Biography

French mathematician (1746–1818), inventor of descriptive geometry and co-founder of the École Polytechnique. A close ally of Napoleon, he played a major role in modernizing scientific and technical education in France.

Gaspard Monge(1746 — 1818)

Gaspard Monge

France

8 min read

SciencesTechnologyPoliticsMathématicien(ne)19th CenturyFrench Revolution and Napoleonic Empire — rise of the grandes écoles and state science

Frequently asked questions

Gaspard Monge (1746–1818) was a French mathematician best known for inventing descriptive geometry, a method for representing three-dimensional objects on a flat drawing surface using orthogonal projections. The key point to remember is that this invention, initially classified as a military secret for thirty years, became the foundation of modern technical and industrial drawing. Monge was also co-founder of the École Polytechnique in 1794, a prestigious institution that revolutionized scientific education in France and served as a model worldwide.

Key Facts

  • 1746: Born in Beaune, Burgundy
  • 1768: Invents descriptive geometry at the Royal School of Military Engineering in Mézières
  • 1794: Co-founds the École Polytechnique with Lazare Carnot and other scholars
  • 1798–1799: Takes part in the Egyptian expedition alongside Napoleon Bonaparte
  • 1818: Dies in Paris; his work lays the foundations of modern differential geometry

Works & Achievements

Invention of Descriptive Geometry (vers 1765)

Monge developed a revolutionary method for representing three-dimensional objects on a flat surface through orthogonal projections. Classified as a military secret for thirty years, this invention founded a new mathematical and technical discipline that became the basis of modern technical drawing.

Co-founding of the École Polytechnique (1794)

Together with Lazare Carnot and other scientists, Monge conceived and launched the École Centrale des Travaux Publics (the future École Polytechnique), France's first major scientific institution. This school lastingly reformed higher education and served as a model around the world.

Géométrie descriptive (1799)

The first printed treatise to systematically set out the method of projections, drawn from his lectures at the École Normale de l'An III. This work established descriptive geometry as a discipline and made it a compulsory subject in engineering education across Europe.

Application de l'analyse à la géométrie (1807)

A major work in analytical geometry in which Monge advanced the study of curves and surfaces using algebraic methods. He greatly enriched the theory of surfaces and laid foundations that would be built upon in differential geometry.

Contribution to the Description de l'Égypte (1798-1801)

As president of the Commission of Sciences and Arts, Monge oversaw the scientific and archaeological survey of Egypt. This colossal undertaking gave rise to the *Description de l'Égypte*, published between 1809 and 1828.

Anecdotes

As a young draftsman at the Royal School of Engineering in Mézières, Monge was given a military fortification problem that officers typically solved through lengthy arithmetic calculations. Within a few hours he proposed a geometric solution so elegant that the commandant initially refused to believe it, suspecting an error. Persuaded by the demonstration, the officer immediately had the method classified as a state secret, judging that it would give France a decisive advantage if it remained unknown to enemy powers. This discovery, kept secret for thirty years, would nonetheless go on to revolutionize the training of engineers throughout the world.

When the École Polytechnique was founded in 1794, Monge threw himself into the work with extraordinary energy: he wrote the curricula, recruited the faculty, personally taught descriptive geometry, and oversaw the administrative organization. He saw in this new institution a means of training a scientific and technical elite capable of serving the nation, combining for the first time pure mathematics and applied sciences within a single course of study. The École Polytechnique rapidly became a model imitated across Europe.

During the Egyptian expedition (1798–1799), Napoleon chose Monge as one of his trusted scholars, and the two men forged a sincere and lasting friendship. Monge presided over the Commission of Sciences and Arts charged with studying ancient and modern Egypt; he took part in measuring the pyramids and surveying the monuments, contributing to the work that would give rise to the monumental *Description de l'Égypte*.

When Napoleon fell in 1815, Monge, then 69 years old, was hit hard by the Restoration: his titles were stripped from him, and in 1816 the Bourbons expelled him from the Académie des sciences — an unbearable humiliation for the aged scholar. He died two years later, in 1818, but his former students from the École Polytechnique, defying the bans imposed by the royalist authorities, came in great numbers to follow his funeral cortège, a moving testament to the loyalty his students bore him.

Primary Sources

Descriptive Geometry, Lessons Given at the École Normale in Year 3 (1795)
Descriptive geometry has two purposes: the first, to provide methods for representing on a drawing sheet, which has only two dimensions — namely length and width — all bodies in nature that have three.
Descriptive Geometry (printed edition) (1799)
Through the combined use of two projections, one can determine exactly the shape and position of any object in space, and from this deduce all the geometric properties belonging to it.
Application of Analysis to Geometry (1807)
The purpose of this treatise is to bring together the principal applications that can be made of algebraic analysis to the geometry of curves and surfaces, and to show how the two sciences can mutually support one another.
Letter from Gaspard Monge to His Wife, from Alexandria (1798)
We are here surrounded by wonders that our Commission strives to measure and describe. The monuments of ancient Egypt surpass anything the imagination could have conceived; I think of you and our daughters every day.

Key Places

Beaune (Burgundy)

Birthplace of Gaspard Monge, born on **9 May 1746**. The son of a traveling merchant, he received his early education from the Oratorians there and showed exceptional mathematical talent from a very young age.

Royal School of Engineering at Mézières

It was at Mézières (now Charleville-Mézières) that Monge invented descriptive geometry around **1765** while solving a military fortification problem. He taught mathematics and physics there for several years before the Revolution.

École Polytechnique, Paris

Co-founded by Monge in **1794** under the name École Centrale des Travaux Publics, it became the crown jewel of French scientific education. Monge taught descriptive geometry there and trained generations of engineers who transformed France.

Cairo (Egypt)

During the Egyptian expedition (**1798–1799**), Monge stayed in Cairo and oversaw the work of the Commission of Sciences and Arts. He contributed to the study of ancient Egyptian monuments, which would eventually give rise to the *Description de l'Égypte*.

Paris (residence and death)

Monge lived and died in Paris on **28 May 1818**, worn down by the persecutions of the Restoration. His funeral prompted a spontaneous gathering of his former students from the École Polytechnique, who came to pay their last respects.

See also