The secret of the rattling kantharos

One of just a handful of “rattling cups” that survive from the fifth and fourth centuries BCE, this elegant black-glazed wine cup from the second half of the 4th century BCE is dedicated to Kastor and Polydeukes (Castor and Pollux), the twin sons of Zeus known as the Dioscouri, who protected sailors, horseman, and chariot racers. Since each brother split his time between Mt. Olympus and Hades, they were often represented by stars, depicted here beneath the cup’s rim.  The cup's ritual purpose is further indicated by a wreath, garlands, and bucrania  bucrania (skulls of sacrificial bulls) decorating the cup’s body.

But, perhaps the most intriguing aspect of the vessel is that lifting and swirling the cup as if drinking or making a libation (liquid offering) during a ceremony produces a rattling noise.  It was assumed the sound was made by loose pellets moving inside the rim but curators at the J. Paul Getty Museum were puzzled by the fact that sometimes they could hear two balls but at other times only one.  So, they wanted to learn more about its construction and conducted a series of radiographic studies to unravel its secrets. The radiographs revealed two small balls that roll along a channel in the vessel’s rim.

Curators speculated that one way the potter might have achieved the construction of the cup is by raising the upper edge of the cup and folding it over to create a hollow space. The clay would be stretched thin by this process, which would reduce the need for ventilation holes that typically prevent pressure from trapped air. As for why it sometimes sounded like there was one ball in the rim and sometimes two, the radiograph revealed that one of the balls was resting in a small niche where it remained caught until it was knocked loose by the other pellet.

So why make an expensive cup rattle in the first place?  Getty curators said it is possible the rattling was intended to trick an unknowing handler into thinking they had broken it—quite a mistake given the cup’s obvious cost! Although the Greeks definitely had a keen sense of humor, I think due to the cup's religious dedication and symbolism, the curators' second theory is far more likely. They point out that the fourth-century BCE poet, Eubulus, mentions a glossy, black “pebble-rattling” cup used as part of a libation ceremony that took place at the end of a meal before a symposium began, in which wine was offered to Zeus Soter (Zeus the Savior). Since ritual events in antiquity were often accompanied by the sound of rattles, cymbals, and tambourines, which were thought to have magical and protective properties, the rattling sound emanating from the cup could have served the same purpose, without the necessity of hiring a cluster of religious performers who would have disrupted a cozy atmosphere conducive to sharing candid thoughts.

Read more about it here: http://blogs.getty.edu/iris/we-shook-an-ancient-ceramic-and-lived-to-tell-the-tale/ 

elegant black-glazed wine cup from the second half of the 4th century BCE is dedicated to Kastor and Polydeukes now in the collections of the J. Paul Getty Museum (Villa location) courtesy of the museum.