The name
of the groove cut several centimeters from the bottom of one of two posts
erected on each side of an opening into which a ground sill or threshold
must fit. Mortises are made at the base of each post and tenons are made
on each end of the sill or threshold. First, the tenon on one end is fitted
into the mortise on one of the posts. Then the tenon on the other slips
into the the top of the groove. By tapping the member, the tenon will move
down the groove until it drops into the mortise beneath. |