“ WALTHER, BERNHARD (1430-1504) , 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. ”