Biography of Johann Paul Bischoff
Johann Paul Bischoff was born on 20th of 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 31.1.1729 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 Markgrave Karl Alexander of Brandenburg-Ansbach in Ansbach, Bavaria. He was something like an Architect and Planning Director of the Court. To the present survived several buildings in Ansbach, designed by Bischoff, between them is the own house of Bischoff, built in 1799 (see the nearby image) and a dairy farm, built in 1795-1796 (see the lower image).
The the dairy farm, built by Bischoff
After spending more than 16 years in collecting information (from 1788), in 1804 Bischoff finished a 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 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 in 1990 (Versuch einer Geschichte der Rechenmaschine (Attempt at a History of Calculating Machines), publisher: Systhema-Verlag, editor: Stephan Weiss).
From the end of 19th century, the manuscript was kept in the library of Technical University of Berlin. Part of this library was destroyed in a fire during the WWII (in 1943), the remaining part was carried away by Russian soldiers at end of the war. Thus the manuscript was lost. Only two undated transcripts from the beginning of 20th century survived to our time (may be 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 of some sheets most of them are lost. Only poor quality black and white photographs of all drawings, taken in the beginning of 20th century, survived to the present.
It is known that in the last quarter of the 18th century Bishoff has undertaken several long trips to take a look personally at the calculating machines and instruments, of which he had heard, in order to describe them in his book.
Johann Bischoff married to Anna Barbara Bauersachs (1738-1787) on 11th of July, 1758, in Sonneberg. The couple had 7 children—3 sons and 4 daughters.
Johann Paul Bischoff died on 14th of April, 1811, in Sonneberg.