Lacaille, Nicola Louis de

Born March 15, 1713 in Ruminini (France). He studied rhetoric and philosophy at the College de Lisieux in Paris, then theology at the Navarre College. Got the rank of abbot. He studied astronomy on his own. His love of the exact sciences helped him decide to move to Paris , where his acquaintance with Cassini and Fushi helped him to get a place at the Paris Observatory in 1736. In 1739, Lacaille was engaged in the verification of large French degree measurement from Paris to Perpignan and was appointed professor of mathematics at Mazarin College . Here, for his students, he prepared excellent textbooks in mathematics, mechanics, and astronomy, which have withstood many editions.

In 1741, Lacaille was elected a member of the French Academy of Sciences. 1750 - 1754, Lacaille spent in the southern hemisphere, on the Cape of Good Hope and on the islands of Ile de Bourbon (Reunion) and Ile de France (Mauritius), determined the parallax of the Moon (according to relevant observations in Berlin ), measured the arc of the meridian in southern Africa and determined the position of 10,000 stars in the southern hemisphere, processed the observations and calculated the positions of 1942 stars, which are included in the preliminary catalog. Lacaille completed the division of the southern sky into constellations, begun by Dutch navigators around 1600; singled out 14 new constellations and gave them names. During the years 1751-1752, he performed numerous observations of the Moon, Mars, Venus at the observatory on Cape of Good Hope to determine the lunar and solar parallaxes by comparing them with similar observations in the Northern Hemisphere, which Lland performed at the Berlin Observatory at that time. Got the value of solar parallax (9.5 ") close to modern. He participated in many geodetic works carried out by the Paris Observatory. In 1738, together with J. D. Maraldi, he mapped the coastline of France between Nantes and Bayonne. In 1739-1741 he carried out work by measuring the large arc of the meridian in France and showed that the equatorial radius of the Earth is greater than the polar (that is, that the Earth is flattened along the axis of rotation). For the first time measured the arc of the meridian in South Africa. Mapped and determined the exact ge geographical location of the islands of Mauritius, Reunion and Ascension. Compiled detailed tables of atmospheric refraction, taking into account the influence of temperature and atmospheric pressure. Compiled tables of eclipses from the beginning of our era to 1800. He wrote widely-known textbooks on mathematics (1741), mechanics (1743), astronomy (1746) and optics (1756).

After returning to Paris, Lacaille continued his work at the observatory of the College of Mazarin, not sparing his health. Lacaille died in Paris on March 21, 1762.

Lacaille was distinguished by disinterestedness and impartiality: by grouping new southern constellations, he could perpetuate the names of the powers of the world, but instead he used the names of astronomical and other scientific instruments for new constellations. However, he did not show much ingenuity, inventing names. He initiated the separation of the constellation Ship Argo into three separate constellations.

He was a foreign member of the Russian Academy of Sciences , from December 13, 1755 - an honorary member of the Russian Academy of Sciences.

Of the students of Lacaille, Bailly and Lalande were especially famous. In addition to the textbooks and many memoirs in the publications of the Paris Academy of Sciences, Lacaille published: Astronomiae Fundamentas (Par., 1757 ) and Coellum australe stelliferum; "Seu Observationes ad construendum stellarum australium catalogum institutae, in Africa ad Caput Bonae-Spei" ( 1763 ).

Almost a hundred years later, the British calculated and published a list of Lacaille stars under the title: “A Catalog of 9766 stars in the southern hemisphere” (London, 1847 ). Biographies of Lacaille were written by Fushi , Lalande and Arago .

In 1935, the International Astronomical Union named Lacaille on the crater on the visible side of the moon .

• Kolchinsky I.G., Korsun A.A., Rodriguez M.G. Astronomers: A Biographical Reference. - 2nd ed., Revised. and additional .. - Kiev: Naukova Dumka, 1986. - 512 p.

• Vitkovsky V.V. Lacaille, Nicolas-Louis // Brockhaus and Efron Encyclopedic Dictionary : 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
• Profile of Nicola-Louis de Lacaille on the RAS official website