C. Auguste Dupin to an orangutan that had been on display at the Masonic Hall in Philadelphia in July 1839. In "The Mystery of Mary Rogêt", he used a true story that had become of national interest. C. Auguste Dupin is generally acknowledged as the first detective in fiction. The character served as the prototype for many that were created later, including Sherlock Holmes by Arthur Conan Doyle and Hercule Poirot by Agatha Christie. Conan Doyle once wrote, "Each [of Poe's detective stories] is a root from which a whole literature has developed... Where was the detective story until Poe breathed the breath
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