Odhner Arithmometer Model I
The Swede Willgodt T. Odhner (1845-1905), who resided in St. Petersburg, began to develop a pinwheel machine in the 1870s, around the time that the American F. S. Baldwin was applying for a US patent for his 4-species pinwheel machine. Around 1877 Odhner had fourteen machines built by Ludvig Nobel according to his design. In 1878-79 Odhner obtained patents for his machine in USA, Germany, Sweden and Russia. But wasn’t until 1890 that Odhner could begin building his second, improved machine (patents DE 64925, US 514725) in St.Petersburg. This machine is one of these, with the low machine No. 765 and with the crank fitted very close to the housing. The earliest known machine with a longer crank axle is No. 4194; the corresponding machine in the Arithmeum (FDM 6180) has the No. 4660. The copper plaque at the top reads “Arithmometer Patent W. T. Odhner” and the round copper plaque at the front reads “Maschinenfabrik W. T. Odhner St. Petersburg”. These machines comprise the prototype of all later pinwheel machines based on the “Odhner Principle”, and two years later (from 1892 onwards) the German Brunsviga machine (FDM 9248, FDM 7055), the first machine to be produced in Germany, was modeled on it. Another Odhner Arithmometer with the low machine No. 3070 is in the Arithmeum (FDM 9563). A detailed history of Odhner’s family and his machines has been published by Timo Leipälä.