GALILEI, Galileo (1564-1642). Discorsi e dimostrazioni matematiche, intorno due nuove scienze attenenti alla mecanica & i movimenti locali. Leiden: Elzevier Press, 1638.
4o (199 x 148 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. (Some light foxing, a few leaves a bit browned, occasional small inkstains.) Eighteenth-century vellum over pasteboard, title gilt lettered on spine and overcolored, edges red-sprinkled (later endpapers); morocco-backed folding case. Provenance: an unidentifed 18th-century Italian reader/owner: extensive manuscript exposition of a geometrical problem, with small diagram of cylindrical solids, following errata on final page and covering the recto of the following flyleaf (slightly cropped at fore-edge), marginal notes and diagram on the first page of the Appendix (p. 289), including translation of a term into Greek, and neat ink corrections to many of the errata; 18th-century ink ?shelfmark "38" on front cover.
FIRST EDITION OF THE FIRST MODERN TEXTBOOK OF PHYSICS AND THE FOUNDATION OF THE SCIENCE OF MECHANICS. Sentenced by the Inquisition to permanent house arrest in 1633, following the condemnation of the outspokenly pro-Copernican Dialogo sopre i due massimi sistemi del mondo in 1633, Galileo was coaxed out of severe depression by his old friend and supporter the Archbishop of Siena Ascanio Piccolomini, who urged him to take up his unfinished work on mechanics and bring it to a conclusion. The death of Galileo's eldest daughter Sister Maria Celeste in the spring of 1634 was another terrible blow; for several months Galileo was incapable of working. The book was finally completed by the middle of 1635, but publication was delayed by the search for a printer: failing in his attempt to obtain an ecclesiastical licence to print the work in Venice, Galileo was obliged to have the work printed by the Elzeviers in Leiden.
The mathematical analyses of the Discorsi provide the foundation for the philosophical exposition of the Dialogo and thus are generally considered to be Galileo's most important scientific contribution. The work is divided into four dialogues, between the interlocutors of the 1632 Dialogo. The first two contain the entirety of Galileo's work on the mechanics of materials, and constitute the first publication in the field of strength of materials. They treat "problems relating 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" (DSB). The last two dialogues are devoted to the mathematical science of motion, or kinematics, and deal with the treatment of uniform vs. accelerated motion and the discussion of parabolic trajectories. Galileo's Two New Sciences laid the foundation for modern physics, not only through his application of mathematics to the study of motion, but because in this work some of the most essential problems of physics were posed along with "suggestive discussions of their possible solutions" (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... Newton said he obtained the first two laws of motion from this book" (Dibner). Of equal import for the history of science was the working method that Galileo here set forth, "a combination of quantitative method with mathematical demonstration, which has remained the ideal method of the exact sciences" (Wolf, A History of Science and Technology).
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.