Leopold discusses traditional astronomy, basic interpretive principles, Lots or “Arabic Parts,” natal astrology, questions or horary, mundane topics such as weather and wars, elections, and even material on using astrological talismans.
Of special interest is Leopold’s treatment of geocentric astronomy based on medieval zijes or books of tables and astronomical theory. To make the text more understandable, Benjamin Dykes has created numerous diagrams and explanatory comments or mini-essays explaining this kind of astronomy in an easy and accessible way.
Because of his long experience with the source texts, Benjamin Dykes is able to makes Leopold’s work more readable, including correcting many errors committed by the medieval editors and typesetters. The Compilation is a resource for both students and experts in medieval Western astrology.