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 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