The Elements of Perspective / arranged for the use of schools and intended to be read in connection with the first three books of Euclid

by John Ruskin

,

r

, etc., and produce them to cut the line E G in P, Q, R, etc.

From the points P Q R draw the lines P P′, Q Q′, R R′, etc., through the center of the circle A B, each cutting the circle in two points of its circumference.

Then these points divide the perspective circle as required.

If from each of the points

p

,

q

,