269, is made by making a projection or "tongue" in the center of the edge of one board, and a corresponding groove in the center of the other so that they will match together.

When used for flooring, the lower side of the grooved board is slightly rebated so that the upper edges will surely touch.

This sort of flooring can be blind-nailed.
_No.73.A beaded joint_, Fig.

269, is similar to a matched joint except that a bead is worked on one edge to disguise the joint for decorative purposes.
_No.74.A spline-joint_, Fig.

269, is made by plowing corresponding grooves in the edges to be joined and inserting a spline or slip-feather.