Jesuit astronomer, born Schemnitz, Hungary, 1720; died Vienna, Austria, 1792, where he directed the Imperial Observatory. At the request of the King of Denmark he made observations of the transit of Venus of 1769 at Vardohuus, Norway, which owing to a delay in publication were considered forgeries. Later research proved this charge false. He published a valuable annual astronomical review for over 30 years, and wrote several astronomical works.