Memoranda list and studies of rays entering the eye
A page of reminders - books, people, goods and tasks - beside optical notes on vision
One of Leonardo's celebrated memoranda pages, its long left-hand column listing books, tools, goods and people to seek out - from the 'Book of the Pandolfini' and the libraries of San Marco and Santo Spirito to spectacles, a world-map held by Giovanni Benci, and a reminder to learn the multiplication of roots from Maestro Luca. Around and across the list run optical notes: a rayed diagram argues that the eye never sees two parallel lines meet, that every image strikes the eye at equal angles, and that the species of things converge on the eye's surface by radiant lines through an air full of their similitudes. A crosswise note defines high and low by distance from the centre of the world, and a fraction computation sits at the foot. The worn sheet carries further faint script beyond the transcribed blocks.
On this page
Memoranda of books, tools and goods to acquire
The left column lists the Book of the Pandolfini, knives, a ruling pen, the libraries of San Marco and Santo Spirito, boots and hose, spectacles, a very thin knife, the grammar of Lorenzo de' Medici, a world-map held by Giovanni Benci, the territory of Milan in print, and a note to learn the multiplication of roots from Maestro Luca.
Personal reminders: people to see and a boy for the model
Among the entries are people and errands - Lattanzio Tedaldi, Antonio Covoni, Giovanni del Sodo, Sansovino, the little chain of Michelagnolo, and a boy to make the model - reading as private reminders of daily business.
Parallel lines never converge; images strike the eye at equal angles
The eye set between two parallel lines will never, at however great a distance, see those lines converge to a point; and every similitude falls upon the eye at equal angles.
The species of all things converge on the eye's surface
All the species of things set before the eye converge by radiant lines to the eye's surface, cutting one another there at equal angles; and the air is wholly full, in every part, of the similitudes of the bodies it contains.
Varying the brush; why 'second' things appear lower than 'third'
Leonardo wants to vary the brush in more obliquities and to know the leap of water where it is struck, and addresses Sandro on why such 'second' things appear lower than the 'third'.