Concept:

A Weather Vane is a tool that is used to tell which direction the wind is coming from. Weather vanes are usually found atop buildings, so they will catch an open unobstructed breeze. Look for them on top of barns, houses, weather stations, hardware stores, and other places that sell or use weather tools. The part of the vane that turns into the wind is usually shaped like an arrow. The other end is wide so it will catch the smallest breeze. Sometimes a metal rooster or other animal sits on top of the weather vane.

Materials

 

• Paper and pencil
  
  
• Scissors
  
  
• Pieces of cardboard
  
  
• A Compass
  
  
• A plastic soft drink bottle
  
  
• Plastic drinking straws
  
  
• A shallow pan filled with rocks or pebbles
  
  
• A felt tipped marker or pen
  
  

Procedure:

1. Draw a picture of a Weather Vane on the cardboard (some Weather Vanes are just plain arrows while others have pictures of animals, angels, or some other sort of artistic idea in order to beautify them).
   
   
   
   
2. With the scissors, carefully cut an arrow with a tab (the part that looks like a black stick coming out of the middle of the arrow) from the cardboard, as shown. Remember that scissors are sharp, so handle them carefully. Bend the tab slightly so that the arrow turns easily when you put it in one end of the straw. Put the other end of the straw into the bottle. Remove enough rocks from the pan to make room for the bottle. Pile the rocks back around the bottle, so that it will not be blown over. (See illustrations above.)
   
   
3. A compass always points North. Use your compass to find North, and then mark the four sides of the bottle E, W, N, and S with a felt pen.
   
   
4. Set your Weather Vane in a high place such as at the top of a playhouse or a slide or on a windowsill. Make sure that it does not wobble or tilt, so that it catches the slightest breeze.
   
   
5. Watch your Weather Vane closely and then describe how it works. Test it on very windy days and again when there is just a light breeze. Write down any differences that you observe and compare what you saw on both days.
   

Background Information

Congratulations!!! You have made a Weather Vane. Wind usually behaves in a certain way across the globe. If the wind is blowing from the South, the wind is usually warm. If the wind is blowing from the North, the wind is usually cooler.

Some Weather Vanes have directional strips underneath the arrow to make it even easier to read. Your markings on the bottle do the exact same thing.

The breeze turns the arrow on the Weather Vane until it catches both sides of the wide end equally. The arrow always points into the wind.

It is easier to see how the energy from the wind moves your Weather Vane if it is up high and in an open area. You might also want to experiment by putting it on the ground.

A Weather Vane is one of the oldest weather tools. It is still used today to measure the direction of the wind. Weather Vanes can only measure wind direction a few yards (meters) off the ground. Large, helium-filled weather balloons are used to measure winds high above the earth's surface. The balloons move with the same speed and direction as the wind.

Here are my Weather Vane Links:

Don't just read this page in Vain. Learn More About Weather Vanes...

Make A Bigger Weather Vane

Learn a little Weather Vane History

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Unisys Corporation		Miami Museum of Science