Odhner Arithmometer
Introduction An Odhner machine made under the management of W.T. Odhner in Saint Petersburg before 1900BrunsvigaThalesThe '''Odhner Arithmometer''' was a very successful pinwheel calculator invented in Russia in 1873 by W. T. Odhner, a Swedish immigrant. Its industrial production officially started in 1890 in Odhner's Saint Petersburg workshop. Even though the machine was very popular, the production only lasted thirty years until the factory was nationalised and closed down during the Russian revolution of 1917.From 1892 to the middle of the 20th century, independent companies were set up all over the world to manufacture Odhner's clones and, by the 1960s, with millions sold, it became one of the most successful type of mechanical calculator ever designed.
History Original designOdhner thought of his machine in 1871 while repairing a Thomas' Arithmometer (which was the only mechanical calculator in production at the time) and decided to replace its heavy, bulky Leibniz cylinder by a lighter, smaller pinwheel disk. This is why the two machines share the same name but look completely different.Odhner developed the first version of his mechanical calculator in 1873.In 1876, he agreed to build 14 machines for Ludvig Nobel, his employer at the time, which he delivered in 1877.He patented his original machine in several countries in 1878–1879 and an improved version of it in 1890.The serial production began with this improved machine in 1890.In 1891 Odhner opened a branch of his factory in Germany. Unfortunately, he had to sell it in 1892 to ''Grimme, Natalis & Co.'' because of the difficulty of having two manufacturing facilities so far apart. ''Grimme, Natalis & Co.'' started production in Braunschweig and sold their machines under the ''Brunsviga'' brand name (Brunsviga is the Latin name of the town of Braunschweig); they became very successful on their own.After Odhner's death, in 1905, his sons Alexander and Georg and son-in-law Karl Siewert continued the production and about  calculators were made until the factory was nationalized during the Russian revolution and was forced to close down in 1918.This makes the Brunsviga arithmometer, with its 1892 start, the longest-lasting Odhner type calculator in production.Desktop Mechanical Calculators in production during the 19th century
Legacy Share of the AB Original-Odhner, issued in August 1918Original-Odhner Arithmos, Type 5, Made in SwedenTowards the end of 1917, the Odhner family went back to Sweden and restarted the manufacturing of their calculator under the ''Original-Odhner'' name. In 1924, the Russian government moved the old production facility to Moscow and commercialized their calculator under the ''Felix Arithmometer'' name which went on well into the 1970s.In 1950, with millions of clones manufactured, the Odhner arithmometer was one of the most popular type of mechanical calculator ever made. The number of machines produced increased constantly until the appearance of the electronic calculators in the early 1970s. For instance, the production of one of them, the ''Felix'' arithmometer of Russia, peaked in 1969 with  machines made.Odhner's arithmometer was copied, manufactured and sold by many other companies all over the world. In Germany there was ''Thales'', ''Triumphator'', ''Walther'' and ''Brunsviga''. In England there was ''Britannic'' and ''Muldivo''. In Sweden ''Multo'' and ''Original-Odhner''. In Russia ''Felix'' and in Japan ''Tiger'' and ''Busicom'' which, incidentally, was made famous because Intel created the first microprocessor, the Intel 4004, while designing one of their electronic calculators in 1970.
References
External links *  John Wolff's web museum - Pin-wheel Calculators*  rechenmaschinen-illustrated - The Odhner Arithmometer*  http://odhner.com/kevin/wtodhner/calcs.html - Odhner Calculator, Memorial site*  Arithmetical Machines & Instruments / 19th Century - 1870s patents*  Guillaume Tello's web page (en) How to use the IMCA, an Italian Odhner machine.