3SO IRON-CLAD SHIPS sides amidships, consists of solid plates 4-J in. thick, backed by 2 ft. of timber. The com- pletion of this ship marks an epoch of the great- est importance in naval warfare and architec- ture. From that day wooden ships gave way to a new class practical- ly impenetrable to the projectiles of artillery, and endowed with speed and sea -going qualities equal to those of the vessels they were des- tined to replace. The science of ordnance and gunnery also received a new impulse, as guns of larger calibre and great- er penetrating power be- came necessary. Every subsequent improvement in the construction of iron-clad ships has been followed if not preceded by a corresponding im- provement in artillery, and in no branch of hu- man industry have greater ingenuity or more persistent efforts been displayed. Shortly after the Gloire was begun, the French laid the keels of the Normandie and the Invincible on the same plans, and the Couronne on the plans suggested by M. Audinet. The construc- tion of these ships was looked upon by all maritime nations as betraying an intention on the part of Napoleon III. to make France the principal naval power of the world, and was regarded by the English as a direct challenge which could only be properly met by the con- struction of a fleet of still more formidable vessels. Accordingly the admiralty ordered the building of the Warrior, and shortly after- ward of the Black Prince, Defence, and Queen. These vessels were the forerunners of a new fleet composed entirely of ironclads, built at an enormous cost, but making good her position as the first naval power of the world. The plating of the Warrior, like that of the Gloire, is only 4$ in. thick, and is applied amidships only. It is backed by 18 in. of teak, and is of uniform thickness, designed to resist 68-pdr. shot and shell. She is a long, handsome frigate, masted and rigged as usual, and sails faster than the Gloire, but owing to her greater length is not so handy at sea. The Defence and the Resistance, constructed upon the same plan, but smaller, soon followed. About the same time the French built the Magenta and the Solferino, admirable vessels, but as war ships in some respects less effective than the Gloire. The example of France and England was soon followed by the second-class naval powers. Austria undertook the construction of two frigates and Italy of two corvettes in 1860. Up to this time all the efforts of con- structors had been directed to the building of vessels after the old patterns, simply using iron instead of wood, or in order to strengthen the wooden walls of old ships, without any essential modification of form or change of model. The outbreak of the civil war in the United States gave a great impulse to invention in this direc. FIG. 5. The St. Louis. tion. The seizure of the important points on the Mississippi river below Cairo enabled the confederates to erect batteries and to stop navigation, and rendered it necessary for the Union fleets to be accompanied by ironclads. The first of these were constructed by James B. Eads, a civil engineer residing in St. Louis. He built the St. Louis, Carondelet, Cairo, Mound City, Louisville, Cincinnati, and Pitts- burgh in 1861, and later the Benton upon the model known subsequently as the "turtle- back." They were plated with iron slabs 2| in. thick and 11 in. wide, rabbeted together and laid on a 4-inch backing of oak inclined at an angle of about 45, and each armed with 13 9- and 10-inch guns. These vessels were built under the orders of the war department, and were the first ironclads actually employed in warfare by the United States. While they were not impenetrable to the fire of heavy rifles, or even to the 8- and 10-inch columbiads used by the confederates, they did excellent ser- vice till the end of the war. Mr. Eads designed and constructed the Osage and the Neosho after the model of the Monitor, each having a turret carrying two 11-inch guns. The turret pla- ting was 6 in. thick, the hull plating 2 in., the deck plating 1 in., while the draught of water was only 4 ft. They were 145 ft. long and 46 ft. wide. He also designed the Winnebago, the Milwaukee, the Chickasaw, and the Kick- apoo, each carrying two turrets, the sides of which were 8 in. thick, with hull plating 3 in. thick, and deck plating 1 in. They were each 226 ft. long, 56 ft. wide, and drew only 6 ft. Each turret carried two 11 -inch guns. The confederates, shortly after the commencement of hostilities, seized the navy yard at Norfolk, in the harbor of which the wooden frigate Merrimack had been scuttled and sunk. They
