Pierre Charles Le Monnier

[1] His first recorded astronomical observation was made before he was sixteen, and the presentation of an elaborate lunar map resulted in his admission to the French Academy of Sciences, on 21 April 1736, aged only 20.

He was chosen in the same year to accompany Pierre Louis Maupertuis and Alexis Clairaut on their geodetical expedition for measuring a meridian arc of approximately one degree's length to Torne Valley in Lapland.

[1] The liberality of King Louis XV of France, in whose favour Le Monnier stood high, furnished him with the means of procuring the best instruments, many made in Britain.

Amongst the fruits of his industry may be mentioned a laborious investigation of the disturbances of Jupiter by Saturn, the results of which were employed and confirmed by Euler in his prize essay of 1748; a series of lunar observations extending over fifty years; some interesting researches in terrestrial magnetism and atmospheric electricity, in the latter of which he detected a regular diurnal period; and the determination of the places of a great number of stars, including at least twelve separate observations of Uranus, between 1750 and its recognition as a planet.

In his lectures at the Collège de France he first publicly expounded the analytical theory of gravitation, and his timely patronage secured the services of Jérôme Lalande for astronomy.