Her armament was carried in a midships armoured compartment which, when used in subsequent designs, became known as a box battery. The designed armament of seventeen guns was discarded, and the offensive power of the ship was concentrated into four 100-pounder Somerset smoothbore cannon, which were at the time the most powerful guns afloat. While these guns were certainly much more effective against armour than smaller pieces, whether a two-gun broadside would have prevailed against more generously armed ironclads is open to question.