Johann Bischoff

A writer is someone for whom writing is more difficult than it is for other people.
Thomas Mann

In the history of computers and computing, there are several figures who are tremendously important despite never actually inventing a thing. One such individual is Johann Paul Bischoff (1736-1811), adviser in the court of the Margrave Karl Alexander of Brandenburg-Ansbach in Ansbach, Bavaria. In the last quarter of the 18th century, Bischoff undertook several long trips to take a look personally at the calculating machines and instruments, that he had heard of, in order to describe them in a book.

After spending more than 16 years collecting information (from 1788), in 1804 Bischoff finished the manuscript for a book, that is a comprehensive account of the history of computing tools and methods used until then. The manuscript contained a meticulous compilation of virtually everything known for calculating methods and devices, from calculation with fingers and Napier’s Bones to the calculating machines of Pascal, Morland, Grillet, Leibniz, Poleni, Lepine, Leupold, Poetius, Boistissandeau, Hahn, Müller, and Reichold.

The book of Bischoff was the second comprehensive representation in this area, after Jacob Leupold’s Theatrum arithmetico-geometricum from 1727. Unlike his predecessor however, Bischoff’s work has never been printed in his time, but as late as 1990 (Versuch einer Geschichte der Rechenmaschine (Attempt at a History of Calculating Machines), publisher: Systhema-Verlag, editor: Stephan Weiss). The book has two parts: Part 1—”Concerning the Simple Tools” carries a historical overview and Part 2—”About Calculating Engines with Wheels” has technical descriptions of the engines. The book concludes with the 29 plates, all beautiful technical drawings.

Interestingly, mentioning Leibniz’s Stepped Reckoner in the ‘simple tools’ section Bischoff says: the realization of his idea seems possible to me, but it seems like much work to me for little use and therefore I don’t think it worth the trouble to lose more time on it. And then: all the trouble so far couldn’t improve nor replace Napier’s counting sticks with better tools. Everything that was done to make them better or simpler to use concerned only the form, and not the essence.

From the end of the 19th century, the manuscript was kept in the library of the Technical University of Berlin. Part of this library was destroyed in a fire during WWII (in 1943), and the remaining part was carried away by Russian soldiers at the end of the war. Thus the manuscript was lost. Only two undated transcripts from the beginning of the 20th century survived to our time (maybe there is something more in Russian archives?). Besides detailed text descriptions, Bischoff’s manuscript also contained many tables, sketches, and large colored drawings. Unfortunately except for some sheets, most of them are lost. Only poor-quality black-and-white photographs of all drawings, taken at the beginning of the 20th century, survived to the present.

Biography of Johann Paul Bischoff

Villa Bischoff in Ansbach, built 1799
The residential house of Bischoff in Ansbach was built in 1799/1800

Johann Paul Bischoff was born on 20 February 1736, in Sonneberg, Thuringia, to Johann Jacob Bischoff (1706-1757) and Anna Margaretha Dreßel (1707-1767). Johann Jacob Bischoff and Anna Margaretha Dreßel married on 31 Jan 1729 in Sonneberg, and from 1729 until 1749 they had 11 children (5 sons and 6 daughters). Johann Paul was the second son.

Bischoff served almost entire his life as a civil clerk (Kriegs- und Domänenrat, adviser in matters of war and the land) in the court of the Margrave Karl Alexander of Brandenburg-Ansbach in Ansbach, Bavaria. He was something like an Architect and Planning Director of the Court. To the present time are standing several buildings in Ansbach, designed by Bischoff, as between them is the own house of Bischoff (see the nearby image), built in 1799/1800 (Feuchtwanger Straße 1), a hospital from 1805 (Kronacher Straße 8), and a dairy farm, that was built in 1795/96 (Steingruberstraße 2).

Johann Bischoff married Anna Barbara Bauersachs (1738-1787) on 11 July 1758, in Sonneberg. The couple had 7 children—3 sons and 4 daughters.

Johann Paul Bischoff died on 14 April 1811, in Sonneberg.