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.