Looking like a "Cheesebox on a raft", this ship is most famous for its participation in the first ever naval battle between two ironclad ships when it battled the CSS Virginia near Hampton Roads, Virginia. The ship was engineered by John Eriksson.
The ship consisted of a heavy, round iron turret on the deck, which housed two large cannon. The armored deck was barely above the water line. Aside from a smoke stack and a few fittings, the bulk of the ship was below the water line, to prevent damage from cannon fire (torpedos were not a worry for another 50 years).
It was lost at sea during a heavy storm, swamped by high waves.