From Mediaeval Stonecutting to Projective Geometry

We tend to think about technology as the application of abstract science to practical problems, but sometimes the inverse is true, as in the case of modern orthogonal projections, which originated empirically in mediaeval workshops and only after a long historical process gave birth to abstract projective geometry. However, this evolution is marked by strong transformations in the media of knowledge transmission, the social groups that control these forms of knowledge, and the very nature of this branch of knowledge. This article charts these transformations, and also serves as an introduction to the eight articles in this special issue of the the NNJ which examime particular issues raised by these historical processes, such as rib vaults by Juan de Álava, the use of ovals at the Escorial, the surbased vault at Arles town hall, staircases in the treatise of Juan de Portor y Castro, axonometric drawing in stonecutting treatises, Frézier’s treatise on stereotomy as an antecedent to Monge’s Descriptive Geometry, Monge’s studies on developable ruled surfaces, and Jules Maillard de la Gournerie’s criticisms on Monge’s system.