of the globe. Shortly after she was begun the French laid the keels of the Normandie and the Invincible on the same plans. England could not afford to lie idle under these circumstances; her naval authorities ordered the building of the Warrior and shortly afterwards of the Black Prince, Defence, and Queen.
In 1861 the seizure of the lower Mississippi by the Confederates rendered the construction of armored ships a necessity, and it was undertaken, not by the Navy, but by the War Department. The first of the iron-clad gun-boats were designed and built by James B. Eads, an engineer of St. Louis, and in a very short time he turned out the St. Louis, Carondelet, Cairo, Louisville, Mound City, Pittsburgh, Cincinnati, and Benton. These boats were plated with iron 2 inches thick on a backing of 4 inches of wood placed at an angle of 45 degrees in order to glance off horizontal shot; they were not impenetrable to heavy guns, but were safe against field-batteries and smaller cannon, and did excellent service in the work for which they were intended. Several other boats of the same kind were built during the course of the war.
Early in 1861, Norfolk, Virginia, was abandoned by the national government and occupied by the Confederates. The retiring garrison set the navy-yard on fire in several places, and much valuable property was destroyed, including several ships. The steam frigate Merrimac was partially burned and then sunk; she was of 3,500 tons burthen, and carried forty guns. After her hull had lain for several weeks under the water, one of the Confederate naval officers proposed to raise her and convert her into an iron-clad gun-boat. The plan was approved by the Navy Department. The Merrimac was raised and cut down to her old berth deck, and at each end of the ship seventy feet of distance was covered over, so that it was only a few inches above the surface of the water when the Merrimac was ballasted for fighting. She was re-
