Commemorative Stamp depicting the Mechanical Calculating Machine

of Johann Christoph Schuster

The cylindrically shaped mechanical calculating machine of Johann Christoph Schuster (1759-1823) was built in the years 1820 to 1822 in Ansbach and is the last artifact of its kind from the pre-industrial era of mechanical calculating. Schuster learnt his trade from the clergyman and mechanical engineer Philipp Matthäus Hahn (1739-1790) from Württemberg. During his apprenticeship he not only learnt to build clocks and watches but also the cylindrically shaped mechanical calculating machines invented by Hahn. From 1786 onwards he worked independently, initially in Westheim in Franconia, later in Uffenheim and finally from 1797 onwards as court watchmaker in Ansbach.

Schuster's oldest mechanical calculating machine dates from 1792 and was built in Uffenheim. It is hardly different from Hahn's machines. During the years 1805 to 1820 when Schuster was in Ansbach, he developed his own construction. Technically it was based on Hahn's ideas, but it featured more compact mechanical components and was more user-friendly. In the last years before his death Schuster built the machine depicted on the commemorative stamp. It was the third machine using his own construction.

In September 1999 the Arithmeum in Bonn was able to acquire this machine with the kind assistance of the Cultural Foundation of the German Federal States, the University of Bonn, the Alfried Krupp von Bohlen und Halbach Foundation, and the Representative of the German Government for Cultural and Media Affairs. As the Arithmeum attaches great importance to having its machines in good running order, the Schuster machine was completey restored over a period of six months before it was officially presented to the Arithmeum by the Federal Chancellor of Germany in March 2000.