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Media Technologies: Class 5, Telegraph

  1. Optical Telegraphy
    • communication by sight
    • line of sight
    • Optical Telegraphy Lives at the Vatican
    • Code
  2. Optical telegraphs
    • visual signals
    • line-of-sight
    • ship-to-shore
    • overland
    • relay stations
  3. Heliograph
    • helios: sun
    • line-of-sight
    • code
  4. Flag Semaphore
    • visual signals
    • ship-to-ship and ship-to-shore
    • alphabetic codes
  5. Semaphore
    • Claude Chappe
    • France, 1793–1850s
    • semaphore arms
    • military strategy
    • messages could be sent between 5–10 minutes
    • shutters to make letters
  6. Electromagnetic Telegraph
    • Samuel Morse
    • electromagnetism, Michael Faraday
    • received Congressional appropriate of $10,000, 1843
  7. Morse Code
    • bits: dot-dash
    • alphabet bytes: sets of dots-dash
    • transcribed on paper
  8. “What Hath God Wrought” (1844)
    • May 24, 1844
    • first message sent between Morse and Alfred Vail
    • Washington, DC to Baltimore
    • 40-mile connection
    • used over B&O railroad right-of-way
  9. Telegraphs in the United States
    • Morse sold and licensed telegraph
    • telegraph network grew
    • Washington to New York, 1846
    • Western Union Telegraph Company formed 1856
  10. Telegrams
    • message dictated at telegraph office
    • transcribed to Morse Code
    • sent over telegraph by dot-dash
    • received at destination by dot-dash
    • transcribed into words on a telegram paper
    • delivered by messenger, usually young boy
  11. Railroads
    • first telegraph came by “right of way” over Baltimore & Ohio train
    • communications for long-distance railroads
  12. Commodities Markets
    • prices were based on local market conditions
    • distant conditions would keep
    • space would be annihilated
  13. Standard Time
    • local meridians, usually a church or town square
    • railroads had their own time zone until 1883
    • synchronized time across various regions
    • International Meridian in Greenwich, October 1884
    • U.S. Standard Time Act, 1918
    • time would be annihilated
  14. Transatlantic Telegraph Cable
    • Cyrus Field
    • undersea cable
    • gutte percha insulation
    • 1866
    • Victorian world united by cable
  15. Disruptive Effects of Telegraph
    • Local vs. Global Communities
    • Commerce and Exchange
    • Newspapers
    • Personal Identities