Aeromancy

Webster's Dictionary

(n.) Divination from the state of the air or from atmospheric substances; also, forecasting changes in the weather.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

was a species of divination practiced among the Greeks and Romans, by which future events were foretold from certain appearances or noises in the air;' One mode of aeromancy was as follows: The person employing' it folded his head in a cloth, and having placed' a bowl of water in the open air, he proposed his question in a low voice, when, if the water was agitated, he considered that what he had asked was answered in the affirmative.