3.
Box.4.

Key-pin.] (2) According to the _method of application_, as rim locks, which are fastened on the surface, and mortise locks which are mortised into the edge of a door or drawer or box.
INSERTING LOCKS To insert a _rim-lock_, measure the distance from the selvage to the key-pin, locate this as the center of the keyhole, and bore the hole.
If the lock has a selvage, gain out the edge of the door or drawer to receive it.

If the lock box has to be gained in, do that next, taking care that the bolt has room to slide.

Cut the keyhole to the proper shape with a keyhole-saw or small chisel.

Fasten the lock in place, and if there is a strike or face-plate, mark its place and mortise it in.
[Illustration: Fig.237.