kwebtransPreview
Open in TheBrain

Perier

Name: Florin Perier

Achievements: French lawyer who assisted Blaise Pascal in his barometric experiments

Born: 1605; Clermont-Ferrand, Auvergne, France

Died: 1672; Clermont-Ferrand, Auvergne, France. Aged 67

Field & Discipline: Science; Law; Physics; Lawyer; Physicist

Language: French

Father: Jean Perier

Mother: Unknown

Siblings: Jeanne Parrinet

Spouse: Gilberte Pascal (sister of Blaise Pascal; m. 1641; 1620-87)

Children: Marguerite (b. 1646); Etienne; Blaise; Louis (b. 1651)

Education: Unknown

Major Work:

The “Great Experiment” at the Puy de Dome, 1647

Life & Times:

In 1628 Perier was appointed as a councillor to the Court of Appeal of Clermont, France the same year he bought a small estate at nearby Bien-Assis. With the exception of periods spent at Rouen and Paris, Perier spent his entire life at Clermont in government and public service, and was best remembered after his death for his supervision of a water pipe-line between Royat and Clermont,  providing fresh water for the town.

In 1640 Perier moved to Rouen, where for two years he assisted Etienne Pascal, tax collector for Upper Normandy and the father of [brother-in-law of] Blaise Pascal*. In 1641 the close relationship between the families was cemented by the marriage of Perier and Etienne's elder daughter.  In 1644 to 1645, when Blaise Pascal was working on his calculating machine, Perier returned to Rouen to work again with Etienne.

In 1645 Perier returned to Clermont with his family, where he had been appointed as assessor to the Court of Customs and Excise, and in 1647, along with the Pascals, he became a follower of  [a follower of] Jansen*.

On 15 November 1647, at the height of the controversy over Pascal's “New Experiments Concerning Vacuums” (October 1647), Pascal wrote to Perier at Clermont-Ferrand, to ask him to prepare the definitive experiment, using a method based on that developed by [repeated experiment of] Torricelli* in 1644.

Florin shared Pascal's fascination with the natural sciences, lived not far from a mountain 1465 metres high (Puy de Dome), and Clermont was a glass-making center, so the instruments could be easily obtained. The aim of this experiment was to establish beyond any doubt that the vacuum which Pascal's earlier experiments in Rouen had shown to be theoretically possible really existed.  Pascal believed that this could be demonstrated by means of experiments at different altitudes. Because of  bad weather, delays in getting the necessary apparatus, and Perier's job, the experiments were delayed until September 1648.

Why Pascal himself did not travel to Auvergne to witness the "Great Experiment" is unclear, although the reason for his absence was probably health.

Early in the morning of 19 September, Perier assembled a group of scholars and functionaries of the city.  In the convent garden (now part of the Place de Jaude), he performed the experiment for the first time.

Perier first upended a glass tube filled with mercury into a dish of mercury.  Some of the mercury in the tube ran out and some remained as a column in the vertical tube.  In two identical test tubes Perier measured how far the mercury ran out; in both,  the top of the mercury column stabilized at 26 and three-tenths inches above the level of mercury in the dish.

A Minim Friar was asked to make periodic notes on the level of mercury in one test tube left behind, while Perier took the other on the ten-mile climb up the Puy de Dome. He then took readings of the mercury level three times while moving up the mountain.  As they climbed the level fell lower.

They then took five readings from different places on the summit.  Each time the level remained the same: 23 and one-sixth inches. On their return, Chastin confirmed that the mercury level in his test tube had never varied from the original reading of 26 and three-tenths.

Their final verification was to now compare the mercury levels in both tubes, and to find them identical again. The next day, Perier repeated the experiment again at the top of Clermont Cathedral, where the level was 26 and one-tenth inches.

This work of Perier and Pascal led directly to the invention of the barometer, and marked the beginning  of meteorology.  It also led to the first practical and scientific method of measuring altitude; and from the knowledge of the existence and properties of the vacuum (the existence of which was soon proved by the experiments of [work verified by] Guericke*) came Pascal's invention of the hydraulic press.

Pascal repeated the experiments again in Paris, and in November 1648 published the findings in his “Narrative Account of the Great Experiment on the Equilibrium of Liquids.”  Perier made no more contributions to the natural sciences.

Extra Connections:

[experiment repeated by] Gassendi* repeated the experiment.

Corresponded with [corresponded with] Mersenne*.

Assessment: Barometric pioneer who worked with Blaise Pascal.

Oneliner: Florin Perier, who did the first barometric experimental test

Bibliography: