  the paixhans gun (french: canon paixhans) was the first naval gun designed to fire explosive shells. it was developed by the french general henri-joseph paixhans in 1822-1823. ==background== explosive shells had long been in use in ground warfare (in howitzers and mortars), but they were only fired at high angles and with relatively low velocities. shells are inherently dangerous to handle, and no method had been found to combine the explosive character of the shells with the high power and flatter trajectory of a high velocity gun. however, before the advent of radar and modern optical controlled firing, high trajectories were not practical for marine combat. naval combat essentially required flat-trajectory guns in order to have some decent odds of hitting the target. therefore naval warfare had consisted for centuries of encounters between flat-trajectory cannons using inert cannonballs, which could inflict only local damage even on wooden hulls.of arms and men robert l. o'connell p.193 ==mechanism== paixhans advocated using flat-trajectory shell guns against warships in 1822 in his nouvelle force maritime et artillerie.artillery jeff kinard, spencer c. (int) tucker p.235-236 paixhans developed a delaying mechanism which, for the first time, allowed shells to be fired safely in high-powered flat-trajectory guns. the effect of explosive shells lodging into wooden hulls and then detonating, was potentially devastating. this was first demonstrated by henri-joseph paixhans in trials against the two-decker pacificateur in 1824, in which he successfully broke up the ship. two prototype paixhans guns had been founded in 1823 and 1824 for this test. paixhans reported the results in experiences faites sur une arme nouvelle. the shell
American_Civil_War_artillery Naval_guns_of_France