Christie’s is to auction an exceptionally rare Arithmetical machine. This ‘pocket-sized’ calculator, measuring 14.5 centimeters in width and 32.5 centimeters in length, is one of the earliest mechanical calculating devices known to exist and is the first portable device; only three other known examples of this design have survived.
The calculating device, contained in a complete walnut wooden box, comprises twenty-four rotating dials arranged in three rows of eight located on the interior lid. Each wheel consists of several concentric circles, while the bottom of the box contains a set of rolling cylinders carrying logarithmic tables. The Arithmetical machine performs all the arithmetic operations including addition, subtraction, multiplication and division through the use of these rolling rotating Napier’s bones.
Grillet exhibited his pocket sized machine during the 1670’s and 1680’s at markets and fairs throughout Paris and the Netherlands. The device is very rare to the market; with only three other known examples; two of these are in the Musée des Arts et Métiers, Paris and the other in the collections of IBM based in New York.