 He thus developed the de Vallière system, which set the standard for French artillery until the advent of the Gribeauval system.Whereas numerous formats and designs had been in place in the French army, de Vallière standardized the French sizes in artillery pieces, by allowing only for the production of 24 (Canon de 24), 12, 8 and 4 pound guns (the weight is the weight of the cannonballs), mortars of 12 and 8 French inches, and stone-throwing mortars of 15 French inches.The French pound weighing 1.097 English pounds, the French guns fired slightly heavier balls (13.164 pounds) than their English equivalent 12-pounder.