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 "R" are a 3-dimensional vectors, and "A" and "B" are constants. Families of cyclides give rise to various cyclidic coordinate geometries. In Maxime Bôcher's 1891 dissertation, "Ueber die Reihenentwickelungen der Potentialtheorie", it was shown that the Laplace equation in three variables can be solved using separation of variables in 17 conformally distinct quadric and cyclidic coordinate geometries. Many other cyclidic geometries can be obtained by studying R-separation of variables for the Laplace equation. 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