History of modern literature born. Mikhail Lermontov published "A Hero of Our Time" In 1841 Phillipe-Ignace François Aubert de Gaspé died. Edgar Allan Poe published two short stories: "A Descent into the Maelström" and "The Murders in the Rue Morgue". The latter introduced the fictional detective C. Auguste Dupin. Mikhail Lermontov was killed in a duel. In 1842, Nikolai Gogol published "Dead Souls". In 1843 the transatlantic author Henry James was born. Edgar Allan Poe published a poem: "Lenore" and four short stories: "The Gold-Bug", "The Black Cat", "The Tell-Tale Heart" and a C. Auguste Dupin short story called "The Mystery of Marie Roget".
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