# Old weights and measures (Roman antiquity)

The Roman system of measurement is based - like many pre-decimal metric measures - on the Nippur cubit and on the Mesopotamian , Egyptian and Greek systems.

It was basically valid throughout the Roman Empire , but it must be noted that on the one hand there were regional differences in the use of measures (e.g. the measure of leugen in the Gallic provinces) and on the other hand neither precise nor always available standard values. Even precision measurements with a high relative accuracy were therefore carried out with their own units, which may differ slightly from other precision measurements. Deviations from the expected values ​​(calculated using modern methods) are therefore completely normal, conversions into modern units of measurement as in the tables in this article can therefore only be approximate values ​​and are only for orientation.

The Roman system continues to operate today in many later units, e.g. B. in English measurements . The ratio of the English foot to the Roman foot is like 36 to 35. The ratio of the Roman foot to the Cyrenean foot is 24 to 25.

The term “Roman foot” is actually anachronistic because this foot was already known to the ancient Egyptians as the Egyptian nippur foot 2000 years before Rome . In Greece it is called the Attic foot.

## Length measurements

Two bronze Roman rules, 1 and ½ feet in length
Roman measures of length   digitus   palmus   pes (Mz. pedes)   cubitus   gradus   passus  pedes Finger breadth = ¼ palmus ≈ 18.5 mm 1/16 A hand's breadth = ¼ pes ≈ 74.0 mm ¼ foot = 1 pes ≈ 296.0 mm 1 Cubit ≈ 1 ½ pes ≈ 444.0 mm 1 ½ Single step = 2 ½ pes ≈ 740.0 mm 2 ½ Double step = 2 gradus ≈ 1,480 m 5 rod = 2 passus ≈ 2.96 m 10 Arpent = 12 perticae ≈ 35.52 m 120 Stadion = ⅛ mille passus ≈ 185.0 m 625 mile = 1000 passus ≈ 1.48 km 5000 Leuge = 1 ½ milia passuum ≈ 2.22 km 7500

The metric dimensions given in the table are orientation values ​​and are mathematically based on a foot of 296 mm.

Note that the plural of the Roman mile is correctly milia passuum . Alternatively, the mile can also be referred to as "milestone", milliarium (plural milliaria ).
Statistically , the Roman foot is 296 mm long, but the measure actually used could differ by several mm due to inaccurate measuring methods and devices. Measurements of archaeological finds also seem to show a reduction to a size of 294.2 mm by the end of antiquity.
In Roman antiquity the foot was not represented by twelve, i.e. H. divided into inches, but practically all digiti, one-sixteenth of a foot.

## Area dimensions

Roman measures of area   scripulum   acnua   actus minimus   clima   actus quadratus   iugerum   heredium   centuria  actus pes quadratus Square feet = 1 pes qu. ≈ 876.16 cm² 1/14400 Square rod = 100 pedes qu. ≈ 8.7616 m² 1/144 = 120 pedes qu. ≈ 10.51 m² 1/120 Ulne furrows * = 1/30 actus ≈ 42.06 m² 1/30 Bit = ¼ actus ≈ 3.1542 a ¼ Field = 1 Square arpent ≈ 12.62 a 1 yoke = 2 actus ≈ 0.2523 Ha 2 tomorrow = 2 iugera ≈ 0.5047 Ha 4th Big hooves = 100 heredia ≈ 50.47 Ha 400 Quadruplex = 4th centuriae ≈ 2.019 km² 1600

* 1 actus minimus is a 4 by 120 foot rectangle.

The metric dimensions given in the table are orientation values ​​and are mathematically based on a foot of 296 mm.

The actus (field) is the square arpent (1 arpent = 12 ten-foot rods). That corresponds to 14,400 pedes quadrati or 144 scripula, i.e. about an eighth of a hectare .

## volume

Ponderaria cafeteria (calibration
table ) for checking the measurements (Municipal Museum “Dörndl”), Wiesloch
Calibration table ( mensa ponderaria ) with inset measuring units for measurements of measure (1st century BC), Pompeii

### Liquid measures

Roman liquid measures       ligula   cyathus   acetabulum   sextans Sester Spoonful = ¼ Can ≈ 11.25 ml 1/48 Can = ½ Sixth semester ≈ 45.0 ml 1/12 = ⅛ Sester ≈ 67.5 ml ⅛ Sixth semester = 1/6 Sester ≈ 90.0 ml 1/6 Third semester = ⅓ Sester ≈ 180 ml ⅓ Hemine = ½ Sester ≈ 270 ml ½ Cheonix = 2 Third semester ≈ 360 ml ⅔ Sester = 1/6 Jug ≈ 540 ml 1 Jug = ¼ urn ≈ 3.24 l 6th urn = ½ Amphora ≈ 12.97 l 24 Amphora = 1 Cubic feet ≈ 25.93 l 48 tube = 20th Amphorae ≈ 518.69 l 960

The metric dimensions given in the table are orientation values ​​and are mathematically based on a foot of 296 mm, which results in a cubic foot of about 25.9 liters.

