Capnomancy is divination by examining smoke. This is done by looking at the movements of the smoke after a fire has been made. A thin, straight plume of smoke is thought to indicate a good omen whereas the opposite is thought of large plumes of smoke.^[1][2] If the smoke touches the ground, this is thought to be a sign that immediate action must be taken to avoid catastrophe.^[3]

When capnomancy involves the smoke from incense, then it is called libanomancy.^[4]

The word capnomancy comes from two Greek words: καπνός (kapnós), meaning smoke, and μαντεία (manteía), meaning divination or to see.^[5]

The first recorded use of capnomancy was in ancient Babylonia, where the ceremony was performed at religious dates throughout the year, using cedar branches or shavings.^[3][6] In ancient Greece, priests would burn animal sacrifices and then perform capnomancy over the smoke that was produced by the fire.^[4][7]

The Celts were thought to practice dendromancy, a form of capnomancy, using oak and mistletoe branches.^[3]

It was also used by the Semang of Malaysia, who would use the ritual to determine whether a camp was safe for the night.^[4] There is reference made to the practice in both 17th and 19th century religious texts, although these do not describe how the practice was performed.^[7]

Capnomancy has been reportedly used as late as 2003 in New England, where citizens would practice the ritual by using smoke plumes from chimneys.^[6] Other modern variations of the ritual involve burning cedar sticks, incense, or candles with ribbons tied around them.^[4] Hands are sometimes used to manipulate the smoke, with practitioners reading the shapes that are then produced.^[4]