Likewise with relief. A bas-relief may have none. A fresco may. Relief then is a matter of contrast, as is shown especially in the mosaics of Taj Mahal; but its nature is easily seen if we compare prose with paint:—

'He stood at the edge of the sea while the waves crept towards him, nearer and nearer, sinuously flowing and ebbing, but ever nearer. Ever.'

I give this as an instance, not as a fragment of literature. The lonely 'ever' gives relief to the sentence of twenty-four words if we assume that another long sentence follows. (If no sentence follows, 'ever' is no longer relief but culmination, see Group C.) The painter renders the same effect by a more vivid line of foam in the middle distance, the musician by interposing a treble motif between basses. Thus, if we find variety of sentence, variety of tone, we have relief.

Density and Depth need not detain us long. Flaubert, the Psalms, Jacob Epstein's Oscar Wilde, the Eroica and Velasquez all give the sensation we call by those names; we mean by them that the work contains a suggestion of something behind. Atmospheric quality, then, together with thought withdrawn, echo unheard and space unlimned, are the bases on which the two terms rest. The suggestion that this 'behind' exists is of course essential, for we must not conclude that where there is nothing to be seen there is something to be guessed: there must be no guessing, but if a feeling of reserve is created then density and depth exist.

Group B. (Linear). The quality of linking is opposed to the quality of discord, though a discord may prove to be a link. The most perfect instances of linking and continuity, for I almost identify the terms, are the solar spectrum and the song of the lark, but in the field of art we must be content with the gamut, the sequence of shades and the concatenation of phrases. In prose:—

'The bird rose up into the air, and its wings beat slowly. The air was laden with mist. The bird rose towards the clouds ...' is an instance where there is a solution of continuity, which could be remedied if the second sentence were related to the flight of the bird. And the same lack of continuity would exist if the painter of a harlequin were to make his skull-cap brown, if in a pause of some work of Locatelli the musician interposed (however skilfully and gradually) some characteristic Grieg chords.

It does not, of course, follow that a discord is discontinuous. Providing it recurs within the scheme of the work, as the clashes in Elektra, the sequence of discords becomes a sequence of links, and we arrive at this paradox, that it is the solutions of continuity provide the continuity, while the apparently continuous portions of the work are carried by the discordant sections. Thus there is continuity in the Louvre Ghirlandajo because equivalent, if minor, discords repeat the motif of the red mantle in two other portions of the picture. The relation of the discords is sometimes vital to more than continuity, namely to rhythm (Group C.).

With Group C. (Kinetic) we touch the most vital portion of the subject, for the kinetic quality in art amounts to the quality of life in man. And its chief component is rhythm. If rhythm be taken as a condition of internal movement within the inanimate, as a suggestion of expanding and retracting life, of phrases (musical, pictorial, or literary) that come to an inevitable resolution, it is seen that its presence in a work of art must baffle until it is realised under what guise it appears. A simple instance of prose rhythm is:—

'The wayfarer stopped by the well. He looked within its depths and the water was far below. Idly he dropped a pebble between the walls; and it seemed minutes while he waited until the water sped its thanks.'

This is not metrical but rhythmic prose, and it would be wearisome if the rhythm were not altered from paragraph to paragraph; short sentences alternate with long at fixed intervals, or passive verbs are inset between actives, while Gothic words, juxtaposed to Latin, or adjectival combinations produce the same effect of rise and fall. The rhythm may be regular as the movement of a woman's breast or spasmodic within the regular as the flight of a gull.