The natural principles and analogy of the harmony of form (1842)
Hay, D. R. (David Ramsay), 1798-1866 · Edinburgh, W. Blackwood · leaf 31
elementary parts; and they are suitable to this purpose, bythe relation they bear, in quantity or pitch, to the notes betweenwhich they are placed. In the scale of the colourist, also, there arethe intermediate or secondary hues, orange, green, purple, and neutralgray. It will be requisite,… … These secondaries differ from the primaries, because they admitof being altered either in their length or width, while their otherdimensions remain the same, and they still retain the same name andcharacter of form. The first of these, the parallelogram, is produced by such of themedient lines as…
Geometrical drawing · Proportion (Art)
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