counting emerged because people had to weigh and measure.
Systems of mathematics provided people with common units
of measurement, which could then be divided by common
factors to produce smaller units or multiplied by common
factors to produce larger units. In this way, for example, the
modern yard consists of 3 feet, a foot consists of 12 inches,
and so on.
Trade and exchange, too, required systems of weights and
measurements. If one country was trading wine for lumber,
the merchants making the trade needed some way of mea-
suring and agreeing on the volume of wine and lumber to
determine prices. Th e result was that systems of weights and
measures were oft en imported and exported along with the
goods they measured. When the value of commodities came
to be measured by money as a medium of exchange, it was
vitally important for merchants to be able to weigh accurately
coins and the gold and silver with which they were made.AFRICA
BY MICHAEL J. O’NEAL
Historians, archaeologists, and scientists use the term metrol-
ogy to refer to the study of weights and measures, particularly
as it applies to the premodern world, when weights and mea-
sures were not universally standardized. Metrology, though,
does more than simply seek to discover which specifi c units
of measurement and weight the ancients used. It also seeks to
understand the underlying system that gave rise to weights
and measurements.
Th us, the types of questions metrologists ask include:
Were units of weight and measure arbitrary values, or were
they based on some phenomenon from the natural world?
How was one unit divisible into, or a multiple of, some other
unit? How did ancient traders and others convert units of
weight and measure into those of another people in the pro-
cess of striking trading bargains? To what extent were units
of measure and weight standardized in a kingdom or region?
Did royalty have one unit of measurement or weight and
common people another? What can ancient artifacts, such
as buildings and their dimensions, reveal about systems of
measurement? What was the relationship between systems of
weights and measurements and mathematical, astronomical,
calendrical, timekeeping, and other systems?
Th e grandest question of all, however, is this: Did ancient
systems of measuring weight, volume, distance, and the like
d e r i v e f r o m s o m e c o m m o n s y s t e m t h a t w a s s p r e a d t h r o u g h o u t
much of the ancient world, including parts of Africa? Many
metrologists have devoted careers to fi nding common units
of measurement that underlay the construction of artifacts as
widely dispersed as the pyramids of Egypt and Stonehenge in
England. Some claim to have found commonalities, in vari-
ous cases based on common astronomical observations from
which the circumference of the earth at the equator may have
been deduced. Many of these conclusions, though, are highly
speculative.Few of these questions can be answered with any cer-
tainty about ancient Africa (other than Egypt). Th e absence
of written records inhibits the work of metrologists who fo-
cus on the continent. Further casting a veil over the subject
is the fact that ancient African kingdoms, cities, and settle-
ments rose and fell with great frequency. People migrated
throughout the continent, oft en in response to climatic
change, taking with them their culture and knowledge sys-
tems and mingling them with the culture and knowledge
they found in their new homes. Warfare wiped out some
African cultures—the kingdom of Kush, for example, fell to
the kingdom of Axum, and the Carthaginian kingdom was
totally destroyed by the Romans—contributing to the lack of
records and artifacts.
At the same time, more powerful empires, including that
of Egypt and later the Roman Empire, would have imposed
their systems on tributary people in Africa; in particular,
Egyptian units of measurement probably became the norm
throughout much of northern Africa. Later, Roman units
probably became accepted. Th ese units were derived from
Greek measurements, which the Greeks in turn had adopted
from numerous cultures in the Near East, who in turn had ad-
opted them from such places as Mesopotamia. Furthermore,
because much of Africa, particularly the northern stretches
of the continent (as opposed to the nomadic southern por-
tions), engaged in trade and other activities with a large set of
other civilizations who routinely passed through the region
known as the Sahel, a strip of settlements that spanned the
continent below the Sahara Desert, the notion of any kind
of standardized, “African” system of weights and measures
remains elusive.
Despite these problems, historians and archaeologists
can make some inferences. It is highly likely that ancient
Africans, in common with numerous other ancient peo-
ples, measured distances using, at least as a starting point,
the human body. Th us, for example, hand spans, knuckles,
arm length, feet, and forearms were probably used as units
of distance. Indeed, the cubit is a unit of measurement used
throughout the entire region of Africa, Rome, the Near East,
and eventually Europe. Th e cubit was a unit of length that
originally measured the distance from a man’s elbow to the
tip of his longest fi nger, although eventually the cubit settled
into a measurement of about 18 inches. Such a unit of mea-
surement, of course, would necessarily be imprecise, since the
unit would be longer for a taller man than for a shorter one.
In the case of royalty, the “royal cubit”—a slightly larger unit
of measure—would have been longer than that used by oth-
ers, in an eff ort to suggest that royals were larger than com-
mon mortals. Similarly, it is little accident that in the modern
world, the foot continues to be a common unit of measure-
ment. Th e foot was used throughout the ancient world to
measure a unit of distance that was, in fact, just about a foot,
or 12 modern inches. Th e knuckle of the thumb could be used
to measure relatively small distances, and thus corresponded
to a modern inch.weights and measures: Africa 11730895-1194_Soc&Culturev4(s-z).i1173 1173 10/10/07 2:31:20 PM