Cubit

# Cubit

Discussion

Encyclopedia
The cubit is a traditional unit
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...

of length
Length
In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...

, based on the length of the forearm
Forearm

. Cubits of various lengths were employed in many parts of the world in Antiquity
Ancient history
Ancient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...

, in the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

and into Early Modern Times
Early modern Europe
Early modern Europe is the term used by historians to refer to a period in the history of Europe which spanned the centuries between the end of the Middle Ages and the beginning of the Industrial Revolution, roughly the late 15th century to the late 18th century...

.

The Egyptian hieroglyph for the cubit shows the symbol of a forearm. The Egyptian cubit was subdivided into 7 palms of 4 digits
Digit (unit)
The digit or finger is an ancient and obsolete non-SI unit of measurement of length. It was originally based on the breadth of a human finger...

each; surviving cubit rods are between 52.3 and 52.9 cm in length.

Over time, various cubits and variations on the cubit have measured:
• 6 palms, or 24 digits
• 7 palms, or 28 digits

## Etymology

The English word 'cubit' comes from Latin cubitum 'elbow', from the verb cubāre, -cumbĕre 'to lie down'; cf. 'recumbent'.

## The Egyptian royal cubit and Sumerian Nippur cubit

The earliest attested standard measure is from the Old Kingdom
Old Kingdom
Old Kingdom is the name given to the period in the 3rd millennium BC when Egypt attained its first continuous peak of civilization in complexity and achievement – the first of three so-called "Kingdom" periods, which mark the high points of civilization in the lower Nile Valley .The term itself was...

pyramids of Egypt and was called the royal cubit (mahe). The royal cubit was 523 millimetre in length, and was subdivided into 7 palms of 4 digits each, for a 28-part measure in total. Evidence for the royal cubit unit is known from Old Kingdom architecture, from at least as early as the construction of the Step Pyramid
Step pyramid
Step pyramids are structures which characterized several cultures throughout history, in several locations throughout the world. These pyramids typically are large and made of several layers of stone...

of Djoser
Djoser
Netjerikhet or Djoser is the best-known pharaoh of the Third dynasty of Egypt. He commissioned his official, Imhotep, to build the first of the pyramids, a step pyramid for him at Saqqara...

from around 2,700 B.C.

In 1916, during the last years of Ottoman Empire
Ottoman Empire
The Ottoman EmpireIt was usually referred to as the "Ottoman Empire", the "Turkish Empire", the "Ottoman Caliphate" or more commonly "Turkey" by its contemporaries...

and in the middle of WWI
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, the German Assyriologist
Assyriology
Assyriology is the archaeological, historical, and linguistic study of ancient Mesopotamia and the related cultures that used cuneiform writing. The field covers the Akkadian sister-cultures of Assyria and Babylonia, together with their cultural predecessor; Sumer...

Eckhard Unger
Eckhard Unger
Eckhard Unger was a German assyriologist.In 1916, as curator of the Archeological Museum of Istanbul, he identified and described a copper-alloy object in the museum collection as an ell or measuring rod from Nippur...

found a copper-alloy bar while excavating at Nippur. The bar dates from c. 2650 BC. and Unger claimed it was used as a measurement standard. This irregularly formed and irregularly marked graduated rule supposedly defined the Sumerian cubit as about 518.6 mm.

## Other systems

The Indian Hasta and Thai sok
Thai units of measurement
Before metrication, the traditional system of measurement used in Thailand employed anthropic units. Some of these units are still in use, albeit standardised to SI/metric measurements. The square wa, ngan and rai are still used in measurements of land area, and the baht is still used as a unit of...

are other traditional units based on the length of the forearm.

• Anthropic units
Anthropic units
Anthropic units are units of measurement which explicitly arose from human physiology or behavior. Some were derived directly from the dimensions of the human body, and as such, are commonly referred to as anthropomorphic...

• History of measurement
History of measurement
Units of measurement were among the earliest tools invented by humans. Primitive societies needed rudimentary measures for numerous tasks such as: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials....

• Systems of measurement
Systems of measurement
A system of measurement is a set of units which can be used to specify anything which can be measured and were historically important, regulated and defined because of trade and internal commerce...

• Units of measurement
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...

• Ancient Mesopotamian units of measurement
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 cultural complex of the Near East. The counting tokens were used to keep accounts of personal...