Mathematician and astronomer, he began working for Homann Heirs (for whom he created maps of Germany and Poland, including for “Major Atlas Scholasticus”) in 1746. In 1749 Homann Heirs published his map of the moon – the first with accurately measured craters. A crater on the moon is named after him. He received his C. P. S. C. M. G. (Cum Privilegio Sacræ Cæsaræ Majestatis Gratia) some time after 1749. He moved to Gottingen in 1751 to become a professor of mathematics. In 1765 he was co-winner of a prize for discovering a means of measuring longitude while at sea. Died Gottingen, Germany.