Gentleman detective English country house. This archetype of British detective contrasts with the more "hardboiled" counterpart in American crime fiction. Gentlemen detectives appeared early in modern detective fiction, which began in the late 19th century. C. Auguste Dupin, created by Edgar Allan Poe, is widely considered to be the first fictional detective in English literature. He appeared in three short stories written in the 1840s: "The Murders in the Rue Morgue" (1841), "The Mystery of Marie Rogêt" (1842) and "The Purloined Letter" (1844). Poe created Dupin before the word "detective" had been coined, but began many common elements of detective fiction: Dupin
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