Description

THE “CALCULATEUR DIDELIN,” French, c. last quarter 19th century, “Brevete France S.G.D.G. et Etranger.” The 19-1/2″ x 8-1/2″ x 2-1/2″ (50 x 22 x 6 cm) softwood case, with hinged lid and sides, contains a system of five lithographed tin rollers, plus a hinged overlay plate with a total of 150 (!) windows opened and closed by 30 independent shutter slides. The rotating tubes (for units, tens, hundreds, thousands, and ten-thousands) are printed with interest due for 30 different percentage rates (from 0.25% up to 9%). Condition is fine throughout noting a little wear and soiling. It is an intriguing and quite rare specialized calculator; we find no example in the published catalogues of the collection in the Science Museum in London, and but one in the Musee des Arts et Metiers, that one given to the Museum by Monsieur Didelin himself in 1892.