Alexis Claude de Clairaut (or Clairault) (May 3, 1713 - May 17, 1765) was a French mathematician, astronomer, geophysicist, and child prodigy. At 13 he read before the Acad矇mie francaise an account of the properties of four curves which he had discovered. At 16 he finished a treatise on tortuous curves entitled, Recherches sur les courbes a double courbure. In 1731, he was admitted into the French Academy of Sciences, although he was below the legal age. In 1736 he took part in the expedition to Lapland undertaken for the purpose of estimating a degree of the meridian arc. In 1743 he published his treatise Th矇orie de la figure de la terre. In 1750 his essay Th矇orie de la lune was published and contains his explanation of the motion of the apsis which had previously puzzled astronomers. He wrote various papers on the orbit of the Moon, and on the motion of comets as affected by the perturbation of the planets. In 1759 he calculated the perihelion of Halley's comet. "He was focused," says Bossut, "with dining and with evenings, coupled with a lively taste for women, and seeking to make his pleasures into his day to day work, he lost rest, health, and finally life at the age of 52."