Skip to content
Catholic Online Logo

Astronomer, b. at La Flêche, 21 July, 1620; d. at Paris, 12 Oct., 1682. He was a priest and prior of Rillé in Anjou. As a pupil of Gassendi he observed with him the solar eclipse of 25 Aug., 1645. In 1655 he succeeded his master as professor of astronomy at the College de France. His principal achievement was the accurate measurement of an arc of a meridian of the earth, the distance from Sourdon, near Amiens, to Malvoisine, south of Paris, in 1669-70. His result, 57060 toises (a toise = about 6.4 ft.) for the degree of arc, has been found to be only 14 toises too small. He applied telescopes and micrometers to graduated astronomical and measuring instruments as early as 1667. The quadrant he used had a radius of 38 inches and was so finely graduated that he could read the angles to one quarter of a minute. The sextant employed for determining the meridian was 6 feet in radius. In 1659 he was able to observe stars on the meridian during day-time and to measure their position with the aid of cross-wires at the focus of his telescope. In order to make sure that his standard toise should not be lost, like those used by others before him, he conceived the idea of comparing it with the length of the simple pendulum beating seconds at Paris, and thus made it possible to reproduce the standard at any time.

Picard is regarded as the founder of modern astronomy in France. He introduced new methods, improved the old instruments, and added new devices, such as the pendulum clock. As a result of Picard's work, Newton was able to revise his calculations and announce his great law of universal gravitation. The discovery of the aberration of light also became a possibility on account of Picard's study of Tycho Brahe's observations. In 1671 he received from Bartholinus at Copenhagen an exact copy of Tycho's records and then went with Bartholinus to the Island of Hveen in order to determine the exact position of Tycho's observatory at Uranienborg. He was modest and unselfish enough to recommend the rival Italian astronomer Cassini to Colbert and Louis XIV for the direction of the new observatory at Paris. Cassini, on the contrary, proved envious, ignoring Picard's insistent recommendations of a mural circle for accurate meridional observations, until after the latter's death.

Picard was among the first members of the Academy. He also started the publication of the annual "Connaissance des temps" in 1679 (Paris, 1678), and continued the same until 1683. Since then it has been published continuously. His "Mesure de la terre" was brought out in 1671, Paris.

More Encyclopedia

The Catholic Encyclopedia is the most comprehensive resource on Catholic teaching, history, and information ever gathered in all of human history. This easy-to-search online version was originally printed between 1907 and 1912 in fifteen hard copy volumes.

Catholic Encyclopedia

Designed to present its readers with the full body of Catholic teaching, the Encyclopedia contains not only precise statements of what the Church has defined, but also an impartial record of different views of acknowledged authority on all disputed questions, national, political or factional. In the determination of the truth the most recent and acknowledged scientific methods are employed, and the results of the latest research in theology, philosophy, history, apologetics, archaeology, and other sciences are given careful consideration.

No one who is interested in human history, past and present, can ignore the Catholic Church, either as an institution which has been the central figure in the civilized world for nearly two thousand years, decisively affecting its destinies, religious, literary, scientific, social and political, or as an existing power whose influence and activity extend to every part of the globe. In the past century the Church has grown both extensively and intensively among English-speaking peoples. Their living interests demand that they should have the means of informing themselves about this vast institution, which, whether they are Catholics or not, affects their fortunes and their destiny.

Copyright © Catholic Encyclopedia. Robert Appleton Company New York, NY. Volume 1: 1907; Volume 2: 1907; Volume 3: 1908; Volume 4: 1908; Volume 5: 1909; Volume 6: 1909; Volume 7: 1910; Volume 8: 1910; Volume 9: 1910; Volume 10: 1911; Volume 11: - 1911; Volume 12: - 1911; Volume 13: - 1912; Volume 14: 1912; Volume 15: 1912

Catholic Online Catholic Encyclopedia Digital version Compiled and Copyright © Catholic Online


Newsletter Sign Up icon

Stay up to date with the latest news, information, and special offers

Subscribe to Catholic OnlineYouTube Channel

the FEED
by Catholic Online

  • Daily Readings for Monday, November 30, 2015
  • President likens Syrian refugees to pilgrims on Mayflower in ...
  • The Miracle Prayer HD Video
  • Who Needs Advent? I do!
  • Prayer For Courage HD Video
  • BIGGER THAN ISIS - There's a hidden power behind ISIS and it's so big ...
  • St. Andrew: Saint of the Day for Monday, November 30, 2015

Daily Readings

Reading 1, Jeremiah 33:14-16
14 "Look, the days are coming, Yahweh declares, when I shall fulfil the ... Read More

Psalm, Psalms 25:4-5, 8-9, 10, 14
4 DIRECT me in your ways, Yahweh, and teach me your paths.5 ... Read More

Gospel, Luke 21:25-28, 34-36
25 'There will be signs in the sun and moon and stars; on earth nations ... Read More

Reading 2, First Thessalonians 3:12--4:2
12 May the Lord increase and enrich your love for each other and for all, ... Read More

Saint of the Day

Saint of the Day for November 29th, 2015 Image

St. Saturninus
November 29: St. Saturninus Bishop of Toulouse and Martyr ... Read More