Mary Rogers body found in the River Seine. Poe presented the story as a sequel to "The Murders in the Rue Morgue" (1841), commonly considered the first modern detective story, and included its main character, C. Auguste Dupin. As Poe wrote in a letter: "under the pretense of showing how Dupin... unravelled the mystery of Marie's assassination, I, in fact, enter into a very rigorous analysis of the real tragedy in New York." In the story, Dupin suggests several possible solutions but never actually names the murderer. Mary Rogers Mary Cecilia Rogers (born c. 1820 – found dead July 28, 1841) was
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