Jowin Bystrzycki (1737-1821)
Court astronomer of King Stanisław August. He made the gnomonic dial of the sundial which stands on the South Terrace of the Palace on the Isle.
He began his education in Drohiczyn, and later joined the Jesuit Order. He studied in Vilnius and Warsaw. That was where he attained knowledge in Mathematics, Philosophy and Astronomy. He also studied Theology. However, he was not able to take his vows, because in 1773, the Pope suppressed the Society of Jesus under the pressure of its opponents. Subsequently, Bystrzycki arrived at the court of Stanisław August. In the span of two years, he organised an astronomical observatory; he was also interested in meteorology. In 1791, he became member of the Mannheim Academy of Sciences. In 1820, he was nominated a bishop, but died before taking vows.