This is a 1761 Claude Buy de Mornas celestial map of the Earth's seasons. Using this orbit diagram, Buy de Mornas explains such concepts as why summer is longer than winter. He illustrates the Earth's elliptical orbit, exchanges how it changes in speed, which causes one part of the orbit (a season) to take longer than the other. He also effectively illustrates how the Earth's tilt with respect to the Sun effects the seasons, although he does not include this detail in the discussion of the seasons to the left of the diagram. To the right, Buy de Mornas discusses heat retention and how the changes daylight certain parts of the Earth receive during different parts of the year results in the temperature changes.
Publication History and CensusThis map was created and published by Claude Buy de Mornas and Louis-Charles Desnot who jointly published the Atlas Méthodique et Elémentaire de Géographie et d'Histoire in 1761. We have not found any cataloged examples of the separate map, although that may be due to the lack of a formal title. The atlas, however, is well represented.
Claude Buy de Mornas (17xx - 1783) was a French geography professor. He published the Atlas Méthodique et Elémentaire de Géographie et d'Histoire jointly with Louis-Charles Desnos (1725 - 1805) in 1761. Desnos claimed the plates for the Atlas Méthodique after Buy de Mornas died. More by this mapmaker...
Louis Charles Desnos (1725 - April 18, 1805) was an important 18th century instrument maker, cartographer and globe maker based in Paris, France. Desnos was born in Pont-Sainte-Maxence, Oise, France, the son of a cloth merchant. From April of 1745 he apprenticed at a metal foundry. Desnos married the widow of Nicolas Hardy, sone of the map, globe, and instrument seller Jacques Hardy. Desnos held the coveted position of Royal Globemaker to the King of Denmark, Christian VII, for which he received a stipend of 500 Livres annually. In return Desnos sent the King roughly 200 Livres worth of maps, books and atlases each year. As a publisher, Desnos produced a substantial corpus of work and is often associated with Zannoni and Louis Brion de la Tour (1756-1823). Despite or perhaps because of the sheer quantity of maps Desnos published he acquired a poor reputation among serious cartographic experts, who considered him undiscerning and unscrupulous regarding what he would and would not publish. Desnos consequently had a long history of legal battles with other Parisian cartographers and publishers of the period. It is said that he published everything set before him without regard to accuracy, veracity, or copyright law. Desnos maintained offices on Rue St. Jacques, Paris. Learn More...
Buy de Mornas, C. and L. C. Desnos, Atlas Méthodique et Elémentaire de Géographie et d'Histoire, (Paris: Mornas and Desnos) 1761.
Very good. Light wear along original centerfold.