RJ: How thick is the glass?

FB: It's 9/16" laminated glass -- so you have a piece of glass, then a piece of plastic, then another piece of glass sandwiched together. If a panel breaks, it will stay together, like on the windshield of a car. Each corner of the glass has a node holding it in place.

RJ: How did they build this whole wall?

FB: First they put the steel arch up, then there is a stainless steel cable that comes through. At the bottom of the cable they put a 12-ton weight. It's like a big bridge, like the Ben Franklin Bridge. On a bridge, you have an arch with cables coming down holding up the roadway. This is the same thing, except we added glass. This has never been done before in the world! It is designed to move 2 1/2 feet in either direction in high winds.

RJ: What if the wall fell?

FB: This wall has been tested with 80 knot winds and water to see if it was strong enough to withstand the wind and rain, and to see if it would collapse or leak. It passed the test without a problem. If the cables did fail, there is a steel bar that will hold up the glass.

RJ: What is the stuff in between the panes of glass?

FB: That's silicone. That's what seals the glass and keeps it from leaking.

> Next Stop: Barrel Vaulted Roof

Visit the resident company Web sites to learn about their education programs. (links will open in a new window):

The Philadelphia Orchestra

Philadelphia Chamber Music Society

Peter Nero and the Philly Pops®

PHILADANCO

Pennsylvania Ballet

Opera Company of Philadelphia

Chamber Orchestra of Philadelphia

American Theater Arts for Youth