Eromancy is one of six different divination practises by the Persians using air and water.
The divinator covered his head in a napkin and exposed to the air a vase filled with water.
Over the vase they then whispered their desires.
If the surface of the water showed bubbles it was regarded as a good sign.
Divination
Exploring Scrying: How to Divine the Future and Make the Most of It (Exploring Series)
Paralumun New Age Village