Gastromancy

Gastromancy (from γαστήρ, the belly, and μαντεία, divination), a mode of divination .practiced among the ancient Greeks, by filling certain round glasses with pure water, placing lighted torches round them, then praying to the deity in a low, muttering voice, and proposing the question which they wished answered. Certain images were now observed in the glass, representing what was to happen.