 Alone and unaided he threw himself into mathematical studies; at the end of a year's incessant toil he was already an accomplished mathematician.Charles Emmanuel III appointed Lagrange to serve as the "Sostituto del Maestro di Matematica" (mathematics assistant professor) at the Royal Military Academy of the Theory and Practice of Artillery in 1755, where he taught courses in calculus and mechanics to support the Piedmontese army's early adoption of the ballistics theories of Benjamin Robins and Leonhard Euler.In that capacity, Lagrange was the first to teach calculus in an engineering school.