Encke

(en´ke), Johann Franz, German astronomer, born at Hamburg in 1791, died in 1865. He studied under the astronomer Gau at Göttingen. During the War of Liberation (1813-5) he served as artillerist in the German army, and after the peace became a istant in the observatory of Seeberg, near Gotha. Here he calculated the orbit of the comet observed by Me chain, Mi Herschel, and Pons, predicted its return, and detected a gradual acceleration of movement, ascribed by him to the presence of a resisting medium. The comet is now known as Encke's comet. The fame of his works Die Entfernung der Sonne (The Distance of the Sun) and Der Venusdurchgang von 1769 (Transit of Venus of 1769) led to his appointment as director of the Berlin Observatory (1825), a position which he held till his death. From 1830 he edited the Berliner A str ono misc hes Jahrbuch .