Shirley Feller, age 13, of Tacoma, Wash., for her question:

WHO STARTED BIRLING?

Birling, or logrolling, started in the 1840s in lumber camps in Canada and in the northern parts of the United States. Lumberjacks became so skilled at "riding" logs downstream from the forest to the sawmill that they began to hold contests to find the most skillful.

Birling contestants stood on each end of a floating log, and each tried to spin it so rapidly with his feet, or reverse the action so quickly, that he could make his rival fall into the water.

These birling contests usually lasted only minutes and sometimes even just seconds. In 1900, however, two men in Ashland, Wis., set a record of three hours and 15 minutes.

The logs used in the sport are about 14 inches in diameter.

Birling competition still flourishes in Canada and at outdoor and resort shows throughout the United States.