upy the center of the picture, and first
catch the eye; little by little we are led away from them to a gleam of
pearly light in the lower corner, and find that, from the head which it
shines upon, we can turn our eyes no more.

196. As, in every good picture, nearly all laws of design are more or
less exemplified, it will, on the whole, be an easier way of explaining
them to analyze one composition thoroughly, than to give instances from
various works. I shall therefore take one of Turner's simplest; which
will allow us, so to speak, easily to decompose it, and illustrate each
law by it as we proceed.

[Illustration: FIG. 32.]

Fig. 32 is a rude sketch of the arrangement of the whole subject; the
old bridge over the Moselle at Coblentz, the town of Coblentz on the
right, Ehrenbreitstein on the left. The leading or master feature is, of
course, the tower on the bridge. It is kept from being _too_ principal
by an important group on each side of it; the boats, on the right, and
Ehrenbreitstein beyond. The boats are large in mass, and more forcible
in color, but they are broken into small divisions, while the tower is
simple, and therefore it still leads. Ehrenbreitstein is noble in its
mass, but so reduced by aerial perspective of color that it cannot
contend with the tower, which therefore holds the eye, and becomes the
key of the picture. We shall see presently how the very objects which
seem at first to contend with it for the mastery are made, occultly, to
increase its preeminence.

2. THE LAW OF REPETITION.

197. Another important means of expressing unity is to mark some kind of
sympathy among the different objects, and perhaps the pleasantest,
because most surprising, kind of sympathy, is when one group imitates or
repeats another; not in the way of balance or symmetry, but
subordinately, like a far-away and broken echo of it. Prout has insisted
much on this law in all his writings on composition; and I think it is
even more authoritatively present in the minds of most great composers
than the law of principality.[54] It is quite curious to see the pains
that Turner sometimes takes to echo an important passage of color; in
the Pembroke Castle for instance, there are two fishing-boats, one with
a red, and another with a white sail. In a line with them, on the beach,
are two fish in precisely the same relative positions; one red and one
white. It is observable that he uses the artifice chiefly in pictures
whe