At a session of the French Academy of Sciences, physicist François Arago detailed the workings of Louis Daguerre's daguerreotype process, the first practical method of photography. The French government had purchased the invention and released it to the world without patent restrictions, in exchange for lifetime pensions to Daguerre and the heirs of his late partner Nicéphore Niépce. The announcement triggered a global craze.
Daguerre had spent over a decade perfecting a process using silver-coated copper plates and mercury vapor, building on the pioneering but commercially unsuccessful work of Nicéphore Niépce, who had died in 1833 without seeing it succeed. The French government's decision to make the process freely available, rather than patent it for private profit, was almost unheard of for the era.
Within months, 'daguerreotypomania' swept Paris, then London, then New York. Studios opened everywhere; exposure times shrank from many minutes to under a minute within a few years, making portraiture practical for ordinary people for the first time in history. Samuel Morse, present in Paris that year, brought the technique back to America, and by the 1850s a technology once considered alchemical magic had become a fixture of middle-class life.
Key people: Louis Daguerre, François Arago, Nicéphore Niépce