1.  Make a chart like the one shown in photo A. Use your chart to record weather observations.

2. Put on your safety goggles. cut off the open end of the balloon. Have a partner hold the jar while you stretch the rest of the balloon over the open end of the jar. hold the balloon in place with a rubber band. use tape to seal the edge of the balloon around the jar.

3. Glue one end of the stirrer to the center of the stretched balloon. Use a small piece of tape to hold the stirrer in place until the glue dries.

4. Stand the metric ruler on end in some clay. Place the ruler next to the end of the stirrer.

5. when the glue has dried, carefully remove the tape from the stirrer. You have made a barometer. Read the number of millimeters at the top edge of the stirrer. Record your measurement in your chart. This represents the air pressure on the balloon.

6. Use your barometer to record changes in the air pressure over ten days. Always measure using the top edge of the stirrer. Record the data in your chart.

7. Each day observe and record the cloud type and weather condition.