repose,—­fulness and rest.  The mind thus disposed, the charmed eye glides into the scene:  a soft, undulating light leads it on, from bank to bank, from shrub to shrub; now leaping and sparkling over pebbly brooks and sunny sands; now fainter and fainter, dying away down shady slopes, then seemingly quenched in some secluded dell; yet only for a moment,—­for a dimmer ray again carries it onward, gently winding among the boles of trees and rambling vines, that, skirting the ascent, seem to hem in the twilight; then emerging into day, it flashes in sheets over towers and towns, and woods and streams, when it finally dips into an ocean, so far off, so twin-like with the sky, that the doubtful horizon, unmarked by a line, leaves no point of rest:  and now, as in a flickering arch, the fascinated eye seems to sail upward like a bird, wheeling its flight through a mottled labyrinth of clouds, on to the zenith; whence, gently inflected by some shadowy mass, it slants again downward to a mass still deeper, and still to another, and another, until it falls into the darkness of some massive tree,—­focused like midnight in the brightest noon:  there stops the eye, instinctively closing, and giving place to the Soul, there to repose and to dream her dreams of romance and love.

From these two examples of their general effect, some notion may be gathered of the different systems of the two Artists; and though no mention has been made of the particular lines employed, their distinctive character may readily be inferred from the kind of motion given to the eye in the descriptions we have attempted.  In the rapid, abrupt, contrasted, whirling movement in the one, we have an exposition of an irregular combination of curves and angles; while the simple combination of the parabola and the serpentine will account for all the imperceptible transitions in the other.

It would be easy to accumulate examples from other Artists who differ in the economy of line not only from these but from each other; as Raffaelle, Michael Angelo, Correggio, Titian, Poussin,—­in a word, every painter deserving the name of master:  for lines here may be called the tracks of thought, in which we follow the author’s mind through his imaginary creations.  They hold, indeed, the same relation to Painting that versification does to Poetry, an element of style; for what is meant by a line in Painting is analogous to that which in the sister art distinguishes the abrupt gait of Crabbe from the sauntering walk of Cowley, and the “long, majestic march” of Dryden from the surging sweep of Milton.

Of Continuity little needs be said, since its uses are implied in the explanation of Line; indeed, all that can be added will be expressed in its essential relation to a whole, in which alone it differs from a mere line.  For, though a line (as just explained) supposes a continuous course, yet a line, per se, does not necessarily imply any relation to other lines.  It will still be a line, though standing alone; but the principle of continuity may be called the unifying spirit of every line.  It is therefore that we have distinguished it as a separate principle.