![Modio de Ponte Puñide (M](https://upload.wikimedia.org/wikipedia/commons/1/1e/Modio_de_Ponte_Pu%C3%B1ide_%28M.A.N._1930-16-1%29_01.jpg)
The ancient Roman units of measurement were primarily founded on the
Hellenic system, which in turn was influenced by the
Egyptian system and the
Mesopotamian system. The
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
units were comparatively consistent and well documented.
Length
The basic unit of Roman linear measurement was the ''pes'' or Roman foot (plural: ''pedes''). Investigation of its relation to the
English foot goes back at least to 1647, when
John Greaves
John Greaves (1602 – 8 October 1652) was an English mathematician, astronomer and antiquarian.
Educated at Balliol College, Oxford, he was elected a Fellow of Merton College in 1624. He studied Persian and Arabic, acquired a number of old boo ...
published his ''Discourse on the Romane foot''. Greaves visited Rome in 1639, and measured, among other things, the foot measure on the tomb of Titus Statilius Aper, that on the statue of Cossutius formerly in the gardens of
Angelo Colocci
Angelo Colocci (1467 at Iesi, Marche – 1549) of Rome, papal secretary of Pope Leo X, romance philologist and a Renaissance humanist at the collegial center of literary and artistic classicism, assembled a collection of antiquities in his vi ...
, the
congius
In Ancient Roman measurement, ''congius'' (pl. ''congii'', from Greek ''konkhion'', diminutive of ''konkhē'', ''konkhos'', "shellful") was a liquid measure that was about 3.48 litres (0.92 U.S. gallons). It was equal to the larger chous of the A ...
of
Vespasian
Vespasian (; la, Vespasianus ; 17 November AD 9 – 23/24 June 79) was a Roman emperor who reigned from AD 69 to 79. The fourth and last emperor who reigned in the Year of the Four Emperors, he founded the Flavian dynasty that ruled the Empi ...
previously measured by
Villalpandus, a number of brass measuring-rods found in the ruins of Rome, the paving-stones of the
Pantheon
Pantheon may refer to:
* Pantheon (religion), a set of gods belonging to a particular religion or tradition, and a temple or sacred building
Arts and entertainment Comics
*Pantheon (Marvel Comics), a fictional organization
* ''Pantheon'' (Lone St ...
and many other ancient Roman buildings, and the distance between the milestones on the
Appian Way
The Appian Way (Latin and Italian language, Italian: ''Via Appia'') is one of the earliest and strategically most important Roman roads of the ancient Roman Republic, republic. It connected Rome to Brindisi, in southeast Italy. Its importance is ...
. He concluded that the Cossutian foot was the "true" Roman foot, and reported these values compared to the iron standard of the English foot in the
Guildhall
A guildhall, also known as a "guild hall" or "guild house", is a historical building originally used for tax collecting by municipalities or merchants in Great Britain and the Low Countries. These buildings commonly become town halls and in som ...
in London
[ (30.4919cm):
]Smith
Smith may refer to:
People
* Metalsmith, or simply smith, a craftsman fashioning tools or works of art out of various metals
* Smith (given name)
* Smith (surname), a family name originating in England, Scotland and Ireland
** List of people wi ...
(1851) gives a value of 0.9708 English feet, or about 295.9 mm.[ An accepted modern value is 296 mm.][
The Roman foot was sub-divided either like the Greek ''pous'' into 16 ''digiti'' or fingers; or into 12 ''unciae'' or inches. ]Frontinus
Sextus Julius Frontinus (c. 40 – 103 AD) was a prominent Roman civil engineer, author, soldier and senator of the late 1st century AD. He was a successful general under Domitian, commanding forces in Roman Britain, and on the Rhine and Danube ...
writes in the 1st century AD that the ''digitus'' was used in Campania
Campania (, also , , , ) is an administrative Regions of Italy, region of Italy; most of it is in the south-western portion of the Italian peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the i ...
and most parts of Italy.[ The principal Roman units of length were:
Other units include the ]schoenus
Schoenus ( la, schœnus; grc-gre, σχοίνος, ''schoinos'', " rush rope"; egy, i͗trw, "river-measure") was an ancient Egyptian, Greek and Roman unit of length and area based on the knotted cords first used in Egyptian surveying.
