Inventio theorematis nobilissimi cujus consequentia necessario demonstrat lineam circularem rectae symmetram in natura extare & idèo illam huic aequalem dari posse [...]

4to (190x149mm). [6] leaves. Collation: A⁴ B². With a woodcut diagram in the text. Unbound.

Rare first edition of this geometrical treatise by the great Danish Astronomer Christen Sørensen Severin, better known as Longomontanus from the name of his hometown, Longborg in Jutland. “Severin was the son of Søren Poulsen and Maren Christensdatter, both of whom were humble peasants. Finding education an uncertain and intermittent luxury, especially after the early death of his father, Severin did not complete his basic education until 1588. At that time he entered the service of Tycho Brahe and stayed with him until 1597, when Tycho left Denmark. After his Wanderjahre in Germany, Severin received the M.A. at the University of Rostock and then returned home to begin his career. By 1607 he was professor of mathematics and astronomy at the University of Copenhagen, where he remained until his death. When Tycho died in 1601, his program for the restoration of astronomy was unfinished. The observational aspects were complete, but two important tasks remained: the selection and integration of the data into accounts of the motions of the planets, and the presentation of the results of the entire program in the form of a systematic treatise. Severin, Tycho's sole disciple, assumed the responsibility and fulfilled both tasks in his voluminous Astronomia danica (Amsterdam, 1622). Regarded as the testament of Tycho, the work was eagerly received and quickly won a place in seventeenth-century astronomical literature. Even after the appearance of Kepler's Tabulae Rudolphinae (1627), a rival work that bore the imprimatur of Tycho, Severin's Astronomia danica retained sufficient prestige (despite its staidness) to warrant reprinting in 1640 and 1663 […] His other major works are Cyclometria ex lunulis reciproce demonstrata (Copenhagen, 1612), Inventio quadraturae circuli (Copenhagen, 1634), and Introductio in theatrum astronomicum (Copenhagen, 1639)” (D.S.B., XII, p. 332).

OCLC, 761308353; Catalogue of the Crawford Library of the Royal Observatory Edinburgh, Ibi, 1890, p. 286.

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