266, is similar to the simple mortise-and-tenon described in 30.

The tenon does not extend thru the mortised member and the cheeks of the tenon may be cut on two or four sides.
To make a blind mortise-and-tenon, first make the tenon thus: Locate accurately with a knife point the shoulders of the tenon and square entirely around the piece.

On the working edge near the end mark the thickness of the tenon.

Set the marking-gage at the proper distance from the working face to one cheek of the tenon and gage the end and the two edges between the end and the knife-lines.

Reset the gage to mark the thickness of the tenon and gage that in the same way from the working face.