On the Three Branches of Perspective.
There are three branches of perspective; the first deals with the reasons of the (apparent) diminution of objects as they recede from the eye, and is known as Diminishing Perspective.—The second contains the way in which colours vary as they recede from the eye. The third and last is concerned with the explanation of how the objects [in a picture] ought to be less finished in proportion as they are remote (and the names are as follows):
Linear Perspective. The Perspective of Colour. The Perspective of
Disappearance.
[Footnote: 13. From the character of the handwriting I infer that this passage was written before the year 1490.].
15.