Nouvelles observations et coniectvres svr l'iris
A 1650 Paris treatise on the rainbow by Marin Cureau de La Chambre, printed by P. Rocolet for a learned audience of natural philosophers. The pictures are precise geometric diagrams of sunlight entering a glass vessel and a triangular prism, with labelled rays traced as straight lines against a plain cream ground. A designer might take from them the clean logic of ray-path diagrams, with lettered rays, dotted construction lines and sunburst faces that suit scientific or historical explanatory graphics.
