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

, the points required. Only notice that if any point, as A, is on the nearer side of the circle A B C, its representative point,

a

, must be on the nearer side of the circle

a b c

; and if the point B is on the farther side of the circle A B C,

b

must be [p44] ]on the farther side of

a b c

. If any point, as C, is so much in the lateral arc of the circle as not to be easily determinable by the vertical line, draw the horizontal C P, find the correspondent

p