In the earliest period the sacred oak was surrounded by three-legged pedestals, each of which supported a bronze cauldron. They were arranged close together to form a fence, leaving only a narrow entry point. The visitor who approached the tree inevitably touched the cauldrons and made a sound that resonated like a gong. The whole row of cauldrons was soon vibrating, and since each cauldron was of different size, each produced a different note. Any gusts of winds that blew into the cauldrons increased the overall impression of moaning and howling. These sounds, the voices of the gods, were interpreted by the oracle priests as the command of the heavens.