NARRATOR: We're taking a close look at this ancient Chinese bronze with Tony Frantz of The Met’s Department of Scientific Research.

TONY FRANTZ: What's most interesting about this piece from a technical perspective is that it combines different methods of casting. The knitted form that you see on top, this very interesting woven pattern of serpent head motifs is cast by the lost wax process. Whereas the body and the lid of the vessel into which the woven pattern is inserted, I believe, are cast by the traditional piece moulding technique.

NARRATOR: That piece mould technique was the method previously used throughout China. Lost wax casting is what's still used today in art casting foundries. It was used widely in ancient Egypt and ancient Mesopotamia, but no one knows exactly when it first appeared in China. This vessel provides a clue.

TONY FRANTZ: This one is very special because it bears an inscription on both the interior of the lid and the interior of the body that tell us who this piece was made for, and it was made for a particular king, King Zhu. And we know the reign dates of this ruler, and so we can assign, quite assuredly, a fairly narrow window of dates to this piece.

NARRATOR: That range? The King Zhu ruled from 590–560 BC.