De Cometis Libelli Tres. I. Astronomicus...II. Physicus...III. Astrologicus de KEPLER, Johannes

Two folding woodcut plates, three folding printed tables (plus two in duplicate), & several woodcuts in the text. 4 p.l., 138 pp., one blank leaf. 4to, antique 18th-century style calf-backed boards. Augsburg: Typis A. Apergeri, sumptibus S. Mylii, 1619-[20]. First edition, and a very good copy of a rare book; it contains the second observation of Halley's comet. In this work, Kepler "discussed in detail the bright comets of 1607 and 1618. Reflecting on the ephemeral nature of comets, he proposed a strictly rectilinear trajectory, which of course appeared more complex because of the earth's motion. Some decades later Edmond Halley made extensive use of the observations recorded in this book when he showed the seventy-six year periodicity of the comet of 1607. The brief second section of Kepler's trilogy concerned the 'physiology of comets': they fill the ether as fish fill the sea but are dissipated by the sun's light, forming the tail that points away from the sun. The final section treated the significations of the comets."-D.S.B., VII, p. 302. Nice large copy with some uncut leaves and without the usual heavy browning. Stamp of the "K[öniglich] K[aiserliche] Universitätsbibliothek," Vienna, to several leaves, including versos of most tables and with the Library's duplicate or release stamp superimposed. One diagram with an old repair. ❧ Caspar 60. Cinti 65. Zinner 4739.