To begin with, ten of the largest ships in the Spanish navy were to be sacrificed: for it seemed like a sacrifice to cut down the huge bulwarks of their towering sides. But show was to be sacrificed to strength. The new constructor would have no more three-deckers, nor two-deckers. All he wanted was one broad deck, reaching the whole length of the ship, from stem to stern, which should be as solid as if it were a part of the mainland, or a floating island, on which he could plant his guns as on the ramparts of a fortress. Having thus dismantled and razeed the great ships, he proceeded to reconstruct them without and within. His method is of interest, as showing how a hundred years ago a naval engineer anticipated the modern construction of ironclads. His battering ships were in outward shape almost exactly what the Merrimac was in our civil war. He did everything except case them with iron, the art of rolling plates of wrought iron, such as are now used in the construction of ships, not being then known. But if they could not be "plated" with iron on the outside, they were "backed" by ribs of oak within. Inside their enormous hulls was a triple thickness of beams, braced against the sides. Next to this was a layer of _sand_, in which it was supposed a cannon-ball would bury itself as in the earth. To this sand-bank, resting against its oaken backing, there was still an inner lining in a thick wall of _cork_, which, yielding like india-rubber, would offer the best resistance to the penetration of shot. Having thus protected the hulls, it was only necessary to protect the crews. For this the decks were roofed with heavy timbers, which were covered with _ropes_, and next with _hides_, after the manner of the ancient Romans; so that the men working at the guns were almost as secure from the enemy's fire as if they were inside of the strongest casemates that the art of fortification could construct. Thus shielded above and below--from the deck to the keel--these novel ships-of-war were in truth floating fortresses, and it was hardly presumptuous in their constructor to say that they "could not be burnt, nor sunk, nor taken."