This kit is made of computer designed precision modern materials, but is as close to the original design as possible. The driving force of the original tea-carrying doll came from a spring made of whale whiskers (actually whale teeth). All the other components, such as its gears, body and escapement for speed adjustments, were made of wood. How does it work? When a tea cup is placed on the tray, the stopper is released by the whale spring attached to the doll’s arms; the spring forces the stopper to engage again when the cup is lifted from the tray. [via] Link.