Perspective, or, The art of drawing what one sees : explained and adapted to the use of those sketching from nature (1872)
Collins, W. H. (William Henry) · London : Longmans, Green · leaf 44
as they receded from the eye ; each set of parallel lines was on its way to its vanishing point. Fre¬ quently one sees a beam of light falling through a break in the clouds, and it appears to expand like a fan as it approaches the earth. This effect is simply due to the aperture in the clouds,… … case of the wall, the edges converge towards each other at the end farthest from the eye. It nov/ becomes necessary to find out where this
Perspective · Drawing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.