Fig. 3.
Fig. 4.
Fig. 5.
The next thing is to connect your four runners with cross bars (Fig. 5) which are each fourteen inches long, two and a half inches broad, and one inch thick. Of these cross bars there are four. The distance from A to B and from C to D is one inch in each case. These ends are shaped to form what joiners call dovetails, and they should fit exactly into the mortices upon the upper edges of the runners. The black dots represent screws. One of the cross bars does not appear in Fig. 13. The runners should be shod with iron by the blacksmith.
Fig. 6.
He will need eleven-and-a-half feet of half round 5/8 inch rolled iron, divided into four, a piece for each runner. Each piece will be 34 inches long pierced for screws as in Fig. 6. A and B are an inch from centre to centre. C is eight inches from the end, D another ten inches; E a further ten inches. F G are like A and B.