66.

The images of objects are all diffused through the atmosphere which receives them; and all on every side in it.  To prove this, let a c e be objects of which the images are admitted to a dark chamber by the small holes n p and thrown upon the plane f i opposite to these holes.  As many images will be produced in the chamber on the plane as the number of the said holes.

67.

General conclusions.

All objects project their whole image and likeness, diffused and mingled in the whole of the atmosphere, opposite to themselves.  The image of every point of the bodily surface, exists in every part of the atmosphere.  All the images of the objects are in every part of the atmosphere.  The whole, and each part of the image of the atmosphere is [reflected] in each point of the surface of the bodies presented to it.  Therefore both the part and the whole of the images of the objects exist, both in the whole and in the parts of the surface of these visible bodies.  Whence we may evidently say that the image of each object exists, as a whole and in every part, in each part and in the whole interchangeably in every existing body.  As is seen in two mirrors placed opposite to each other.

68.

That the contrary is impossible.

It is impossible that the eye should project from itself, by visual rays, the visual virtue, since, as soon as it opens, that front portion [of the eye] which would give rise to this emanation would have to go forth to the object and this it could not do without time.  And this being so, it could not travel so high as the sun in a month’s time when the eye wanted to see it.  And if it could reach the sun it would necessarily follow that it should perpetually remain in a continuous line from the eye to the sun and should always diverge in such a way as to form between the sun and the eye the base and the apex of a pyramid.  This being the case, if the eye consisted of a million worlds, it would not prevent its being consumed in the projection of its virtue; and if this virtue would have to travel through the air as perfumes do, the winds would bent it and carry it into another place.  But we do [in fact] see the mass of the sun with the same rapidity as [an object] at the distance of a braccio, and the power of sight is not disturbed by the blowing of the winds nor by any other accident.

[Footnote:  The view here refuted by Leonardo was maintained among others by Bramantino, Leonardo’s Milanese contemporary.  LOMAZZO writes as follows in his Trattato dell’ Arte della pittura &c.  (Milano 1584.  Libr.  V cp.  XXI):  Sovviemmi di aver gia letto in certi scritti alcune cose di Bramantino milanese, celebratissimo pittore, attenente alla prospettiva, le quali ho voluto riferire, e quasi intessere in questo luogo, affinche sappiamo qual fosse l’opinione di cosi chiaro e famoso pittore intorno alla prospettiva . .  Scrive Bramantino che la prospettiva e una cosa che contrafa il naturale, e che cio si fa in tre modi