Gaspard Monge

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Gaspard Monge


French Mathematician, Physicist and Chemist

The most widely recognized of the many achievements attributed to Gaspard Monge, sometimes known as the comte de Péluse, was his development of descriptive geometry as a means of representing three-dimensional objects in two dimensions. So valued was this technique for its military applications that the French government pledged him to secrecy. Monge also contributed to the adoption of the metric system, and his other work as a mathematician, physicist, and chemist took him into a variety of arenas, including caloric theory, acoustics, and optics.

Born on May 9, 1746, in Beaune, France, Monge was the son of Jacques and Jeanne Rousseaux Monge. The father, a knife grinder and peddler, believed in his son's ability to rise above his humble beginnings through education, and at an early age the talented youth was enrolled in the College of the Orations at Beaune. From Beaune in 1762 he went on to Lyons for two more years of college, at which point the 18-year-old Monge was declared a physics instructor. On vacation in his hometown, he created a detailed map of Beaune using projection methods and surveying equipment he developed himself, and this so impressed an army officer that he was recommended for the military school at Mézières.

As a young military engineer, Monge soon developed a revolutionary plan for gun emplacements in a proposed fortress, substituting a geometric process for the cumbersome arithmetic calculations then in use. This was the birth of descriptive geometry, and though Monge's commanding officer initially ignored it as a form of trick, its value for representing three-dimensional objects in two dimensions was soon recognized. For many years thereafter, Monge was ordered to keep this valuable military secret to himself.

Beginning in 1768, Monge held a dual professorship in physics and mathematics at Mézières, a position he would hold for the next 15 years. He married Catherine Huart in 1777, and together they had three daughters. Elected to the French Académie Royale des Sciences in 1780, his center of activity began to shift from the provinces to the capital, and when in 1783 he was appointed examiner of naval cadets, he was forced to relocate to Paris.

Monge was a supporter of the French Revolution, which broke out in 1789, but his liberal and republican sympathies put him at odds with the radical Jacobin faction that took control in 1793. Thus he was removed from his position as minister of the navy, to which he had been appointed by the revolutionary leadership, after just eight months of service. He did help establish the metric system, as well as the Ecole Polytechnique, which opened in 1795. Later some of his lectures at the school were published in what came to be known as Application de l'analyse a la géométrie. In the latter, Monge explained the algebraic principles of three-dimensional geometry, ideas that would have an enormous impact on engineering design.

He served in a mission to Italy in 1796, and from there followed Napoleon Bonaparte on the latter's campaign in Egypt, where Monge helped establish the Institut d'Egypt in Cairo. Over the years that followed, as Napoleon held sway over France and Europe, Monge enjoyed great success and honors, including the title of comte or count, bestowed on him in 1808. But when Napoleon's star fell, so did Monge's. In 1816 he was stripped of all the honors accorded him by Napoleon, and spent the last two years of his life as a pariah under the restored monarchy. So great was Monge's reputation, however, that upon his death in 1818, many defied a government ban and placed wreaths on his grave.