This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
This is a useful joint for uniting pieces of wood at right angles, as in the sides of a box, where much strength is not needed. Each end is mitred off and the bevels are then joined by glue. When the glued joint is quite firm, a few saw cuts are made in the angle, so as to cross both pieces forming the joint, and into the kerfs are driven small slips of wood previously well glued. After all has dried, the projecting ends of the keys are cut off. The direction of the saw cuts should not be horizontal: some may incline upwards and some downwards.