The amphora ("amphora quadrantal") corresponds to the cubic foot. The jug is two handspreads in cubic form, it contains exactly six sisters. Hence her name: Sester, a sixth Congius. With Amphora also an Italian volume measurement is called.

### Grain Measures

Modius ( 4th century )
Roman grain measures       acetabulum     quartarius   hemina   sextarius Slut Ladle = ½ Quarter semester ≈ 67.5 ml 1/128 Quarter semester = ½ Hemine ≈ 135 ml 1/64 Hemine = ½ Sester ≈ 270 ml 1/32 Sester = ⅛ gallon ≈ 540 ml 1/16 Gallon* = ½ Slut ≈ 4.32 l ½ Slut = ⅓ bushel ≈ 8.64 l 1 bushel = 1 Cubic feet ≈ 25.93 l 3

* literally:   half a mess

The metric dimensions given in the table are orientation values ​​and are mathematically based on a foot of 296 mm, which results in a cubic foot of about 25.9 liters.

## Weights

The dimensions given in the table in metric units are orientation values ​​and relate arithmetically to the arbitrarily determined value of 47 milligrams for the Roman barley grain ; see below for attempts to determine the historical value (the Libra).

Roman weights     granum Gran Chalcus Obolus drachma ounce lb Mina 1 1/6912 Gran = ⅔ Chalcus ≈ 47 mg ⅔ 1/12 1/72 1/576 1/9216 Chalcus = ⅛ Obolus ≈ 70.5 mg ⅛ 1/48 1/384 1/6144 Siliqua = ⅓ Obolus ≈ 188 mg 2 ⅔ ⅓ 1/18 1/144 1/2304 Obolus = ½ Scruples ≈ 564 mg 8th 1/6 1/48 1/768 Scruples = ⅓ drachma ≈ 1.13 G 16 2 ⅓ 1/24 1/384 drachma = ½ Shekel ≈ 3.38 G 48 6th ⅛ 1/128 Shekel = 2 Drachmas ≈ 6.77 G 96 12 2 ¼ 1/64 ounce = 4th Shekel ≈ 27.1 G 384 48 8th 1/16 lb = 12 Ounces ≈ 325 G 4608 576 96 12 ¾ mine = 16 Ounces ≈ 433 G 6144 768 128 16

### The weight of the Libra

Countless attempts have been made to pinpoint the historical value of the Roman Libra from the Renaissance to the present day .

#### The heavy Libra

In 1838 August Böckh suggested that the Roman pound equals 6165 French grän . This gives a value of (1 / 18.82715) × 6165 equal to approx. 327.453 g. This value was adopted in 1856 by Theodor Mommsen in his First Book on Roman History and later in his work “History of Roman Coin Management”, Berlin, 1860.

#### The easy Libra

In 1920, Lucien Naville claimed that a Roman Libra weighed only 322.56 grams, assuming a solidus (= 1/72 Libra) of exactly 4.48 grams. Rosati represented the same value in 1953. However, this value implies that the Romans would have to get their pound by dividing the Egyptian-Roman talent of exactly 26 kilograms first by 63, then again by 128, and then finally multiplying the result by 100. Or, which gives the same result: Talent through 80.64 - that is equal to the (later) Karl pound - through 2, through 63 [but why?], Times 100. A very cumbersome and therefore less likely path. Such a low value for the Roman Libra is not supported by anything else. That is why today such a light Roman Libra is no longer represented by anyone.

#### The middle libra

Nevertheless, today's historical metrologists largely agree that the Böckh value is probably too high. As early as 1960 Grierson wrote:
“Most reference works [continue] to assume the correctness of the value 327.45 grams for the Roman pound. Scholars are usually willing to do this for reasons of convenience (literally: "for the sake of convenience") , although at the same time they admit that this value is probably too high. "

The Szikáncs treasure found in Hungary in 1963 , which contains almost 1500 Roman solidi from late antiquity , supports a value less than approx. 327½ grams.

All values ​​between about 323.2 and 326.4 grams, i.e. in the interval 324.8 ± 1.6 grams, can be referred to as the mean Roman Libra .

