Thomas Arithmomètre

Four-species stepped drum machine

1875

Charles Xavier Thomas (1785-1870), a French insurance salesman from Colmar in Alsace, produced his Arithmomètre, a four-species stepped drum machine, from 1820 onwards. In the spirit of the Industrial Revolution, the machine was designed from the outset for serial production. It became the first commercially used calculating machine for which Thomas had a worldwide monopoly between 1820 and 1878. From 1858 onwards, Thomas machines had a multi-digit revolution counter (without tens transfer) and a deletion device for all inspection holes. In 1879 it became known that Thomas produced about 1200 machines until 1875; until 1870 about 800 Arithmomètres were sold, until 1878 another 700 copies, 60 percent of which were exported. From 1870 to 1878 the machines were manufactured by A.M. Hoart, who ran a calculating machine workshop in the house of the Parisian insurance company "Le Soleil".

This machine with the number 1203 can therefore be dated 1875. It has a 9-digit revolution counter and a rotary erasing device via racks for erasing the revolution and main counter. In the seal next to the adjuster it bears the inscription: "Thomas de Colmar Paris, Inventeur, No. 1203". Unfortunately, the digits of the main register were numbered by hand using a pointed object in the brass above. The original wooden box is no longer present, so the machine was built into a plexiglass case to serve as a demonstration model.