tone, the original ornamental purpose of the design is
sacrificed or forgotten. But when nothing of this kind can be attempted,
and a slight outline is all that the sculptor can command, we may
anticipate that this outline will be composed with exquisite grace; and
that the richness of its ornamental arrangement will atone for the
feebleness of its power of portraiture. On the porch of a Northern
cathedral we may seek for the images of the flowers that grow in the
neighboring fields, and as we watch with wonder the grey stones that
fret themselves into thorns, and soften into blossoms, we may care
little that these knots of ornament, as we retire from them to
contemplate the whole building, appear unconsidered or confused. On the
incrusted building we must expect no such deception of the eye or
thoughts. It may sometimes be difficult to determine, from the
involutions of its linear sculpture, what were the natural forms which
originally suggested them: but we may confidently expect that the grace
of their arrangement will always be complete; that there will not be a
line in them which could be taken away without injury, nor one wanting
which could be added with advantage.

Sec. XLI. Farther. While the sculptures of the incrusted school will thus
be generally distinguished by care and purity rather than force, and
will be, for the most part, utterly wanting in depth of shadow, there
will be one means of obtaining darkness peculiarly simple and obvious,
and often in the sculptor's power. Wherever he can, without danger,
leave a hollow behind his covering slabs, or use them, like glass, to
fill an aperture in the wall, he can, by piercing them with holes,
obtain points or spaces of intense blackness to contrast with the light
tracing of the rest of his design. And we may expect to find this
artifice used the more extensively, because, while it will be an
effective means of ornamentation on the exterior of the building, it
will be also the safest way of admitting light to the interior, still
totally excluding both rain and wind. And it will naturally follow that
the architect, thus familiarized with the effect of black and sudden
points of shadow, will often seek to carry the same principle into other
portions of his ornamentation, and by deep drill-holes, or perhaps
inlaid portions of black color, to refresh the eye where it may be
wearied by the lightness of the general handling.

Sec. XLII. Farther. Exactly in proportio