It started out in the '80s, but at the beginning it was machines carving out of a foam block a model that was very, very fragile, and could not have any real use.

And it's carving things down from the top, with 96 percent waste left over and only 4 percent product. You heat it up you beat it with high pressures you use chemicals. OK. Heat, beat and treat.

The image of Thomas Jefferson was originally intended to appear in the area at Washington's right, but after the work there was begun, the rock was found to be unsuitable, so the work on the Jefferson figure was dynamited, and a new figure was sculpted to Washington's left.