Turn the piece over, and repeat the operation on the other side, when the chips can be easily removed. Proceed to test the work; see that the mortise is straight on the ends. Generally the student will leave the ends rounding as shown in [Fig. 70]; this, if the tenon is driven into the mortise, will squeeze the edges out of true ([Fig. 71]) and leave an opening on the ends of the mortise, as shown in [Fig. 72].

Fig. 71.

Fig. 72.

Care should be taken to avoid this fault in this exercise. (A mortise gauge such as a joiner uses is shown in [Fig. 73]; it has two spurs, one being adjusted by the thumb screw at the end of the shank. We will use a mortise gauge in our work later on.)

Fig. 73.

After the pieces have been cut, put them together, having the face sides together, and finish smoothly.

EXERCISE NUMBER 4.
KEYED MORTISE AND TENON,
WITH BRACE.