Encyclopædia Britannica, Ninth Edition/Regiomontanus

REGIOMONTANUS (1436-1476). The real name of this astronomer was, but from his birthplace, Königsberg, a small town in Franconia, he called himself. The name Regiomontanus occur for the first time on the title page of his Scripta, published in 1544, but he has since become best known by it. He was born in June 1436 and became the pupil of Purbach at the university of Vienna, and jointly with him endeavoured, with such imperfect instruments as they could onstruct, to test the accuracy of the Alphonsine tables of the motions of the planets. After Purbach's death Regiomontanus finished and published his Epitome in Ptolemæi Almagestum, but, having in the meantime become acquainted with Cardinal Bessarion, who was anxious to spread the knowledge of the Greek literature among the Western nations, he proceeded with him to Italy in 1462, and for the following eight years devoted a great deal of time to the study of the Greek language and to collecting

Greek manuscripts. He returned from Italy in 1471 and settled at Nuremberg, at that time one of the chief centres of German industry and literary life. Here he became associated with Bernhard Walther (1430-1504), a wealthy patrician and an enthusiastic astronomer. An observatory was erected, and the finest instruments the skilful artisans of Nuremberg could make were regularly used by the two friends for observing the heavens. Clocks driven by weights were here used for the first time for scientific purposes, the influence of refraction in altering the apparent places of the stars better appreciated, Venus substituted for the moon as a connecting link between observations of the sun and of stars, and other improvements introduced in practical astronomy. Regiomontanus also published a number of calendars and ephemerides, which induced Pope Sixtus IV. to summon him to Rome to assist in reforming the confused calendar. He died very shortly after his arrival in Rome, July 6, 1476.