painting (9--13).--The plan of the book on painting (14--17).--The
use of the book on painting (18).--Necessity of theoretical
knowledge (19, 20).--The function of the eye (21--23).--Variability
of the eye (24).--Focus of sight (25).--Differences of perception by
one eye and by both eyes (26--29).--The comparative size of the
image depends on the amount of light (30--39).

II.

LINEAR PERSPECTIVE

General remarks on perspective (40--41).--The elements of
perspective:--of the point (42--46).--Of the line (47--48).--The
nature of the outline (49).--Definition of perspective (50).--The
perception of the object depends on the direction of the eye
(51).--Experimental proof of the existence of the pyramid of sight
(52--55).--The relations of the distance point to the vanishing
point (55--56).--How to measure the pyramid of vision (57).--The
production of the pyramid of vision (58--64).--Proof by experiment
(65--66).--General conclusions (67).--That the contrary is
impossible (68).--A parallel case (69).--The function of the eye, as
explained by the camera obscura (70--71).--The practice of
perspective (72--73).--Refraction of the rays falling upon the eye
(74--75).--The inversion of the images (76).--The intersection of
the rays (77--82).--Demonstration of perspective by means of a
vertical glass plane (83--85.)--The angle of sight varies with the
distance (86--88).--Opposite pyramids in juxtaposition (89).--On
simple and complex perspective (90).--The proper distance of objects
from the eye (91--92).--The relative size of objects with regard to
their distance from the eye (93--98).--The apparent size of objects