Both wall and front stringers are to be mortised, or housed; for the steps, the treads and risers are to be glued together, wedged and back nailed, as before explained, in order to secure good, solid work. The front stringer has a vertical strip 4 inches wide spliced and glued to it so as to receive the winders. The well hole must be framed wide enough to include, beside the figured width of the stairway, the thickness of the enclosing lining.