An iron base-plate with an upright arm welded to it will hold the shaft and the smaller gear, which is to be arranged the right height to lock in with the teeth of the large gear. This plate is shown in Fig. 26; and through the four holes at the corners long screws are passed to bolt the plate securely to a wooden base, which last is set in the ground as shown at A in Fig. 27. The shaft B, to the end of which the small gear wheel is made fast, extends out beyond one of the upright posts, and at the outer end a crank and handle C are made fast, so that by hand-power the platform and shaft may be revolved.
Construct an overhead framework of six by two inch spruce beams twelve feet long, and set them in the ground twelve feet apart, bracing the uprights well, braced at both sides with angle beams as shown in Fig. 23. The top bar should be well braced also with one or two angle brackets, to prevent the frame from rocking. If the ground props are not strong enough to properly brace the frame, attach heavy wires to the corners and carry them out in both directions, making the ends fast to stout pieces of joist embedded in the ground.
At the middle of the top cross-bar arrange a plate of wood eighteen inches long with a groove cut in it in which the pin at the top of the square shaft may revolve. This plate should be attached to the bar with lag screws, so that it can be removed when it is necessary to unstep the shaft and platform. The outer line of deck planking is shown in the deck plan (Fig. 28), and inside of these boards as many others can be laid down as desired; or the entire frame may be all decked over, leaving a small space near the middle so as to reach the gear and lower pin in order to grease them. Where the shaft passes one of the uprights of the supporting frame an iron strap will hold it in place against the wood, and this bearing will require lubrication from time to time.
Four stout wire guys must be drawn from the top of the shaft and fastened at the outer edge of the platform to one of the beam ends. The anchorage should be made with very stout, strong screw-eyes, and to make it easier to draw the wires taut four small turn-buckles should be purchased at a hardware store and made fast to the lower ends of the wires, the hook on the buckle being caught in the large screw-eyes.