The Purloined Letter The Purloined Letter "The Purloined Letter" is a short story by American author Edgar Allan Poe. It is the third of his three detective stories featuring the fictional C. Auguste Dupin, the other two being "The Murders in the Rue Morgue" and "The Mystery of Marie Rogêt". These stories are considered to be important early forerunners of the modern detective story. It first appeared in the literary annual "The Gift for 1845" (1844) and was soon reprinted in numerous journals and newspapers. The unnamed narrator is discussing with the famous Parisian amateur detective C. Auguste Dupin some of his most
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