Hungarian-born astronomer and traveler. In his youth, moved to Vienna, where he became an astronomer at the observatory of the Company of Jesus. In 1751, took his vows, later becoming professor of astronomy at the College of Clausenburg in Transylvania. In 1768, journeyed to Lapland to observe the transit of Venus across the Sun. His observations proved to be among the fullest made by the scientists who traveled across the globe that year to study the event.