Ancient Mesopotamian units of measurement
Ancient Mesopotamian units of measurement originated in the loosely organized city-states of Early Dynastic Sumer. The units themselves grew out of the tradition of counting tokens used by the Neolithic (c 6000 BCE) cultural complex of the Near East. The counting tokens were used to keep accounts of personal wealth and had both metrological and mathematical functions. Each city, kingdom and trade guild had its own standards until the formation of the Akkadian Empire when Sargon of Akkad issued a common standard. This standard was improved by Naram-Sin, but fell into disuse after the Akkadian Empire dissolved. The standard of Naram-Sin was readopted in the Ur III period by the Nanše Hymn which reduced a plethora of multiple standards to a few agreed upon common groupings. Successors to Sumerian civilization including the Babylonians, Assyrians, and Persians continued to use these groupings. Akkado-Sumerian metrology has been reconstructed by applying statistical methods to compare Sumerian architecture, architectural plans, and issued official standards such as Statue B of Gudea and the bronze cubit of Nippur.
 Archaic system
The systems that would later become the classical standard for Mesopotamia were developed in parallel with writing during Uruk Period Sumer (c 4000 BCE). Studies of protocuneiform indicate twelve separate counting systems used in Uruk.
- Sexagesimal System S used to count slaves, animals, fish, wooden objects, stone objects, containers.
- Sexagesimal System S' used to count dead animals, certain types of beer
- Bi-Sexagesimal System B used to count cereal, bread, fish, milk products
- Bi-Sexagesimal System B* used to count rations
- GAN2 System G used to count field measurement
- ŠE system Š used to count barley by volume
- ŠE system Š' used to count malt by volume
- ŠE system Š" used to count wheat by volume
- ŠE System Š* used to barley groats
- EN System E used to count weight
- U4 System U used to count calendrics
- DUGb System Db used to count milk by volume
- DUGc System Db used to count beer by volume
In Early Dynastic Sumer (c 2900–2300 BCE) metrology and mathematics were indistinguishable and treated as a single scribal discipline. The idea of an abstract number did not yet exist, thus all quantities were written as metrological symbols and never as numerals followed by a unit symbol. For example there was a symbol for one-sheep and another for one-day but no symbol for one. About 600 of these metrological symbols exist, for this reason archaic Sumerian metrology is complex and not fully understood. In general however, length, volume, and mass are derived from a theoretical standard cube, called 'gur', filled with barley, wheat, water, or oil. The mass of a gur-cube, called 'gun2' is defined as the weight a laden ass can carry. However, because of the different specific gravities of these substances combined with dual numerical bases (sexagesimal or decimal), multiple sizes of the gur-cube were used without consensus. The different gur-cubes are related by proportion, based on the water gur-cube, according to four basic coefficients and their cubic roots. These coefficients are given as:
- Komma = correction when planning rations with a 360-day year
- Leimma = conversion from decimal to a sexagesimal number system
- Diesis =
- Euboic =
One official government standard of measurement of the archaic system was the Cubit of Nippur (2650 BCE). It is a Euboic Mana + 1 Diesis (432g). This standard is the main reference used by archaeologists to reconstruct the system.
 Classical system
A major improvement came in 2150 BCE during the Akkadian Empire under the reign of Naram-Sin when the competing systems were unified by a single official standard, the royal gur-cube. His reform is considered the first standardized system of measure in Mesopotamia. The royal gur-cube (Cuneiform: LU2.GAL.GUR, 𒈚𒄥; Akkadian: šarru kurru) was a theoretical cube of water approximately 6m × 6m × 0.5m from which all other units could be derived. The Neo-Sumerians continued use of the royal gur-cube as indicated by the Letter of Nanse issued in 2000 BCE by Gudea . Use of the same standard continued through the Babylonian, Assyrian, and Persian Empires.
Units of Length are prefixed by the logogram DU (𒁺) a convention of the archaic period counting system from which it was evolved. Basic length was used in architecture and field division.
