Can You Hear Me Now · Episode 2 of 14 · 21 min
Flags, Arms and Placards
In 1836 France found that two Bordeaux bankers had bribed operators to hide Paris bond prices inside errors on the state's optical telegraph, and the courts found no law forbidding it. The episode follows towers, shutters and signal flags, from the Chappe network to Nelson's signal at Trafalgar and the International Code of Signals. It ends with hazardous-materials placards, a visual code still read at speed on American highways.
Who's who
- Claude ChappeInventor who devised the optical telegraph with his brothers from 1790
- Ignace ChappeClaude's brother, a legislator who helped bring the proposal to government
- Alexandre DumasNovelist whose Count of Monte Cristo features a bribed telegraph operator
- Lord George MurrayClergyman whose six-shutter telegraph the British Admiralty accepted in 1795
- Home Riggs PophamRoyal Navy officer who devised the numbered-flag Marine Vocabulary in 1800
- Horatio NelsonAdmiral who ordered the signal England expects at Trafalgar
- John PascoNelson's signal officer who suggested the word expects
- John Richards LapenotièreLieutenant who carried the news of Trafalgar to London
Where it happens
- Bordeaux, FranceWhere the bankers received Paris bond prices
- Tours, FranceWhere telegraph operators were bribed
- Brûlon, FranceSite of Chappe's first public test in 1791
- Trafalgar, SpainSite of Nelson's 1805 battle and famous signal
- Deal, EnglandEnd of the Admiralty shutter telegraph chain from London
- Falmouth, EnglandWhere the schooner Pickle landed news of Trafalgar
Timeline
- March 2, 1791First public test of the Chappe telegraph, about sixteen kilometers in the Sarthe
- July 1793Chappe is appointed telegraph engineer by decree
- October 21, 1805Nelson's flagship hoists England expects at Trafalgar
- 1834 to 1836The Blanc brothers' scheme on the Paris to Bordeaux line runs until discovered
- 1837France makes unauthorized transmission of signals a crime
- 1844The French network links twenty-nine cities over more than five thousand kilometers
Still debated
Accounts differ on the Blanc brothers' first names, the network's exact size, and when the last optical line closed, with dates from 1852 to 1855. Calling Chappe's system the first telecommunications network is disputed, since earlier relays existed and Sweden's Edelcrantz worked at the same time.