Telegraph

ORDERBY-NAME:  Telegraph

OTHER-NAME:  Electric telegraph

DATE INVENTED/BEGAN:  1837

PLACE INVENTED/BEGAN:  London, England

DATE ENDED:

PLACE ENDED:

CATEGORY: Technology

DISCIPLINE: Precision instrument

ASSESSMENT: The telegraph introduced the modern world of telecommunications and was first used to run railroad systems.

LANGUAGE: English and German

DETAILS:  The first public use of the telegraph was by the German scientists <first public use by> Gauss* and <first public use by> Wilhelm Weber* at the University of Gottingen, Germany in 1833.  The first successful commercial application was by <first commercial use by> Wheatstone* in England where it was used on the railroad.  Its most famous appearance was when a version was demonstrated to Congress by <developed by>  Samuel Morse* (his partner, who developed the code known now as ‘Morse Code’  was Alfred <developed by> Vail*) in 1844 when he sent the telegram reading ‘What Hath God Wrought’ from Baltimore to Washington DC.

Telegraph transmission occurs when the operator uses a sprung metal lever to make and break contact, thus interrupting electric current along a wire, for short or long periods (‘dot’ and ‘dash’). At the other end of the wire, this pattern of interruptions in current cause an electromagnet to move and release a key which taps out the original set of interruptions (‘dot’ and ‘dash’).  A dot-and-dash code represents all the alphabet letters and numbers from 0 to 10.  In this way the dots and dashed can be decoded by the receiving operator.

ONELINER:  The telegraph

EXTRA-CONNECTIONS:  None

BIBLIOGRAPHY:

Encyclopedia Britannica

http://en.wikipedia.org/wiki/Electrical_telegraph#Alter_and_the_Elderton_Telegraph

http://inventors.about.com/library/bl/bl12.htm

http://www.enchantedlearning.com/inventors/

http://inventors.about.com/library/bl/bl12.htm

http://www.howstuffworks.com/