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 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