materials of imperfect and
variable character; and, what is more, there are very few cliffs which
do not display alternations between compact and friable conditions of
their material, marked in their contours by bevelled slopes when the
bricks are soft, and vertical steps when they are harder. And, although
we are not hence to conclude that it is well to introduce courses of bad
materials when we can get perfect material, I believe we may conclude
with great certainty that it is better and easier to strengthen a wall
necessarily of imperfect substance, as of brick, by introducing
carefully laid courses of stone, than by adding to its thickness; and
the first impression we receive from the unbroken aspect of a wall veil,
unless it be of hewn stone throughout, is that it must be both thicker
and weaker than it would have been, had it been properly coursed. The
decorative reasons for adopting the coursed arrangement, which we shall
notice hereafter, are so weighty, that they would alone be almost
sufficient to enforce it; and the constructive ones will apply
universally, except in the rare cases in which the choice of perfect or
imperfect material is entirely open to us, or where the general system
of the decoration of the building requires absolute unity in its
surface.

[Illustration: Fig. III.]

Sec. VII. As regards the arrangement of the intermediate parts themselves,
it is regulated by certain conditions of bonding and fitting the stones
or bricks, which the reader need hardly be troubled to consider, and
which I wish that bricklayers themselves were always honest enough to
observe. But I hardly know whether to note under the head of aesthetic
or constructive law, this important principle, that masonry is always
bad which appears to have arrested the attention of the architect more
than absolute conditions of strength require. Nothing is more
contemptible in any work than an appearance of the slightest desire on
the part of the builder to _direct attention_ to the way its stones are
put together, or of any trouble taken either to show or to conceal it
more than was rigidly necessary: it may sometimes, on the one hand, be
necessary to conceal it as far as may be, by delicate and close fitting,
when the joints would interfere with lines of sculpture or of mouldings;
and it may often, on the other hand, be delightful to show it, as it is
delightful in places to show the anatomy even of the most delicate human
frame: bu