The last of the great forms of composition is the rectangle, but this always in connection with oppositional balance. Such a form attaches itself to two sides of the picture and the importance of a reacting measure is obvious. In this lies the warrant for its use, for without it unity is impossible. Of the six fundamental forms of composition this is the only one which is dependent, all the others containing within themselves the element of balance.
The rectangle plus the isolated measure approaches the completeness of the cross and in the degree it lacks this completeness it develops opportunities for originality.
In the landscape by Corot 1 the letter L is plainly shown. (See diagram of Fundamental Forms.) The tree mass, cow and river bank in shadow serve as a sombre foil for the clump of trees upon the opposite shore which are bathed in the soft luminous haze of early morning. This is the real subject which, grafted upon the heavy structure of the foreground affects us the more through the contrast. In Mr. Pettie’s picture of ” James II and the Duke of Monmouth,” we have the opposition of the two lines, the attraction in the open space being the line of seats along the wall. These, in the dimly lighted interior, are scarcely assertive enough to effect the diversion which the open structure demands.
In perspective this arrangement merges into the triangle which has already been discussed. The ” Sheep and Shepherd,” by Jacque is constructed upon the L reversed and is an unusually strong example of a rare arrangement.