its surface, a myriad of bubbles fleck it with light; yet its terrible unity remains unbroken.  Not a bubble or a line gives a thought of minuteness; they flash and flit, ere the eye can count them, leaving only their aggregate, in the indefinite sense of multitudinous motion:  take them away, and you take from the mass the very sign of its power, that fearful impetus which makes it what it is,—­a moving mountain of water.

We have thus endeavoured, in the opposite characters of the Sublime and the Gay or Magnificent, to exhibit the two extremes of Variety; of the intermediate degrees it is unnecessary to speak, since in these two is included all that is applicable to the rest.

Though it is of vital importance to every composition that there be variety of Lines, little can be said on the subject in addition to what has been advanced in relation to parts, that is, to shape and quantity; both having a common origin.  By a line in Composition is meant something very different from the geometrical definition.  Originally, it was no doubt used as a metaphor; but the needs of Art have long since converted this, and many other words of like application, (as tone, &c.,) into technical terms. Line thus signifies the course or medium through which the eye is led from one part of the picture to another.  The indication of this course is various and multiform, appertaining equally to shape, to color, and to light and dark; in a word, to whatever attracts and keeps the eye in motion.  For the regulation of these lines there is no rule absolute, except that they vary and unite; nor is the last strictly necessary, it being sufficient if they so terminate that the transition from one to another is made naturally, and without effort, by the imagination.  Nor can any laws be laid down as to their peculiar character:  this must depend on the nature of the subject.

In the wild and stormy scenes of Salvator Rosa, they break upon us as with the angular flash of lightning; the eye is dashed up one precipice only to be dashed down another; then, suddenly hurried to the sky, it shoots up, almost in a direct line, to some sharp-edged rock; whence pitched, as it were, into a sea of clouds, bellying with circles, it partakes their motion, and seems to reel, to roll, and to plunge with them into the depths of air.

If we pass from Salvator to Claude, we shall find a system of lines totally different.  Our first impression from Claude is that of perfect unity, and this we have even before we are conscious of a single image; as if, circumscribing his scenes by a magic circle, he had imposed his own mood on all who entered it.  The spell then opens ere it seems to have begun, acting upon us with a vague sense of limitless expanse, yet so continuous, so gentle, so imperceptible in its remotest gradations, as scarcely to be felt, till, combining with unity, we find the feeling embodied in the complete image of intellectual