Ross Grant, age 13, of Amerst View, Ontario, Canada, for his question:

WHY DOES A FAN'S AIR COOL?

Long ago it was discovered that moving air on a hot day was cooler than air that didn't move. And the first fan was most likely a big leaf held in the hand of an ancient Egyptian: He moved it back and forth to create an artificial breeze.

Ancient Greeks used fans, too. Many of their vases picture pretty fans being held by servants.

The first folding fans were probably dated about 700 A.D. and were made in Japan. The inventor probalby saw the way a bat folded his wings and copied the format. Artists painted the fans in bright colors and they were used both for cooling purposes and also as props in ceremonial dances.

Through all the ages fans have helped to cool man's environment.