so elaborate that it would be a
great loss if it were broken, but as the clay yields at once to the
hand, and the sculptor can do anything with it he likes, it is a
material for him to sketch with and play with,--to record his fancies
in, before they escape him--and to express roughly, for people who can
enjoy such sketches, what he has not time to complete in marble. The
clay, being ductile, lends itself to all softness of line; being easily
frangible, it would be ridiculous to give it sharp edges, so that a
blunt and massive rendering of graceful gesture will be its natural
function; but as it can be pinched, or pulled, or thrust in a moment
into projection which it would take hours of chiselling to get in stone,
it will also properly be used for all fantastic and grotesque form, not
involving sharp edges. Therefore, what is true of chalk and charcoal,
for painters, is equally true of clay, for sculptors; they are all most
precious materials for true masters, but tempt the false ones into fatal
license; and to judge rightly of terra-cotta work is a far higher reach
of skill in sculpture-criticism than to distinguish the merits of a
finished statue.

157. We have, secondly, work in bronze, iron, gold, and other metals; in
which the laws of structure are still more definite.

All kinds of twisted and wreathen work on every scale become delightful
when wrought in ductile or tenacious metal, but metal which is to be
_hammered_ into form separates itself into two great divisions--solid,
and flat.

[Illustration: PLATE XI.--THE FIRST ELEMENTS OF SCULPTURE.

Incised Outline and Opened Space.]

(A.) In solid metal work, _i. e._, metal cast thick enough to resist
bending, whether it be hollow or not, violent and various projection may
be admitted, which would be offensive in marble; but no sharp edges,
because it is difficult to produce them with the hammer. But since the
permanence of the material justifies exquisiteness of workmanship,
whatever delicate ornamentation can be wrought with rounded surfaces may
be advisedly introduced; and since the colour of bronze or any other
metal is not so pleasantly representative of flesh as that of marble, a
wise sculptor will depend less on flesh contour, and more on picturesque
accessories, which, though they would be vulgar if attempted in stone,
are rightly entertaining in bronze or silver. Verrochio's statue of
Colleone at Venice, Cellini's Perseus at Florence, and Ghiberti's g