Le ...
(from the Greek for "rush
Rush(es) may refer to:
Places
United States
* Rush, Colorado
* Rush, Kentucky
* Rush, New York
* Rush City, Minnesota
* Rush Creek (Kishwaukee River tributary), Illinois
* Rush Creek (Marin County, California), a stream
* Rush Creek (Mono Cou ...
rope") used for the distances in Isidore of Charax
Isidore of Charax (; grc, Ἰσίδωρος ὁ Χαρακηνός, ''Isídōros o Charakēnós''; la, Isidorus Characenus) was a Greco-Roman geographer of the 1st century BC and 1st century AD, a citizen of the Parthian Empire, about whom noth ...
's ''Parthian Stations
Isidore of Charax (; grc, Ἰσίδωρος ὁ Χαρακηνός, ''Isídōros o Charakēnós''; la, Isidorus Characenus) was a Greco-Roman geographer of the 1st century BC and 1st century AD, a citizen of the Parthian Empire, about whom nothi ...
'' (where it had a value around ) and in the name of the Nubia
Nubia () (Nobiin: Nobīn, ) is a region along the Nile river encompassing the area between the first cataract of the Nile (just south of Aswan in southern Egypt) and the confluence of the Blue and White Niles (in Khartoum in central Sudan), or ...
n land of Triacontaschoenus
The Triakontaschoinos ( el, Τριακοντάσχοινος, "Land of the Thirty '' Schoinoi''"), Latinized as Triacontaschoenus, was a geographical and administrative term used in the Greco-Roman world for the part of Lower Nubia between the Fir ...
between the First
First or 1st is the ordinal form of the number one (#1).
First or 1st may also refer to:
*World record, specifically the first instance of a particular achievement
Arts and media Music
* 1$T, American rapper, singer-songwriter, DJ, and rec ...
and Second Cataract
The Cataracts of the Nile are shallow lengths (or whitewater rapids) of the Nile river, between Khartoum and Aswan, where the surface of the water is broken by many small boulders and stones jutting out of the river bed, as well as many rocky ...
s on the Nile
The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered ...
(where it had a value closer to ).
Area
The ordinary units of measurement of area were:
Other units of area described by Columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...
in his ''De Re Rustica'' include the ''porca'' of 180 × 30 Roman feet (about ) used in Hispania Baetica
Hispania Baetica, often abbreviated Baetica, was one of three Roman provinces in Hispania (the Iberian Peninsula). Baetica was bordered to the west by Lusitania, and to the northeast by Hispania Tarraconensis. Baetica remained one of the basic ...
and the Gallic ''candetum'' or ''cadetum'' of 100 feet in the city or 150 in the country. Columella also gives uncial divisions of the ''jugerum'', tabulated by the anonymous translator of the 1745 Millar edition as follows:
Volume
Both liquid and dry volume measurements were based on the sextarius. The sextarius was defined as of a cubic foot, known as an amphora quadrantal. Using the value for the Roman foot, an amphora quadrantal can be computed at approximately , so a sextarius (by the same method) would theoretically measure , which is about 95% of an imperial pint
The pint (, ; symbol pt, sometimes abbreviated as ''p'') is a unit of volume or capacity in both the imperial and United States customary measurement systems. In both of those systems it is traditionally one eighth of a gallon. The British impe ...
(568.26125 ml).
Archaeologically, however, the evidence is not as precise. No two surviving vessels measure an identical volume, and scholarly opinion on the actual volume ranges between and .[
The core volume units are:
* '']amphora quadrantal
An amphora (/ˈæmfərə/; Ancient Greek: ἀμφορεύς was the unit of measurement of volume in the Greco-Roman era. The term ''amphora'' comes from ancient Greece where people used a tall jar looking container with two opposed handles near t ...
