The pressure of the clamps may be depended upon to close up the middle, and, especially if dowels are inserted, as in No.

75, the joint will be strong enough to resist the elasticity of the boards.
When the fit is good, warm the wood if possible, prepare the clamps, put a thin film of glue over both edges which are to be together, apply the clamps rapidly, keeping the faces flush, and set away to dry for at least six hours.

Then another piece may be added in the same manner.

If the boards are thin and wide, and therefore likely to buckle, they may first be handscrewed to cross-strips to prevent their buckling.

The cross-strips are, of course, slightly shorter than the combined width of the boards so that the full pressure of the clamps may come on the glued joint.
_No.71.A rebated, rabbeted or fillistered joint_, Fig.269.