C. Auguste Dupin with artistic imagination. As an observer, he pays special attention to what is unintended, such as hesitation, eagerness or a casual or inadvertent word. Dupin's method also emphasizes the importance of reading and writing: many of his clues come from newspapers or written reports from the Prefect. This device also engages the readers, who follow along by reading the clues themselves. Poe may have gotten the last name "Dupin" from a character in a series of stories first published "Burton's Gentleman's Magazine" in 1828 called "Unpublished passages in the Life of Vidocq, the French Minister of Police". The name also
Dupin cyclide Dupin cyclide In mathematics, a Dupin cyclide or cyclide of Dupin is any geometric inversion of a standard torus, cylinder or double cone. In particular, these latter are themselves examples of Dupin cyclides. They were discovered by (and named after) Charles Dupin in his 1803 dissertation under Gaspard Monge. The key property of a Dupin cyclide is that it is a channel surface (envelope of a one-parameter family of spheres) in two different ways. This property means that Dupin cyclides are natural objects in Lie sphere geometry. Dupin cyclides are often simply known as "cyclides", but the latter term is