Text on Roman weight systems?

Discussion in 'Ancient Coins' started by EWC3, May 21, 2019.

  1. EWC3

    EWC3 (mood: stubborn)

    Can anyone assist concerning the existance of any ancient text regarding the basic Roman (or Greek) units of small weight?

    Very clearly the Roman ounce was 6 solidi of 24 carat/siliquae, so c.27g/144 – thus a carat of c. 0.188g

    I append the text of Isildore of Seville – but that was written after 600 AD.

    From that we find his smaller weight c. 600 AD was a “lentil” which was about 0.07g

    I just got my wife to raid the pantry and got about 0.037 for both red and yellow modern lentils – so I suppose 0.07g might (?) be OK for ancient ones of some type…… Odd that Isidore did not use grains, like near everyone else, (the various version being in the range c. 0.045 to 0.065)

    Anyhow - let see how that compares with other cultures

    The Babylonians were working down to the “half grain” - c. 0.023g, deep into pre-history. Already much smaller than any Roman weight I saw mentioned

    The ancient Hindus seem to figured coin weight down to what they called (in translation) “white mustard seeds” which were about 0.0024g (about 30 times smaller than Isidore's “lentil”)

    The ancient Chinese figured coin weight down a to millet seed defined at c. 0.0066g. (about 10 times smaller than Isidore's “lentil”)

    This raises two puzzles when we compare the Romans (and maybe the Greeks too?) with other cultures

    1) If I am correct why is there no Greek or Roman classical text laying out clearly understood small weights – or indeed anything really comprehensive about weight at all until after the fall or Rome?

    2) Why, even then, is the roll out of the system rudimentary in comparison to prominent Chinese and Hindu thought?

    Rob T


    Isidore wrote: A calcus (lit. “pebble”), the smallest unit of weight, is one fourth of an obol, and is equivalent to two lentils. ………....The siliqua (lit. “carob pod”) is a twenty-fourth of a solidus, and takes its name from the tree whose seed it is. 10.A ceratin is half an obol, containing one and a half siliquae. In Latin usage this is a ‘semi-obol.’ ……....An obol (obolus) weighs three siliquae,or two ceratin,or four calci.

    Thus: lentil x 2 = calcus, calcus x 2 = ceratin, ceratin x 2 = obol, and obol = 3 siliquae


    Manu wrote, before 300 AD:

    The fleck of dust seen when the sun shines through a lattice is called
    Trasarenu,* the primary weight. One should know that eight Trasarenus make one Liksa in weight; three Liksas, one Rajasarsapa; three Rajasarsapas, one Gaurasarsapa;* six Gaurasarsapas, one middling Yava; three Yavas, one Krsnala;


    One should know that two Krsnalas weighed together make one silver Masaka,
    and sixteen Masakas, one silver Dharana, as also a Purana.

    We can be pretty sure Purana here just means “old coin” - and thus the Mauryan silver punchmarked coin of c. 3.43g

    so the Krsnala (= ratii seed) was 3.43g/32 = 0.107g

    the Trasarenu was surely theoretical only but

    8 x 3 x 3 x 6 x 3 = 1,296 thus the “atom” or Trasarenu was 0.000083

    However at a practical level - the Arthashatra tells us the silver dharana of 16 mashakas had 88 white mustard seeds to the mashaka

    3.43g/16 = 0.21g/88 = 0.0024g thus 30 times smaller than the 600 AD Roman lentil


    The smallest practical Ancient Chinese weight was the millet seed defined in the Han shu as going 1200 to the half liang.

    Or elsewhere the same the liang = 24 zhu = 10 lei = 10 millet seeds. As the Han liang was about 15.8g thus the millet seed was 0.0066g so 1/10 of the calculus
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  3. Scipio

    Scipio New Member

    EWC3 likes this.
  4. EWC3

    EWC3 (mood: stubborn)

    Thanks. Actually – there was an error in my first post. The Wiki page chalcus of 0.071g is actually the same as the calcus mentioned by Isidore. So its half, the Roman “lentil” is actually quite a good fit for a physical lentil. Apologies for that. Still - a lot bigger than Hindu and Chinese units though.

