GALILEI, Galileo (1564-1642). Discorso al serenissimo Don Cosimo Il Gran Duca di Toscana intorno alle cose, che stanno in s l'acqua, che in quella si muovono... Seconda editione. Florence: Cosimo Giunti, 1612.
4o (195 x 141 mm). Italic type, revised passages in roman type, woodcut of Medici arms on title, 15 woodcut text diagrams, printer's large woodcut device on recto of final leaf, woodcut initials. (Light foxing, waterstain to first 2 leaves, upper blank fore-corner of title-leaf torn away, larger piece torn from front fly-leaf, single small wormhole through second half, catching an occasional letter, paper flaw to C3r obscuring 9 or 10 letters.) Contemporary limp vellum.
Second edition, extensively revised, and with additional woodcuts, 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 discovieres: sunspots, the rings of Saturn, and the phases of Venus.
Galileo's challenge to orthodoxy raised a furor and the first edition, published earlier the same year, was quickly sold out. For the second edition Galileo expanded upon certain passages that he deemed unclear, without altering the original text, as explained in the publisher's preface. The additional passages are innovatively printed in a different typeface to facilitate identification. M. Biagioli, Galileo Courtier (Chicago, 1993), chapter 3, passim; Carli and Favaro 48; Cinti 35; Norman 856; Riccardi I, 509.