Picard, Jean

1. Dates

Born: La Flèche, 21 July 1620

Died: Paris, 12 October 1682

Dateinfo: Dates Certain

Lifespan: 62

2. Father

Occupation: Pub

Picard's father was almost certainly Jean Picard, a bookseller in La Flèche; possibly I should consider him a small merchant in a provincial town, but I am listing everyone connected with the book trade under "Pub." Nothing is known of Picard's youth.

No information on financial status.

3. Nationality

Birth: French

Career: French

Death: French

4. Education

Schooling: Paris, M.A.

Picard probably did his early studies at the Jesuit college at La Flèche. Considerably later he earned an M.A. from Paris is 1650. As usual, I assume a B.A. There is no indication of what he did between La Flèche and his studies in Paris, a period of about twelve years.

5. Religion

Affiliation: Catholic

Picard was ordained a priest in 1650. He held at least four benefices.

6. Scientific Disciplines

Primary: Astronomy, Cartography, Instrumentation

Subordinate: Physics, Optics, Hydraulics

The usual story of Picard is that he was the gardener of the Duke of Crequi. Jacques de Valois, having met Picard, inspired him to make astronomical observations. The Picolet volume demonstrates that this story is not true.

Picard became very involved in astronomy and made observations with Gassendi in Paris in the period 1645 to 1652. With Auzout he perfected the movable-wire micrometer and utilized it to measure the diameter of the sun, moon, and planets. In 1667 Picard applied the astronomical telescope to the quadrant and the sector expanding their usefulness in observations. He made other innovations in instrumentation as well.

Picard became an important member of the group of academiciens carrying out cartographic measurements. He was placed in charge first of making a map of the region of Paris and then of the operation to remeasure an arc of the meridian. He utilized Snell's method of triangulation. His method and measurements were the topic of his Mesure de la terre (1671). He was also an important member of the team that began to compile a map of France based on scientific principles. He was a major figure in the development of scientific cartography.

In 1673 he was at the Paris observatory collaborating with Cassini, Roemer, and La Hire on the institute's regular project of observations.

Picard directed his attention to other projects of the Académie such as the surveying operations at Marly and Versailles, the whole problem of supplying Versailles with water (a project in which he was central) and barometric experiments and other topics of physics. He left behind papers on hydraulics.

Picard was also skilled in optics. He made suggestions to improve the telescope and left behind manuscripts on dioptrics.

7. Means of Support

Primary: Government, Church Life

Secondary: Academia

There is some evidence to suggest that Picard taught in the University of Paris during the 1650's, but his life during this period is very obscure.

Picard was apparently not one of the founding members of the Académie in 1666. However, he was appointed in 1667 with a pension of 1200 livres, raised to 1500 in 1669. From that time he spent his entire career devoted to Académie projects.

When He died, Picard held two priories and two other minor benefices, all four of them in his native Anjou. Although the exact dates have not been established, he received one of the priories (worth about 400 livres per annum) about 1661, and the other (worth about 300 livres per annum) between 1661 and 1675. The two minor benefices were worth about 100 livres together. Picolet concludes that Picard had an income of between 700 and 1000 livres in addition to his pension from the Acadmie.

8. Patronage

Types: Eccesiastic Official, Scientist

In 1664 Picard was the confidant of Abbé de Richelieu (a great-nephew of the Cardinal), and there is good cause to believe that he received at least one of his benefices from the Abbé.

Olmstead offers convincing evidence that Auzout, who was a well established astronomer at the time, was directly responsible for Picard's appointment to the Académie.

9. Technological Involvement

Types: Instruments, Cartography, Hydraulics

With Auzout, he perfected the movable-wire micrometer. He was the one who incorporated the astronomical telescope into surveying instruments such as the quadrant and sector. He also developed a new leveling instrument (also with telescope attached) that remained the standard one used in leveling for a long time.

He was the central figure in planning and implementing the water supply for the fountains at Versailles.

10. Scientific Societies

Memberships: Académie Royal des Sciences, 1666-82

Picard was not a founding member of the Académie but was added soon after its establishment.

He corresponded directly or indirectly with Erasmus Bartholin, Johan Blaeu, Martin Fogel, Michel Antoine Hacki, Johann Hevelius, Jan Hudde, Lodewijk Huygens, Stanislaus Lubieniecki de Roles, Andreas Spole, and Jules Reichelt. His correspondence with Hevelius (on telescopic sights) has been published.

Sources

1. J.W. Olmsted, "Recherches sur la biographie d'un astronome et geodesien méconnu: Jean Picard (1620-1682)," Revue d'Histoire, 29 (1976), 213-22.
2. Guy Picolet, "La Correspondence de Jean Picard avec Johann Hevelius (1671-1679)," Revue d'Histoire, 31 (1978), 3-41.
3. Guy Picolet, ed., Jean Picard et les débuts de l'astronome de precision au XVIIe siècle. Actes du colloque du tricentaire, (Paris, 1987). This is the fundamental work.
4. Robert McKeon, "Les débuts de l'astronomie de precision," Physis, 13 (1971), 225-88; 14 (1972), 221-42; especially 13, 275-8 and 14, 230-5.

Compiled by:

Richard S. Westfall

Department of History and Philosophy of Science

Indiana University

Note: the creators of the Galileo Project and this catalogue cannot answer email on geneological questions.