 |
Joseph Jerome Lefrancois De LalandeFrench astronomer.
Date of Birth: 11.07.1732
Country:  France |
Content:
Joseph-Jérôme Lefrançais de Lalande
Early Life and EducationBorn in Bourg-en-Bresse, France, Joseph-Jérôme Lefrançais de Lalande graduated from the Lyon College in 1748. While studying law in Paris, he attended lectures on astronomy, mathematics, and physics at the Collège de France. His passion for astronomy ignited with his observations of the Great Comet of 1744 and the solar eclipse of 1748.
Career in Astronomy
In 1752, at the age of 20, Lalande was sent by the French Academy of Sciences to Berlin to observe the moon. This mission aimed to calculate the Earth's satellite's parallax, with simultaneous observations by LaCaille at the Cape of Good Hope. The success of this endeavor resulted in Lalande's election to the Berlin Academy of Sciences at just 21 years old.
Lalande worked as an observer at the Montpellier Observatory in 1774. He later became a professor of mathematics at the École militaire and dedicated himself to astronomy. During the turbulent years of the French Revolution, he observed and cataloged 50,000 stars, published as "Histoire céleste française." His nephew Michel and his wife Marie assisted in these observations.
Publications and Legacy
Aside from his numerous memoirs on astronomy, Lalande authored significant works such as "Astronomie," a three-volume treatise published in Paris (1764, 1781, 1792). Translated into many European languages, it remained a valuable resource until the early 20th century. His "Bibliographie astronomique" (1803) was a comprehensive guide for astronomers.
Lalande edited Jean Étienne Montucla's "History of Mathematics," writing the last two volumes himself. He also published "Connaissance des temps," a renowned ephemeris containing improvements for longitude determination at sea. His "Five-Figure Logarithmic Tables" remained widely used until the 20th century.
Masonic Affiliations
Lalande was a member of the prominent Masonic lodge, the "Nine Sisters." In 1792, he published a treatise on navigation by P. Bouguer, adding his own annotations to it.
