Kepler, Johannes

folio (369 x 235mm.), blank leaf after title-page and at end, folding letterpress table, woodcut initials, head- and tailpieces, woodcut diagrams, contemporary manuscript table on rear flyleaf headed "Expositio verborum astrologicorum", contemporary reversed calf, blind triple fillet border, in modern calf-backed box with morocco lettering-pieces, without the engraved portrait, table slightly torn without loss, first few leaves frayed at edges, slight damp-staining and worming in margins, binding repaired at corners and ends of spine, binding slightly soiled

Jo. Winstanley, seventeenth-century inscription at head of title-page

Caspar 31; Norman 1206; PMM 112; VD17 23:000587W; Zinner 4237

Condition is described in the main body of the cataloguing, where appropriate
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

FIRST EDITION of Kepler's masterpiece of modern astronomy, boldy entitled The New Astronomy. Here Kepler describes his first two laws of planetary motion, in which the orbits of planets are shown to be elliptic rather than circular, demonstrated by his calculations of the orbit of Mars, and the law of equal areas, which shows that the planets move faster when they are closer to the sun. Its influence on other great astronomers, from his contemporary Galileo to the later Newton, was substantial and enabled Newton to form his own laws of motion and universal gravitation. Kepler's and Newton's laws became the basis of celestial mechanics.

Kepler, a student of the "cautious Copernican" Michael Maestlin in Tübingen, used Copernicus's theory of heliocentrism as the basis for his treatise, and combined it with the observational accuracy of Tycho Brahe, whose calculations he acquired through his post as imperial mathematician to Rudolf II, following Tycho's death in Prague in 1601. Disagreement with Tycho's heirs led to delays with the publication which only commenced in the summer of 1608, once Tycho's son-in-law, Franz Tengnagel, was able to add a note to the reader regarding Kepler's deviance from Tycho's calculations. The publication was supposed to be distributed privately by the Emperor, but Kepler sold some copies to the printer in an attempt to recoup some of his salary which was in arrears.