Gaspard Monge Founder of "Constructive Geometry"

As a mathematician, or as the “father of the Ecole polytechnique”, the most famous French engineering school, Gaspard Monge has been the object of numerous studies by historians of science. In this article, I wish to address another aspect of Monge's work, which also allows one to see in Monge the father of “constructive geometry”. This field comprises two aspects: either one wishes to determine a surface with construction properties that meet a number of given constraints, or one seeks to build a surface that is given a priori in the best possible way. It is the second aspect that Monge developed in his course of descriptive geometry through a “theory of stone assembly”. In spite of the imperfections of his theory, Monge inaugurated a highly original way of linking geometry and construction.