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 that the class of Dupin cyclides is invariant under Möbius (or conformal) transformations. In complex space formula_2 these three latter varieties can be mapped to one another by inversion, so Dupin cyclides can be defined as inversions of the torus (or the cylinder, or the double cone). Since a standard torus is the orbit of a point under a two dimensional abelian subgroup of the Möbius group, it follows that the cyclides also are, and this provides a second way to define them. A third property which characterizes Dupin cyclides is that their curvature lines are all circles (possibly through