The New International Encyclopædia/Bessel, Friedrich Wilhelm

BESSEL, (1784–1846). An eminent German astronomer. He was born at Minden. Though destined by his father for a commercial life, he exhibited at a very early age an unconquerable fondness for astronomy. Though he yielded to his father's wishes and entered a mercantile house in Bremen, he worked continually at astronomy, and it was not long before it became evident that no career but that

of an astronomer would suit him. His undivided attention once turned to science, he achieved speedy success. In 1810 he was director of the observatory at Königsberg and professor of astronomy. In 1818 he published his Fundamenta Astronomiæ, a work which marks an epoch in the progress of astronomy, and in 1830 his Tabulæ Regiomontanæ. His important contributions are too numerous to mention here. The most startling was perhaps his determination of the parallax of 61 Cygni. By this remarkable achievement, which was the first measurement of a star's distance from the solar system, Bessel inaugurated a new era in sidereal science. It is not too much to say that Bessel was the father of modern observational astronomy, and there is scarcely a department of this science that was not improved or perfected by him; and in mathematical astronomy his work was almost equally important. Among other achievements, he was one of the first (1823) scientifically to consider the personal equation of observers.