One of the simplest and most graceful forms the tying lines of a composition may take is a continuous flow, one line evolving out of another in graceful sequence, thus leading the eye on from one part to another and carrying the attention to the principal interests.

Two good instances of this arrangement are Botticelli’s “Birth of Venus” and the “Rape of Europa,” by Paolo Veronese, reproduced on pages 166 [Transcribers Note:  Diagram XV, Plate XXXVII] and 168 [Transcribers Note:  Diagram XVI, Plate XXXVIII].  The Venetian picture does not depend so much on the clarity of its line basis as the Florentine.  And it is interesting to note how much nearer to the curves of the circle the lines of Europa approach than do those of the Venus picture.  Were the same primitive treatment applied to the later work painted in the oil medium as has been used by Botticelli in his tempera picture, the robustness of the curves would have offended and been too gross for the simple formula; whereas overlaid and hidden under such a rich abundance of natural truth as it is in this gorgeous picture, we are too much distracted and entertained by such wealth to have time to dwell on the purity of the line arrangement at its base.  And the rich fullness of line arrangement, although rather excessive, seen detached, is in keeping with the sumptuous luxuriance the Venetian loved so well to express.  But for pure line beauty the greater restraint of the curves in Botticelli’s picture is infinitely more satisfying, though here we have not anything like the same wealth and richness of natural appearance to engage our attention, and the innocent simplicity of the technique leaves much more exposed the structure of lines, which in consequence play a greater part in the effect of the picture.

[Illustration:  Diagram XIV.

ILLUSTRATING POWER OF CURVED LINES TO CONVEY ENERGY.  A, B, C, D.]

[Illustration:  Diagram XV.

ILLUSTRATING THE FLOW OF LINES ON WHICH THE RHYTHMIC UNITY OF THIS
PICTURE DEPENDS.]

[Illustration:  Plate XXXVII.

THE BIRTH OF VENUS.  BOTTICELLI (FLORENCE)

A beautiful example of Botticelli’s refined line rhythm. (See diagram on opposite page for analysis.)

Photo Anderson]

In both cases note the way the lines lead up to the principal subject, and the steadying power introduced by means of horizontal, vertical, and other straight lines.  Veronese has contented himself with keeping a certain horizontal feeling in the sky, culminating in the straight lines of the horizon and of the sea edge.  And he has also introduced two pyramids, giving straight lines in among the trees, the most pronounced of which leads the eye straight on to the principal head.

Botticelli has first the long line of the horizon echoed in the ground at the right-hand lower corner.  And then he has made a determined stand against the flow of lines carrying you out of the picture on the right, by putting straight, upright trees and insisting upon their straightness.