The great ships of the early Tudors were an exaggeration of the cogs of the Middle Ages. They were longer, broader, and built much higher in the sides. But they had the same towering castles at bow and stern. The word forecastle preserves the memory of the species of fort which once cumbered the fore part of ships. These fortresses were shut off from the rest of the ship by barriers, called, in later times at least, cobridges, and defended even when the enemy was in possession of the waist. Small guns, called "murdering pieces," were mounted on them, to clear the deck on emergency. As parts of a castle they had their merits, but they were very dangerous top hamper for a ship. The fate of the =Mary Rose=, which will be mentioned later on, shows how easily vessels of the time were upset. Their instability was exaggerated by the nature of the rigging. In the largest vessel there were four masts--one at the prow, another at the stern, and two between. They were apparently complete spars, not divided, as in later times, into lower mast and topmast. Each carried a great square sail or course of excessive height, to which a topsail could be added. The strain thrown on the hull by these great sails must have been severe. It was aided by the castles, which had a constant tendency to tear away when the ship was rolling. As the structure was weak, and the caulking alone was trusted to keep the ships watertight, it is easy to understand that a very short cruise or a very moderate spell of bad weather was enough to reduce the noblest of them to the condition of a sieve. Indeed, the unfitness of the "capital ships" of the sixteenth century for winter cruising was recognised by everybody. Even a hundred years later, when many improvements had been introduced, naval officers were reluctant to keep large vessels at sea after summer was over. As late as the reign of William III., at the end of the seventeenth century, a council of officers declared that the heavier line-of-battle ships could not be safely kept out after the first days of autumn. In the earlier Tudor times they were of use only in fine-weather months. The smaller vessels, being less built upon, and not subject to the same amount of leverage tending to tear them to pieces, were more seaworthy. As they must also have sailed very badly, there is no apparent reason for the confidence inspired in our ancestors by the presence of one of these "capital ships." They must be supposed to have trusted it to bear down opposition by its mere weight, just as a very fine corps of mail-clad horsemen would sweep lighter opponents before them on the field of battle.