Chappe optical telegraph
Telégrafo óptico de Chappe
- Date
- 1791 · confidence high
- Place
- Brûlon and Parcé-sur-Sarthe, Sarthe, France
- Credited to
- Claude Chappe and his brothers
- Field
- Communication
What it is
Chappe publicly demonstrated his semaphore telegraph: towers with movable wooden arms that, viewed by telescope from the neighbouring tower, encoded letters and relayed messages across France in minutes.
Wikidata dates this to 1792, but the documented public demonstration took place on 2 March 1791, between Brûlon and Parcé; the Convention did not approve building the Paris-Lille line until 1793, opened in 1794.
What it led to
- National network of optical telegraphs in France and Europe
- Precursor concepts of error control and routing in data networks
- Electric telegraph, which replaced it by the mid-19th century