October 21, 1879. Prolific inventor and entrepreneur Thomas Edison announces the first successful test of an electric light bulb capable of staying lit for 13.5 hours at his laboratory in Melo Park, New Jersey. Although incandescent electric light bulbs were not new in themselves, this was by far the longest lasting filament and soon Edison’s practical bulb would be produced, and sold, en masse. Its success was due to a combination of the vacuum effect produced by the bulb and the use of carbon as a filament. One of Edison’s research assistants came up with the carbon by baking cotton threads and after the success Edison went to great lengths searching for the best source of carbon, eventually bamboo which would last for 1,200 hours. Edison, a shrewd businessman, quickly went on to develop a process for delivering electric power, so he not only sold the bulbs, but also the electricity that made them work.
Also on October 21: the Battle of Trafalgar (1805); women vote for the first time in France (1945); Siad Barre comes to power in a coup d’etat in Somalia (1969).
Born on October 21: Samuel Taylor Coleridge (1772), Alfred Nobel (1833), Dizzie Gillespie (1917), Liliane Bettencourt (1922), Geoff Boycott (1940), Jade Jagger (1971)