Traité de l'équilibre des liqueurs, et de la pesanteur de la masse de l'air

12mo of (14) ff., 232 pp., (4) ff. and 2 folding plates.

Green morocco Jansenist binding, raised bands on spine, gilt inner dentelle, double gilt fillet on edges, gilt edges over marbling. Cuzin.

142 x 82 mm.

It is adorned with 2 large folding plates illustrating Pascal’s various experiments. (245 x 170; 235 x 170 mm).

"The relationship between barometric changes and changes in the weather was first outlined here" (Dibner Heralds).

First edition of Pascal's Treatise on the Equilibrium of Liquids.

Paris 1663.

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Pascal, Blaise. Treatise on the Equilibrium of Liquids, and on the Weight of the Mass of Air.

Paris, Guillaume Desprez, 1663.

First edition of the foundational treatise on the principles of hydrostatics.

Tchemerzine, V, 59; Dibner Heralds ("The relationship between barometric changes and changes in the weather was first outlined here"); Sparrow Milestones of Science, 157; Waller, 12161; Norman, 1650; DSB X, 330.

“In 1638, the fountain workers of the Duke of Florence, wishing to raise water to more than 32 feet high (10.4 m) by means of a suction pump, found that the water could rise no higher than 31 feet. They consulted Galileo. All of Aristotelian antiquity had said that water rose in pumps because nature abhors a vacuum. Galileo, while doubting this assertion, could not find an answer and tasked his disciple Torricelli (1608-1647) to investigate the matter further. Torricelli conceived the idea of replacing the water with quicksilver (mercury), which was 14 times denser, and anticipated that the liquid would rise less high. The experiment was verified by Viviani in 1643. Torricelli then thought that only atmospheric pressure could raise the mercury in the tube.”

These experiments were followed with great interest by Pascal. He recorded his first results in a small book published in 1647, New Experiments on the Vacuum, where he clearly proved that all the effects previously attributed to the “horror of the vacuum” are caused by the weight of air. He had many detractors. So, he decided on an experiment that would be decisive.

The great experiment on the equilibrium of liquids was conducted at the Puy de Dôme on September 19, 1643, and entrusted to Florin Périer, Pascal’s brother-in-law.The latter proved irrefutably that the height of the mercury suspended in Torricelli’s tube could vary with altitude. It follows, said Pascal, that the weight and pressure of air are the only cause of the suspension of mercury, not the horror of the vacuum, and that, on the contrary, nature adapts very well to the vacuum.

Pascal generalized all these results by formulating the principles of hydrostatics, which would be recorded in theTreatises on the Equilibrium of Liquids and the Weight of the Mass of Air.

This collection was published in 1663, a year after Pascal’s death. The experiments of Pascal and Torricelli had the great merit of proving not only the experience of atmospheric pressure, but also the existence of a vacuum—a vacuum that would play such an important role in modern physics.”

The last copy bound by Cuzin, in brown morocco, was sold for €7,500 on November 15, 2007 (Ref. Livres Précieux, Cat. XXXIV, n°38).