GALILEI, Galileo. Discorsi e dimostrazioni matematiche, intorno due nuove scienze attenenti alla mecanica & i movimenti locali. Leiden: Elzevier Press, 1638.
4^{o} (199 x 159 mm). Text of the dialogues in italic type, formal proofs in Roman type, errata leaf at end, printers' woodcut device on title, numerous woodcut illustrations and diagrams in text, letterpress tables, woodcut initials, head- and tailpiece. 18th-century Italian vellum-backed mottled boards (some light rubbing); quarter morocco folding case. Provenance: a few early marginalia, two slips with early ink corrections or additions pasted in at H2v, I2v.
FIRST EDITION OF THE FIRST MODERN TEXTBOOK OF PHYSICS AND THE FOUNDATION OF THE SCIENCE OF MECHANICS. Galilio's trial had left him "so crushed that his life had been feared for" (DSB). At the urgings of his friend and supporter the Archbishop of Siena, Ascanio Piccolomini, Galileo began to pull together his life's work in physics. Forbidden to publish in Florence or Rome by the Congregation of the Index, and unable to obtain an ecclesiastical licence to print the work in Venice, Galileo managed to have a manuscript copy smuggled out of Italy to France, from where it was brought to the Elzeviers in Holland.
The mathematical analyses of the Discorsi complement the philosophical discussion of the Dialogo, and Galileo retained the formal device of the dialogue with the same interlocutors. "The two new sciences with which the book principally deals are the engineering science of strength of materials and the mathematical science of kinematics... Of the four dialogues contained in the book, the last two are devoted to the treatment of uniform and accelerated motion and the discussion of parabolic trajectories. The first two deal with problems related to the constitution of matter; the nature of mathematics; the place of experiment and reason in science; the weight of air; the nature of sound; the speed of light; and other fragmentary comments on physics as a whole. Thus Galileo's Two New Sciences underlies modern physics not only because it contains the elements of the mathematical treatment of motion, but also because most of the problems that came rather quickly to be seen as problems amenable to physical experiment and mathematical analysis were gathered together in this book with suggestive discussions of their possible solution" (DSB). "The Aristotelian concept of motion was replaced by a new one of inertia and general principles were sought and found in the motion of falling bodies, projectiles and in the pendulum... The concept of mass was implied by Galileo's conviction that in a vacuum all bodies would fall with the same acceleration" (Dibner). "Mathematicians and physicists of the later seventeenth century, Isaac Newton among them, rightly supposed that Galileo had begun a new era in the science of mechanics. It was upon his foundations that Huygens, Newton and others were able to erect the frame of the science of dynamics, and to extend its range (with the concept of universal gravitation) to the heavenly bodies" (PMM). Carli and Favaro 162; Cinti 102; Dibner Heralds of Science 141; Grolier/Horblit 36; Norman 859; PMM 130; Riccardi I, 516.12/1; Roberts & Trent Bibliotheca Mechanica, pp. 129-30; Sparrow Milestones of Science 75; Wellcome 2648; Willems 2648.