**Amédée Mannheim** was a French mathematician and the inventor of the modern slide rule.

- From an early age Amédée showed a very strong aptitude for the exact sciences.
- Now although the Institution Martelet was the standard route for pupils going on to the École centrale, nevertheless, Mannheim quickly left the École and, instead, prepared for entering the Grand Écoles at the Collège de Charlemagne.
- The summer of 1848 between Mannheim completing his studies at the Collège de Charlemagne and entering university, was a time of revolution in Paris.
- These must have been extremely difficult time for the young Mannheim, particularly since his teacher Catalan was involved in the revolution.
- Mannheim entered the École Polytechnique in Paris in 1848 at the age of 17, again the youngest student in the course.
- While he was at the École Polytechnique he got to know his fellow student Charles Nicolas Peaucellier (1832-1919) who later invented mathematical instruments inspired by Mannheim.
- One of their teachers was Michel Chasles whose lectures on geometry had a major influence on the young student Mannheim.
- The director of the École Polytechnique for the two years that Mannheim studied there was Jean-Victor Poncelet who, like Chasles, was to have a major influence on Mannheim.
- Poncelet retired in the year that Mannheim graduated but the two collaborated some years later.
- After two years studying at the École Polytechnique, Mannheim went to Metz where he attended the École d'Application.
- Although slide rules existed before Mannheim's time, invented by William Oughtred and Edmund Gunter and others, it was Mannheim who standardised the modern version of the slide rule which was in common use until pocket calculators took over a few years ago.
- It was around 1850, while he was a student at Metz, that the ideas for this slide rule came to Mannheim.
- Such is the Mannheim Slide Rule.
- The glass Runner that Cox mentions was a clever idea by Mannheim and it is more often today called a cursor or indicator.
- After graduating from the École d'Application in Metz, Mannheim became an officer of the French artillery.
- After several years in the military, Mannheim was appointed to the École Polytechnique in Paris, while continuing his army career.
- In the following year Mannheim was appointed as Professor of Descriptive Geometry at the École Polytechnique.
- We mentioned above that Charles Nicolas Peaucellier was a fellow student of Mannheim's at the École Polytechnique.
- Like Mannheim, he made a career in the French army.
- Inspired by Mannheim, in 1864 he reported on his invention of a mechanism to convert rectilinear motion into circular motion.
- Mannheim was involved with the Society from its foundation and published Sur les trajectoires des points d'une droite mobile dans l'espace Ⓣ(On the paths of points of a movable line in space) (1873) in the first volume of the Bulletin.
- In 1880 Mannheim published the book Cours de géométrie descriptive de l'École Polytechnique comprenant les éléments de la géométrie cinématique Ⓣ(Course in descriptive geometry given at the Ecole Polytechnique, including the elements of the kinematic geometry.).
- Mannheim retired from his army post in 1890, having attained the rank of colonel in the engineering corps.
- Mannheim's own definition of kinetic geometry considered it to be the study of motion of a figure without reference to any forces, time or other properties external to the figure.
- The list of Mannheim's publications shows that in the four years before he retired he published very little (by his standard) but after retiring he returned to his remarkable, but typical, quantity of papers right up to the time of his death.

Born 17 July 1831, Paris, France. Died 11 December 1906, Paris, France.

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**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive