The ribs are divided into several parts, which are called futtocks. To the ribs the planking is nailed, and bolted through them; after which the seams are caulked. This is done by forcing oakum, saturated in tar or pitch, into the spaces between the planks, when a good coat of tar is laid over the whole. That part of the ship which is always under water is covered with thin sheets of copper. This is done to prevent the attack of a destructive little animal called the wood-worm, which eats its way into and through the planks, making holes nearly an inch in diameter. These holes would, by admitting the water into the hold of the ship, soon sink her, as it is impossible to stop the ravages of these insects while the ship is at sea. The worm attacks every part that is below the water-line in such immense numbers, that every plank in the bottom of a vessel that has not the protection of copper has been found full of them on her arrival into port. The ribs of the ship are of a bent form. Of course no tree would be large enough to form them of one piece; they are, therefore, made in different lengths, each length being called a futtock; and they are distinguished as first, second, or third futtock, according to their position in the ship. These are joined together with great exactness: if not joined properly the vessel would soon tumble to pieces, for, when on a heavy sea, a ship is very much strained in various directions, and the creaking noise the timbers make is so dreadful, that inexperienced persons think the ship is going to pieces. A great deal also depends on the position in which these ribs are placed, not only for the purpose of containing her cargo, but to enable the ship to sail well. Now, if the broadest part be placed too near the stern or after-part of the vessel, which is towards you in the drawing of the launch, she will not pass through the water so swiftly as she would if it were nearer to her bow, or the fore-part of the ship. [Illustration] In the after-part of the ship is the captain’s cabin; the poop is directly over it; and here is the quarter-deck; the middle of the upper deck is called the waist or gangway, and beyond that (forward) the fore-castle. These are all the divisions of the upper-deck, which is largest in the ship, and, in some of our great men-of-war, is three hundred feet long—the depth of hold being from fifty to sixty, and the breadth fifty-five feet. The next deck is the main-deck, and immediately under the captain’s cabin is the admiral’s state cabin. In the fore-part of the ship is the galley or cook’s room, and near to it the sick bay. These are the principal divisions of the main-deck. A portion of this deck, in front of the admiral’s cabin, is commonly called the half-deck.