As early as 1690, François Le Blanc had such an average value. Also Soetbeer , 1858 and Guilhiermoz, 1906 came to the same conclusion. However, all three assumed the - in their opinion probably ideal * - value of exactly 6144 French grains, i.e. 6144 × (1 / 18.82715) equal to approx. 326.337 grams. In the last few decades, three other mean values ​​in particular have been represented: Exactly 324 grams by Crawford (1974), with the explicit reference to the good divisibility of this number. In 2004 the professional Belgian numismatist Jean Elsen suggested a value of 326 grams in a well-documented work . As early as 1973, Wolfgang Hahn calculated the value of 325 grams.

The latter, Hahn's value, appears appropriate because this value follows the path of the simplest, most reasonable derivation of the Greek mine. The Greeks therefore simply divided the Egyptian-Roman talent of almost exactly 26 kilograms by 60 to get to their mine. The Roman Libra is known to be ¾ the Greek mine.

The Greek mine is therefore 60:64 and 15:16 to the Karl pound ; just as the Roman Libra maintains the simple ratio of 125: 100 or 5: 4 with the Karl pound.
Likewise, the ratio: mine compared to the Cologne mark is 54: 100, or 27:50. Exactly like the ratio between Libra and Cologne mark is 72: 100, or in shortened form 18:25.

The table above adopts Hahn's value in principle. However, since the decimally rounded value containing the prime number 13 results in : 325 g, a mathematical Roman grain of exactly 47.01967 592 grams, the simplified, 7-smooth value of precisely 47.04 mg was preferred for the Roman grain weight. The actual Hahn value is only 0.0432% below the seven-smooth. However, seven- even values do not claim that the Roman metrologists determined their grain weight to one hundredth of a milligram, nor that modern historical metrology today could determine this value with the same precision. Seven-even values ​​only represent a practical - but also clearly within the coefficient of variation determined for the respective dimension - over-all rounding of all, including the derived dimensions.

* In fine, Le Blanc, Soetbeer and Guilhiermoz were not at all wrong. However, they ignored the French weight point of 3136: 3125. Hence their not entirely correct value. (Cf. Karlspfund # French derivatives .)

### Greek vs. roman drachma

The Greek drachma is the 100th part of the mina; the Roman the 96th part of the Libra. The ratio between the Roman and Greek drachma is exactly 25:32.

### The multiples of the ounce

All simple multiples of the Roman ounce have their own names.

 1 Ounce: uncia 2 Ounces: sextans = 1/6 as 3 Ounces: quadrans = ¼ as 4th Ounces: trians = ⅓ as 5 Ounces: quincunx 6th Ounces: semis = ½ as 7th Ounces: septunx 8th Ounces: esp = ⅔ as 9 Ounces: dodrans = ¾ as 10 Ounces: dextans = 5/6 as 11 Ounces: deunx = 11/12 as 12 Ounces: as = 1 libra

One and a half ounces was called sescuncia by the Romans .

## Time calculation

See main article: Julian Calendar

The Julian calendar with a year (annum) of 365 ¼ days (a leap year every 4 years, without exception) was introduced in 45 BC. Chr. Introduced.

## Scriptores gromatici

The Roman surveyors were named Gromatici after their instrument , the groma . A Latin text "Gromatici veteres" from late antiquity, probably from the fifth century AD, gives the proportions of that time:

Latin text:

German translation:

 The finger, the inch and the width of a hand, the half-foot, the foot and the single step, the double step, the rod and the 12- pygmen rod, the arpent length, the stadium and the mile. The width of a hand measures 4 fingers, or 3 inches. The half-foot measures 2 hand widths. The foot measures 4 hand widths. The cubitus measures 1½ feet. The simple step measures 2½ feet. The ulne measures 4 feet. The double step measures 5 feet. The normal rod measures 10 feet by 16 fingers. The 12 pygmen rod measures 12 feet by 18 fingers wide.    (So: 12 pygmen equals 216 fingerbreadths) The length of the pole is 120 feet or 10 12-pygmen rods. The stadium measures 625 feet. The mile is 5,000 feet. The porca measures 7,200 square feet.    (Two pieces of land or half an acre.) The acre is 14,400 square feet. The yoke measures 28,800 square feet. The Versus measures 8,640 square feet.    (Equal to 60 square rods or 1 ⅔ piece.) The half sela is the twelfth part of the ounce.    (Two scruples.) The sela is the sixth part of the ounce.    (Four scruples.) The Lycus, the quarter-ounce.    (Two siliqua.) The double sela, the third ounce.    (Eight scruples.) The semiuncia , half an ounce. The ounce . The sescuncia , an ounce and a half. The sextans , two ounces. The Quadrans , three ounces. The Trians , four ounces. The quincunx , five ounces. The semis ("half-ace"), six ounces. The Septunx , seven ounces. The bes , eight ounces. The dodrans , nine ounces. The dextans , ten ounces. The Deunx , eleven ounces. The ace , twelve ounces.    (In other words, a pound .)

