GALILEI, Galileo (1564-1642). Le operazioni del compasso geometrico, et militare. Padua: in the house of the author by Pietro Marinelli, 1606. [Bound with:] Galileo GALILEI. Difesa contro alle calunnie & imposture di Baldessare Capra. Venice: Tomaso Baglioni, 1607.
2 works in one volume, 4° (246 x 170mm). Woodcut device on titles and at end of second work, woodcut diagrams and initials, second work with final blank. (Tiny tear at top gutter of A1 in first work and small repair to margin of H1 in second work, a few leaves with faint dampstaining, somewhat heavier in second work.) Contemporary calf, single fillet border, author's name and title in gilt, gilt edges (spine chipped at foot, joints cracked, a few tiny wormholes, a little rubbed, front pastedown renewed); modern box. Provenance: Samuel Verplanck Hoffman (1866-1942, astronomer; bookplate; sold, Christie’s London, 12 November 1975, lot 51, £9,000 to Perman) — [sold, Sotheby’s London, 27 September 1988, lot 187].
EXTRAORDINARILY RARE FIRST EDITION OF GALILEO'S FIRST PRINTED WORK AND THE FIRST PUBLISHED WORK ON AN ANALOGUE CALCULATOR. Privately issued in an edition of only 60 copies for presentation to patrons and buyers of the compass, Galileo may have issued the Operazioni del compasso in order to establish his sole priority as the inventor of the ‘geometrical and military compass’ or sector, a calculating and observation device that he had begun manufacturing in 1597. It was based on the proportional compass, an instrument first developed by Commandino prior to 1568, but Galileo's version included numerous additions and improvements that rendered it the most useful mathematical instrument of its period and even beyond a calculating device: Galileo's compass remained unsurpassed until the advent of the slide rule in the mid-19th-century. The success and popularity of Galileo's instrument naturally made it attractive to imitators, and Galileo deliberately omitted any illustration of the compass in his treatise as a deterrent to unauthorized copying. Nevertheless, Galileo's design was copied, most notably by Baldassare Capra, who published a work entitled Usus et fabrica circini cuiusdam proportionis (1607) claiming that he himself was the inventor of the compass, and accusing Galileo of plagiarism. Galileo took legal action against Capra and won: all copies of Capra's book were suppressed, and Galileo published the present Difesa contro alle calunnie & imposture di Baldessare Capra (1607), exonerating himself in the affair. Galileo's compass consisted of a pointed sector, made from a pair of pivoted arms, which could be converted to an observation instrument by the addition of a quadrant. The front faces of the arms were engraved with a scale of logarithmically based ‘lines of numbers’ by which an operator could compute the results of any arithmetical multiplication or division to within an accuracy of 0.1. Supplementary scales, including squares, cubes, roots, and densities of metals and stones, were also added. Historian of science Stillman Drake, author of the definitive modern translation of Operazioni del compasso, noted how Galileo's compass revolutionized and democratized practical mathematics in the same way that the pocket calculator has done in our own time. Galileo kept producing compasses until at least 1610, and this treatise of the compass was reprinted several times during his lifetime. At the very end of his life, Galileo finally authorized a large engraving illustrating his invention (included in the 1640 edition of the Operazioni del compasso), thereby ending the virtual monopoly on its manufacture that he had been careful to preserve. Samuel Verplanck Hoffman studied and taught astronomy at the Johns Hopkins University, he was a collector of astrolabes and a member of the New York Historical Society; one of his most prized possessions was the astrolabe used by Samuel de Champlain on his early American explorations. According to ABPC/RBH ONLY 3 OTHER COPIES HAVE SOLD AT AUCTION IN THE LAST 30 YEARS. Owen Gingerich confirmed the authenticity of the present copy in an email dated 30 May 2006 accompanying the work. Bedini, Science and Instruments in Seventeenth-Century Italy I, pp. 262-68; Carli and Favaro 23; Cinti 16; not in Dibner Heralds or Norman.