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 cyclide Dupin cyclide In mathematics, a Dupin cyclide or cyclide of Dupin is any geometric inversion of a standard torus, cylinder or double cone. In particular, these latter are themselves examples of Dupin cyclides. They were discovered by (and named after) Charles Dupin in his 1803 dissertation under Gaspard Monge. The key property of a Dupin cyclide is that it is a channel surface (envelope of a one-parameter family of spheres) in two different ways. This property means that Dupin cyclides are natural objects in Lie sphere geometry. Dupin cyclides are often simply known as "cyclides", but the latter term is