Pitiscus was born to poor parents in Grünberg (Zielona Góra) in Lower Silesia, the part of Austrian-ruled Duchy of Glogau (Głogów). He studied theology in Zerbst and Heidelberg. A Calvinist, he was appointed to teach the ten year-old Frederick IV, Elector Palatine of the Rhine, by Frederick's Calvinist uncle Johann Casimir of Simmern, as Frederick's father had died in 1583. Pitiscus was subsequently appointed court chaplain at Breslau (Wrocław) and court preacher to Frederick. Pitiscus supported Frederick's subsequent measures against the Roman Catholic Church.
Pitiscus achieved fame with his influential work written in Latin, called Trigonometria: sive de solutione triangulorum tractatus brevis et perspicuus (1595, first edition printed in Heidelberg), which introduced the word "trigonometry" to the English and French languages, translations of which had appeared in 1614 and 1619, respectively. It consists of five books on plane and spherical trigonometry. Pitiscus is sometimes credited with inventing the decimal point, the symbol separating integers from decimal fractions, which appears in his trigonometrical tables and was subsequently accepted by John Napier in his logarithmic papers (1614 and 1619).
The classical scholar Samuel Pitiscus (1637-1727) was his nephew.
- Groundbreaking Scientific Experiments, Inventions, and Discoveries
- http://locomat.loria.fr contains a reconstruction of Pitiscus' tables.
- S. Gottwald, H.-J. Ilgauds, K.-H. Schlote (Hrsg.): Lexikon bedeutender Mathematiker. Verlag Harri Thun, Frankfurt a. M. 1990 ISBN 3-8171-1164-9
- Biography MacTutor History of Mathematics archive
- Allgemeine Deutsche Biographie de:s:ADB:Pitiscus, Bartholomaeus