Philibert Maurice d'Ocagne

Pioneer of nomography — the systematization of graphical calculation methods using nomograms — d'Ocagne was a French engineer and mathematician whose scientific personality soon fell into oblivion, leaving only a few milestones of his professional life registered, embodied in various engineering positions and senior teaching roles in French public life.

In 1885 d'Ocagne joined the French corps of engineers of bridges and roads (Corps de Ponts et Chaussées) and moved to Cherbourg, in whose area he spent several years working on water projects. In 1894 he occupied a chair at the École Nationale des Ponts et Chaussées, and in 1901 he was appointed director of the French mapping service. In 1912 he was appointed professor at the École Polytechnique. In 1920 he became the general inspector of roads and bridges in France.

In 1922 d'Ocagne joined the prestigious Académie des Sciences, which had awarded him twice before — once in 1892 (Leconte Award) for his work on nomografía, and again in 1894 (Prix Dalmonte) for his mathematical work. His main interest focused on mechanical aids to perform complex mathematical calculations, a field in which he was a recognized expert. Within this field, his most personal and innovative contributions took the form of graphical methods, whose multiplicity he systematized and clarified, and he was assigned the name nomografía, or calculation by means of nomograms.

He published the book Cours de Géométrie descriptive et de Géométrie infinitésimale in 1896, and in 1899 he published Traité de Nomographie. Another of his works, Le calcul simplifié, is the most systematic and comprehensive catalog of all types of resources used throughout history for the facilitation of mathematical calculations to the end of the first quarter of the twentieth century, when the great revolution that began in this area came to be assumed by the major mechanical calculating machines, and especially electronics.