hydromancy

Hydromancy (from Greek "hydro", meaning water, and "manteia", meaning divination) is a method of divination by means of water, including the color, ebb and flow, or ripples produced by pebbles dropped in a pool.

The Jesuit M. A. Del Rio (1551–1608) described several methods of hydromancy. The first method described depicts a ring hanging by a string that is dipped into a vessel of water which was shaken. A judgment or prediction is made by the number of times which the ring strikes the sides of the vessel.

A second method is when three pebbles are thrown into standing water and observations are made from the circles formed when the objects strike the water.