Pt. 1. The scientific approach to the study of architectural heritage. Ch. 1. The role of structure in the history of architecture. Ch. 2. The decay of materials and structural damage. Ch. 3. Acquisition of information and data. Ch. 4. Criteria and techniques for conservation and restoration. Ch. 5. Soil settlement and remedial measures. Ch. 6. Seismic actions and remedial measures. Ch. 7. Diagnosis and Safety evaluation -- Pt. 2. Structural analysis of masonry buildings. Ch. 8. Structural analysis of masonry buildings: general aspects. Ch. 9. Structural analysis of masonry buildings: specific calculations -- Author's Report: Dramatic rescue of the tympanum of the Basilica of St. Francis of Assisi.