still left in the south aisle. There is no attempt to represent the
other mosaics on the roof, the scale being too small to admit of their
being represented with any success; but some at least of those mosaics
had been executed at that period, and their absence in the
representation of the entire church is especially to be observed, in
order to show that we must not trust to any negative evidence in such
works. M. Lazari has rashly concluded that the central archivolt of St.
Mark's _must_ be posterior to the year 1205, because it does not
appear in the representation of the exterior of the church over the
northern door; [Footnote: Guida di Venezia, p. 6. (He is right,
however.)] but he justly observes that this mosaic (which is the other
piece of evidence we possess respecting the ancient form of the
building) cannot itself be earlier than 1205, since it represents the
bronze horses which were brought from Constantinople in that year. And
this one fact renders it very difficult to speak with confidence
respecting the date of any part of the exterior of St. Mark's; for we
have above seen that it was consecrated in the eleventh century, and yet
here is one of the most important exterior decorations assuredly
retouched, if not entirely added, in the thirteenth, although its style
would have led us to suppose it had been an original part of the fabric.
However, for all our purposes, it will be enough for the reader to
remember that the earliest parts of the building belong to the eleventh,
twelfth, and first part of the thirteenth century; the Gothic portions
to the fourteenth; some of the altars and embellishments to the
fifteenth and sixteenth; and the modern portion of the mosaics to the
seventeenth.

SECTION IX. This, however, I only wish him to recollect in order that I
may speak generally of the Byzantine architecture of St. Mark's, without
leading him to suppose the whole church to have been built and decorated