Chapter II: THE SIGHT-LINE.—Through the Sight-point, S, draw a horizontal

line, _GH_, right across your paper from side to side, and call this line the “Sight-Line.”

This line is of great practical use, representing the level of the eye of the observer all through the picture. You will find hereafter that if there is a horizon to be represented in your picture, as of distant sea or plain, this line defines it.