Detective fiction underworld and undercover surveillance, rather than brilliance of imagination or intellect. Detective fiction in the English-speaking world is considered to have begun in 1841 with the publication of Poe's "The Murders in the Rue Morgue", featuring "the first fictional detective, the eccentric and brilliant C. Auguste Dupin". When the character first appeared, the word detective did not even exist. However, the character's name, "Dupin", originated from the English word dupe or deception. Poe devised a "plot formula that's been successful ever since, give or take a few shifting variables." Poe followed with further Auguste Dupin tales: "The Mystery of Marie
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