Ancient Egyptian units of measurement

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Ancient Egyptian units of measure include units for length, area and volume.

Length[edit]

Units of length date back to at least the early dynastic period. In the Palermo stone, for instance, the level of the Nile river is recorded. During the reign of Pharaoh Djer the height of the river Nile was given as measuring 6 cubits and 1 palm. This is equivalent to approximately 3.2 m (roughly 10 feet 6 inches).[1]

A third dynasty diagram shows how to construct an elliptical vault using simple measures along an arc. The ostracon depicting this diagram was found in the area of the Step Pyramid in Saqqara. A curve is divided into five sections and the height of the curve is given in cubits, palms and fingers in each of the sections.[2] [3] Egyptian Circle

Hiero in tables refers to Gardiner Numbers from the Sign List starting p. 438, values of measurements refer to section 266 p. 199-200;[3] see also [4][5]

Lengths could be measured by ordinary cubit rods, examples of which have been found in the tombs of officials for lengths up to the sizes measured by remen (see list of units below) and royal cubits which were used for land measures such as roads and fields, using rods, poles and knotted cords. Fourteen such rods, including one double cubit rod, were described and compared by Lepsius in 1865.[6] Two examples are known from the tomb of Maya – the treasurer of Tutankhamun – in Saqqara. Another was found in the tomb of Kha (TT8) in Thebes. These cubits are about 52.5 cm long and are divided into palms and hands: each palm is divided into four fingers from left to right and the fingers are further subdivided into ro[clarification needed] from right to left. The rules are also divided into hands[7] so that for example one foot is given as three hands and fifteen fingers and also as four palms and sixteen fingers(see the second register of the Turin cubit illustrated below)[1][3][3][4][5][5] [7]

Cubit rod from the Turin Museum.

For longer distances, such as land measurements, the Ancient Egyptians used rope. A scene in the tomb of Menna in Thebes shows surveyors measuring a plot of land using rope with knots tied at regular intervals. Similar scenes can be found in the tombs of Amenhotep-Sesi, Khaemhat and Djeserkareseneb. The balls of rope are also shown in New Kingdom statues of officials such as Senenmut, Amenemhet-Surer and Penanhor.[2]

Units of Length[1][2]
Name Egyptian name Equivalent Egyptian values Approx Metric
Equivalent
Finger
D50
djeba
1 finger = 1/4 palm 1.875 cm
Palm
D48
shesep
1 palm = 4 fingers 7.5 cm
Hand
D46
drt
1 hand = 5 fingers 9.38 cm
Fist
D49
3mm
1 fist = 6 fingers 11.25 cm
Span (small)
H7 G36
pedj-sheser
1 small span = 3 palms = 12 fingers 22.5 cm
Span (large)
H7 O29
pedj-aa
1 large span = 3.5 palms = 14 fingers 26 cm
Djeser
D45
djeser
1 djeser = 3 hands = 4 palms = 16 fingers = 1 ft 30 cm
Remen
D41
remen
1 remen = 5 palms = 20 fingers 37.5 cm
Short cubit
D42 G36
meh nedjes
1 short cubit = 6 palms = 24 fingers 45 cm
Royal cubit
M23 t
n
D42
meh niswt
1 royal cubit = 7 palms = 28 fingers 52.5 cm
Pole
N35
D58
M17 V1 T19
nbiw
1 nbiw =6 hands = 8 palms = 32 fingers 60 cm
Rod of cord
W24 G43 V28
khet
1 rod of cord = 100 cubits 52.5 m[1]
River measure
M17 X1
D21
G43 N35B N36
N21 Z1
iteru
1 iteru = 20,000 cubits 10.5 km

Area[edit]

The records of areas of land date back to the early dynastic period. Gifts of land recorded in the Palermo stone are expressed in terms of kha, setat, etc. Further examples of units of area come from the mathematical papyri. Several problems in the Moscow Mathematical Papyrus for instance give the area of a rectangular plot of land (measured in setjats) and given a ratio for the lengths of the sides of the rectangles one is asked to compute the lengths of the sides.[1]

