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

[p10]
][PROBLEM I.]

TO FIX THE POSITION OF A GIVEN POINT.[Footnote 8] ]

Let P, [Fig. 4.], be the given point.

Fig. 4.

Let its direct distance be D T; its lateral distance to the left, D C; and vertical distance beneath the eye of the observer, C P.

[Let G H be the Sight-line, S the Sight-point, and T the Station-point.][Footnote 9] ]

It is required to fix on the plane of the picture the position of the point P.

[p11]
]Arrange the three distances of the object on your paper, as in [Fig. 4.][Footnote 10] ]

Join C T, cutting G H in Q.