SCHRöTER, JOHANN HIERONYMUS

(b Erfurt, Germany, 30 August 1745; d Erfurt, 29 August 1816)

astronomy.

Schröter studied law at Göttingen but also attended lectures in mathematics, physics, and astronomy, the last under Kästner. Upon completing his law studies he was appointed junior barrister in Hannover. Through his appreciation of music he met the Herschel family, who revived his interest in astronomy. In 1781 he became chief magistrate at Lilientha, a post that left him free time to devote to astronomy. With the aid of the optician J. G. Schrader he built and equipped an observatory that subsequently became world-famous for the excellence of the instruments. Some were made in his own workshop: others he bought from Herschel, the latter including a reflector with a twenty-seven-foot focal length, the largest on the Continent. George III of England enabled Schröter to continue his astronomical work by buying all of his instruments, with the stipulation that they remain in Schröter’s possession untill his death, when they would become the property of the University of Göttingen. Schröter was also awarded a grant to hire an assistant. K. L. Harding and , later F. W. Bessel were among those who held the post.

For theirty years the observatory at Lilienthal was a center of astronomical research and was visited by foreign astronomers. On 21 September 1800 it was the site of the congress organized to search the space between Mars and Jupiter for a planetary body.

Lilienthal was occupied during the Napoleonic Wars by the French, who looted and party destroyed the observatory, although most of the instruments were saved. In the ensuing fire Schröter lost all copies of his own works, which he had published himself. He returned to Erfurt and built a new observatory, but his health failed and he did little observing. He died soon afterward.

Schröter was the first to observe the surface of the moon and the planets systematically over a long period. He made hundreds of drawings oflunar mountains and other features, and discovered and named the luner rills. Unfortunately, his drawings were rough; and the standard of the images obtainable with the large reflectors was soon greatly improved by the refractors from the Munich workshops. Selenotopographiche Fragmente zurgenauern Kenntniss der Mondfläche was published at Lilienthal in 1791–1802. His observations of Venus appeared in Aphroditographische Fragemente... (Helmstedt, 1796), in which he estimated a rotation period of twenty-three hours and twenty-one minutes. He also thought that he observed mountains on the surface of Venus. In other works he noted lines on Mars (but did not call them canals). and he thought that the ring of Saturn was a solid body.

Schröter’s reputation has been damaged by the many extravagant conclusions he drew from his observations. It may well be that his lasting influence on astronomy lies in the fact that he enabled Bessel and Harding to work in astronomy and that the selenographer J.F.J.Schmidt acquired his life long interest in the moon after he had read a copy of Schröter’s work.

BIBLIOGRAPHY

A list of Schröter’s publications can be found in Pogendorff, II, 846–847.

Secondary literature includes H-B. Brenske, “Johann Hieronymus Schröter, der Amateurastronom von Lilienthal,” in Walter STein, ed., Von Bremer Astronomen und Sternfreunden (Bremen, 1958), 64–74: Gunther’s article on Schröter in Allgemeine deutsche Biographie, XXXII, 570–572; and Dieter B. Hermann, “Johann Hieronymus schröter im Urtel seiner Zeit.” in sterne, 41 (1965), 136–143.

Lettie S. Multhauf