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

Obs. The dividing-points found by the above rule, used with the ordinary measuring-line, will lay off distances on the retiring inclined line, as the ordinary dividing-points lay them off on the retiring horizontal line.

Another dividing-point, peculiar in its application, is sometimes useful, and is to be found as follows:—

[p56] ]

Fig. 47.

Let A B, [Fig. 47.], be the given inclined line drawn in perspective, and A

c

the relative horizontal.

Find the vanishing-points, V and E, of A

c