Arthur Conan Doyle study of such a character [viz., Bell] I used and amplified his methods when in later life I tried to build up a scientific detective who solved cases on his own merits and not through the folly of the criminal." Robert Louis Stevenson was able, even in faraway Samoa, to recognise the strong similarity between Joseph Bell and Sherlock Holmes: "My compliments on your very ingenious and very interesting adventures of Sherlock Holmes. ... can this be my old friend Joe Bell?" Other authors sometimes suggest additional influences—for instance, the famous Edgar Allan Poe character C. Auguste Dupin. Dr. (John)
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