ration, or influencing
the feelings of a civilized community.

The inquiry before us is twofold. Throughout the first volume, I
carefully kept the study of _expression_ distinct from that of abstract
architectural perfection; telling the reader that in every building we
should afterwards examine, he would have first to form a judgment of its
construction and decorative merit, considering it merely as a work of
art; and then to examine farther, in what degree it fulfilled its
expressional purposes. Accordingly, we have first to judge of St. Mark's
merely as a piece of architecture, not as a church; secondly, to
estimate its fitness for its special duty as a place of worship, and the
relation in which it stands, as such, to those northern cathedrals that
still retain so much of the power over the human heart, which the
Byzantine domes appear to have lost for ever.

Sec. XXIII. In the two succeeding sections of this work, devoted
respectively to the examination of the Gothic and Renaissance buildings
in Venice, I have endeavored to analyze and state, as briefly as
possible, the true nature of each school,--first in Spirit, then in
Form. I wished to have given a similar analysis, in this section, of the
nature of Byzantine architecture; but could not make my statements
general, because I have never seen this kind of building on its native
soil. Nevertheless, in the following sketch of the principles
exemplified in St. Mark's, I believe that most of the leading features
and motives of the style will be found clearly enough distinguished to
enable the reader to judge of it with tolerable fairness, as compared
with the better known systems of European architecture in the middle
ages.

Sec. XXIV. Now the first broad characteristic of the building, and the
root nearly of every other important peculiarity in it, is its confessed
_incrustation_. It is the purest example in Italy of the great school of
architecture in which the ruling principle is the incrustation of brick
with more precious materials; and it is necessary before we proceed to
criticise any one of its arrangements, that the reader should carefully
consider the principles which are likely to have influenced, or might
legitimately influence, the architects of such a school, as
distinguished from those whose designs are to be executed in massive
materials.

It is true, that among different nations, and at different times, we may
find examples of every sort and deg