The setat was equal to one square khet, where a khet measured 100 cubits. The setat could be divided into strips one khet long and ten cubit wide (a Kha).[2][8][9]

Units of Area[1][2]
Name Egyptian name Equivalent Egyptian values Approx Metric
Equivalent
S3
G38
s3
18 st3t[clarification needed] (Greek Aroura of 1 sq khet)
1250 sq cubits
345 m2
hsb
Aa2
Y1
hsb
14 st3t (Greek Aroura of 1 sq. khet)
2500 sq cubits
689 m2
rmn
Y5
N35
M40
rmn
12 st3t (Greek Aroura of 1 sq. khet)
5000 sq cubits
1378 m2
Khet
V28 G1 X1 N37 M12
khet
100 sq cubits, (sq side of setat) 52.5 m2 (Gillings)
Setat (setjat)
s t F29 t
Z4
setat
1 sq khet = 10,000 sq cubits 0.276 ha
h3-t3[clarification needed]
M12
kha
1000 of land
10 arouras, 100,000 sq cubits
2.76 ha
Ta ta 100 sq cubits = 1/100 setat 27.6 m2[8]
Shoulder (Remen)
D41
remen
12 ta = 50 square cubits 13.7 m2[8]
Heseb
Z9
heseb
12 remen = 25 sq cubits 6.9 m2[8]

Volume, capacity and weight[edit]

Several problems in the mathematical papyri deal with volume questions. For example in RMP 42 the volume of a circular granary is computed as part of the problem and units of cubic cubits, khar, quadruple heqats and heqats are used.[1][5]

Problem 80 on the Rhind Mathematical Papyrus recorded how to divide grain (measured in heqats), a topic included in RMP 42 into smaller units called henu:

Problem 80 on the Rhind Mathematical Papyrus

The text states: As for vessels (debeh) used in measuring grain by the functionaries of the granary, done into henu : 1 hekat makes 10 [henu]; 1/2 makes 5 [henu]; 1/4 makes 2½ etc.[1][5]

Units of volume and capacity[1][2]
Name Egyptian name Equivalent Egyptian values Approx Metric
Equivalent
Deny deny 1 cubic cubit
Khar (sack)
Aa1
r
khar
20 heqat (Middle Kingdom)
16 heqat (New Kingdom)[10]
96.5 liters (Middle Kingdom)
76.8 liters (New Kingdom)[10]
quadruple heqat
T14 U9
hekat-fedw
4 heqat = 40 hinu 19.2 liters
double heqat hekaty 2 heqat = 20 hinu 9.6 liters
Heqat (barrel)
U9
hekat
10 hinu 4.8 liters
Hinu (jar)
h n
W24 V1
W22
hnw
1/10 heqat = 32 ro 0.48 liters
Dja dja 5/8 hinu = 20 ro[11] .3 liters
Ro
r
r
1/320 heqat 0.015 liters

Weights were measured in terms of deben. This unit would have been equivalent to 13.6 grams in the Old Kingdom and Middle Kingdom. During the New Kingdom however it was equivalent to 91 grams. For smaller amounts the kite (1/10 of a deben) and the shematy (1/12 of a deben) were used.[2][5]

Units of weight[2]
Name Egyptian name Equivalent Egyptian values Metric Equivalent
Deben
D46 D58 N35
F46
dbn
13.6 grams in the Old Kingdom and Middle Kingdom.
91 grams during the New Kingdom
Kite
Aa28 X1
S106
qd.t
0.1 deben
Shematy shȝts 112 deben

Time[edit]

Years were not numbered but rather named. When named after rulers they are thus regnal years. The Egyptians divided their year (rnpt) into three 120-day seasons of four months of 30 days (hrw) named 3ht or Akhet (inundation), prt or Peret, (emergence) and shmu or Shemu (summer). Akhet was the season of inundation. Peret was the season which saw the emergence of life after the inundation. The season of Shemu was named after the low water and included harvest time. Thus the Egyptian calendar had a total of 12 months (abd) of 30 days each plus 5 epagomenal days (hryw rnpt) making 365 days; as this is less than the actual 365.25 (approx), the seasons shifted in the calendar over time.[1][3][12]

