Juan Monroy — Media Technologies: Telegraph

Optical Telegraphy
- visual signals
- line of sight
  - ship-to-shore
  - overland
- relay stations
- optical code
The Vatican
- ancient announcement system
- visible throughout Rome
- selection of Pope Francis, 2013
- signal: plume of smoke
  - black: “no Pope"
  - white: “Pope!!”
Optical telegraphs
- heliograph
- flag semaphoe
- Napoleonic Semaphore
Heliograph
- helios: sun
- line-of-sight
- code, by flashes
Flag Semaphore
- visual signals
  - ship-to-ship
  - ship-to-shore
- alphabetic codes, by flags
Semaphore
- Claude Chappe
- France, 1793–1850s
- semaphore arms
- messages could be sent in 5–10 minutes
Napoleonic telegraph
- important for military strategy
- relay network
- messages could be sent in 5–10 minutes
- used until 1850s because…
Electromagnetic Telegraph
- Samuel Morse
- electromagnetism
  - discovered by Michael Faraday
  - 1820s–1830s
- Morse received Congressional appropriate of $10,000, 1843
Electromagnetic Telegraph
- polarized electrical signal
  - - postive
  - - negative
- pressing down completed an electrical circuit
- duration
  - short
  - long
- signal would travel by wire
Morse Code
- bits
  - long short
  - dot-dash
- alphanumeric bytes
  - series of dots-dash
- transcribed on paper
“What Hath God Wrought”
- first message sent between Morse and Alfred Vail
- May 24, 1844
- Washington, DC to Baltimore
- 40-mile connection
- used over B&O railroad right-of-way
Telegraphy in the United States
- Morse sold and licensed telegraph equipment
- telegraph network grew
- Washington to New York, 1846
- Western Union Telegraph Company, 1856
“Instant Communication”
- message dictated at telegraph office
- transcribed to Morse Code
- sent over telegraph by long-short
- received at destination by long-short
- transcribed into words onto paper, telegram
- delivered by messenger boy
Victorian Internet
- Connection and interconnection
- Annihilation of…
  - space
  - time
Railroads
- first telegraph came by “right of way” over Baltimore & Ohio train
- communications for long-distance railroads
- synchronized schedules
- transcontinental rail
Commodities Markets
- prices were based on local market conditions
- distant conditions would keep prices local pricing
- eliminated arbitrage
- established futures pricing
- space would be annihilated
Standard Time
- local meridians, usually a church or town square
- each railroad had its own time zone until 1883
- telegraph 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
  - weak-signal detector by Lord Kelvin
- link completed 1866
- “Victorian world united by cable”
Disruptive Effects of Telegraph
- Local communities grew…to global communities?
- Synchronized commerce and exchanges
- Newspapers and wire exchanges standardized reporting and dialect
- Changed an individual’s relationship to the world