C. Auguste Dupin implies "duping" or deception, a skill Dupin shows off in "The Purloined Letter." Detective fiction, however, had no real precedent and the word "detective" had not yet been coined when Poe first introduced Dupin. The closest example in fiction is Voltaire's "Zadig" (1748), in which the main character performs similar feats of analysis, themselves borrowed from "The Three Princes of Serendip", an Italian rendition of Amir Khusrau's Hasht Bihisht. In writing the series of Dupin tales, Poe capitalized on contemporary popular interest. His use of an orangutan in "The Murders in the Rue Morgue" was inspired by the popular reaction
Dupin cyclide also used to refer to a more general class of quartic surfaces which are important in the theory of separation of variables for the Laplace equation in three dimensions. Dupin cyclides were investigated not only by Dupin, but also by A. Cayley und J.C. Maxwell. Today, Dupin cylides are used in computer-aided design (CAD), because cyclide patches have rational representations and are suitable for blending canal surfaces (cylinder, cones, tori, and others). There are several equivalent definitions of Dupin cyclides. In formula_1, they can be defined as the images under any inversion of tori, cylinders and double cones. This shows