'' (Roman jar) – one cubic ''pes'' (Roman foot)
* ''congius'' – a half-''pes'' cube (thus ''amphora quadrantal'')
* ''sextarius'' – literally of a ''congius''
Liquid measure
Dry measure
Weight
The units of weight or mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...
were mostly based on factors of 12. Several of the unit names were also the names of coins during the Roman Republic
The Roman Republic ( la, Res publica Romana ) was a form of government of Rome and the era of the classical Roman civilization when it was run through public representation of the Roman people. Beginning with the overthrow of the Roman Kin ...
and had the same fractional value of a larger base unit: libra for weight and as for coin. Modern estimates of the libra range from with 5076 grains or an accepted figure.[ The ''as'' was reduced from 12 ounces to 2 after the ]First Punic War
The First Punic War (264–241 BC) was the first of three wars fought between Rome and Carthage, the two main powers of the western Mediterranean in the early 3rd century BC. For 23 years, in the longest continuous conflict and grea ...
, to 1 during the Second Punic War
The Second Punic War (218 to 201 BC) was the second of three wars fought between Carthage and Rome, the two main powers of the western Mediterranean in the 3rd century BC. For 17 years the two states struggled for supremacy, primarily in Ital ...
, and to half an ounce by the 131 BC Lex Papiria
The ballot laws of the Roman Republic (Latin: ''leges tabellariae'') were four laws which introduced the secret ballot to all popular assemblies in the Republic.Yakobson (1995), p. 426. They were all introduced by tribunes, and consisted of th ...
.[.][.]
The divisions of the libra were:
The subdivisions of the uncia were:
Time
Years
The complicated Roman calendar
The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. The term often includes the Julian calendar established by the reforms of the Roman dictator, dictator Julius Caesar and Roman emperor, emperor Augustus in the ...
was replaced by the Julian calendar
The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandr ...
in 45 BC. In the Julian calendar, an ordinary year is 365 days long, and a leap year
A leap year (also known as an intercalary year or bissextile year) is a calendar year that contains an additional day (or, in the case of a lunisolar calendar, a month) added to keep the calendar year synchronized with the astronomical year or s ...
is 366 days long. Between 45 BC and AD 1, leap years occurred at irregular intervals. Starting in AD 4, leap years occurred regularly every four years. Year numbers were rarely used; rather, the year was specified by naming the Roman consul
A consul held the highest elected political office of the Roman Republic ( to 27 BC), and ancient Romans considered the consulship the second-highest level of the ''cursus honorum'' (an ascending sequence of public offices to which politic ...
s for that year. (As consuls' terms latterly ran from January to December, this eventually caused January, rather than March, to be considered the start of the year.) When a year number was required, the Greek Olympiads
An olympiad ( el, Ὀλυμπιάς, ''Olympiás'') is a period of four years, particularly those associated with the ancient and modern Olympic Games.
Although the ancient Olympics were established during Greece's Archaic Era, it was not unti ...
were used, or the count of years since the founding of Rome, "ab urbe condita
''Ab urbe condita'' ( 'from the founding of the City'), or ''anno urbis conditae'' (; 'in the year since the city's founding'), abbreviated as AUC or AVC, expresses a date in years since 753 BC, the traditional founding of Rome. It is an exp ...
" in 753 BC. In the Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
, the year numbering was changed to the Anno Domini
The terms (AD) and before Christ (BC) are used to label or number years in the Julian and Gregorian calendars. The term is Medieval Latin and means 'in the year of the Lord', but is often presented using "our Lord" instead of "the Lord", ...
count.
The calendar used in most of the modern world, the Gregorian calendar
The Gregorian calendar is the calendar used in most parts of the world. It was introduced in October 1582 by Pope Gregory XIII as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years dif ...
, differs from the Julian calendar in that it skips three leap years every four centuries to more closely approximate the length of the tropical year
A tropical year or solar year (or tropical period) is the time that the Sun takes to return to the same position in the sky of a celestial body of the Solar System such as the Earth, completing a full cycle of seasons; for example, the time fro ...
.
Weeks
The Romans grouped days into an eight-day cycle called the , with every eighth day being a market day.
Independent of the , astrologer
Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Dif ...
s kept a seven-day cycle called a '' hebdomas'' where each day corresponded to one of the seven classical planets
In classical antiquity, the seven classical planets or seven luminaries are the seven moving astronomical objects in the sky visible to the naked eye: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. The word ''planet'' comes from ...
