Vol. I: I. Prolegomena and General Introduction to the Book on Painting: 16.
The Da Vinci Notebooks
Perspective, as bearing on drawing, is divided into three principal sections; of which the first treats of the diminution in the size of bodies at different distances. The second part is that which treats of the diminution in colour in these objects. The third [deals with] the diminished distinctness of the forms and outlines displayed by the objects at various distances.