A very popular early 13th Century treatise on astronomy and astrology, by Johannes de Sacrobosco. Very popular in medieval Universities where it was used for teaching the fundamentals of astronomy. Based largely on Ptolemy’s Almagast, it incorporated more detailed astronomical and astrological ideas derived from Al Kindi, AL Jabir, Avicenna and other Muslim auctores. The book depicts the universe as a series of spheres, with earth at the center, and shows the earth tilted at 23 degrees. The book describes nine spheres of creation, starting with the “Primum mobile” – the sphere of the stars, followed by the spheres of the seven planets, and the earth. The author, Johannes Sacrobosco also refered to the universe as machina mundi, which is a reflection of the medieval concept of a “clockwork universe”, set in motion by God. Some versions of the book also included magical / mathematical constructs such as a volvelle.
Multiple versions of De Sphaera were produced from the time of its original creation around 1230 through the medieval and into the Early Modern period. The first printed version appeared in 1472. By the 16th Century the new heliocentric ideas from Copernicus were challenging the Ptolemaic model of the Universe, but it was almost as important as an astrological reference as it was for the Classical concept of physics. This is reflected in the wonderful artwork with which later versions of the book are adorned, such as the following images of the planets. Due in part to the popularity of De Sphaera Mundi and the Almagast, most people in the medieval world knew the earth was a sphere, contrary to the modern assumption.
Sol – Numbers: 1,4 – Element: Fire – Day: Sunday – Supervisory Angel: Michael – Metal: Gold
Brings the favor of the powerful, preserves from fainting, heart attacks, and aneurism.
Associated with leadership, exercise, fencing, wisdom, and political power.
Luna – Numbers: 2,7 – Element: Water – Day: Monday – Supervisory Angel: Gabriel – Metal: Silver
Protects travelers and those dwelling in foreign lands. Preserves against death by shipwreck.
Associated with the night, with travel, with negotiation and harmony.
Mercury – Number: 5 – Element: Earth – Day: Wednesday – Supervisory Angel: Raphael – Metal: Silver / mercury almalgam
Protects industry and commerce, brings prosperity, protects from death by treason, murder or poison.
Associated with magic, music, poetry, science, and artisanship.
Venus – Number: 6 – Element: Air – Day: Friday – Supervisory Angel: Anael – Metal: Copper
Preserves women from cancer, protects men and women from death by poisoning, criminal assault or accidents. Associated with love, pleasure, and leisure.
Mars – Number: 9 – Element: Fire – Day: Tuesday – Supervisory Angel: Samael – Metal: Iron
Preserves against attack, protects against death by torture. Associated with wrath, war, and violence.
Jupiter – Number: 3 – Element: Fire – Day: Thursday – Supervisory Angel: Zachariel – Metal: Tin
Promotes goodwill and sympathy, drives away all cares, favorable to honest enterprises, increases wellbeing, protects against unforeseen accidents and diseases of the lungs, genitals and liver. Associated with leadership, judgement, and equanimity.
Saturn – Number: 8 – Element: Air – Day: Saturday – Supervisory angel: Oriphiel – Metal: Lead
Protects from fatal diseases, poison, and violent death from plots or ambush. Protects women in childbirth. Associated with magic, crime and clandestine activity.
For more on medieval astronomy, alchemy, mysticism, and magic: check out Codex Superno.