The Sound Mechanism
‘Others struck their drums with palms upraised, or stirred piercing jangles from rounded bronze cymbals; horns blew repeated raucous buzzing, and the barbarous flute howled with hair-raising song.’ Catallus 64: 261-4.
Bacchic revelry was a rich cacophony of sound. The orgiastic worship of Dionysus was synonymous with noises and sounds erupting unexpectedly. Punctuating the cries, clapping and singing of participants were the sounds of reverberating kettledrums and clashing brass cymbals.
By making lead balls fall first onto a slanting tympanon (kettledrum) and then ricochet onto the kumbalion (cymbal), Hero recreated these startlingly discordant sounds every time either Dionysus turned or the bacchae danced around the shrine.
Release of the lead balls from the container was controlled by a sliding plate mechanism, similar to that used in the self-lighting altar.
Both instruments were hidden in the base of the automaton near the wheels.