The GAN2 system G counting system evolved into area measurements. A special unit measuring brick quantity by area was called the brick-garden (Cuneiform: SIG.SAR 𒊬𒋞; Sumerian: šeg12-sar; Akkadian: libittu-mūšaru) which held 720 bricks.
|shekel||1/60||1kuš3 × 1kuš3||1m²||gin2||šiqlu||𒂆|
|garden||1||12kuš3 × 12kuš3||36m²||sar||mūšaru||𒊬|
|quarter-field||5||60kuš3 × 60kuš3||900m²||uzalak||?||𒀺|
|half-field||10||120kuš3 × 60kuš3||1,800m²||upu||ubû||𒀹𒃷|
|field||100||60ĝiri3 × 60ĝiri3||3,600m²||iku||ikû||𒃷|
|estate||1,800||3eše2 × 6eše2||64,800m²||bur||būru||𒁓|
Capacity was measured by either the ŠE system Š for dry capacity or the ŠE system Š* for wet capacity
Mass was measured by the EN system E
In the Archaic System time notation was written in the U4 System U. Multiple lunisolar calendars existed; however the civil calendar from the holy city of Nippur (Ur III period) was adopted by Babylon as their civil calendar. The calendar of Nippur dates to 3500 BCE and was itself based on older astronomical knowledge of an uncertain origin. The main astronomical cycles used to construct the calendar were the synodic month, equinox year, and sideral day.
 Relationship to other metrologies
The Classical Mesopotamian system formed the basis for Elamite, Hebrew, Urartian, Hurrian, Hittite, Ugaritic, Phoenician, Babylonian, Assyrian, Persian, Arabic, and Islamic metrologies. The Classical Mesopotamian System also has a proportional relationship, by virtue of standardized commerce, to Bronze Age Harappan and Egyptian metrologies.
Although not directly derived from it, there is a 1:2 proportional relationship between SI and Sumerian metrology. SI inherited the convention of the second as 1/86,400th of a solar day from Sumer thus, two Sumerian seconds are approximately one SI second.
 See also
- Stecchini 1971, section 1.1
- Melville 2006.
- Stenecci 1971, section 1.1
- Stecchini 1971, section 5.4
- Powell 1995, p.1955.
- Ronan, 2008
- Conder 1908, p. 87.
- Butler 2005
- Conder, Claude Reignier (1908). The Rise of Man. University of Michigan: J. Murray. p. 368.
- Melville, Duncan J (2006-06-06). "Old Babylonian Weights and Measures". Archived from the original on 13 May 2008. Retrieved 2008-06-28.
- Powell, Marvin A (1995). "Metrology and Mathematics in Ancient Mesopotamia". In Sasson, Jack M. Civilizations of the Ancient Near East III. New York, NY: Charles Scribner’s Sons. p. 3024. ISBN 0-684-19279-9
- Ronan, Colin Alistair (2008). "Measurement of time and types of calendars » Standard units and cycles". Encyclopædia Britannica Online. Archived from the original on 25 June 2008. Retrieved 2008-06-28.
- Stecchini, Livio C. (1971). "A History of Measure". Archived from the original on 23 June 2008. Retrieved 2008-06-28.
- Whitrow, G.J. (1988). Time in History: Views of Time from Prehistory to the Present Day. New York: Oxford University Press. p. 217. ISBN 0-19-285211-6.
 Further reading
- Katz, Victor,J (2007). The Mathematics of Egypt, Mesopotamia, China, India, and Islam: A Sourcebook. Princeton University Press. p. 712. ISBN 0-691-11485-4.
- Nissen, Hans Jörg; Peter Damerow, Robert K. Englund, Paul Larsen (1993). Archaic Bookkeeping: Early Writing and Techniques of Economic Administration. University of Chicago Press. p. 169. ISBN 0-226-58659-6.
- Robson, Eleanor (1999). Mesopotamian Mathematics, 2100–1600 BC: Technical Constants in Bureaucracy. Oxford University Press. ISBN 0-19-815246-9.
- Sarton, George (1993). Ancient science through the golden age of Greece. Courier Dover Publications. p. 646. ISBN 0-486-27495-0.
- An online calculator 
- Robson, Eleanor (2007). "Digital Corpus of Cuneiform Mathematical Texts". Retrieved 2008-08-13.
- Aleff, H. Peter (2008). "Auspicious latitudes". Retrieved 2008-08-13.
- Kreidik, L. G.; T. S. Kortneva and G. P. Shpenkov (2005). "4. Fundamental periods of the World and ancient metrology". Journal of theoretical Dialectics-Physics-Mathematics (Dialectical Academy, Russia-Belarus). Retrieved 2009-08-20.