The visual pyramid: how bodies radiate their images
Numbered propositions on points, rays and the pyramids that carry likenesses through the air
A dense two-column page of numbered propositions on the geometry of vision. Leonardo argues that every body is bounded by an outer surface full of infinite points, each emitting a ray of infinite diverging lines, so that the air between bodies teems with intersecting 'similitudes' (images) carried by pyramids. He then analyses the visual pyramid itself: each body is the base of innumerable pyramids, whose tip holds the whole likeness of the base, and whose sharpness governs how faithfully form and colour are conveyed. The transmitted-light capture makes the mirror-script faint but the whole sheet is text.
On this page
Every body fills the air with infinite images of itself
The opening propositions build up the mechanism of sight: every body is surrounded by an extreme surface, each surface is full of infinite points, and every point makes a ray composed of infinite diverging lines. The air found between bodies is therefore full of the intersections made by their raying similitudes, so that each body fills the surrounding air with infinite likenesses of itself.
The pyramid of vision and its base
The likenesses of the figures and colours of each body pass from one to another by pyramid, so that every body becomes the base of innumerable and infinite pyramids turned in various directions and lengths. The pyramid born among the most equal angles gives the truest likeness of its body, and the tip of each pyramid holds within itself the entire similitude of its base.
How a pyramid's tip and base-angles transform the image
Leonardo compares pyramids by the sharpness of their tips and the equality of their base angles: a pyramid of thinner tip shows the true form and quality of its body less well, and it is thinner the more unequal its base angles. One central line carries infinite tips of other pyramids passing through one another without confusion, while the pyramid of thicker tip most strongly tinges the place it strikes with the body's colour.
