You could not draw anything much simpler than this figure; and yet it is sufficient to illustrate two principles of contrast in composition--first, that the contrast is interesting, and second, that it is made more interesting, when the contrasted parts are carefully balanced. Now take the compasses and, centering on the point of intersection of the two lines, describe a circle. The latter will introduce into the figure a still further contrast between curved and straight lines. And again your sense of balance will be brought into play. How far will you make your circle extend? It is for you to say, because you are trying to satisfy your own feeling for what will look best. Now, as a contrast to this circle, add four smaller ones at the extremities of the cross. Next, from the center of the big circle draw radiating lines. As a last touch of contrast, suppose you draw a segment of a circle in each of the four corners of the rectangle.