The Flavian Amphitheater is usually
known as the Colosseum either because of its huge
size or because a colossal statue in gilded bronze
of Nero in the guise of the Sun god originally stood
nearby.
The Coliseum was begun by Vespasian in 72 A.D. and
inaugurated in 80 A.D. by Titus with a hundred days
of celebrations, during which several thousand wild
beasts and gladiators were reputedly killed. The
amphitheater was completed, however, by the emperor
Domitian.
The Coliseum, like the much earlier amphitheater at
Pompeii, could not have been built without concrete
technology. The enormous oval seating area is
sustained by a complex system of radial and concentric
corridors covered by concrete barrel
(or tunnel) vaults. This concrete
"skeleton" reveals itself today to anyone who enters
the amphitheater; in the centuries following the fall
of Rome the Coliseum served as a convenient for
ready-made building materials, and almost all its
marble seats were hauled away, exposing the network of
vaults below.
The Exterior
Elliptical
in shape, the exterior consists of four stories in
travertine stone. The blocks were not held together
with mortar but with pins of iron and other metal.
- The first three stories, in the
form of arcades, have arches with half columns of
the Tuscan,
Ionic
and Corinthian
orders respectively
- The top story has rectangular
windows instead of arches framed by pilasters
with Corinthian capitals
- The ground-floor arches gave
access to the staircases leading to the various
sectors of the "Cavea"
The Romans used
Greek orders to embellish an architectural form that
is foreign to Greek post-and-lintel architecture,
namely the arch. Revived during the Italian
Renaissance, the motif has a long, illustrious
history in Classical architecture. The Roman
practice of framing an arch with an applied Greek
order has no structural purpose but fulfills the
aesthetic function of introducing variety into a
monotonous surface, while unifying a multistoried
facade by casting a net of verticals and
horizontals over it that ties everything together.
Entrances
There are four main
entrances, each with a triple opening those at the
ends were reserved for the emperor, while those on
the sides were used for the processional entry of
the gladiators and other participants.
The spectators (some 40,000-50,000) entered through
the lower arcades, which were numbered, and found
their way to their seats by the appropriate
staircases.
Concrete
In
contrast with Greek practice, the Romans employed a
kind of "artificial stone" of recent invention: concrete.
Roman concrete was made from a changing recipe of
lime mortar, volcanic sand, water, and small stones
("caementa," from which the English word cement is
derived).
The mixture was placed in wooden
frames and left to dry and bond with a facing of
brick or stone in a procedure somewhat like the
casting of statues in bronze or other metals. When
the concrete was completely dry, the wooden molds
were removed, leaving behind a solid mass of great
strength, though rough in appearance, which was
often covered afterward with stucco or even sheathed
with marble revetment.
Despite this, concrete walls were
much less costly to construct than walls built of
imported Greek marble or even local Italian tufa and
travertine. The advantages of concrete, however, go
well beyond economy of construction, for it is
possible to fashion shapes out of concrete that
cannot be achieved by masonry construction,
especially the huge vaulted and domed ceilings
(without internal supports) that the Romans came to
prefer over the post-and-lintel structures of the
Greeks and Etruscans.
The use of concrete enabled the
Roman architect to think of architecture in terms
radically different from those used by earlier
builders. Roman architecture became an architecture
of space rather than of sheer mass.
Sources:
- "Gardner's Art
Through the Ages, Tenth Edition," by Richard G.
Tansey and Fred S. Kleiner. Harcourt Brace
College. Pub.1996.
- Leonardo B. Dal
Maso, "Rome: From the Palatino to the Vaticano."
1992.
- Leonardo B. Dal
Maso, "Rome of the Caesars"
