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 that the class of Dupin cyclides is invariant under Möbius (or conformal) transformations. In complex space formula_2 these three latter varieties can be mapped to one another by inversion, so Dupin cyclides can be defined as inversions of the torus (or the cylinder, or the double cone). Since a standard torus is the orbit of a point under a two dimensional abelian subgroup of the Möbius group, it follows that the cyclides also are, and this provides a second way to define them. A third property which characterizes Dupin cyclides is that their curvature lines are all circles (possibly through