Germany: New €20 silver Proof coin remembers the 400th anniversary of inventor Wilhelm Schickard’s calculator

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The German Ministry of Finance, along with Munze Deutschland, have released this year’s third €20 silver commemorative coin, which marks the 400th anniversary of the invention of the first mechanical calculator that could perform all four basic arithmetic operations. The device was the brainchild of astronomer and mathematician Wilhelm Schickard (1592–1635), who in 1623 successfully demonstrated that the central mechanism of his calculating machine was capable of adding and subtracting numbers of up to six digits.

Born in Herrenberg, a small town in present-day Baden-Württemberg, in 1592, he was the son of a sculptor and nephew of the eminent architect of the Renaissance-era, Heinrich Schickard. At the age of 18, Wilhelm was awarded a scholarship to study at the University of Tübingen, where he chose to study theology, ultimately becoming a professor of Hebrew in 1619. One of his early notable contributions to higher learning was the Hebrew language school he founded and which was still in use long after his death. In addition to his teaching activities, Schickard was keenly interested in astronomy, and in 1631, he also became a professor of the subject. As a very versatile scientist, he created the first precise map of Württemberg as well as various mechanical constructions, such as the Rota Hebraea, a mechanical device for reading the conjugation of Hebrew verbs. Schickard’s hand-held planetarium was capable of accurately showing the movement of the the sun, the earth, and illustrated the moon that could be switched between heliocentric and geocentric representation. However, it was the creation of what Schickard’s contemporaries referred to as the calculating clock, which was, for many, a device that was clearly ahead of its time. The central mechanism consisted of six gears with the numbers zero to nine, each of which is firmly connected to an underlying gear that has only one tooth. This ensured that when changing from nine to zero and vice versa, the adjacent number wheel turned exactly one digit forward or backwards. The movements and its operation demonstrated it was capable of adding and subtracting numbers of up to six digits as well as having the accurate ability to calculate multiplication and division. In correspondence with the famed astronomer Johannes Kepler (1571–1630), whom Schickard had met in 1617, he wrote about his invention, “Machinam extruxi quae datos numeros computer,” (“I constructed a machine that can calculate”). Sadly, no versions of the device survived to the present day. However, as biographers of Kepler uncovered Schickard’s sketches and notes for the machine that he sent to Kepler in letters, the Tübingen philosophy professor Bruno Baron von Freytag-Loeringhoff succeeded in reconstructing the machine in 1957. Today, replicas of the machine are in the Stadtmuseum Tübingen and in the computer museum of the Wilhelm Schickard Institute.

The Proof-quality coins are produced by the Bayerisches Hauptmünzamt at their facilities in Munich on behalf of the Ministry of Finance and designed by the artist Florian Huhoff. His depiction of Schickard’s schematized historical calculating machine is centred along with representations of functional connections, such as the gear mechanism, that are illustrated in the style of a diagram. The commemorative inscription 400 JAHRE RECHENMASCHINE (“400 years of the calculator”) is placed above the primary design and the name WILHELM SCHICKARD in stylised text is shown just under the calculator. The reverse side depicts a stylised eagle, which is centred with the coins’ denomination of 20 EURO with the issuer BUNDESREPUBLIK DEUTSCHLAND placed below the face value. There are vertical rows of four, five-pointed stars placed on each side of the eagle and one horizontal row below the eagle. Below those stars is the coin’s fineness SILBER 925, with the year of issue 2023 seen on the left side of the coin and D mintmark denoting the Munich Mint on the right. The coins include an incused inscription on the edge, which reads MACHINAM EXTRUXI QUAE DATOS NUMEROS COMPUTET × (“I constructed a machine that can calculate”).

Denom.	Metal	Weight	Diameter	Quality	Mintage Limit
20 euro	.925 Silver	18 g	32.5 mm	Uncirculated	120,000
20 euro	.925 Silver	18 g	32.5 mm	Proof	*n/a

Available from the 3rd August, the Brilliant Uncirculated pieces are available for their face value at leading commercial banks and post office counters. The Proof-quality collector’s edition is encapsulated and presented in a folder which is available by visiting the website of Munze Deutschland.

*Towards the end of the year, the entire €20 coin collection consisting of four 2023-dated pieces will be available in Proof quality and as a set presented in an official blister-pak type folder.

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