As published, Country Living Magazine, September 2007, South Central Local Page, p 28

Reviving the Ancient Science and Math of the Trebuchet

Harry Leonard and American Legion Post 134 of Circleville bring math and science to life in a rather unusual way for the seniors at Logan Elm and Teays Valley high schools.

"I teach them about trebuchets. Math and science both are important to their construction and use," says Leonard, who is a member of the Post.

In medieval times, trebuchets were used as weapons to break through walls or propel projectiles over walls. They were invented in China in about the 4th century BC and arrived in Europe in the 6th century AD. They initially were operated by traction mechanisms, but counterweight trebuchets were found in and around the Mediterranean in the 12th century AD. The weapons were used until about the 16th century.

"We need more scientists and mathematicians, and this is a project that engages students and makes them think. There are many programs for athletes, but the Post wanted to offer something that was directed at academics," Leonard says.

He visits the clasrooms. "I explain a trebuchet and the physics concepts behind it. I bring in models to demonstrate how it works." He also hands out a detailed drawing and parts list.

"They construct one through the school year. They build it in teams and use the knowledge they learn in class as they go," Leonard says.

The parts list costs about $25. "They use a tremendous amount of imagination, but also physics. Whatever they do, though, they can use only a 10-pound counterweight and the throwing arm must be no more than 48 inches," Leonard says.

Near the end of the school year, the students unveil their trebuchets and compete against their classmates to see which machine throws a golf ball the farthest distance.

"They have to make the maximum use of the counterweight's energy to overcome inertia and the friction of the unit," he says.

For each school, the Post awards the top three teams, $400, $200 and $100 gift certificates that they share. The last-place team receives a $40 gift certificate to share. Each school's winning team also has the students' names engraved on the trebuchet trophy on display in the trophy cases.

"Math and science are fun. I'm an engineer, but I'm a dreamer. The idea must be in the head before it can be built," he says.

Copyright 2007 Ohio Rural Electric Cooperatives, Inc., and South Central Power Co.