Beschreibung:

PASCAL, Blaise (1623-1662). Traitez de l'equilibre des liqueurs, et de la pesanteur de la masse de l'air . Edited by Florin Prier. Paris: Guillaume Desprez, 1663. 12 o (144 x 82 mm). Two folding engraved plates, one woodcut text illustration. (The plates each with a small repaired tear, light uniform browning.) Contemporary calf (rebacked), mottled edges. Provenance : 18th-century library note "no. 494. [?]21 vol" on front pastedown, 2 or 3 small corrections to punctuation. FIRST EDITION OF "A CLASSIC OF SEVENTEENTH-CENTURY SCIENCE" (DSB), in which Pascal decisively refuted the Aristotelian theory that "nature abhors a vacuum". In the Traits , completed in 1654 but unpublished until a year after his death, Pascal distilled the results of his own previous work in hydrostatics and the problem of the vacuum, as well as the mass of information recently accumulated by other scientists -- Galileo, the Pre Mersenne, Stevin, and Torricelli. This short but significant book contains two closely related treatises, on fluid mechanics and on the various effects of the weight of air, the first of which includes the first published statement of the basic hydrostatic axiom known as "Pascal's Law", which states that the pressure exerted on a liquid at rest is transmitted undiminished in all directions and that it acts upon the liquid at right angles. The second treatise shows, inter alia , that air pressure accounts for several phenomena traditionally attributed to the "horror vacui," and outlines for the first time the relationship of weather and barometric change. To these the editor Florin Prier, Pascal's brother-in-law and collaborator, appended several related reports and fragments: Pascal's 1648 report of the famous Puy de Dme experiment, in which Prier, under Pascal's direction, demonstrated the weight of air by carrying the new Torricellian barometer to the top of that mountain and watching the mercury fall; one of two surviving fragments of a major treatise on the vacuum written in the early 1650s; and an account of Robert Boyle's experiments and observations on the same subject. Prier's biographical preface contains interesting anecdotes of Pascal's prodigious youth. The long delay in publication of the Traits substantially diminished their timeliness, for in the nine years that the manuscript remained unpublished the work of Otto von Guericke and Robert Boyle had radically altered scientific knowledge of air-pressure and the vacuum. Pascal's little work remained important, however, for the clarity with which he formulated the basic principles of the science and for his lucid exposiiton of the "fundamental concept of pressure" (DSB). Dibner Heralds of Science 143; En franais dans le text 101; Norman 1650; Roberts & Trent Bibliotheca Mechanica pp. 246-247; Sparrow Milestones of Science 157; Tchemerzine V, 59.