The Four-blade Windmill shown in Fig. 6 has a hub 4 inches in diameter and 1 inch thick (Fig. 7). This should be cut out of hard wood. Draw two lines across one face, through the center, and at right angles to each other. Then carry these lines across the edge of the block, not at right angles to the sides, but at an angle of 45 degrees. Saw along these lines to a depth of 1¼ inches. The ends of the windmill blades are to fit in these slots.
Fig. 6.—A Four-blade Windmill.
Fig. 7.—Hub.
Fig. 8.—How to Slot End of Shaft for Tail.
Cut the blades of equal size, 9 inches long, 5 inches wide on the wide edge, and 1½ inches wide on the narrow edge, and fasten them in the slots with nails.
With the blades in position, pivot the hub to the end of the windmill shaft, a stick 20 inches long (Fig. 6). The end opposite to that to which the hub is pivoted is whittled round, and slotted with a saw to receive a tail (Fig. 8). The tail may be of the same size as the blades, though it is shown shorter in the illustration.
Mount the Windmill upon a post, pivoting its shaft at
