David Smith, Zig IV, 1961

Narrator: One of the most interesting parts of the sculpture Zig IV—though not one of the most noticeable—is the small wheeled cart it sits on.

Charles Ray: The space underneath that cart is a kind of a beginning point or a gate to the sculpture.

Narrator: Sculptor Charles Ray.

Charles Ray:And it's like the space underneath this table. It's our everyday space. I don't have to tell you anything about the space underneath the cart. You know that maybe there's a quarter underneath the cart. Right? But God's maybe not underneath the cart. But a gum wrapper or a crack in the cement or an ant or a bug or a spider is underneath the cart.

You begin there and you go into another much more difficult space to describe. And perhaps you would never get to that kind of space if you didn't have somewhere in the sculpture that everyday space in this particular one.

Narrator: An L-shaped form projects out near the sculpture’s top corner.

Charles Ray: But the space, as you go up and around it, that the L makes and that the other elements make, that sort of tie a dimensional space into a knot. It kind of leaves a third dimension. You can only tie your shoe in the third dimension. You can't tie a knot in the fourth dimension. Space is sculpture's primary medium, and it's really magical and difficult, and you can't talk about it.