SHIP BUILDING. 41 



against leeway and to increase its capacity for bearing weight. The stem 

 and stern-posts are mortised to each end of the keel at obtuse angles. The 

 former consists of one or more pieces of curved timber, of equal strength 

 with the keel. Behind this is placed the apron, which is of equal breadth, 

 and one third thicker. A knee passes under it to secure it with greater 

 strength to the keel. The stern-post stands inclining back from the keel, 

 in its mortise called the heel. Its thickness equals that of the keel ; its 

 breadth increases towards the lower end five lines for every inch in 

 height, and lessens about one eighth at the top. It also has an apron, with 

 a knee. In large ships there is another post on the outside, which receives 

 the sockets for the rudder pintles. The stern-post must have great 

 strength, as it bears the rudder and the beams which form the stern-frame. 

 The principal timbers in this are the transoms and fashion-pieces. The 

 transoms are placed crosswise of the stern-post, to which they are bolted. 

 Their ends are fastened to the transom knees. The fashion-pieces are 

 similar to the transoms, but shorter, and also bolted to the stern-post and 

 the transonl knees. Besides these are the braces between the bottom of 

 the stern and the transoms. As soon as the stern and stem-posts are 

 erected, a rope is stretched from one to the other, perpendicularly over 

 the keel, in order to guide the carpenter in the symmetrical construction of 

 the remainder of the vessel. The inside timbers (the bow timbers and 

 quarter timbers), consisting of several pieces, are then placed at certain 

 distances on each side of the keel. The form of these timbers, which make 

 an arch of more or less curvature, together with the position of the stem 

 and stern posts, determines the shape of the ship's body. These timbers are 

 either placed directly on the keel, or on planks with which it is covered. A 

 strong piece of timber, called the kelson, is placed over the ends of the tim- 

 bers resting on the keel, and bolted to them and the keel. These timbers 

 are protected by thin ribbons of wood, running the whole length of the 

 vessel, which are removed when the vessel is planked. PL 8, fig. 1, repre- 

 sents a ship of the line on the stocks. 



The deck timbers are then placed across the ship, which not only support 

 the deck planks, but also hold together both sides of the ship. 



All the parts of the frame are made of oak timber, and are fastened with 

 iron or copper bolts and nails. In the East Indies teak-wood and oak 

 are used, and in South America and other warm countries mahogany and 

 cedar. In Sweden and Norway fir timber is also used, but this is wholly 

 unfit for ships of war, since it is splintered by gun-shot, which is not the 

 case with oak timber, a cannon ball passing through that making a round hole. 



2. Planking. When the frame is completed, the main or outside planks, 

 which form the covering of the vessel, are laid on the ribs throughout its 

 whole length. These form the principal connexion between the different 

 parts, and protect the vessel from the pouring in of the Avater. The bottom 

 planks are grooved to the keel ; the ends of the fore and aft planks are 

 attached to the stem and stern-posts in the same manner, but are connected 

 with each other only by close joints. The narrow space between two planks 

 is called a seam, and is caulked with oakum and coated with hot pitch {pi. 8, 



693 



