History of crime fiction (1839) and Maurits Christopher Hansen's ""Mordet paa Maskinbygger Roolfsen" - The Murder of Engineer Roolfsen" (1839). An example of an early crime/revenge story is the American poet and short story writer Edgar Allan Poe's (1809–1849) tale "The Cask of Amontillado", published in 1846. Poe created the first fictional detective (a word unknown at the time) in the character of C. Auguste Dupin, as the central character of some of his short stories (which he called "tales of ratiocination"). In the words of William L. De Andrea ("Encyclopedia Mysteriosa", 1994), he One of the early developments started by Poe was the
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