Juan Monroy — Media Technologies: Class 5, Telegraph

Optical telegraph
- visual signals
- line-of-sight
- ship-to-shore
- overland
- relay stations
Semaphore
- Claude Chappe
- France, 1792
- military strategy
- shutters to make letters
Flag Semaphores
- ship-to-shore communication
Heliographs
- solar telegraphs
- polished metal
- reflecting beams of light
Wired Telegraphy
- Samuel Morse
  - electronic magnetic telegraph
  - Congress chartered cable between Washington and Baltimore, December 1842
  - formed Magnetic Telegraph Company, 1845
- Morse Code
  - dot
  - dash
- “What Hath God Wrought?”
  - Samuel Morse
  - Alfred Vail
  - May 24, 1844
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
Railroads
- first telegraph came by “right of way” over Baltimore & Ohio train
- communications for long-distance railroads
Commodities Markets
- prices were based on local market conditions
- distant conditions would keep
- space would be annihilated
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
Transatlantic Telegraph Cable
- Cyrus Field
- undersea cable
- gutte percha insulation
- 1866
- Victorian world united by cable