When drawings are copied repeatedly in sequence by different people, they tend to undergo characteristic processes of change. Parts of an image become separated out, the whole design is flattened, the outline is emphasized, and perspective occlusion is removed. The drawing becomes more abstract, more schematic—in a word, more diagrammatic. This article focuses on such drawing processes and on the results of experiments in repeated copying by anthropologists, psychologists, architectural students, and Surrealists. The tentative conclusion is that designs are represented mentally in a ‘diagrammatic’ way that affects not only how they are seen but also how they are changed when reproduced.
Philip Steadman is Emeritus Professor of Urban and Built Form Studies at University College London and a Senior Research Fellow at the UCL Energy Institute. He trained as an architect and has taught at Cambridge University and the Open University. His main research interests are the geometries of buildings and cities and their relationship to energy use. He has published several books on geometry in architecture and computer-aided design. His most recent book is Why Are Most Buildings Rectangular? (2017). He also works in art history and published Vermeer's Camera: Uncovering the Truth Behind the Masterpieces (2001). A forthcoming book is titled “Renaissance Fun: The Machines Behind the Scenes.” E-mail: j.p.steadman@ucl.ac.uk