Take a piece of glass of the size of a half sheet of royal folio paper, and fix it... between your eye and the object you wish to portray. Then move it away until your eye is two-thirds of a braccio away from the piece of glass, and fasten your head by means of an instrument in such a way as to prevent any movement of it whatsoever. Then close or cover up one eye, and with a brush or a piece of red chalk finely ground mark out on the glass what is visible beyond it; afterwards, copy it by tracing on paper from the glass, then prick it out upon paper of a better quality and paint it if you so desire, paying special attention to the aerial perspective.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "Take a piece of glass of the size of a half sheet of royal folio paper, and fix it... between your eye and the object you wish to portray. Then move it away until your eye is two-thirds of a braccio away from the piece of glass, and fasten your head by means of an instrument in such a way as to prevent any movement of it whatsoever. Then close or cover up one eye, and with a brush or a piece of red chalk finely ground mark out on the glass what is visible beyond it; afterwards, copy it by tracing on paper from the glass, then prick it out upon paper of a better quality and paint it if you so desire, paying special attention to the aerial perspective." in the context of "Leonardo da Vinci, The Notebooks of Leonardo Da Vinci XXIX Precepts of the Painter, Tr. Edward MacCurdy (1938)." to mean that wisdom is timeless.