C. Auguste Dupin with an emphasis on the analysis and not trial-and-error. Brander Matthews wrote: "The true detective story as Poe conceived it is not in the mystery itself, but rather in the successive steps whereby the analytic observer is enabled to solve the problem that might be dismissed as beyond human elucidation." In fact, in the three stories which star Dupin, Poe created three types of detective fiction which established a model for all future stories: the physical type ("The Murders in the Rue Morgue"), the mental ("The Mystery of Marie Rogêt"), and a balanced version of both ("The Purloined Letter"). Fyodor
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