French mathematician, physicist, and public official Gaspard Monge (also known as Comte de Péluse; 1746-1818) was the first to lay down ideas about modern descriptive geometry, a field that is essential to mechanical and architectural drawing. He is also called the founder of differential geometry. As one of the founders of the école Polytechnique, he served as professor of descriptive geometry, and around 1800 published the first textbook on the subject based on his lectures, aptly called Géométrie descriptive. Today, the system once called “géométrie descriptive” is now known as orthographic projection, a graphical method used in modern mechanical drawing.