Whirligig Science

No one knows who invented the first whirligig. Centuries ago, Asian peasants carved these wind machines from bamboo. Some whirligigs served as kinetic (moving) toys for children. Other whirligigs made pleasant sounds in the breeze. American pioneers used whirligigs as shop signs and to scare hungry birds away from their crops.

What is a whirligig?

Think of a windmill connected to a mechanical statue. Whirligigs combine the science of wind power and motion with the art of sculpture. When the wind blows, the statue moves!

You can create a whirligig small enough to be held in your hand or large enough to tower above an elephant. In fact, the most famous whirligig inventor in the United States makes most of his wind machines about 15 meters tall, or about one-third of the height of the Statue of Liberty!

Vollis Simpson lives in North Carolina and attaches life-size figures of people and animals to his whirligigs. With the slightest breeze the figures come to life. On one whirligig, a man pedals a unicycle. On another, a team of mules kicks its hooves into the air.

“I've constructed things all my life,” says Simpson, who is an 80-year-old grandfather now.

When he was eight years old, Simpson worked hard at his dad's farm and sawmill. He constructed rabbit traps and learned how to fix the machinery in the mill. As a young man, he built his first whirligig during World War II. This whirligig, however, did not power a whimsical work of art. Simpson was living on a South Pacific island named Saipan with a group of US Army Air Corps soldiers.

“Our clothes were always sweaty and dirty,” he says. So the inventor took the propeller and other parts off a wrecked airplane and made a whirligig that powered a washing machine.

Many of Simpson's whirligigs use a propeller to harness wind energy. As a strong wind pushes against the tilted blades, the propeller begins to spin faster and faster. Attached to the whirligig's propeller is a camshaft, which turns the circular motion generated by the propeller into back-and-forth (reciprocating) movement that can be used to animate the arms and legs of a mechanical sculpture.

When Simpson was 67 years old, people from the American Visionary Art Museum in Baltimore, Maryland, asked him to build a giant whirligig to put on display there. He did, and then used a large crane to lift the 6,750-kilogram wind machine into place by the city's boat harbor.

“It has an angel, a cat, an airplane, and other moving things on it,” says Simpson. “It has bright aluminum blades, and every time they turn, it glitters all over the harbor.”

Now people from cities and museums across the United States are asking Simpson to build wind designs for them. He created four whirligigs for the 1996 Olympic Games in Atlanta, Georgia.

Young children often stare at Simpson's whirligigs and ask him, “Are you an inventor or a scientist?”

“I'm not a scientist,” he tells them, “but I know how mechanical things work.”

The beauty of his moving wind forms comes naturally to him.

Activity

  1. What simple machine does Simpson use in creating his whirligigs?
  2. Draw a diagram that illustrates how a whirligig harnesses wind energy to move an animated sculpture with arms and legs. Draw lines to show in what direction forces move each part of the sculpture. Give your whirligig machine a descriptive title. Write an explanation of how the simple machine works. Include details about what kind of materials you would use to build this machine.