In this text from late antiquity, on the threshold of the Middle Ages, there are minor differences in the use of weights and measures compared to the classical period. However, the basic dimensions mentioned - both in almost all names and in their relationship to the other dimensions - have remained the same.

## literature

• Oswald Ashton Wentworth Dilke: Mathematics, Weights and Measures in Antiquity. RUB 8687. Reclam, Stuttgart 1991, ISBN 3-15-008687-6
• Friedrich Hultsch : Greek and Roman metrology. 2nd edition Weidmann, Berlin 1882. Reprint: Akademische Druck- und Verlags-Anstalt, Graz 1971, ISBN 978-1143275074 (online at www.archive.org )
• Friedrich Hultsch : Castrensis modius . In: Paulys Realencyclopadie der classischen Antiquity Science (RE). Volume III, 2, Stuttgart 1899, Sp. 1775 f.
• Otto Klasing: The book of collections 6th edition, Bielefeld u. Leipzig 1906, Velhagen & Klasing publishing house
• Karl Ernst Georges: Comprehensive Latin-German concise dictionary. Hannover 1913 (reprint Darmstadt 1998), Volume 1, Col. 85.
• R. Klimpert: Lexicon of coins, measures, weights, counting methods and time sizes. Verlag C. Regenhardt, Berlin 1896, p. 3.
• G. Chouquer - F. Favory: L'arpentage romain. Histoire des textes - Droit - Techniques. Editions Errance, Paris 2001

## Individual evidence

1. Distribution of the Roman / Attic foot, page by Rolf CA Rottländer
2. G. Choquer - F. Favory: L'arpentage romain. Histoire des textes - Droit - Techniques. Editions Errance, Paris 2001, p. 72.
3. August Böckh : Metrological investigations on weights, coin feet and mass of antiquity. Berlin 1838. p. 165.
4. http://www.e-text.org/text/Mommsen, Theodor - Roemische Geschichte, by Theodor Mommsen - Volume 1.txt (link not available)
5. Lucien Naville: Fragments de métrologie antique. In: Revue suisse de numismatique. 22 (1920), pp. 42-60, 257-263
6. F. Panvini Rosati: Ripostiglio di aurei tardo-imperiali a Comiso. In: Accademia degli Lincei, Rendiconti morali, series 8, pp. 422-440
7. ^ Philipp Grierson: The monetary reforms of 'Abd al-Malik. In: Journal of the Economic and Social History of the Orient 3 (1960). P. 252: "... since calculations based on the Roman pound in most works of reference assume the correctness of 327.45 g., Scholars have usually been prepared to retain it for the sake of convenience while admitting that it is probably too high."
8. ^ François le Blanc: Traité historique des monnoyes de France. Paris 1690.
9. Adolf Soetbeer: About the coin and weight ratios among the Merovingians and Carolingians, as well as about the origin and distribution of the mark weight. Hamburg 1858
10. Paul Guilhiermoz: Notes sur les poids du moyen age. Bibliothèque de l'Ecole des chartes 67 (1906), pp. 161-233, 402-450.
11. Michael Hewson Crawford: Roman Republican Coinage. 2 vols. Cambridge 1974.
12. ^ Jean Elsen: Le système pondéral romano-byzantine (fin 3e siècle - fin 8e siècle). 2004 (PDF; 453 kB) ( Memento from October 7, 2007 in the Internet Archive )
13. ^ Wolfgang RO Hahn: Moneta Imperii Byzantini. Reconstruction of the structure of the embossing on the basis of synoptic tables, Vol. 1: From Anastasius I to Justinianus I (491-565). Publishing house of the Austrian Academy of Sciences, Vienna 1973, ISBN 3-7001-0005-1 .
14. Helmut Kahnt, Bernd Knorr: Old measures, coins and weights, a lexicon. Bibliographisches Institut, Mannheim / Vienna / Zurich, 1986, ISBN 3-41102-148-9 , p. 65.
15. ^ Friedrich Bluhme , Karl Lachmann , Theodor Mommsen, Andreas Rudorff (eds.): Gromatici veteres. The writings of the Roman surveyors. Berlin 1848