page_title: Pinwheel calculator
hierarchical_section_title: Pinwheel calculator
caption_attribution_description: Deutsch: Scan aus Wassén, Henry: The Odhner History&#160;? An Illustrated Chronicle of "A Machine to Count on", Gothenburg: Wezäta, 1951
context_page_description: A pinwheel calculator was a class of mechanical calculator popular in the 19th and 20th century using, for its calculating engine, a set of wheels that had an adjustable number of teeth. These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a counter they could, at each rotation, add a number from 0 to 9 to the result. By linking these wheels with carry mechanisms a new kind of calculator engine was invented. Turn the wheels one way and one performs an addition, the other way a subtraction. As part of a redesign of the arithmometer, they reduced by an order of magnitude the cost and the size of a mechanical calculators on which one could easily do the four basic operations.
  Pinwheel calculators became extremely popular with the success of the Odhner Arithmometer.
context_section_description: A pinwheel calculator was a class of mechanical calculator popular in the 19th and 20th century using, for its calculating engine, a set of wheels that had an adjustable number of teeth.  These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a counter they could, at each rotation, add a number from 0 to 9 to the result.  By linking these wheels with carry mechanisms a new kind of calculator engine was invented.  Turn the wheels one way and one performs an addition, the other way a subtraction.  As part of a redesign of the arithmometer, they reduced by an order of magnitude the cost and the size of a mechanical calculators on which one could easily do the four basic operations (add, subtract, multiply and divide).
  Pinwheel calculators became extremely popular with the success of the Odhner Arithmometer.
caption: The teeth are moved by a second wheel located inside the first and moved by a side lever.
exif: {}