Make a mould to ia), from the upper breadth upwards, some length above the gunwale, by which mould most of the timbers in the top-side may be drawn, by keeping them nearly parallel to each other, by so fixing the mould as to inter sect the upper breadth sweep and top timber half breadth. But observe, the top timbers, as they approach the back head in the fore body, they flair out, or curve the reverse of the midship timbers, and considerably so in ships with a beak head ; this not only gives more room on the forecastle, but assists the cat-heads to cull the anchors clearer of the bow, and this flairing, though much less in other ships, has a tendency to keep off the spray of the sea, and make a dry fore castle.
Above the top-timber line in this ship, and sometimes at the plank sheer in others, the top-side is perpendicular; con sequently an angle, called the knuckle, is formed at the intersection, and as many of the foremost timbers as partake of this shape, before they can be broken in fair with the others, are called knuckle tim bers.
Forward and aft to the top-sides run higher than the top-timber line, set up their greatest heights to prove that their breadths at that place may make a fair line in the half breadth plan. Set up from F to forward, in the sheer plan, 2 feet 10 inches above, and draw a line pa rallel to the top-timber line ; and from 12 to 24, in the after body, 4 feet 6 inches ; and from 24, quite aft, 6 feet 6 inches these risings above the gunwale, or the midships, are called drafts. Transfer those heights from the sheer plan to in tersect their corresponding timbers in the body plan, as they are then limited by curves parallel to the top-timber line; then transfer their several half breadths to their corresponding timbers in the half breadth plan, and if curves drawn through those breadths should prove fair, the top-side is rightly constructed ; if other wise, each must be altered until they agree.
What remains to be described relates equally to both the fore and after bodies; for their being thus far completed, we have an opportunity of shifting the seve ral timbers to the various lengths that compose them from the keel upwards, such as the floors, futtocks, and top-tim bers. First, the length of the floors for a ship of this magnitude is 26 feet long at e, or midships, and the lengths of those forward and aft may be determined by a diagonal line thus drawn in the body plan ; set up the middle line above the upper edge of the keel 14 feet 6 inches, and on the base line, 14 feet on each side the middle line, draw lines to those spots, and the length of each floor is limited be tween those lines. Then, to determine
the heads or lengths of the lower or first futtocks, set up the middle as before 22 feet 10 inches, and alone the base line on each side 24 feet, drawing diagonal lines as for the floors, and the length of the lower futtocks are limited from the side of the keel to the diagonal line at their heads. Then, for the lengths of the se cond futtocks, set up the middle line 28 feet 8 inches, and up each side line from the base 10 feet, and draw the diagonals and the lengths of the second futtocks as limited from their junction at the floor head, called the heel, to the diagonal last drawn or head. Then, for the lengths of the third futtocks, set up the middle line 34 feet 8 inches, and up each side 18 feet 5 inches; then diagonals, when drawn to these spots, will limit the length of the third futtocks from its heel at the first head. The fourth futtocks, when they can be gotten, are in one length from the second futtock head to the top of the side, and the top.timbers from the third futtock head to the top of the side.
The heads of the timbers being shown in the body plan, direct the stations for the ribbands thus : place the floor ribband about 20 inches below the floor head, and parallel thereto ; then the next or first futtock ribband about midway be tween the floor and first futtock heads. and so with the others, keeping their heights forward and aft, the most conve nient for supporting the heads and heels of the timbers, before they need be dis turbed by working the planks outside.
Now these are called the ribband lines, and only appear as diagonal lines in the body plan, but they take their names from the ribbands, which are pieces of oak or fir timber, about 6 inches square, the lenger the better; but those close for ward and aft are called harpists, and are trimmed by moulds and bevellings to the form of the ship at those places. Rib band lines form curves on a ship's bottom by the intersection of a plane inclined, or canted, as shipwrights term it, to the plane of elevation, and their curves on the half breadth plan are denominated by them canted, or level, according as their several half breadths are taken off from the body plan, whether diagonally, or in a direction square from the middle line, which is a level or perpendicular to the plan of elevation; and although they agree in one and the same line on the ship's bottom, they represent very differ ent curves in the half breadth plan.