Check out our Weather & Climate CD-ROMwhich includes similar activities.

The Beaufort wind scale uses visual clues to estimate the speed of the wind. These descriptions?calm, gentle breeze, strong gale, hurricane?are often given in weather forecasts. Actual wind speed is measured with an anemometer, which measures wind speed in number of revolutions per minute. In this activity, you'll build a simple anemometer and measure wind speeds. You'll also use the Beaufort wind scale to describe the wind speeds you measure.

• 4 plastic drinking straws
• Tape
• Four small paper cups (such as those in bathroom dispensers)
• One straight pin
• One pencil with an eraser
• Beaufort wind scale (included below)

1. Arrange the four plastic drinking straws to form a cross. Then tape the straws together where they meet at the center of the cross.
2. Tape one drinking cup to the end of each straw, making sure that the bottoms of the cups face the direction that your anemometer will rotate.
3. Push a straight pin through the center of the straws into an eraser on the end of a pencil. This provides the axle on which the straws and cups will rotate.
4. Mark one cup as a reference. You'll be measuring the speed of the wind by noting the number of complete revolutions that the anemometer makes in one minute.
5. Measure the wind speed in your classroom and at several locations outside, noting your results on the worksheet below. In addition, use the Beaufort wind scale to describe the wind speeds at each location you test.