Birge Harrison,
Landscape Painting
(1909)
“ Now any interesting picture motive generally has a focus, or centre of interest on which the artist's eye rests with especial pleasure; and in view of the visual limitation just described it is evident that this portion will appear much more definite in outline than the outlying regions of the composition; which will become more and more blurred, as they recede, with the softened or lost edge everywhere. This is refraction ”
