Michael Harrison (writer) Michael Harrison (writer) Michael Harrison (25 April 1907 – 13 September 1991) was the pen name of English detective fiction and fantasy author Maurice Desmond Rohan. Michael Harrison was born in Milton, Kent, England, on 25 April 1907. He attended the University of London and served briefly in the British Military Intelligence during World War II. He married Marie-Yvonne Aubertin. Harrison published seventeen novels between 1934 and 1954 when he turned to writing detective fiction. He wrote pastiches of Conan Doyle's Sherlock Holmes and Poe's C. Auguste Dupin and was a noted Sherlock Holmes scholar. His most successful work, "In
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