Bartholomaeus Pitiscus

Bartholomaeus Pitiscus (1561 to 1613) was a German trigonometrist, astronomer and Calvinist theologian who coined the word trigonometry. His Trigonometria, printed with a work by Abraham Scultetus, introduced the word to English and French readers, and a standalone edition of 1608 added trigonometric tables. In 1613 he published the Thesaurus mathematicus, in which he improved the trigonometric tables of Georg Joachim Rheticus, work that depended on long hand calculation. He is also often credited with inventing the decimal point, the symbol that separates whole numbers from decimal fractions, which appears in his tables of 1612 and was accepted by John Napier. He served as court chaplain at Breslau and court preacher to the Elector Palatine Frederick IV.