Willgodt Theophil Odhner

Willgodt Theophil Odhner was a Swedish engineer and entrepreneur who spent his working life in St. Petersburg, Russia, and invented the Odhner Arithmometer, a mechanical calculator that by the 1940s was among the most popular portable calculators in the world. He studied at the Royal Institute of Technology in Stockholm from 1864 to 1867 without graduating, then moved to St. Petersburg in 1868, where the Swedish consulate found him work in a mechanical workshop. He later worked at the mechanical factory of Ludvig Nobel until 1877 and at the Expedition, a large paper mill and printing house, until 1892. In 1871 he repaired a Thomas calculating machine, which convinced him that mechanical calculation could be solved more simply, and it took him some nineteen years to perfect his design for manufacture. He opened his own workshop in 1885, making printing presses, cigarette-making machines and scientific instruments, and began producing the arithmometer there in 1890. After his death in 1905 his sons and son-in-law carried on the firm, making about 23,000 calculators before it closed in 1918, and clone makers kept the design in production into the 1970s.