A Payen Arithmometer in Istanbul and Its User’s Guide in Turkish

Early mechanical calculators were designed in the seventeenth century and produced in limited numbers. They were elaborated subsequently and their production only increased in the 19th century after the French mathematician Thomas (de Colmar, 1785-1870) invented the arithmomètre in 1820. Arithmomètre was the first commercially successful mechanical calculator. Following Thomas’s death, first his family, then his collaborator Louis Payen (1839-1901) continued to elaborate the instrument which became widely used in Europe, especially in France. Presently, arithmometers produced by Thomas and Payen are kept in the collections worldwide. A Payen arithmometer dated 1888 and numbered 2378 is presently kept at Istanbul University’s Library for Rare Books. The present article aims to introduce this particular arithmometer, its user’s guide in Turkish, and its translator Mehmed ？zzet