From ancient to modern, architects have looked for fundamental underlying principles of geometry and proportion on which to found their designs. Such principles not only provide an order for the formal elements, they ground the architecture in timeless values and provide an order for the formal elements, they ground the architecture in timeless values and provide a source of cultural meaning. This book illustrates the use of fundamental principles of geometry and proportion in two ancient cultures, the Bronze Age and the Roman Age, as well as in twentieth-century North America.

In celebration of the 2009 International Year of Astronomy, this issue of the Nexus Network Journal is devoted to relationships between astronomy, mathematics and architecture. Ancient cultures looked to the heavens in order to identify timeless principles for their own creations. Knowledge gained in astronomy was transformed into culture through architecture and design. Papers in this issue look at how astronomy influenced architecture and urban design.

This book presents an exploration of the arch from the points of view of architecture, mathematics, engineering, construction history, and cultural symbolism. Leonardo da Vinci described the arch as "two weaknesses which, leaning on each other, become a strength," a metaphor for the way that science and art lean on each other to strengthen our lives.

This issue is dedicated to Mechanics in Architecture. It explores the latest findings in the science of structural mechanics, including the behavior of structures, internal forces, and deformation. It also explores the development of new structural systems designed to resist thrusts resulting from new architectural forms. Some of the papers published in this issue were presented at the Nexus 2006 during a special session dedicated to mechanics.

The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing systems, proportional systems, descriptive geometry and correspondence analysis. The issue concludes with a book review.