Because the Ecole Polytechnique had such a far-reaching influence upon the point of view from which mechanisms were contemplated by scholars for nearly a century after the time of Watt, and by compilers of dictionaries of mechanical movements for an even longer time, it is well to look for a moment at the early work that was done there. If one is interested in origins, it might be profitable for him to investigate the military school in the ancient town of Mézières, about 150 miles northeast of Paris. It was here that Lazare Carnot, one of the principal founders of the Ecole Polytechnique, in 1783 published his essay on machines,[60] which was concerned, among other things, with showing the impossibility of "perpetual motion"; and it was from Mézières that Gaspard Monge and Jean Hachette[61] came to Paris to work out the system of mechanism classification that has come to be associated with the names of Lanz and Bétancourt. [Footnote 60: Lazare N. M. Carnot, _Essai sur les machines en général_, Mézières, 1783 (later published as _Principes fondamentaux de l'equilibre et du mouvement_, Paris, 1803).] [Footnote 61: Biographical notices of Monge and Hachette appear in _Encyclopaedia Britannica_, ed. 11. See also _L'Ecole Polytechnique, Livre du Centenaire_, Paris, 1895, vol. 1, p. 11ff.] Gaspard Monge (1746-1818), who while a draftsman at Mézières originated the methods of descriptive geometry, came to the Ecole Polytechnique as professor of mathematics upon its founding in 1794, the second year of the French Republic. According to Jean Nicolas Pierre Hachette (1769-1834), who was junior to Monge in the department of descriptive geometry, Monge planned to give a two-months' course devoted to the elements of machines. Having barely gotten his department under way, however, Monge became involved in Napoleon's ambitious scientific mission to Egypt and, taking leave of his family and his students, embarked for the distant shores. "Being left in charge," wrote Hachette, "I prepared the course of which Monge had given only the first idea, and I pursued the study of machines in order to analyze and classify them, and to relate geometrical and mechanical principles to their construction." Changes of curriculum delayed introduction of the course until 1806, and not until 1811 was his textbook ready, but the outline of his ideas was presented to his classes in chart form (fig. 28). This chart was the first of the widely popular synoptical tables of mechanical movements.[62] [Footnote 62: Jean N. P. Hachette, _Traité élémentaire des machines_, Paris, 1811, p. v.] [Illustration: Figure 28.--Hachette's synoptic chart of elementary mechanisms, 1808. This was the first of many charts of mechanical movements that enjoyed wide popularity for over 100 years. From Jean N. P. Hachette, _Traité Élémentaire des Machines_ (Paris, 1811, pl. 1).]