century b.c.e. but had been well known long before then.
Workers would raise blocks slightly with wooden levers, place
wooden supports underneath, and repeat until the stone was
high enough to move into place by sliding it over wooden
rollers.
Th ere were variations and innovations in the basic tech-
niques of post-and-lintel structures in stone. Most notably,
the historian Th ucydides reports that the Temple of Athena
Chalkioikos in Sparta was lined in bronze (chalkioikos means
“bronze-house”); the bronze was melted down from weapons
the Spartans captured during a battle at Aphidna.
In the Hellenistic Period (323–31 b.c.e.) building tech-
niques did not change fundamentally, with the main in-
novations being aesthetic fl ourishes (oft en combined with
cost-saving measures), such as the use of colored stone, mar-
ble veneers over cheaper limestone construction, or bricks
covered with plaster painted to look like marble.
ROME
BY TOM STREISSGUTH
The craft and science of architecture made important
advances in Roman times. Roman leaders considered
public buildings as personal monuments to themselves,
legacies of their power and benevolence. For this reason,
many imposing structures were raised in the Roman cit-
ies, and Roman architects enjoyed wide renown and lucra-
tive patronage. The early Roman builders borrowed their
construction techniques from the Greeks and from the
Etruscans of northern Italy. The Etruscan arch, adopted by
the Romans in the third century b.c.e., marked an impor-
tant advance over the post-and-beam construction tradi-
tional to the Greeks. The first arches were corbeled—made
up of horizontal courses of stone, overlaid slightly as the
courses rose higher and extended across a limited space.
Later arches were true arches, made of stone that was cut
and fitted to produce a regular semicircle.
Th e Roman discovery of caementum (cement), in approx-
imately the second century b.c.e., made possible not only the
longevity but also the more grandiose scale of Roman build-
ings. Caementum was made of three parts sand and one part
burnt lime, mixed with a volcanic ash known as pozzolana.
Th e ash helped the mixture dry quickly and evenly into con-
crete a nd a lso made it water proof. Bui lders oft en added a rub-
ble of small stones and broken brick to the mix to strengthen
it. Concrete was impervious to fi re and weather, and it bore
more weight than stone. It was also more abundant and easier
to handle than stone, which had to be laboriously cut, trans-
ported, raised into place, and fi tted. Concrete allowed walls
to support heavier loads and gave builders more fl exibility in
designing interior spaces.
Simple leveling devices, including the chorobates and the
groma, ensured precise alignment of foundations, walls, and
piers. Th e chorobates was a long, narrow wooden bench, with
plumb lines hanging near both ends. Th e plumb lines were
precisely matched to a vertical line marked on the bench sup-
ports. To ensure the measure, the surveyor checked a small
trough of water or oil on top of the chorobates; if the water
line was straight, the device lay horizontal. Th e surveyor then
sighted along the top of the device to a distant ranging pole
to mark position and height. To align vertical surfaces, Ro-
man builders used the groma, a wooden crosspiece suspend-
ed from a pole. Plumb lines hung from the four ends of the
crosspiece. Th e surveyor verifi ed that the lines hung a match-
ing distance off the ground and then sighted along the plumb
lines to ensure that a distant wall or pier (vertical support)
was at a perfect right angle to the ground.
Once a site was surveyed and marked out, builders raised
wooden frames to begin construction. Caementum could be
poured into frames of nearly any size and shape. Th e dry-
ing concrete was faced with stones of tufa, a soft and porous
volcanic rock. Diff erent facing patterns went in and out of
style over the course of Roman history. Th e earliest style was
the incertum wall, in which tufa stones were placed random-
ly into the concrete. Reticulum walls had regularly shaped
blocks, a technique begun at the end of the fi rst century b.c.e.
Dressed stones, commonly of tufa or travertine (limestone),
were joined to the concrete in the quadratum wall. In later
years, marble, porphyry, and alabaster were also used to face
Roman buildings.
Finished stone walls were given a fi lm of stucco, which
could be decorated with painted signage or simple geomet-
ric designs. Interior spaces in both private homes and pub-Iron window grill, Roman Britain, late third or fouth century c.e. (©
Th e Trustees of the British Museum)160 building techniques and materials: Rome