still more, the
difference between the delicate overhanging of the natural cliff,
cautiously diminished as it gets higher[87], and the ideal danger of the
Liber Veritatis.

[Illustration: FIG. 87.]

Sec. 38. And the fact is, generally, that natural cliffs are very cautious
how they overhang, and that the artist who represents them as doing so
in any extravagant degree entirely destroys the sublimity which he hoped
to increase, for the simple reason that he takes away the whole
rock-nature, or at least that part of it which depends upon weight. The
instinct of the observer refuses to believe that the rock is ponderous
when it overhangs so far, and it has no more real effect upon him than
the imagined rocks of a fairy tale.

[Illustration: FIG. 88.]

Though, therefore, the subject sketched on this page is sufficiently
trifling in itself, it is important as a perfect general type of the
overhanging of that kind of precipices, and of the mode in which they
are connected with the banks above. Fig. 88 shows its abstract leading
lines, consisting of one great parabolic line _x y_ falling to the brow,
curved aqueous lines down the precipice face, and the springing lines of
its vegetation, opposed by contrary curves on the farther cliff. Such an
arrangement, with or without vegetation, may take place on a small or
large scale; but a bolder projection than this, except by rare accident,
and on a small scale, cannot. If the reader will glance back to Plate
+37+, and observe the arrangement of the precipices on the right hand,
he will now better understand what Turner means by them. But the whole
question of the beauty of this form, or mode of its development, rests
on the nature of the bank above the cliffs, and of the aqueous forces
that carved it; and this discussion of the nature of banks, as it will
take some time, had better be referred to next chapter. One or two more
points are, however, to be stated here.

Sec. 39. For the reader has probably been already considering how it is
that these overhanging cliffs are formed at all, and why they appear
thus to be consumed away at the bottom. Sometimes if of soft material
they actually _are_ so consumed by the quicker trickling of streamlets
at the base than at the summit, or by the general action of damp in
decomposing the rock. But in the noblest instances, such cliffs are
constructed as at c in Fig. 73, above, and the inward retirement of the
precipice is the result of the