Renowned for his unpredictable moods and immense capacity for hard work, Joseph Jérôme de Lalande was one of the greatest astronomers of the eighteenth century. Famous during his lifetime for writing many works, he was the author not only of astronomy books but of volumes on other subjects too, such as travel literature and the arts.
Lalande was born in the town of Bourg-en-Bresse in the east of France. The science of astronomy first captured his imagination as a teenager. While taking classes in this science at the Jesuit school in Lyon, he was especially inspired after observing a total eclipse of the Sun on 25 July 1748 with his teacher. He went on from there to study this science informally under the guidance of Joseph-Nicolas Delisle (1688-1768) in Paris, while at the same time taking a law degree.
Lalande practised law for a short time but his real passion was astronomy, and in 1753 he was appointed astronomer adjoint at the French Academy of Sciences. He was more a meticulous observer than an innovator, but he took part in some of the time’s most important astronomical events such as calculating the orbit of Halley’s comet. He also coordinated expeditions to measure transits of Venus (1761 and 1769) and calculated the astronomical unit to have a value of 153 million kilometres.
Lalande was successful in popularising astronomy, and gave lively lectures throughout his working life. His book Astronomie des Dames (Astronomy for Women) is certainly an excellent work, accessible to everyone not just astronomers and scientists. Lalande was a very good teacher and taught astronomy at the Collège Royale (later named Collège de France) from 1762 for 46 years. He reached the pinnacle of his career with his appointment as director of the Paris Observatory in 1795. While holding this position he completed a catalogue of 30,000 stars which expanded to 41,000 by 1797. In 1802 he instituted the Lalande prize which was to be awarded annually for the most important contribution to astronomy that year. His death in 1807 is thought to be from tuberculosis.
L'anniversaire de Joseph-Jérôme Lefrançais de Lalande (11/07/1732-4/04/1807)
Renommé pour ses humeurs et son caractère difficile, Jérôme de Lalande était sans doute l’un des meilleurs astronomes français du dix-huitième siècle. Il était célèbre pendant sa vie pour ses oeuvres sur une grande variété de sujets
Né à Bourg-en-Bresse l’astronomie il découvre une passion pour l’astronomie au collège. A l’université il a étudié le droit tout en assistant aux cours que Joseph Delisle donne au collège de France.
Après ses études Il travaille brièvement comme avocat mais l’astronomie restait sa vraie passion, et en 1753 il est élu membre de l’ Académie des Sciences. Pendant sa carrière il est un observateur assidu et un écrivain prolifique. Il contribue à la vulgarisation de l’astronomie et il encourage les femmes à l’étudier. Il est célèbre surtout pour son livre Astronomie des Dames, un livre excellent et accessible à tout le monde.
Lalande était un tres bon professeur et enseignait l’astronomie au Collège de France pendant 46 ans. En 1795 il est nommé directeur de l’observatoire de Paris fonction qu’il occupera jusqu’ à sa mort d’une tuberculose en 1807.