GALILEI, Galileo. Discorso al serenissimo Don Cosimo Il Gran Duca di Toscana intorno alle cose, che stanno in s l'acqua, che in quella si muovono. Florence: Cosimo Giunti, 1612.
4o (187 x 142 mm). Italic type, revised passages in roman type, woodcut of Medici arms on title, 14 woodcut text diagrams, printer's large woodcut device on recto of I6, woodcut initials. (Most running titles and pagination trimmed.) Modern leather-backed boards (some rubbing); cloth folding case. Provenance: Andrew Fletcher of Saltoun (1655-1716), Scottish bibliophile, author of political works, and member of parliament (signature on title and inside of lower cover).
FIRST EDITION of Galileo's important treatise on hydrostatics, constituting his first direct attack on Aristotelian science. Written in the context of an ongoing dispute on the nature of buoyancy between Galileo and a group of pro-Aristotelian Pisan professors led by the Florentine philosopher Ludovico delle Colombe, the Discourse on Bodies in Water represented an attempt by Galileo to transfer the dispute from a narrowly focussed and even ad hominem line of argument to a more general and systematic approach. In it Galileo refuted the Aristotelian view that a solid body's ability to float is a function of its shape, demonstrating instead the truth of the Archimedean principle that flotation depends on the relative densities of the floating body and the fluid. Galileo greatly extended the scope of Archimedes' propositions by applying the concept of momento and the principle of virtual velocities. "The views on buoyancy of both the Aristotelians and Galileo were closely tied to their more general views about motion, causality, the structure of the cosmos, and mathematics' place in it. Galileo strove to make sure that his theory would be perceived as having fundamental cosmological implications as well as dynamical dimensions" (Biagiolo, p. 193). In fact, in the Discourse on Bodies in Water Galileo first presented the "core of a more general theory of sublunary motion" (op. cit., p. 185). The work also contains the earliest announcements of some of Galileo's astronomical discoveries: sunspots, the rings of Saturn, and the phases of Venus. This copy includes the rare extra half sheets, with 3 Italian sonnets and a note to the reader. M. Biagioli, Galileo Courtier (Chicago, 1993), chapter 3, passim; Carli and Favaro 47; Cinti 34; Norman 856; Riccardi I, 509.