Crime fiction by the Danish author Steen Steensen Blicher, published in 1829. Better known are the earlier dark works of Edgar Allan Poe. His brilliant and eccentric detective C. Auguste Dupin, a forerunner to Arthur Conan Doyle’s Sherlock Holmes, appeared in works such as "The Murders in the Rue Morgue" (1841), "The Mystery of Marie Roget" (1842), and "The Purloined Letter" (1844). With his Dupin stories, Poe provided the framework for the classic detective story. The detective’s unnamed companion is the narrator of the stories and a prototype for the character of Dr. Watson in later Sherlock Holmes stories. Wilkie Collins' epistolary
Charles Dupin and value of French exports and imports, with comparative figures for 1823, 1827 and 1834. In addition, he had a political career and was appointed to the Senate in 1852. His mathematical work was in descriptive and differential geometry. He was the discoverer of conjugate tangents to a point on a surface and of the Dupin indicatrix. Charles Dupin Baron Pierre Charles François Dupin (6 October 1784, Varzy, Nièvre – 18 January 1873, Paris, France) was a French Catholic mathematician, engineer, economist and politician, particularly known for work in the field of mathematics, where the Dupin cyclide and Dupin indicatrix