The Murders in the Rue Morgue C. Auguste Dupin and the Paris setting. Dupin reappeared in "The Purloined Letter", which Poe called "perhaps the best of my tales of ratiocination" in a letter to James Russell Lowell in July 1844. The original manuscript of "The Murders in the Rue Morgue" which was used for its first printing in "Graham's Magazine" was discarded in a wastebasket. An apprentice at the office, J. M. Johnston, retrieved it and left it with his father for safekeeping. It was left in a music book, where it survived three house fires before being bought by George William Childs. In 1891, Childs
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