Fig. 3.
Fig. 4.
Having made both uprights alike, you now turn your attention to the ridgepole. This ought to be somewhat heavier than the uprights, two by six scantling being none too strong for the strain which the weight of your canvas and an occasional gale of wind will put upon it. It is twelve feet long, of course, and six inches from each end will have an iron pin 18 inches in length driven through from its upper side, intended to go through the eyes at the top of the uprights. This is shown in [fig. 5].
On each side of this ridgepole screw in four stout staples or eyes, one at three inches from each end, and the others at equal distances between; to these the rafters are to be attached. (See figs. [3] and [5].) Similar staples must be placed an inch below the upper inside edge of the side walls to contain the irons at the lower end of the rafters, as in [fig. 6]; of course, therefore, it is necessary that the staples in the walls should fall exactly opposite those on the ridgepole.
Fig. 5.