Units of Time[1][2]
Name Egyptian name Values
hour
E34 N35 W24 X1 N14
wnwt
1 day = 24 hours
day
O4 D21 G43 N5
hrw
month
N11
N14
d
abd
30 days
Inundation season
M8 Aa1
t
N5
akhet
4 months = 120 days
Emergence season
pr
r
t
N5
peret
4 months = 120 days
Harvest season
S n
n
n
N5
shemu
4 months = 120 days
year
M4 X1 Z1
renpet
365 days

The introduction of equal length hours occurred in 127 BC. The Alexandrian scholar Claudius Ptolemaeus introduced the division of the hour into 60 minutes in the second century AD.

Problems of Equitable Distribution and Accurate Measurement[edit]

Not all measurements were units. Ro for example were unit fractions which Egyptians used instead of decimals or other fractions. Tables of unit fraction were used in the RMP. "Table 11.1 is a translation of the one made by the scribe in preparation for the first six problems of the RMP. In these problems which immediately follow the original table, 1,2,6,7,8,and 9 loaves are to be divided equally among 10 men." The table is in effect a ruler which allows a computation. Division of the numbers 1 to 9 by 10[5] Table 11.1

Quotients of 1,2,...9 divided by 10 as listed in the RMP
Number 1st Quotient Second Quotient Third Quotient
1 '10
2 '5
3 '5 '10
4 '3 '15
5 '2
6 '2 '10
7 '3 '30
8 '3 '10 '30
9 '3 '5 '30

A similar computation can use a remen as the diagonal of a square with side a cubit or give a value for pi. In the RMP the scribes method of finding the area of a circle is "subtract from the diameter its '9 part and square the remainder."[5] At Saqarra an architect used numerical analysis to state a formula in the form of 3 '8 '64...where each added term from the formula would arrive at a better approximation. The formulas from the RMP include finding areas and volumes; the area of a rectangle, the area of a triangle, the area of a circle, the volume of a cylindrical granary, equations of the first and second degree, geometric and arithmetric progressions, the volume of a truncated pyramid, the area of a semicylinder and the area of a hemisphere

References[edit]

  1. ^ a b c d e f g h i j k Clagett, Marshall (1999). Ancient Egyptian science, a Source Book. Volume Three: Ancient Egyptian Mathematics.. Philadelphia: American Philosophical Society. ISBN 978-0-87169-232-0. 
  2. ^ a b c d e f g h i Corinna Rossi, Architecture and Mathematics in Ancient Egypt, Cambridge University Press, 2007
  3. ^ a b c d e Englebach, Clarke (1990). Ancient Egyptian Construction and Architecture. New York: Dover. ISBN 0486264858. 
  4. ^ a b Faulkner, Raymond (1991). A Concise Dictionary of Middle Egyptian. Griffith Institute Asmolean Museum, Oxford. ISBN 0900416327. 
  5. ^ a b c d e f g h Gillings, Richard (1972). Mathematics in the Time of the Pharaohs. MIT. ISBN 0262070456. 
  6. ^ Lepsius, Richard (1865). Die altaegyptische Elle und ihre Eintheilung (in German). Berlin: Dümmler. 
  7. ^ a b Loprieno, Antonio (1996). Ancient Egyptian. New York: CUP. ISBN 0521448492. 
  8. ^ a b c d Clagett, Marshall (1999). Ancient Egyptian Science A Source Book Vol III Ancient Egyptian Mathematics. Philadelphia: American Philosophical Society. ISBN 0871692325. 
  9. ^ Digital Egypt: Measuring area in Ancient Egypt
  10. ^ a b Katz, Victor J. (editor),Imhausen, Annette et al. The Mathematics of Egypt, Mesopotamia, China, India, and Islam: A Sourcebook, Princeton University Press. 2007, p 17, ISBN 978-0-691-11485-9
  11. ^ T. Pommerening, Altagyptische Rezepturen metrologisch neu onterpretiert, Berichte zur Wissenschaftgeschichte 26 (2003) p. 1 - 16
  12. ^ Marshall Clagett, Ancient Egyptian Science: Calendars, clocks, and astronomy, 1989

External links[edit]