Primus[--Tertius] tractatus

3 vol. in one., FIRST EDITIONS, pp[32],303, [1] – [16], 215, [1]-[16],106, [2], woodcut armillary sphere printers device to titles, woodcut inhabited initials, 17 folding tables, 2 large celestial maps, occasional light browning, small tear to P5 without loss, early limp vellum, manuscript title on spine, hinges repaired, 8vo, Wittenberg: J. Kraft, 1563-1565-1565

First editions of these extremely rare astronomical treatises, with the two celestial maps which are virtually unknown. The two maps of the stars and constellations of the northern and southern hemispheres, are derived from the Honter charts of 1532: Hemisphaerum boreale xxi. asterismorum cum xxi. dodecatemoriis and Hemisphaerum australe, cum xii. Dodecatemoriis., which they closely copy. There are a couple of minor additions, notably the “Coma Berenices” in the northern hemisphere. Both charts are dedicated to contemporary astronomer Adam Gefugius of Vellendorph, and the first chart is dated 1565. Warner, in The Sky Explored, p.92, records the northern hemisphere chart only, which she wrongly attributes to the dedicatee Grefugius. She mentions “There may well have been a southern mate”.

Johannes Garcaeus (1530-1575) was a German astronomer, mathematician, meteorologist and astrologer who studied at Wittenberg. As a primarily astrological work, Garcaeus uses Copernicus’ numbers to get the celestial positions of the planets but omits Copernicus’ heliocentric system. According to Owen Gingerich, in The Eye of Heaven, it was common for 16th-century astronomers to reference Copernicus in their work while heliocentrism is rarely discussed. Garcaeus is an important early example of this phenomenon.

Despite being put on the Papal Index of Banned works, this book made Garcaeus famous in certain circles.

Extremely rare, with maps.

[Gingerich, Eye of Heaven, p.294; Zinner 2306, 2366, 2367;Houzeau and Lancaster 2623-5; Lalande p.90; VD16 G464-466]