Thomas Arithmometer
From the collection of National Museum of American History. Free to download, adapt and use — no permission needed.
This is the oldest surviving example of the type of stepped drum calculating machine constructed under patents obtained by the Frenchman Charles Xavier Thomas of the French town of Colmar in 1820. Machines that could do arithmetic automatically were built as mechanical marvels in the 1600s on the design of mathematicians such as Blaise Pascal and Gottfried Leibniz. However, it was only with the introduction and improvement of the machine of Thomas that calculating machines became part of the world of practical calculation. The instrument was made for Thomas by the Parisian mechanician and clockmaker Devrine. Thomas arithmometers, as the machines were called, became the first commercially successful calculating machines.
National Museum of American History’s own description
