No mechanical toy is more interesting to make, nor more interesting to watch in operation, than a miniature windmill. It is a very simple toy to construct, and the material for making one can usually be found at hand, which are two reasons why nearly every boy and girl at one time or another builds one.

The Paper Pinwheel shown in Fig. 1 is one of the best whirlers ever devised. A slight forward thrust of the stick handle upon which it is mounted starts it in motion, and when you run with the stick extended in front of you it whirls at a merry speed.

A piece of paper 8 or 10 inches square is needed for the pinwheel. Fold this piece of paper diagonally from corner to corner, both ways. Then open the paper, and with a pair of scissors cut along the diagonal creases, from the corners to within ½ inch of the center (Fig. 2). Next, fold corners A, B, C, and D over to the center, as shown in Fig. 3, run a pin through the corners and through the center of the sheet of paper, drive the point of this pin into the end of the stick handle, and the pinwheel will be completed.

The Pinion-wheel Windmill in Fig. 4 may be made of cardboard or tin. A circular piece 10 or 12 inches in diameter is required. After marking out the outer edge with a compass, describe an inner circle about 1 inch inside of it; then draw two lines through the center at right angles to each other, and another pair at an angle of 45 degrees to these. These lines are shown by the heavy radial lines in Fig. 5. One-half inch from each of these lines draw a parallel line, as indicated by dotted lines in Fig. 5. The next thing to do is to cut out the disk, and cut along the heavy lines just as far as the lines are shown in the diagram (Fig. 5), and then to bend up the blades thus separated, to an angle of about 45 degrees, bending on the second set of radial lines (dotted lines in Fig. 5).

You had better make a cardboard pinion-wheel first, then a tin one afterwards, as cardboard is so much easier to cut. A pair of heavy shears will be necessary for cutting a tin wheel, and a cold chisel for separating the edges of the blades.

To Mount the Pinion-wheel drive a long nail through the center, through the hole in a spool, and into the end of a stick. Then nail the stick to a post or a fence top.

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.

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 the balancing center with a nail or screw. Bore a hole large enough so the shaft will turn freely upon the pivot, and the windmill will thus keep headed into the wind.

The Eight-blade Windmill in Fig. 9 has a spool hub (Fig. 10), and blades made of cigar-box wood, shingles, tin, or cardboard (Fig. 11). You will see by Figs. 10 and 11 that the blades are nailed to the side of short spoke sticks, and the sticks are driven into holes bored in the spool hub. The hub turns on the rounded end of the shaft stick (Fig. 12), and the square end of this shaft is slotted to receive the fan-shaped tail (Figs. 12 and 13).

For the Hub use a large ribbon-spool. You can get one at any drygoods store. Locate eight holes around the center of the spool at equal distances from one another, and bore these with a gimlet or bit, or cut them with the small blade of your jack-knife.

Cut the Eight Blades 6 inches long, 5 inches wide on their wide edge, and 1½ inches wide on their narrow edge. Prepare the hub sticks about ½ inch by ¾ inch by 4½ inches in size, and whittle one end pointed to fit in the hub (Fig. 11). Fasten the blades to the spokes with nails long enough to drive through the spokes and clinch on the under side. Glue the spokes in the hub holes, turning them so the blades will stand at about the angle shown.

The Shaft should be made of a hard wood stick about ¾ inch by 1½ inches by 30 inches in size. Cut the round end small enough so the hub will turn freely on it, and punch a small hole through it so a brad may be driven through to hold the hub in place. Cut the slot in the square end with a saw.

Cut the Tail of the shape shown in Fig. 13.

Pivot the Windmill upon the top of a post support, in the same manner as directed for the other windmills.

Figure 14 shows how the toy windmill may be rigged up

To Operate a Toy Jumping-Jack, by supporting the jumping-Jack on a bracket, and connecting its string to the hub of the windmill. You can make your jumping-Jack like the one in Fig. 110, the details of which are shown in Fig. 113.

Cut the upright of the bracket (A, Figs. 14 and 15) 14 inches long, and the crosspiece (B) 7 inches long. Nail A to B, and nail the jumping-Jack at its center to the end of B (Fig. 15). Fasten the triangular block (C) to the lower end of A, and then nail both A and C to the edge of the shaft at a point that will bring the string of the jumping-Jack a trifle beyond the windmill blades.

Fasten a small stick with a brad driven in one end, in notches cut in the hub's flanges (Fig. 16), and connect the brad and Jack's string with a piece of wire or strong string. Then as the windmill revolves it will operate the toy in the manner indicated in Figs. 14 and 15.