Nouuelles obseruations et conjectures sur l'iris
A French optical treatise on the rainbow by physician Marin Cureau de La Chambre, printed in Paris by Pierre Rocolet in 1650 for natural philosophers and court readers. Engraved text diagrams trace lettered rays from a face-bearing sun through goblets, prisms and hatched color bands, offering designers radiating sunbursts, dotted construction lines and lettered geometry for scientific collage.
