He was the author of a Tractatus spherae (Treatise of the Spheres), and acquired a reputation as an astrologer and geomancer.
[1] Geomancy, one of his main interests, he described as the practical side or ‘little daughter’ of the art of astrology, and also as ‚another astrology‘: ‚Note that in this art every point is deposited according to a star of the heavens.
Similarly every figure is deposited according to the sign of the star among the twelve signs of the heavens, a planet and the part of the world, which are 4: east, west, south and north.
')[2] Of Astrology, considered an "art" in 13th century Italy, feudal princes wanted to know their civic "fortune".
Works by astrologers such as Bartholomew of Parma's Treatise of the Spheres were considered invaluable as they described how the information gained from celestial movement could be interpreted to guide civic leaders and maintain governance over the Italian city states.