Pinwheel calculator

The teeth are moved by a second wheel located inside the first and moved by a side lever.

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,[1] 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.

History

This drawing from Leibniz reads in French: Adjustable teeth of a multiplication wheel

Operation

"The operation of machines of this type was accomplished by means of pulling levers or knobs to set up the desired number. Addition, subtraction, multiplication, and division were accomplished by means of revolving drums. For addition they revolved in one direction, and for subtraction the direction was reversed. For multiplication the revolutions were repeated in the same direction as for addition, and for division they were repeated in the same direction as for subtraction. Two sets of dials provided a means of reading totals. In one the accumulation of totals appeared; in the other, there appeared the figure which was added, subtracted, multiplied, or divided." (The Office Appliance Manual, p. 88)

References

Sources

  • Wolf, Abraham (1959). A History of Science Technology & Philosophy in the 16th & 17th centuries, Volume II. Harper. p. 562. 
  • Smith, David Eugene (1929). A Source Book in Mathematics. New York and London: McGraw-Hill Book Company, Inc. 
  • Trogemann, Georg; Nitussov, Alexander Y.; Ernst, Wolfgang, eds. (2001). Computing in Russia: The History of Computer Devices and Information Technology Revealed. GWV-Vieweg. ISBN 3-528-05757-2. 
  • Felt, Dorr E. (1916). Mechanical arithmetic, or The history of the counting machine. Chicago: Washington Institute. 
  • Marguin, Jean (1994). Histoire des instruments et machines à calculer, trois siècles de mécanique pensante 1642-1942 (in French). Hermann. ISBN 978-2-7056-6166-3. 
  • Shaw, David J. (1998). The Cathedral Libraries Catalogue. The British Library and the Bibliographical Society. 

External links

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