Second, the bevels thus obtained are transferred to the bevel board. It is not always necessary to number them. If they are taken, say at every other frame, and in order, then it is only necessary for the bevel taker to remember where he started taking the bevels.

Figure 94. Figure 95. Ceiling Bevels.

Figure 96. Board.

Figure 97.

The drawings show the beveled edges of the ceiling fitting together for their full width, but it is quite common to fit them together over only two-thirds their width. Where this is done the line for working, or sawing the timber to bevel has to be placed on the inboard face. Also in many yards the ceiling is ordered dressed only on one side, and since the dressed side is the inboard side it is much more convenient to have the cutting fine on this side. But the bevel has been taken for the outboard side, and it therefore must be converted into the proper bevel reading from the inboard side. This is a very simple operation and need not be at all confusing if a little system is followed.

Mark one end of the bevel board "OUT" and the other end "IN." Then in transferring the bevels to the bevel board hold the bevel with the handle pointing as at "A." When taking the bevels off the board, for marking on the inboard face of the ceiling, hold the handle of the bevel as at "B" toward "IN." If the strake is to be marked out on the outboard face hold the bevel with the handle as at "A" or toward "OUT".

The bevels, as marked on the timber, must read in degrees, and must be marked under or standing as the case may be. The degree board is about the most convenient device for converting the angles to degrees. It is best laid out as shown in Fig. 97, and if well made will serve a multitude of uses around the ship.

The widths of the strakes are measured on the outboard faces, and when they are lined, or marked out, on the inboard faces, due allowance must be made for the amount of bevel at each point where the width of the strake is measured.

When ceiling strakes are to be fitted at the bilge or at any point where there is curvature in the frame the outboard faces must be worked off to fay to the frame. In working this face care should be used to take the same amount off each outboard corner so that the bevels will remain correct. The correct shape for working the outside face can be easily found by scribing fids, or small molds from the frames. At the ends of the ship, where the frames change shape rapidly, this should be done at frequent intervals. Experienced men will often estimate the shape with sufficient accuracy.

All ceiling is generally scarfed flat with outboard nibs feathered against the frames. It as also quite common to hold the lengths of these scarfs to two frame spaces, unless the depth of the scarf calls for a greater length when proportioned to rule. The inboard nibs should alwaya be of standard depth.

The scarfs should be well shifted. A common rule is that scarfs in adjoining strake shall have not less than three frame bays between them, and scarfs falling on the same frame shall have not less than three strakes between them. It will be noted that this provides for a closer shift of scarfs than that given in the rules for scarfs in such members as the clamps, shelves and waterways. This is due to the fact that the lengths of ceiling timbers, being generally less than the lengths of clamp strakes, etc., do not permit as great shift of scarfs as can be obtained with the longer timbers.

Ceiling fastening, is commonly driven in the center of the frame timber as shown in Fig. 93. This arrangement reserves the space from the center to edge of the timber for the planking fastening. The staggered arrangement shown in Fig. 92 is an unusual one.

Most ceiling is square fastened, that is, four bolts to each frame are driven, two of them being button-headed bolts driven from the inside to within about one inch of the outside of the frame, and two being headed blunt bolts driven from the outside and clinched over rings on the inside. All of the fastening driven from the outside must be set into the frame to clear the dubbing.

In addition to the above fastening, each strake is usually edge bolted, in alternate frame bays with drifts long enough to pass through two and one-half strakes. In exceptional cases these bolts are driven in each bay. The customary arrangement of these edge bolts is shown in Fig.

92. In Fig. 93 there are no edge bolts, and the bolts driven from the outside are button-headed bolts instead of headed blunt bolts. This is an unusual arrangement.

Thin bottom ceiling, not over five inches thick may be fastened with standard boat spikes. If thicker than this it should be fastened with button-headed drifts as shown in Fig. 92. All of these are of course driven from the inside. Fig. 93 shows thin ceiling between decks fastened with spikes, also thin bottom ceiling fastened in the same manner.

In closing this discussion of ceiling, it may be stated, in order that the reader may obtain a better idea of the reasons for the marked differences in the ceiling shown in Figs. 92 and 93, that the type shown in 92 is used on a vessel which is strengthened with diagonal steel straps on the outside of the frames, while the type shown in Fig.

93, is used in a vessel that is double diagonally planked in the manner indicated in Fig. 85, and which is further reinforced by a belt of steel work in way of the bulwarks.