Fig. 5 shows the going rod. Put one end of this rod against the back wall, and mark on to it all doorways, trimmer joists, &c. The width of landing and the going must be regulated by circumstances, but the risers, newels and all joists must be marked on to the rod as shown. In putting in these trimmers it is always as well to square them, that is, put them in square to the side walls, then should the back wall be out of square the difference will be in the landing.
Fig. 6 shows the pitch board. These are best made of zinc. Make the rise equal the height of one rise on the height rod, and the going equal the going of one step on the going rod.
Fig. 7 shows the construction of one step. A plan and elevation of the stairs should always be made to a scale of, say, ¾ of an inch to the foot, or, if possible, to 1½ inch to the foot, and all openings, headroom, &c., should be shown. The line H H, Fig. 2, is drawn parallel to the line of nosings on the bottom flight, and at a height above them of 7 feet. Then the bottom edge of the top landing must be kept above this line to give sufficient headroom. The setting out of the strings and glueing up of the steps, &c., will be seen on Plate III.
THE CONSTRUCTION OF VARIOUS PARTS OF STAIRS, SHOWING THE APPLICATION OF THE STEEL SQUARE FOR SETTING OUT STRINGS, ETC.
Fig. 1 shows a cradle for glueing up the steps. Let A be a piece of wood about 18 inches long by 6 inches wide by 2 inches thick, and B should be a piece about 2 feet 6 inches long by 3 inches wide by 2 inches thick. Put a ¾-inch mortise through B and tenon A into it. Well glue and wedge, and pin as shown. Two of these should be made. It will be noticed that E is cut out for the projection of the front edge of the tread past D, which is the face of the riser, and the mortise in B is kept back to E. F is cut out to fit over the scotia. The holes in the edges C and D are for pins to go in, to wedge against when glueing up the steps. The process of glueing up the steps is as follows: first cut off treads, risers, and scotia about 1 inch or 1½ inch longer than their proper length. Now plane up the treads, and shoot the front edges straight and square; then plough the under side for the scotia to go in about ¼ inch deep; then plane up the scotia and gauge them to a width and thickness so as to fit tight into the groove. These scotias should next be glued into the grooves and allowed to dry while the risers are being planed up. Plane up the face of the risers, and shoot the edge to go against the tread straight and square. Now fix the two cradles on the bench, by screwing them through B into the top of the bench. In fixing these, try them with one of the treads so as to get them square; keep them about 6 inches from each end.