Pierre Charles Le Monnier, a French astronomer, born in Paris, Nov. 23, 1715, died at Heric, near Bayeux, May 31, 1799. The son of a noted savant, he made astronomical observations at the age of 16, and before he was 21 he was received into the academy of sciences, having already presented to that body an elaborate map of the moon. In 1736 he accompanied Maupertuis to Tornea for the measurement of a degree in Lapland; and on his return, by introducing superior instruments and the methods of Flamsteed, he caused great improvements in practical astronomy. In 1742 the king gave him apartments at the Capuchins, rue St. Honore, which he occupied till the revolution. In 1748 he went to Scotland to observe the solar eclipse, which was there almost annular, and succeeded in measuring the diameter of the moon on the disk of the sun. The results of his observations are contained in the memoirs of the academy, to nearly every volume of which he furnished one or more papers for more than 50 years. He also produced various independent works on astronomical subjects.