The art of foretelling future events by the observation of atmospheric
phenomena, as, for example, when the death of a
great man is presaged by the appearance of a comet. Francois
de la Tour Blanche stated that aeromancy is the art of fortunetelling
by means of specters that are made to appear in the air,
or the representation by the aid of demons, of future events,
which are projected on the clouds as a film is projected onto a
screen. As for thunder and lightning, he adds, these are
concerned with auguries, and the aspect of the sky and of the
planets belonging to the science of astrology.
Waite, Arthur Edward. The Occult Sciences. 1891. Reprint, Secaucus,
N.J.: University Books, 1974.