Armour (iron)--Belt 6in., Battery 6in., Bulkhead 5in., Conning tower 8in. Speed--14.17 knots. Coal--650 tons. Launched--1865; completed, 1866. Cost--Hull and machinery--£322,701. The 12-ton guns were on the main deck, the 6½-ton on the upper deck, two of them being in an armoured bow battery. The _Bellerophon_, completed in 1866, was ship rigged, and carried the then novel feature of an armoured conning tower, abaft the mainmast.[96] She proved extremely handy, her turning circle being 559yds. as against 939yds. for the _Minotaur_ and 1,050yds. for the _Warrior_. A balanced rudder, introduced in her for the first time, helped this result to some extent; but the well thought-out design of this, the first real “battleship,” was the main cause. The _Bellerophon_ was followed by a series of “improved _Bellerophons_,” which will be dealt with later. First, however, it is necessary to revert to the coming of the turret-ship. So long ago as the Crimean War Captain Cowper-Coles had introduced the _Lady Nancy_, “gun-raft,” previously mentioned in connection with that war. In the year 1860 his plans had matured sufficiently for him to make public the designs of a proposed turret ship, with no less than nine turrets in the centre line, each carrying two guns which were to recoil up a slope and return automatically to position. There has been much discussion in the past as to whether Coles or Ericsson, the designer of the _Monitor_, first hit upon the turret-ship idea. As a matter of fact neither of them invented it, as the idea was first propounded in the 16th century, and “pivot guns” had long existed. In so far as adapting the idea to modern uses is concerned, Ericsson was first in the field, but his turret revolved on a spindle. The merit of the Cowper-Coles design was that he evolved the idea of mounting the turret on a series of rollers, thus making it of real practical utility. [Illustration: THE _ROYAL SOVEREIGN_, 1864.] Coles’ ideal turret ship was not received officially with any great show of enthusiasm; as a matter of fact it was an impracticable sort of ship. The famous fight between the _Monitor_ and the _Merrimac_, early in 1862, in the American Civil War, was, however, followed by a perfect “turret craze.” Turret ships were popularly acclaimed as essential to the preservation of British naval power. The idea of a sea-going ship without sail power was unthinkable; but the turret ships for coast defence purposes were demanded with such insistence that in 1862 Captain Coles, now more or less a popular hero, was put to supervise the reconstruction of the old steam wooden line-of-battleship _Royal Sovereign_ into a turret ironclad.