DUPUIS, CHARLES FRANÇOIS (1742-1809), French scientific writer and politician, was born of poor parents at Trye-Château, between Gisors and Chaumont, on the 26th of October 1742. His father, who was a teacher, instructed him in mathematics and land-surveying. While he was engaged in measuring a tower by a geometrical method, the duc de la Rochefoucauld met him and was so taken by the lad's intelligence that he gave him a bursary in the college of Harcourt. Dupuis made such rapid progress that, at the age of twenty-four, he was appointed professor of rhetoric at the college of Lisieux, where he had previously passed as a licentiate of theology. In his hours of leisure he studied law, and in 1770 he abandoned the clerical career and became an advocate. Two university discourses which he delivered in Latin were printed, and laid the foundation of his literary fame. His chief attention, however, was devoted to mathematics, the object of his early studies; and for some years he attended the astronomical lectures of Lalande, with whom he formed an intimate friendship. In 1778 he constructed a telegraph on the principle suggested by Guillaume Amontons (q.v.), and employed it in keeping up a correspondence with his friend Jean Fortin in the neighbouring village of Bagneux, until the Revolution made it necessary to destroy his machine to avoid suspicion. About the same time Dupuis formed his theory as to the origin of the Greek months. He endeavoured to account for the want of any resemblance between the groups of stars and the names by which they are known, by supposing that the zodiac was, for the people who invented it, a sort of calendar at once astronomical and rural, and that the figures chosen for the constellations were such as would naturally suggest the agricultural operations of the season. It seemed only necessary, therefore, to discover the clime and the period in which the constellation of Capricorn must have arisen with the sun on the day of the summer solstice, and the vernal equinox must have occurred under Libra. It appeared to Dupuis that this clime was Upper Egypt, and that the perfect correspondence between the signs and their significations had existed in that country at a period of between fifteen and sixteen thousand years before the present time; that it had existed only there; and that this harmony had been disturbed by the effect of the precession of the equinoxes. He therefore ascribed the invention of the signs of the zodiac to the people who then inhabited Upper Egypt or Ethiopia. This was the basis on which Dupuis established his mythological system, and endeavoured to explain fabulous history and the whole system of the theogony and theology of the ancients. Dupuis published several detached parts of his system in the _Journal des savants_ for 1777 and 1781. These he afterwards collected and published, first in Lalande's _Astronomy_, and then in a separate volume in 4to, 1781, under the title of _Mémoire sur l'origine des constellations et sur l'explication de la fable par l'astronomie_. The theory propounded in this memoir was refuted by J.S. Bailly in his _Histoire de l'astronomie_, but, at the same time, with a just acknowledgment of the erudition and ingenuity exhibited by the author.