lic buildings, displayed fresco paintings of mythological or
pastoral scenes or of more utilitarian pictures, giving visitors
a hint at the profession or business at hand. Floor mosaics,
employing colored tiles placed into concrete fl oors, grew
popular aft er their introduction from Greece in the fi rst cen-
tury b.c.e. In the early empire, brick facing was a fairly un-
common technique, as the sun-dried (unfi red) brick cracked
easily from weather and stress. Later, kiln-drying techniques
made bricks harder and stronger. Vast brickyards on the out-
skirts of Rome provided the basic facing material that en-
dured until the Western Roman Empire’s decline and fall in
the fi ft h century c.e.
During the empire, cement mixed with a lighter ash
known as scoria allowed the Romans to construct larger and
loft ier interior spaces. For their public baths and consecrated
temples, such as the Pantheon, the Romans designed slen-
der arches over entrances and raised domes and half-domes
over interior spaces. A series of regularly spaced arches over
a rectangular hall provided the frame for a barrel vault, while
intersecting arches framed the groin vault. Stronger concrete
walls could also be pierced with large window spaces, which,
in this era before sheet glass, were commonly fi lled with
wooden latticework.
Th e expanding empire raised a great variety of large
public buildings, including markets, baths, temples, meet-
ing halls, palaces, and such outdoor structures as hillside
terraces, aqueducts, racecourses, amphitheaters, watchtow-
ers, and speaking platforms. Th e arch and vault, along with
concrete, gave architects great fl exibility in the design of
these structures and in the fl oor plans of large homes and
insulae, or apartment blocks. Th ousands of these massive
Roman structures have endured more than two millennia,
while modern concrete buildings, which are raised on skel-
etons of steel beams and slender iron bars, begin wearing
out in a few decades.
Under the emperor Augustus, the fi rst great public baths
and theaters as well as multistory insulae were built in the city
of Rome. In 64 c.e., however, a massive fi re destroyed entire
neighborhoods, and thousands of buildings had to be demol-
ished. Th e emperor Nero passed new building regulations to
prevent another such disaster. Building height was limited to
seven stories, and all buildings were required to have porti-
coes (a colonnade, or row of columns, supporting a roof ) for
easier access to upper stories. Private homes had to keep fi re
buckets and equipment handy, and no common walls were
allowed—all new Roman buildings had to be freestanding.
Th e gradual decline of the later empire degraded Roman
construction and architecture. Late-empire architects re-
placed scoria and pozzolana with pumice, a weaker bonding
material. Th ere were few design innovations, and builders
had to rely on inexpensive materials. Without the resources
to maintain and repair buildings or to replace those lost to
fi re, war, or earthquake, Roman cities grew more chaotic
and public buildings smaller and plainer. Th e great public
structures, such as the Colosseum and the Pantheon, be-
came public meeting halls, storage yards, useful stone quar-
ries, and fi nally empty monuments to Rome’s past glory and
engineering genius.THE AMERICAS
BY ARDEN DECKER
Much of what is known of early building practices centers
around the movement and shaping of the natural landscape.
Everyday buildings were usually created from perishable
materials, so it is architecture of a more monumental nature
that has provided archaeologists with much of what they un-
derstand about building techniques and materials in ancient
times. Adobe bricks, mud, clay, stone, and perishable materi-
als made up the majority of building materials for all ancient
American cultures.
In ancient Mesoamerica the wattle-and-daub build-
ing technique was one of the simplest and most prevalent
methods used. A wood latticework (wattle) was covered in
a mixture of clay, mud, and straw (daub) to create a struc-
ture. Posts were added for houses that would have been
covered with thatched roofs and sometimes with plaster.
During the Late Preclassic period (400 b.c.e.–150 c.e.) the
simple wattle-and-daub style of housing became larger,
incorporating cut stone and plaster. The development of
columns during this period allowed for the construction of
larger enclosed rooms.
More monumental structures, such as platforms and tem-
ple pyramids, were also made using this method. Platforms
from the Early Preclassic period (1800–1200 b.c.e.) have been
found at San José Mogote, in the Oaxaca Valley of Mexico,
which were made using wattle and daub and then faced with
bun-shaped adobe brick. Such platforms would have served as
bases for large-scale public buildings. However, adobe brick
was used less oft en as the working of stone became more and
more sophisticated. At the early Mayan site of Nabké, in the
Petén (present-day Guatemala), this sophistication was car-
ried forward with the development of apron moldings (joint
stones that slightly hang over the bottom stonework of a wall),
which allowed cut stones to be secured to walls that were
growing ever higher and steeper, which would be exploited by
later Mayan centers.
Th e Early Preclassic site of San Lorenzo (dating to around
1700–1200 b.c.e.), located on the Gulf Coast of Mexico, was
built on a large, man-made platform constructed from ex-
cavated, existing earth as well as imported fi ller materials.
Measuring 3,937 feet by 1,969 feet and standing 164 feet high,
this is the fi rst example of large-scale construction in Meso-
america. Such a structure would have required large forces of
organized labor. Th e platform pyramid style of construction
would reach mammoth scale at Teotihuacán, Mexico (around
100 c.e.). For the Pyramid of the Sun, the fi rst major structure
built here, nearly 30 million baskets of dirt and rubble were
hauled to the site. Th e fi nal structure was fi nished off with a
layer of mud and volcanic gravel that was then covered with abuilding techniques and materials: The Americas 161