Английская Википедия: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.[1] It was a fundamental unit of length in the Ancient Egyptian, Mesopotamian, Hebrew, Ancient Greek and Roman systems of measurement.
In astronomy a digit is one twelfth of the diameter of the sun or the moon.[2]
History
Ancient Egypt
Шаблон:Main The digit, also called a finger or fingerbreadth, is a unit of measurement originally based on the breadth of a human finger. In Ancient Egypt it was the basic unit of subdivision of the cubit.[1]
On surviving Ancient Egyptian cubit-rods, the royal cubit is divided into seven palms of four digits or fingers each.[3] The royal cubit measured approximately 525 mm,[4] so the length of the ancient Egyptian digit was about 19 mm.
| Name | Egyptian name | Equivalent Egyptian values | Metric equivalent |
|---|---|---|---|
| Royal cubit | <hiero>M23-t:n-D42</hiero> meh niswt | 7 palms or 28 digits | 525 mm |
| Fist | 6 digits | 108 mm | |
| Hand | 5 digits | 94 mm | |
| Palm | <hiero>D48</hiero> shesep | 4 digits | 75 mm |
| Digit | <hiero> D50</hiero> djeba | 1/4 palm | 19 mm |
Mesopotamia
In the classical Akkadian Empire system instituted in about 2250 BC during the reign of Naram-Sin, the finger was one-thirtieth of a cubit length. The cubit was equivalent to approximately 497 mm, so the finger was equal to about 17 mm. Basic length was used in architecture and field division.
| Unit | Ratio | Metric equivalent |
Sumerian | Akkadian | Cuneiform |
|---|---|---|---|---|---|
| grain | 1/180 | 2.8 mm | še | uţţatu | Шаблон:Cuneiform |
| finger | 1/30 | 17 mm | šu-si | ubānu | Шаблон:CuneiformШаблон:Cuneiform |
| foot | 2/3 | 331 mm | šu-du3-a | šīzu | Шаблон:CuneiformШаблон:CuneiformШаблон:Cuneiform |
| cubit | 1 | 497 mm | kuš3 | ammatu | Шаблон:Cuneiform |
Ancient Hebrew system
Ancient Greece
Ancient Rome
Britain
Шаблон:Main A digit (lat. digitus, "finger"), when used as a unit of length, is usually a sixteenth of a foot or 3/4" (1.905 cm for the international inch).[6] The width of an adult human male finger tip is indeed about 2 centimetres. In English this unit has mostly fallen out of use, as do others based on the human arm: finger (7/6 digit), palm (4 digits), hand (16/3 digits), shaftment (8 digits), span (12 digits), cubit (24 digits) and ell (60 digits).
It is in general equal to the foot-nail, although the term nail can also be used as 1/16 of yard and other units.Шаблон:Citation needed
Astronomy
In astronomy a digit is, or was until recently, one twelfth of the diameter of the sun or the moon.[2][7] This is found in the Moralia of Plutarch, XII:23,[8] but the definition as exactly one twelfth of the diameter may be due to Ptolemy. Sosigenes of Alexandria had observed in the 1st century AD that on a dioptra, a disc with a diameter of 11 or 12 digits (of length) was needed to cover the moon.[9]
The unit was used in Arab or Islamic astronomical works such as those of Ṣadr al‐Sharīʿa al‐Thānī (d.1346/7),[10] where it is called Шаблон:Lang-ar iṣba' , digit or finger.[11]
The astronomical digit was in use in Britain for centuries. Heath, writing in 1760, explains that 12 digits are equal to the diameter in eclipse of the sun, but that 23 may be needed for the Earth's shadow as it eclipses the moon, those over 12 representing the extent to which the Earth's shadow is larger than the Moon.[12] The unit is apparently not in current use, but is found in recent dictionaries.[7]
Alcoholic Beverages
A 'finger' of an alcoholic beverage is colloquially referred to as a 'digit'.
See also
References
- ↑ 1,0 1,1 Ошибка цитирования Неверный тег
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<ref>; для сносокselinне указан текст - ↑ Ошибка цитирования Неверный тег
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<ref>; для сносокclagettне указан текст - ↑ Шаблон:Cite book
- ↑ 7,0 7,1 Ошибка цитирования Неверный тег
<ref>; для сносокchambне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокplutне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокneugне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокhockeyне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокsadrне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокheathне указан текст
