Length is a measure of distance. In the International System of Quantities, length is any quantity with dimension distance. In most systems of measurement, the unit of length is a base unit, from which other units are derived.
Biblical and Talmudic units of measurement were used primarily by ancient Israelites and appear frequently within the Hebrew Bible as well as in later rabbinic writings, such as the Mishnah and Talmud. These units of measurement continue to be used in functions regulating Jewish contemporary life. The specificity of some of the units used and which are encompassed under these systems of measurement have given rise, in some instances, to disputes, owing to the discontinuation of their Hebrew names and their replacement by other names in modern usage.
The hand is a non-SI unit of measurement of length standardized to 4 inches (101.6 mm). It is used to measure the height of horses in some English-speaking countries, including Australia, Canada, the Republic of Ireland, the United Kingdom and the United States. It was originally based on the breadth of a human hand. The adoption of the international inch in 1959 allowed for a standardized imperial form and a metric conversion. It may be abbreviated to "h" or "hh". Although measurements between whole hands are usually expressed in what appears to be decimal format, the subdivision of the hand is not decimal but is in base 4, so subdivisions after the radix point are in quarters of a hand, which are inches. Thus, 62 inches is fifteen and a half hands, or 15.2 hh.
The pyramid inch is a unit of measure claimed by pyramidologists to have been used in ancient times. Supposedly it was one twenty-fifth of a "sacred cubit", 1.00106 imperial inches, or 2.5426924 centimetres.
A Megalithic Yard (MY) is a unit of measurement of about 2.72 feet (0.83 m), that some researchers believe was used in the construction of megalithic structures. The proposal was made by Alexander Thom as a result of his surveys of 600 megalithic sites in England, Scotland, Wales and Brittany. Thom also proposed the Megalithic Rod of 2.5 MY, or on average across sites 6.77625 feet. As subunits of these, he further proposed the Megalithic Inch of 2.073 centimetres (0.816 in), one hundred of which are included in a Megalithic Rod, and forty of which composed a Meglithic Yard. Thom applied the statistical lumped variance test of J.R. Broadbent on this quantum and found the results significant, while others have challenged his statistical analysis and suggested that Thom's evidence can be explained in other ways, for instance that the supposed megalithic yard is in fact the average length of a pace.
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. It was a fundamental unit of length in the Ancient Egyptian, Mesopotamian, Hebrew, Ancient Greek and Roman systems of measurement.
The palm is an obsolete anthropic unit of length, originally based on the width of the human palm and then variously standardized. The same name is also used for a second, rather larger unit based on the length of the human hand.
The cubital fossa or elbow pit is the triangular area on the anterior view of the elbow of a human or other hominid animal. It lies anteriorly to the elbow when in standard anatomical position.
Ancient Mesopotamian units of measurement originated in the loosely organized city-states of Early Dynastic Sumer. 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.
The ancient Egyptian units of measurement are those used by the dynasties of ancient Egypt prior to its incorporation in the Roman Empire and general adoption of Roman, Greek, and Byzantine units of measurement. The units of length seem to have originally been anthropic, based on various parts of the human body, although these were standardized using cubit rods, strands of rope, and official measures maintained at some temples.
A knotted cord was a primitive surveyor's tool for measuring distances. It is a length of cord with knots at regular intervals. They were eventually replaced by surveyor's chains, which being made of metal were less prone to stretching and thus were more accurate and consistent.
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction, and trade. Early standard units might only have applied to a single community or small region, with every area developing its own standards for lengths, areas, volumes and masses. Often such systems were closely tied to one field of use, so that volume measures used, for example, for dry grains were unrelated to those for liquids, with neither bearing any particular relationship to units of length used for measuring cloth or land. With development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified and uniform systems of weights and measures were developed, with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units.
A yojana is a Vedic measure of distance that was used in ancient India. A yojana is about 12–15 km.
A measuring rod is a tool used to physically measure lengths and survey areas of various sizes. Most measuring rods are round or square sectioned; however, they can also be flat boards. Some have markings at regular intervals. It is likely that the measuring rod was used before the line, chain or steel tapes used in modern measurement.
An equatorial ring was an astronomical instrument used in the Hellenistic world to determine the exact moment of the spring and autumn equinoxes. Equatorial rings were placed before the temples in Alexandria, in Rhodes, and perhaps in other places, for calendar purposes.
A number of different units of measurement were used in Sri Lanka to measure quantities like length, mass and capacity from very ancient times. Under the British Empire, imperial units became the official units of measurement and remained so until Sri Lanka adopted the metric system in the 1970s.
The Eastern Wall is an ancient structure in Jerusalem that is both part of the eastern side of the city wall of Jerusalem and the eastern wall of the ancient Temple Mount.