, with the first day of the week being Saturn-day, followed by Sun-day, Moon-day, Mars-day, Mercury-day, Jupiter-day, and lastly Venus-day. Each astrological day was reckoned to begin at sunrise. The Jew
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""Th ...
s also use a seven-day week, which began Saturday evening. The seventh day of the week they called Sabbath
In Abrahamic religions, the Sabbath () or Shabbat (from Hebrew ) is a day set aside for rest and worship. According to the Book of Exodus, the Sabbath is a day of rest on the seventh day, commanded by God to be kept as a holy day of rest, as G ...
; the other days they numbered rather than named, except for Friday, which could be called either the Parasceve or the sixth day. Each Jewish day begins at sunset. Christians
Christians () are people who follow or adhere to Christianity, a monotheistic Abrahamic religion based on the life and teachings of Jesus Christ. The words ''Christ'' and ''Christian'' derive from the Koine Greek title ''Christós'' (Χρι ...
followed the Jewish seven-day week, except that they commonly called the first day of the week the , or the Lord's day
The Lord's Day in Christianity is generally Sunday, the principal day of communal worship. It is observed by most Christians as the weekly memorial of the resurrection of Jesus Christ, who is said in the canonical Gospels to have been witnessed al ...
. In 321, Constantine the Great
Constantine I ( , ; la, Flavius Valerius Constantinus, ; ; 27 February 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337, the first one to Constantine the Great and Christianity, convert to Christiani ...
gave his subjects every Sunday off in honor of his family's tutelary deity, the Unconquered Sun, thus cementing the seven-day week into Roman civil society.
Hours
The Romans divided the daytime into twelve ''horae'' or hour
An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as of a day and scientifically reckoned between 3,599 and 3,601 seconds, depending on the speed of Earth's rotation. There are 60 minutes in an hour, and 24 ho ...
s starting at sunrise and ending at sunset. The night was divided into four watches. The duration of these hours varied with seasons; in the winter, when the daylight period was shorter, its 12 hours were correspondingly shorter and its four watches were correspondingly longer.
Astrologers divided the solar day
A synodic day (or synodic rotation period or solar day) is the period for a celestial object to rotate once in relation to the star it is orbiting, and is the basis of solar time.
The synodic day is distinguished from the sidereal day, which is ...
into 24 equal hours, and these astrological hours became the basis for medieval clock
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the ...
s and our modern 24-hour mean solar day
Solar time is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the day, based on the synodic rotation period. Two types of solar time are apparent solar time (sundial ti ...
.
Although the division of hours into minute
The minute is a unit of time usually equal to (the first sexagesimal fraction) of an hour, or 60 seconds. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds (there is a provision to insert a nega ...
s and second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...
s did not occur until the Middle Ages, Classical astrologers had a ''minuta'' equal to of a day (24 modern minutes), a ''secunda'' equal to of a day (24 modern seconds), and a ''tertia'' equal to of a day (0.4 modern seconds).
Unicode
A number of special symbols for Roman currency were added to the Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...
Standard version 5.1 (April 2008) as the Ancient Symbols block (U+10190–U+101CF, in the Supplementary Multilingual Plane ).
As mentioned above, the names for divisions of an coin (originally one libra of bronze) were also used for divisions of a libra, and the symbols U+10190–U+10195 are likewise also symbols for weights:
* U+10190 (𐆐): Sextans
* U+10191 (𐆑): Uncia
* U+10192 (𐆒): Semuncia
* U+10193 (𐆓): Sextula
* U+10194 (𐆔): Semisextula
* U+10195 (𐆕): Siliqua
See also
* Ancient Egyptian units
* Ancient Greek units
Ancient history is a time period from the beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian cuneiform script. Ancient history cove ...
* Biblical and Talmudic units of measurement
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 ...
* Byzantine units
Byzantine units of measurement were a combination and modification of the ancient Greek and Roman units of measurement used in the Byzantine Empire.
Until the reign of Justinian I (527–565), no universal system of units of measurement existed i ...
* History of measurement
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 ap ...
References
External links
Proposal to Add Ancient Roman Weights and Monetary Signs to UCS (Universal Character Set)
{{Systems of measurement