1831-1906

French mathematician who developed the style of slide rule that would become the standard for over 100 years. Although Mannheim did not invent the slide rule (versions had existed for some years), he was responsible for standardizing it in the form that became commonplace until the popularization of pocket calculators in the 1970s. Mannheim, an officer with the French Artillery, also studied surfaces and Chasles's theory of transformations.