A branch of crystalomancy (divination by water). One method
was to toss an object into a full container of water and interpret
either the image formed by it or else the sound it made
striking the water. Another more complex method involved
placing water in a silver vase on a clear, moonlit night. The
light from a candle would be reflected onto the water by the
blade of a knife and the inquirer would concentrate on the
image formed in the water. (See also pegomancy)