To make a anemometers you have to have :

• ping pong ball
• some dowelling (some wood)
• a photocopy of a protractor
• a miniture spirit level
• a drill
• a glue gun
• some fishing line

The first thing you have to do is cut some dowelling so it measures the same size as the photocopy of the protracter. When you have done that you stick the photocopy of the protractor on to the dowelling. You have to measure some more dowelling and stick it to the photocopy of the protracter so the model is stable. Match the middle of the spirit level with the middle of the protracter and stick it on the dowelling. Now you have to thread the fishing line through the ping pong ball ( this is the hard part ), make sure that the fishing line is 30 cm long. When you have done this you have your very own anemometer.

This is one I made earlier.