Henry Rankin Poore,
Pictorial Composition and the Critical Judgment of Pictures
“ BALANCE BY GRADATION Gradation will be mentioned in another connection but as a force in balance it must be noticed here. It matters not whither the tone grades, from light to dark or the reverse, the eye will be drawn to it very powerfully because it suggests motion. Gradation is the perspective of shade; and perspective we recognize as one of the dynamic forces in art. When the vision is delivered over to a space which contains no detail and nought but gradation, the original impulse of the line is continued. ”
