(MS. H. 227 in the Ambrosian Library).]
GENERAL INTRODUCTION.
Prolegomena.
110.
You must first explain the theory and then the practice. First you must describe the shadows and lights on opaque objects, and then on transparent bodies.
Scheme of the books on Light and shade.
111.
INTRODUCTION.
[Having already treated of the nature of shadows and the way in which they are cast [Footnote 2: Avendo io tractato.—We may suppose that he here refers to some particular MS., possibly Paris C.], I will now consider the places on which they fall; and their curvature, obliquity, flatness or, in short, any character I may be able to detect in them.]
Shadow is the obstruction of light. Shadows appear to me to be of supreme importance in perspective, because, without them opaque and solid bodies will be ill defined; that which is contained within their