Page:A Treatise on Painting.djvu/347

 ried to the distance O R of the lines A F, B F; so that there is the difference C O and R D. It follows that the line C F, and the line D F, in order to become shorter, have to go and find the paper where the whole height is drawn, that is to say, the lines F A, and F B, where the true size is; and so it makes the difference, as I have said, of C O, and R D.



  nature is seen with two eyes, it will be impossible to imitate it upon a picture so as to appear with the same relief, though the lines, the lights, shades, and colour, be perfectly imitated. It is proved thus: let the eyes A B, look at the object C, with the concurrence of both the central visual rays A C Rh