You can also measure the direction and speed of the wind using a wind sock—a type of kite. Wind socks are used at airports so pilots can easily see the strength and direction of the wind. (Airports also use anemometers and wind vanes.) A wind sock is a tapered tube of cloth that is held open at one end by a stiff ring. Wind is directed down the tube, causing the narrow end to point the same direction the wind is blowing.
1. | Fold a piece of 8 1/2 x 11 inch paper lengthwise to make the border strip for the wind sock. |  |  |
2. | Form a loop from the strip and tape the ends of the paper together. Mark the outside edge with the letter A. |
3. | On the tissue paper use a marker to draw a line 1 1/2 inch from one edge and across the paper. Mark the 1 1/2 by 11 inch area with the letter B. |  |
4. | Beginning along one end of the line drawn in step 3 above, measure and mark a point 1 1/8 inch from the edge. Continue marking the edge with additional points each separated by a distance of 1 1/8 inch. |
5. | Repeat step 4 to mark points along the opposite end of the tissue paper. |
6. | Using the points, draw a series of lines on the tissue paper. With scissors, cut along these lines to make strips. |
7. | Glue edge B of tissue paper to edge A of the loop strip made in step 2. Allow time for the glue to dry. |  |
8. | Use a hole punch to punch three holes equal distance around the paper ring. |
9. | Cut 3 pieces of string 1 foot long. Tie one end of each string to the wind sock at each of the three holes. |
10. | Tie the 3 loose ends of the string to a single paper clip. Add an additional 1 foot length of string to the paper clip. |  |
11. | Test the wind sock by holding the single string in front of a fan. |
12. | Tape the wind sock to a wooden dowel and place outside to monitor wind direction and speed. To help determine wind direction, use a compass to mark north, south, east and west below the wind sock. (Note: the wind sock measures relative wind strength, not the actual speed.) |  |
In deciding where to build a wind park, it’s important to measure how strong the wind is and its direction. Engineers use an instrument called an anemometer to measure the strength of the wind. Usually this is mounted with a wind vane on a tower so the winds are not blocked and the speed is accurately measured.