pas pour l'inscription sur le papier. Le relais était alimenté par une pile dont l'intensité du courant s'ajoutait au courant de ligne. L'établissement et la fermeture de ce courant supplémentaire s'effectuaient par l'intermédiaire de l'électro-aimant du relais. (Compiled from various sources)
Source : Major Downing, (1844), “From Major Downing’s Bunker Hill. To uncle Joshua, of Downingville, away from East. New York Aug 22, 1844”, In The Rover : A Weekly Magazine of Tales, Poetry and Engravings, edited by Seba Smith, Vol.III, New York : published by S.B. Dean & Co, 123 Fulton Street, 1844, p. 393.
Source : Standage, Tom (1998), “The Victorian Internet”, The Berkley Publishing Group, New York, p. 49 and 139.
Urls : http://www.worldwideschool.org/library/books/tech/engineering/HeroesoftheTelegraph/chap3.html (last visited ) http://visite.artsetmetiers.free.fr/telegr_enregistreur.html (last visited ) http://distantwriting.co.uk/appendices.aspx (last visited )

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