According to the Lemegeton (Book of the Spirits), a famous work attributed to King Solomon, Vassago was one of the seventy-two spirits to be conjured up by magical evocation. Vassago is described as a prince in the hierarchy of genii, favored by those who would know the unknown; he could tell of the future and find anything lost or stolen. As with other princes among the spirits, Vassago could be conjured into a mystical triangle, but kings and emperors among the spirits could be conjured into a magical crystal.
(See also crystal gazing )
"Vassago." Encyclopedia of Occultism and Parapsychology. . Encyclopedia.com. (November 15, 2018). https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vassago
"Vassago." Encyclopedia of Occultism and Parapsychology. . Retrieved November 15, 2018 from Encyclopedia.com: https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vassago