BERNHARD

WALTHER (1430-15o4)  , German astronomer, was born at Nuremberg in 1430 . He was a man of large means, which he devoted to scientific pursuits . When Regiomontanus (q.v.) settled at Nuremberg in 1471, Walther built for their common use an observatory at which in 1484 clocks driven by weights were first used in astronomical determinations . He further brought into prominence the effects of refraction in altering the apparent places of the heavenly bodies, and substituted Venus for the moon as a connecting-link between observations of the sun and stars . Walther established a printing-press, from which some of the earliest editions of astronomical works were issued . His observations, begun in 1475 and continued until his death in May 1504, were published by J . Schoner in 1544, and by W . Snell in 1618, as an appendix to his Observationes Hassiaceae . See J . G . Doppelmayr, Hist . Nachricht von den niirnbergischen Mathematicis, p .

23 (1730); G . A . Will, Nurnbergisches Gelehrten-Lexikon, vii . 381 (1806); J . F .

Montucla,Hist. des mathematiques, i . 546; J . S . Bailly, Hist. de Paste. moderne, i . 319; E . F . Apelt, Die Reformation der Sternkunde, p .

54; J . P. von Wurzelbaur, Uranies Noricae basis astronomica (1719) ; J . F . Weidler, Hist.astronomiae, p . 322; A . G . Kastner, Geschichte der Mathematik, ii . 324; Mitteilungen des Vereins

fur Gesch. der Stadt Nurnberg, vii . 237 (1888) (H . Petz) ; R . Wolf, Gesch. der Astr. p . 92, &e .