TYCHO

BRAHE (1546-1601)  , Danish astronomer, was born on the 14th of December 1546 at the family seat of Knudstrup in Scania, then a Danish province . Of noble family, he was early adopted by his uncle, Jorgen Brahe, who sent him, in April 1559, to study philosophy and rhetoric at Copenhagen . The punctual occurrence at the predicted time, August 21st, 1560, of a total solar eclipse led him to regard astronomy as " something divine "; he purchased the Ephemerides of Johann Stadius (3rd ed., 157o), and the works of Ptolemy in Latin, and gained some insight into the theory of the planets . Entered as a law-student at, the university of Leipzig in 1562, he nevertheless secretly pro8ecuted celestial studies, and began continuous observations with a globe, a pair of compasses and a "cross-staff." He quitted Leipzig on the 17th of May 1565, but his uncle dying a month later, he repaired to Wittenberg, and thence to Rostock, where, in 1566, he lost his nose in a duel, and substituted an artificial one made of a copper alloy . In 1569 he matriculated at Augsburg, and devoted himself to chemistry for two years (1570-1572) . On his return to Denmark, in 1571, he was permitted by his maternal uncle, Steno Belle, to instal a laboratory at his castle of Herritzvad, near Knudstrup; and there, on the 11th of November 1572, he caught sight of the famous " new star " in Cassiopeia . He diligently measured its position, and printed an account of his observations in a tract entitled De Nova Stella (Copenhagen, 1573), a facsimile of which was produced in 1901, as a tercentenary tribute to the author's memory . Tycho's marriage with a peasant-girl in 1573 somewhat strained his family relations . He delivered lectures in Copenhagen by royal command in 1574; and in 1575 travelled through Germany to Venice . The execution of his design to settle at Basel was, however, anticipated by the munificence of Frederick II., king of Denmark, who bestowed upon him for life the island of Hveen in the Sound, together with a pension of 500 thalers, a canonry in the cathedral of Roskilde, and the income of an estate in Norway . The first stone of the magnificent observatory of Uraniborg was laid on the 8th of August 1576; it received the finest procurable instrumental outfit; and was the scene, during twenty-one years, of Tycho's labours in systematically collecting materials—the first made available since the Alexandrian epoch—for the correction of astronomical theories . James VI. of Scotland, afterwards James I. of England, visited him at Uraniborg on the 20th of March 1590 .

But by that time his fortunes were on the wane; for Frederick II. died in 1588, and his successor,

Christian IV., was less tolerant of Tycho's arrogant and insubordinate behaviour . His pension and fief having been withdrawn, he sailed for Rostock in June 1597, and re-commenced observing before the close of the year, in the castle of Wandsbeck near Hamburg . He spent the following winter at Wittenberg, and reached Prague in June 1599, well assured of favour and protection from the emperor Rudolph II . That monarch, accordingly, assigned him the castle of Benatky for his residence, with a pension of 3000 florins; his great instruments were moved thither from Hveen, and Johannes Kepler joined him there in January 1600 . But this phase of renewed prosperity was brief . After eleven days' illness, Tycho Brahe died on the 24th of October 1601, at Benatky, and was buried in the Teynkirche, Prague . Tycho's principal work, entitled Astronomiae Instauratae Progymnasmata (2 vols., Prague, 1602—1603) was edited by Kepler . The first volume treated of'the motions of the sun and moon, and gave the places of 777 fixed stars (this number was increased to 1005 by Kepler in 1627 int.he " Rudolphine Tables ") . The second, which had been privately printed at Uraniborg in 1588 with the heading De Mundi Aetherei recentioribus Phaenomenis, was mainly concerned with the comet of 1577, demonstrated by Tycho from its insensible parallax to be no terrestrial exhalation, as commonly supposed, but a body traversing planetary space . It included, besides, an account of the Tychonic plan of the cosmos, in which a via media was sought between the Ptolemaic and Copernican systems . The earth retained. its immobility; but the five planets were made to revolve round the sun, which, with its entire cortege, annually circuited the earth, the sphere of the fixed stars performing meanwhile, as of old, its all-inclusive diurnal rotation (see ASTRONOMY: History) . Under the heading Astronomiae Instauratae Mechanica, Tycho published at Wandsbeck, in 1598, a description of his instruments, together with an autobiographical account of his career and discoveries, including the memorable one of the moon's " variation " (see MooN) .

The

book was reprinted at Nuremberg in 1602 (cf . Hasselberg, Vierteljahrsschrift Astr . Ges. xxxix. iii . 18o) . His Epistolae Astronomicae, printed at Uraniborg in 1596 with a portrait engraved by Geyn of Amsterdam in 1586, were embodied in a complete edition of his works issued at Frankfort in 1648 . Tycho vastly improved the art of astronomical observation . He constructed a table of refractions, allowed for instrumental inaccuracies, and eliminated by averaging accidental errors . He, moreover, corrected the received value of nearly every astronomical quantity; but the theoretical purpose towards which his practical reform was directed, was foiled by his premature death . See J . L . E . Dreyer's Tycho Brahe (Edinburgh, 1890), which gives full and authentic information regarding his life and work .

Also Gassendi's Vita (

Paris, .1654); Lebensbeschreibung, collected from various Danish sources, and translated into German by Philander von der Weistritz (Copenhagen and Leipzig, 1756) ; Tyge Brahe, by F . R . Friis (Copenhagen, 1871); Prager Tychoniana, collected by Dr F . I . Studnicka (Prague, 1901), a description of the scanty Tychonian relics which survived the Thirty Years' War and are still preserved at Prague . (A . M .