for the bow and stern (see A, A′, Fig. 115), to fit between the sides and centre-piece. Make them each a trifle wider than H, I, Fig. 114, so that after they have been fitted they can be trimmed down with a plane, and bevelled on the same slant as the bottom at G, I, Fig. 114. It being 8 feet between the outside of each centre-piece, and the sides and the centre-piece being each 2 inches thick, that gives us 8 feet - 6 inches, or 7-1/2 feet as the combined length of A and A′ (Fig. 115). In other words, each end-piece will be half of 7-1/2 feet long--that is, 3 feet 9 inches long. After making the four end-pieces, each 3 feet 9, by 9 inches, fit the ends in place so that there is an inch protruding above and below. See that your bow and stern are perfectly square, and nail with wire nails through the sides into A and A′; toe-nail at the centre-piece--that is, drive the nails from the broad side of A and A′ slantingly, into the centre-piece, after which trim down with your plane the projecting inch on bottom, to agree with the slant of the bottom of the boat. [Illustration: FIG. 117.--Cross-Section of Boat.] Now for the Bottom. This is simple work. All that is necessary is to have straight, true edges to your one-inch planks, fit them together, and nail them in place. Of course, when you come to the slant at bow and stern the bottom-boards at each end will have to have a bevelled edge, to fit snugly against the boards on the flat part of the bottom of the boat; but any boy who is accustomed to shake the gray matter in his brain can do this. Remember, scientists say that thought is the agitation of the gray matter of the brain, and if you are going to build a boat or play a good game of football you must shake up that gray stuff, or the other boys will put you down as a “stuff.” No boy can expect to be successful in building a boat, of even the crudest type, unless he keeps his wits about him, so I shall take it for granted that there are no “stuffs” among my readers. [Illustration: FIG. 118.] After the boards are all snugly nailed on the bottom, and fitted together so that there are no cracks to calk up, the hull is ready to have The Bumpers nailed in place, at bow and stern. See the plan, Fig. 116, and the elevation, Fig. 117. The bumpers must be made of 2-inch plank, 8 feet long by about 9 inches wide; wide enough to cover A and A´ of Fig. 115, and to leave room for a bevel at the bottom edge to meet the slant of the bow and stern, and still have room at the top to cover the edge of the deck to the hull (see Fig. 117). The Hull May Now be Painted, with two coats of good paint, and after it is dry may be turned over and allowed to rest on a number of round sticks, called rollers. If you will examine Fig. 116 you will see there Twenty-odd Ribs. These are what are called two-by-fours--that is, 2 inches thick by 4 inches wide. They support the floor of the cabin and forward locker, at the same time adding strength to the hull.