Cubit
Cubit is the name for any one of many units of measure used by various ancient peoples and is among the first recorded units of length.
The cubit is based on measuring by comparing – especially cords and textiles, but also for timbers and stones – to one's forearm length. The Egyptian hieroglyph for the unit shows this symbol. It was employed consistently through Antiquity, the Middle Ages up to the Early Modern Times.
The distance between thumb and another finger to the elbow on an average person and measures about 24 digits or 6 palms or 1½ feet. This is about 45 cm or 18 inches. This so-called "natural cubit" of 1½ feet is used in the Roman system of measures and in different Greek systems.
Over time, units similar in type to the cubit have measured:
- 6 palms = 24 digits, i.e. ~45.0 cm or 18 inches (1.50 ft)
- 7 palms = 28 digits, i.e. ~52.5 cm or 21 inches (1.75 ft)
- 8 palms = 32 digits, i.e. ~60.0 cm or 24 inches (2.00 ft)
- 9 palms = 36 digits, i.e. ~67.5 cm or 27 inches (2.25 ft)
From late Antiquity, the Roman ulna, a four-feet-cubit (about 120 cm) is also attested. This length is the measure from a man's hip to the fingers of the outstretched opposite arm.
The English yard could be considered to be a type of cubit, measuring 12 palms, ~90 cm, or 36 inches (3.00 ft). This is the measure from the middle of a man's body to his fingers, always with outstretched arm. The English ell is essentially a kind of great cubit of 15 palms, 114 cm, or 45 inches (3.75 ft).
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References [change]
- Vormetrische Längeneinheiten by Rolf C. A. Rottländer, Rottenburg / Köln (also see Search-Engine).
- Recovery of the Ancient System of Length Units by Dieter Lelgemann, former Director of the Institute for Geodesy and Geo-Information Technology, TU Berlin.
- On the Ancient Determination of Meridian Arc Length by Eratosthenes of Kyrene Dieter Lelgemann, WS – History of Surveying and Measurement, Athens, Greece, May 22-27, 2004.
- Knobloch, Eberhard, Dieter Lelgemann und Andreas Fuls: "Zur hellenistischen Methode der Bestimmung des Erdumfangs und zur Asienkarte des Klaudios Ptolemaios." published in zfv (Zeitschrift für Geodäsie, Geoinformation und Landmanagment) 128. Jahrgang, Heft 3/2003, S. 211-217.
Other websites [change]
- Measurements of the Nippur Ell, now in a museum in Istanbul (Turkey).