This joint depends entirely upon the glue unless it is strengthened by a slip feather, as dotted in Fig. 140.
If the boards are of different thicknesses the joint is made as in Fig. 141.
Fig. 131. Scale, 2 inches = 1 foot.
Fig. 142 is a modification of the above; it is a good joint for exterior angles, and can be nailed both ways.
In Fig. 143 the parts are kept together by the form of the joint itself, but it requires a great deal of labour, is very liable to split, and not often used.
A keyed mitre is most generally used for joints visible only on the inside, as the keys are unsightly.