‘I’m Just a Mathematician’: Why and How Mathematicians Collaborated with Military

Abstract. This article examines the way in which mathematicians were led to contribute to ballistic studies in France during World War I. It pays special at-tention to the French Navy’s Gâvre Experiments Commission first established in 1829, where university professor Jules Haag, military engineer Maurice Gar-nier and high school teacher Osée Marcus jointly developed a new method for computing ballistic trajectories (the so–called GHM method). It highlights the difficulties and successes encountered by mathematicians when they ap-proached this military culture that already was mathematically sophisticated. It reviews briefly the history of ballistics at Gâvre before the First World War to understand the bitter feeling among artillerymen serving on the front about the inadequacies of their ballistic tables. In a final part, the technical con-tributions made by mathematicians, their experimental practices, and their effort for dissiminating their results are examined. This paper focuses on the role of several tensions between civilians and military science, betwen theory and experiment, between front and rear, etc. for undertanding the value of mathematicians ’ contributions to the war effort