inating in more scientific mechanics;
as indeed the Greek tradition refers it to the natural philosopher
Democritus (294-397). With this priority of Hellenic over Roman
arch-building the hypothesis, which has been often and perhaps justly
propounded, is quite compatible, that the vaulted roof of the Roman
great -cloaca-, and that which was afterwards thrown over the old
Capitoline well-house which originally had a pyramidal roof,(34) are
the oldest extant structures in which the principle of the arch is
applied; for it is more than probable that these arched buildings
belong not to the regal but to the republican period,(35) and that
in the regal period the Italians were acquainted only with flat or
overlapped roofs.(34) But whatever may be thought as to the invention
of the arch itself, the application of a principle on a great scale is
everywhere, and particularly in architecture, at least as important as
its first exposition; and this application belongs indisputably to the
Romans. With the fifth century began the building of gates, bridges,
and aqueducts based mainly on the arch, which is thenceforth
inseparably associated with the Roman name. Akin to this was the
development of the form of the round temple with the dome-shaped roof,
which was foreign to the Greeks, but was held in much favour with the
Romans and was especially applied by them in the case of the cults
peculiar to them, particularly the non-Greek worship of Vesta.(37)

Something the same may be affirmed as true of various subordinate,
but not on that account unimportant, achievements in this field.
They do not lay claim to originality or artistic accomplishment;
but the firmly-jointed stone slabs of the Roman streets, their
indestructible highways, the broad hard ringing tiles, the everlasting
mortar of their buildings, proclaim the indestructible solidity and
the energetic vigour of the Roman character.

Plastic and Delineative Art

Like architectural art, and, if possible, still more completely, the
plastic and delineative arts were not so much matured by Grecian
stimulus as developed from Greek seeds on Italian soil. We have
already observed(38) that these, although only younger sisters of
architecture, began to develop themselves at least in Etruria, even
during the Roman regal period; but their principal development in
Etruria, and still more in Latium, belongs to the present epoch, as is
very evident from the fact that in those district