mon material was fi red clay, and large factories that manu-
factured mass-produced terra-cotta lamps were prevalent
throughout the empire. Clay lamps were usually made with
molds, the top and bottom halves pressed into hollow forms
and joined together. Once assembled, they were oft en glazed.
With this simple fabrication technique, elaborate decorative
elements could easily be impressed into the surface of the clay.
Decoration included patterns as well as images of a religious,
mythological, or quotidian nature. In addition, manufactur-
ers oft en stamped their names into the bottom of the lamp, a
feature that permits archaeologists to look in some detail at
patterns of production and distribution.
Analysis of these distribution patterns suggests that
Italian lamps dominated the provincial markets in the fi rst
century of the empire but were later superseded across the
empire by locally made products. Manufactured lamps could
be shipped in bulk or perhaps used as fi ller with (or packed
within) other commodities and sometimes transported over
great distances. A wooden shipping box found at Pompeii in
1881 contained 37 lamps from southern Gaul, with a range of
manufacturers’ stamps that suggest that they may have been
shipped as a consignment.
Th ere were numerous and frequent variations on the ba-
sic lamp design. Lamps with multiple wicks were manufac-
tured, and models with as many as a dozen wicks arranged in
a circle around the discus were not unusual. Portable lamps
(lanterns), with bodies made of bronze, iron, clay, or wood,
were also common. Th ese had high, protected sides and
windows covered with a translucent material, such as thinly
shaved animal skin, horn, or parchment. Stationary lamps
were frequently placed upon purpose-built stands or sus-
pended from chains in order best to radiate their light.
Th e Romans utilized artifi cial illumination for a range
of functions. Private residences and businesses (both com-
mercial and industrial) required some degree of lighting in
the evening, though the Romans chose as much as possible to
organize their activities around the daylight hours. At night
public spaces were oft en lit by torchlight, and the city of An-
tioch was reported to have had an organized street lighting
system by 350 c.e. For certain industrial operations, such as
mining and tunneling activities, extensive artifi cial lighting
was required. Open-fl amed torches would have presented
problems, so portable lanterns and lamps placed within wall
niches could have been used. Th e author Diodorus Siculus
(ca. 90–ca. 30 b.c.e.), in his Bibliotheca historica, mentions
that lamps were also mounted on miners’ heads, but there is
no other evidence of this practice.
Artifi cial illumination also played an important role
in transmitting information. Th e Romans built many light-
houses along the coasts, both to mark harbors and to warn
against shoreline hazards. During the day large mirrors were
used to alert ships while fi res were ignited at night. A number
of these lighthouses survive, including well-preserved struc-
tures in La Coruña, Spain, and Dover, England. Additional
information is provided about other major lighthouses—such
as the one at Ostia—by surviving depictions on coins and in
mosaics. Th e most famous lighthouse of antiquity, the Pharos
of Alexandria in Egypt, was actually built by the Hellenistic
rulers Ptolemy I Soter and his son and successor, Ptolemy II
Philadelphus, but may not have been transformed into a light-
house until the fi rst century c.e. by the Romans. Although it
was destroyed by earthquakes in 1303 c.e. and 1323 c.e., we
are well informed about its size and appearance by later Arab
chroniclers.
One especially sophisticated use of artifi cial illumina-
tion was its application to military signaling. Signaling was
important in ancient warfare, and various communication
systems permitted complex messages to be relayed by torches
over great distances. Th e Romans adapted and modifi ed sys-
tems from the Greeks and the Carthaginians, among others,
and employed them both tactically (on the battlefi eld) and
strategically (along the frontier). Th ese systems were akin to
an early form of Morse code, in which a patterned display of
torches could relay letters, phrases, or codes.
Illumination also played an important role in several as-
pects of religious practice. Lamps were an important feature
of the household altar (lararium) and were used in variousLamp showing a chariot race, Roman, about 175–225 c.e. (© Th e
Trustees of the British Museum)
illumination: Rome 591