European art has left a mountain of astounding masterpieces in painting, sculpture, and architecture, but today it is often a mystery as to how these feats of human expression were accomplished. Classical architecture in the ancient world was based on precise mathematical principles of symmetry. Proportion is a form of symmetry that requires all of the parts of a building to maintain a precise relationship to the whole. Decorative elements of a building must therefore be designed and fabricated in order to make an architectural design into a unified work of art.  This lecture will discuss both the design and production of original architectural details.