What subjects are covered in the four books of I quattro libri dell’architettura?

Andrea Palladio’s I quattro libri dell’architettura (The Four Books of Architecture), published in 1570, serves as a comprehensive summary of his studies on classical architecture. The work is divided into four books, each covering specific architectural subjects:

• Book I: Focuses on the study of building materials, the classical orders, and decorative ornaments.
• Book II: Features many of Palladio’s own designs for town and country houses, alongside his reconstructions of classical buildings. These designs are presented with dimensions based on mathematical ratios derived from musical intervals.
• Book III: Contains designs for bridges, ancient town planning, and basilicas—ancient Roman public assembly halls that later served as prototypes for church architecture.
• Book IV: Dedicated to the reconstruction of ancient Roman temples.1