The Exploits of Chevalier Dupin the introduction by Ellery Queen, and the non-fiction piece on Dupin by Harrison. "The Exploits of Chevalier Dupin" contains the following tales: The Exploits of Chevalier Dupin The Exploits of Chevalier Dupin is a collection of detective short stories by author Michael Harrison. It was released in 1968 by Mycroft & Moran in an edition of 1,917 copies. The stories are pastiches of the C. Auguste Dupin stories of Edgar Allan Poe. The stories were first published in Ellery Queen's Mystery Magazine. There is an expanded UK edition by a different publisher which adds a further five stories This appeared
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