Fig. 278. The drawings should be as in fig. 278, showing plan, end, and side elevation.

The timber is 1 3/8 in. wide, 7/8 in. thick, and two pieces 12 1/2 ins. long and two 8 1/2 ins. long will be required.

In this case the tenon is dovetailed from edge to edge, as will be seen in the end section of the isometric sketch of joint (fig. 279). This form of dovetailing is preferable to the preceding, where strength is required, although the altered shape does not bring the shoulders of the tenon up so well.

Elevation.

Side elevation.

Plan.

Fig. 278.

Set out the work, marking opposite similar pieces simultaneously, and observe that both ends of the shorter pieces or rails are cut into tenons, and the rails are mortised to take them. This is done for convenience in cramping, for it is obviously easier to screw up a short piece than a long one. After cutting out the tenons, as in the former case, apply them to the mortices - this time, of course, to the side, not the end of the wood, and mark with a chisel as before. The gauging is done on the ends of the stiles, and there is no need to mark out the shape of the mortice on the back edge, as an inaccuracy in marking would lead to error in work. By this time, too, the pupil should not have much difficulty in sawing down the mortice without a line on the back edge to guide him.

Fig. 279.

Great care must be taken in making this framing true and square in all its joints.

Should it be wished to rebate the frame to take a picture or looking-glass, the shoulders of the tenon will be of unequal length, and the cheeks of the mortice will vary correspondingly. Fig. 280 shows the shape of the joint in this case.

Fig. 280.