Johannes Praetorius
, Also called Johann Richter Johannes Praetorius, (* 1537 in Jáchymov, † October 27, 1616 in Altdorf bei Nürnberg ) was a German mathematician, astronomer and instrument maker.
Life
About his early life nothing is known, from 1557 he studied at the University of Wittenberg and earned a degree in liberal arts ( this included rhetoric, grammar, arithmetic, geometry, music, astronomy, and logic ) from. From 1562 to 1569 he lived in Nuremberg. There, he designed a series of astronomical and mathematical instruments, which are now preserved in the Germanic National Museum in Nuremberg. He is considered the inventor of the measuring table, an auxiliary for graphic solution of surveying.
After living in Prague, Vienna, Krakow 1571 he followed a call from the University of Wittenberg and professor of higher mathematics ( astronomy) at the University of Wittenberg was appointed. He buys here on March 4, 1572 the academic degree of Master of philosophical sciences and is received in the Senate of the Faculty of Arts on March 7, 1572. During this time he made Valentinus Otho attention to the work of Joachim Rheticus trigonometric and published his observations of the visible in the constellation Cassiopeia, comet ( De cometis ).
For political reasons, he had to vacate the chair in 1575, but received about his brother Paul Praetorius in the winter semester 1576/77, a mathematics professor at the University of Altdorf. The invention of the measuring table ( Mensula or tab Praetoriana ) is attributed to him, it is not secured, however. Lived in Altdorf, and he worked until his death in 1616. His disciple Peter Saxonius was successor to his chair.
Works
- De cometis, qui antea visi sunt, et de eo, qui mense nouvissime novembri apparuit, narratio. Nuremberg: Gerlach & Montanus 1578
- Problema, quod ex iubet qvatvor rectis lineis Datis qvadrilaterum fieri, quod sit in circulo, aliquot modis explicatum. Nuremberg: Valentin Fuhrmann 1598