C. Auguste Dupin Vanished Treasure" (May 1965) and "The Fires in the Rue St. Honoré" (January 1967). This collection was subsequently published in England by Tom Stacey in 1972 as "Murder in the Rue Royale and Further Exploits of the Chevalier Dupin" and included a further five stories written since the original publication. Dupin had considerable impact on the Agatha Christie character Hercule Poirot, first introduced in "The Mysterious Affair at Styles" (1920). Later in the fictional detective's life, he writes a book on Edgar Allan Poe in the novel "Third Girl" (1966). "The Man Who Was Poe", a juvenile novel by Avi,
Dupin indicatrix Dupin indicatrix In differential geometry, the Dupin indicatrix is a method for characterising the local shape of a surface. Draw a plane parallel to the tangent plane and a small distance away from it. Consider the intersection of the surface with this plane. The shape of the intersection is related to the Gaussian curvature. The Dupin indicatrix is the result of the limiting process as the plane approaches the tangent plane. The indicatrix was invented by Charles Dupin. For elliptical points where the Gaussian curvature is positive the intersection will either be empty or form a closed curve. In the