This type of pin-wheel calculator was, invented by Willgodt T. Odhner in St. Peterburg, Russia, in 1874. A calculator on similar principles was invented independently two years earlier by Frank Baldwin in the USA, but the Odhner was the successful design. Following the Russian Revolution of 1917 and the nationalization of the factory there, production moved to Sweden and the name "Original Odhner" was adopted. This was the most successful type of general purpose mechanical calculator (ie. intrinsically capable of multiplication and division and not just "adding machines").

For further information on performing the basic arithmetic operations see Operating a Pinwheel Calculator in the "Collecting Calculators" section at http://www.vintagecalculators.com/html/operating_a_pinwheel_calculato.html

Swedish, mid 20th century, signed "ORIGINAL ODHNER." This small pin-wheel type mechanical calculator stands 4 3/4" high x 6 1/4" deep x 13" long overall, with its case finished in gray enamel. The calculator has 10 setting levers, 8 places in the revolution counter, and 13 places in the results mechanism. The calculator comes with its original vinyl cover.

This model type was in production from 1955 to 1968.

Our model has a stamped serial number on the base: 227-826390 and was very kindly donated by Graham Denton.

Manufacturer: Odhner
Date: 1955

This exhibit has a reference ID of CH4883. Please quote this reference ID in any communication with the Centre for Computing History.

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