1. Letter From The Editor

   • Kim Williams

   Letter from the editor Pages: 5 - 6

2. The Arch: Born in the Sewer, Raised to the Heavens

   • Matthys Levy

   Research Articles Pages: 7 - 12

3. As Hangs the Flexible Line: Equilibrium of Masonry Arches

   • Philippe Block
   • Matt DeJong
   • John Ochsendorf

   Research Articles Pages: 13 - 24

4. Galileo was Wrong: The Geometrical Design of Masonry Arches

   • Santiago Huerta

   Research Articles Pages: 25 - 52

5. Gateway to Mathematics Equations of the St. Louis Arch

   • Paul Calter

   Research Articles Pages: 53 - 66

6. Arches and Culture

   • Don Hanlon

   Research Articles Pages: 67 - 72

7. Solving Ertha Diggs’s Ancient Stone Arch Mystery

   • Michael Serra

   Research Articles Pages: 73 - 78

8. Mathematical Elements in Historic and Contemporary Architecture

   • Elena Marchetti
   • Luisa Rossi Costa

   Research Articles Pages: 79 - 92

9. On Division in Extreme and Mean Ratio and its Connection to a Particular Re-Expression of the Golden Quadratic Equation x ² − x − 1 =  0

   • J. Iñiguez
   • A. Hansen
   • J. Acuña

   Research Articles Pages: 93 - 100

10. Structure of Phenomenological Forms: Morphologic Rhythm

    • L. Consiglieri
    • V. Consiglieri

    Research Articles Pages: 101 - 110

11. Branko Mitrović—Serene Greed of the Eye: Leon Battista Alberti and the Philosophical Foundation of Renaissance Architectural Theory

    • Kim Williams

    Book review Pages: 111 - 114

12. George Hersey–Architecture and Geometry in the Age of the Baroque

    • James McQuillan

    Book review Pages: 115 - 118

13. L’uomo del Rinascimento. Leon Battista Alberti e le Arti a Firenze tra Ragione e Bellezza

    • Marcello Scalzo

    Exhibit Review Pages: 119 - 122