BOWDITCH, NATHANIEL

(b. March 26, 1773, Salem, Mass. d. March 16, 1838, Boston, Mass., U.S.), self-educated American mathematician and astronomer, author of the best book on navigation of his time, and discoverer of the Bowditch curves, which have important applications in astronomy and physics. Between 1795 and 1799 Bowditch made four lengthy sea voyages, and in 1802 he was put in command of a merchant vessel. Throughout that period he pursued his interest in mathematics. After investigating the accuracy of The Practical Navigator, a work by the Englishman J.H. Moore, he produced a revised edition in 1799. His additions became so numerous that in 1802 he published The New American Practical Navigator, based on Moore's book, which was adopted by the U.S. Department of the Navy and went through some 60 editions. Bowditch also wrote many scientific papers, one of which, on the motion of a pendulum swinging simultaneously about two axes at right angles, described the so-called Bowditch curves (better known as the Lissajous figures, after the man who later studied them in detail). Bowditch translated from the French and updated the first four volumes of Pierre-Simon Laplace's monumental work on the gravitation of heavenly bodies, Trait de mcanique cleste, more than doubling its size with his own commentaries. The resulting work, Celestial Mechanics, was published in four volumes in 182939. Bowditch refused professorships at several universities. He was president (180423) of the Essex Fire and Marine Insurance Company of Salem and worked as an actuary (182338) for the Massachusetts Hospital Life Insurance Company of Boston. From 1829 until his death he was president of the American Academy of Arts and Sciences.