To reduce the operation of this principle to precise rules is, perhaps, without the province of human power:  we might else expect to see poets and painters made by recipe.  As in many other operations of the mind, we must here be content to note a few of the more tangible facts, if we may be allowed the phrase, which have occasionally been gathered by observation during the process.  The first fact presented is, that equal quantities, when coming together, produce monotony, and, if at all admissible, are only so when absolutely needed, at a proper distance, to echo back or recall the theme, which would otherwise be lost in the excess of variety.  We speak of quantity here as of a mass, not of the minutiae; for the essential components of a part may often be equal quantities, (as in a piece of architecture, of armour, &c.,) which are analogous to poetic feet, for instance, a spondee.  The same effect we find from parallel lines and repetition of shapes.  Hence we obtain the law of a limited variety.  The next is, that the quantities must be so disposed as to balance each other; otherwise, if all or too many of the larger be on one side, they will endanger the imaginary circle, or other figure, by which every composition is supposed to be bounded, making it appear “lop-sided,” or to be falling either in upon the smaller quantities, or out of the picture:  from which we infer the necessity of balance.  If, without others to counteract and restrain them, the parts converge, the eye, being forced to the centre, becomes stationary; in like manner, if all diverge, it is forced to fly off in tangents:  as if the great laws of Attraction and Repulsion were here also essential, and illustrated in miniature.  If we add to these Breadth, I believe we shall have enumerated all the leading phenomena of Harmony, which experience has enabled us to establish as rules.  By breadth is meant such a massing of the quantities, whether by color, light, or shadow, as shall enable the eye to pass without obstruction, and by easy transitions, from one to another, so that it shall appear to take in the whole at a glance.  This may be likened to both the exordium and peroration of a discourse, including as well the last as the first general idea.  It is, in other words, a simple, connected, and concise exposition and summary of what the artist intends.

We have thus endeavoured to arrange and to give a logical permanency to the several principles of Composition.  It is not to be supposed, however, that in these we have every principle that might be named; but they are all, as we conceive, that are of universal application.  Of other minor, or rather personal ones, since they pertain to the individual, the number can only be limited by the variety of the human intellect, to which these may be considered as so many simple elementary guides; not to create genius, but to enable it to understand itself, and by a distinct knowledge of its own operations to correct its mistakes,—­in