Jean-Charles, chevalier de Borda (May 4, 1733 - February 19, 1799) was a French mathematician, physicist, political scientist, and sailor. In 1778, He published his method of reducing Lunar Distances for computing the longitude, still regarded as the best of several similar mathematical procedures for navigation and position-fixing in pre-chronometer days; and used, for example, by Lewis and Clarke to measure their latitude and longitude during their exploration of the North-western United States. Read more