Ruskin, John; Cook, Edward T. [Editor]: The works of John Ruskin: The elements of drawing. The elements of perspective. And the laws of Fésole (London, 1904)

PROBLEM II

TO DRAW A RIGHT LINE BETWEEN TWO
GIVEN POINTS
C' D'


LET A B, Fig. 6, be the given right line, joining the given
points A and B.
Let the direct, lateral, and vertical distances of the point
A be T D, D c, and c A.
Let the direct, lateral, and vertical distances of the point
B be T D', D c', and c' B.
Then, by Problem 1., the position of the point A on the
plane of the picture is <3.
And similarly, the position of the point B on the plane
of the picture is
Join %
Then <3 ^ is the line required.
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