Armour: _Agamemnon_ (1906) 8-in. armour equal to 12-in. four years earlier, 253; _Hercules’_, impenetrable, 159; value of, proved at Lissa, 157; concentration of, at sides, 119; increased thickness, 162; French, 163; _Warrior_, _Devastation_ and _Hercules_ compared, 162, 163; _Inflexible’s_, 2 ft. thick, 176; limit, 176; belts, 165; Armstrong-Whitworth competition, 275; on deflective principle, 242; targets, 275; steel and iron compared, 267, 277; developments, 321; _Rossia’s_ in Japanese battle, 259; tests with H.M.S. _Ruby_, 100; iron plates superposed, 100; rolled armour plates for Crimean War, 100; steel, 20 inches thick, 246; compound belt, 18 inches thick, 247; Harveyised steel, 247, 248 Armour-cased screw frigate, 194 “Armour-patched” ship, 121 Armour plate experiments, 183, 266, 268, 269, 270; “impregnable armour plating,” 269; Italian experiments at Spezzia, 276 Armour plates: _Warrior’s_ costly, 118; tests, 118; _Black Prince’s_, 121; _Glutton’s_, 183 (_see_ Armour _and_ Artillery) Armoured bow citadel, 148; bulkheads, 119, 148 Armoured frigates, 118, 181 Armoured ships (_see also_ Floating Batteries): French Emperor decides to use against Russian forts, 109; French floating batteries, 109, 110; first iron-clad citadel ship in Europe, 109; similar floating batteries built by British, 110; objections to retention of, after Crimean War, 115; Royal Commission (1858) reports French building four iron-plated ships, 117; _Gloire_, battleship, converted to armoured frigate, 117; Britain’s reply with the _Warrior_, 118 Armstrong breech loaders, 148 Armstrong, Sir W., 274