OCAGNE

FRANCE (see also List of Individuals)

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25.3.1862 Paris/F - 23.9.1938 Le Havre/F

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Philbert-Maurice d'Ocagne graduated in 1882 from Ecole Polytechnique as a mathematician to continue his career in the Corps des Ponts et Chaussées. He was then attached to the service of marine works in Rochefort and Cherbourg, then in the Seine-et-Oise Department, and later in the national surveying service in Paris. He was appointed Lecturer at Ecole Polytechnique in 1893 and presided from 1892 to 1905 over the Section of mathematical sciences of the French National Association. In 1901 d'Ocagne was the president of Société Mathématique de France. From 1912 to 1932 he was a professor of geometry at Ecole Polytechnique and of applied geometry at Ecole des Ponts et Chaussées. d'Ocagne was awarded Prix Dalmont in 1894 and Prix Poncelet in 1902 from Académie des Sciences, Paris. He was elected Commander of Légion d'Honneur in 1931.

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d'Ocagne has not particularly contributed to hydraulics but to nomography as was extensively used in hydraulics. Up to the end of the 19th century, experimental data were hardly plotted in diagrams, but mainly listed in tables. A reader then either applied relations proposed by the author directly, or checked them by the data published. Accordingly, the visual data check was hardly used as is currently. d'Ocagne introduced a number of alternative techniques, such as logarithmic diagrams or graphical procedures for solving relatively complex equations. Engineers were always attached to geometrical methods, such as graphical integration up to the computer age or the slide ruler being his typical tool for the solution of daily problems. d'Ocagne thus opened the door for engineers to apply mathematical methods with an engineering approach. He also contributed significantly to the history of mathematical sciences.

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_{Anonymous (1894). Maurice d'Ocagne. Revue Encyclopédique 4: 65. P}

_{Kimpflin, G. (1933). Un grand mathématicien français à l'honneur. L'Illustration (4712):}

_{266. P}

_{Ocagne, M. d' (1891). Nomographie. Les calculs usuels effectués au moyen des abaques. Essai d'une théorie générale, Règles pratiques, Exemples. Gauthier-Villars: Paris.}

_{Ocagne, M. d' (1931). Mathématiciens polytechniciens. Bulletin Société des Amis de l'Ecole Polytechnique (64): 47-66.}

_{Ocagne, M. d' (1932). Hommes et choses de science. Vuibert: Paris.}

_{Ocagne, M. d' (1955). Histoire abrégée des sciences mathématiques. Vuibert: Paris. Poggendorff, J.C. (1898). d'Ocagne, Philbert M. Biographisch-Literarisches Handwörterbuch 3: 982; 4: 1086-1088; 5: 298-299; 6: 1892; 7b: 690-691. Barth: Leipzig, bibliography.}