Gaspard-Clair-François-Marie-Richez, a celebrated French engineer, was born at Chamelet, in the department of the Rhone, in 1755, and was educated at the École des Ponts et Chaussées. An essay on the Thrust of Arches, published in 1783, was the means of introducing him to a long course of public employment. He was engaged under Peronnet in restoring the fort of Dunkirk in 1785, and in erecting the bridge of Louis XVI. in 1787. The laborious enterprise of drawing up the famous Tables du Cadastre was entrusted to his direction in 1792. In 1794 he was charged with the professorship of mechanics in the École Polytechnique, and in 1798 he was appointed Directeur-Général des Ponts et Chaussées. His success continued after the overthrow of the republic and the establishment of the empire. He was employed by Napoleon to superintend the engineering operations both for protecting the province of Ferrara against the inundations of the Po, and for draining and improving the Pontine Marshes. He was likewise engaged after the restoration in regulating the course of the Rhone, and in several other important works. By the accomplishment of so many laborious undertakings, Prony had gained a high place in the estimation of the patrons of science. The title of baron was conferred upon him in 1828, and that of peer in 1835. He was also, at the time of his death in 1839, a member of the principal academies and scientific societies of Europe.

Among the numerous publications of Prony are the following:— Nouvelle Architecture Hydraulique, in 2 vols., 1790-96; Mécanique Philosophe, in 4to, 1800; Analyse de l'Expédition du Système du Monde par Laplace, in 8vo, 1801; Recherches sur la Poussée des Terres, in 4to, 1802; Recherches Physico-Mécaniques sur la Théorie des États Courants, in 4to, 1804; Cour de Mécanique Concernant les Corps Solides, in 2 vols., 4to, 1815; and Description Hydrographique et Historique des Marais Poitiers, in 4to, 1822-23.