Charles Eugene Delainay, a French astronomer, born at Lusigny, in the department of Aube, April 9, 1816, drowned off Cherbourg, Aug. 5, 1872. He left the polytechnic school in 1836 with high honors as an engineer, and was the first to receive the new Laplace prize. In 1841 he became a teacher at the polytechnic school, in 1853 professor of mechanics, and in 1855 a member of the academy. In 1869 he was elected a member of the royal astronomical society of London, which awarded a medal to him in 1870. In the latter year he succeeded Leverrier in the Paris observatory; and in 1871 he was appointed professor of astronomy and geology at the polytechnic school. He published highly esteemed treatises on various scientific subjects, Notice sur la construction de l'univers, and Theorie du mozwement de la lune (2 vols. 4to, Paris, 1866-7), which differs in its results from those obtained by Hansen and Leverrier, and which was made by the French institute the basis for a new construction of the tables of the phases of the moon.