PUTTING the wind to work has always been a lot of fun, so here are three novel animations driven by small windmills. In the first a hopeful fisherman tries everlastingly to land a whale. The cutouts are of waterproof outdoor plywood and are operated by a connecting rod on a crank disk, as shown. Bearings of brass tubing make for easy running and long life. Note that both spindle and revolving shaft are set off-center to avoid interference. The propellers in this and the other two projects are of conventional two-blade design.
The brightly painted, old-time "iron horse" never gets anywhere, but it runs at full speed whenever the breeze freshens. The drive wheels ride on a roller turned by the propeller through a cord belt. Connecting rods of duralumin (there is one on each side) or other rustproof metal slide back and forth through an oversize hole in each dummy wood cylinder.
Steeplechase Steve consists of a plywood silhouette and a rocking link.
ALL you need here is a toy balloon, nozzle (like an eyedropper with the rubber removed) a rubber band and match sticks.
Fasten the rubber band around the mouth of the balloon fairly tightly, yet loose enough so that a little air will escape after you blow it up. In between the folds of the rubber band, stretch two or more match sticks or a cork, so that the nozzle will be nearly horizontal, and just a little below the surface of the water.
Now blow up the balloon, and place in a bathtub of water, with the nozzle just covered with water. The escaping compressed air will put-put the boat ahead.
Illustrate one of the greatest scientific discoveries-how an engine may be worked by steam-and have fun at the same time!
Take an old coffee can and in the center of the cover cut out a small round hole. Fill the can half full with water, and place it over the stove until it begins to spout steam. Then place loosely in the hole a solid rubber stopper.
The pressure of the steam will cause the stopper to pop merrily up and down.
A somewhat similar effect can be gained by stopping up the spout of an ordinary tea kettle, whereupon its lid, if it fits loosely, will bob up and down in a similar manner.
A weight revolving in a circle is pulled, by the force or power known as centrifugal force, as far as possible away from the center of the circle.
You can easily demonstrate this force right in your own home by means of an umbrella and a glass of water. Pick a spot in the kitchen or down in the basement, rather than on your best living room rug.
Open the umbrella, and pour the water into it near the center. Meanwhile, climb onto a nearby chair, and leaning over, spin the bumbleshoot rapidly. The water will creep up over the edges and make a circle on the floor.
As stated at the beginning, the centrifugal forces of the revolving water moves the water away from the center of the circles, up and over the edges.
Let your imagination and ingenuity have a chance, the next time you build a kite. Here are a number of suggestions. Note particularly the pentagon box kite by a California boy, and the reel he uses when flying it. The sailboat messenger at the bottom of the page is another novelty; when it reaches the kite, its sail is automatically furled and it slides down again.
Below is shown an airplane kite with a light frame of balsa and rattan.