Noble, Thomas; Clark, John Heaviside [Ill.]: Practical Perspective, Exemplified On Landscapes (London, 1809)

(Explanatory Elate.)

Sect. 1st. I. Persp ectiv e is the art of delineating objects on a single plane (as paper,
canvas, &c.), in such a manner as that they may appear to retain their original distances
beyond that plane and beyond each other, and their original inclination towards that plane
and towards each other.

Thus: KT U Ft is the perspective representation of the original pyramids on the plane
PLNE, as they appear to the figure who is looking at them.

II. In drawing the perspective representation KT U R, the figure who is supposed
to have drawn it must have used these following lines and points.

1st. The line H O, called the horizontal line, because parallel to the ground and
horizon.

2nd. The line C D, which is the distance of the eye from the plane of the picture.

3d. The point of sight, or perspective center C, which is a point in which a line, drawn
from the eye of the spectator perpendicular to the horizontal line, would cut the plane of
the picture. This point will always be on the horizontal line, and should be near the mid-
dle of the drawing or painting.

D

OBSERVATIONS.