    The Wiki page much resembles what we see in most coin books. And it matches many coins and old weights quite well. But it is not tied to any ancient source. Actually, its a tertiary source, derived from 19th century secondary sources. So we are not told where the information is coming from.

    This is important because we have quite a lot of coins which do not make much sense in the Roman weight system, and also quite a few very prestigious ancient weights that do not fit either. The story we are told seems to have been edited to make it seem simpler than it is.

    Rob T
  5. EWC3

    EWC3 (mood: stubborn)

    Actually, elsewhere this matter has meanwhile progressed quite far (on an old Yahoo group, thanks Ross G)

    see this link From Epiphanius of Salamis Late 4th cent AD


    It reports two different systems

    System A

    1 libra = 12 ounces = 288 grams/scruples = 1,728 carats = 3,456 (fat) barleycorns.

    It fits the standard model quite well except making the “fat barleycorn” equal half a carat is oddly large. Skinner found physical barley grains average in weight 0.052g. Thus the troy barley grain (= “troy carat”/3) at 0.064799 is already “fat”. The one from Epiphanius is about 0.095g – so starting to look morbidly obese. If Epiphanius is correct then his grain looks to be almost three times the size of Isidore’s lentil……………..


    System B

    Nomisma = Talent = 60 assaria (mina?)
    Assaria = 100 denaria
    Nomisma = 6,000 lepta
    Libra = 12 ounces
    ounce = 2 staters = 4 shekels = 8 zuze = 8 denarii = 8 chalkoi = 80 obol

    So, unlike Isidore Epiphanius always puts the denarius at 100 to the pound. Contrary to the standard numismatic model – and most of the weights themselves - who make it 96.

    Further – again contrary to all the leading modern numismatic authorities – he makes 10 obols to the denarius rather than six

    Thus far then, the only Roman primary source mentioned contradicts the modern accounts we find in coin books. But it is consistent with the early Dark Age Isidore – who also mentions a 100 denarius pound.

    Actually, this concerns how I got confused earlier. The Romans had a least three sorts of elements to their weight set. A dozenal/duodecimal splitting, a binary splitting, and a decimal splitting. Almost looks deliberately confusing

    Rob T
  6. Scipio

    Scipio New Member

    About your request, in my knowledge the most ancient source regarding roman ponderal system in coinage is Plinius the Young, De Naturalis Historia. I enclose a quote of the original text from a very complete book, “La monetazione romana repubblicana” by Lorenzo Catalli, Roma 2001.

    Attached Files:

  7. Scipio

    Scipio New Member

    In my opinion, anyway, as the Romans easily adopted elements of other people’s religions, they didn’t bother to issue coins based on other people’s weight system, to ease trade with them. So probably we won’t ever understand the logic of certain issues.
  8. EWC3

    EWC3 (mood: stubborn)

    Thanks. I append a translation of that well known passage from Pliny the Elder’s encyclopedia.

    I feel it strengthens my case. Any modern encyclopedia, (eg Wiki), tells you what the basic weights systems today are. Ancient Indian and Chinese texts did the same - as did even the one from Dark Age Europe. Pliny does not – nor does any Roman I know of until the late 4th century AD. To me, that in itself suggests an unusual situation.

    Rob T


    The next1 crime committed against the welfare of mankind was on the part of him who was the first to coin a denarius2 of gold, a crime the author of which is equally unknown. The Roman people made no use of impressed silver even before the period of the defeat3 of King Pyrrhus. The "as" of copper weighed exactly one libra; and hence it is that we still use the terms "libella"4 and "dupondius."5 Hence it is, too, that fines and penalties are inflicted under the name of "æs grave,"6 and that the words still used in keeping accounts are "expensa,"7 "impendia,"8 and "dependere."9 Hence, too, the word "stipendium," meaning the pay of the soldiers, which is nothing more than "stipis pondera;"10 and from the same source those other words, "dispensatores"11 and "libripendes."12 It is also from this circumstance that in sales of slaves, at the present day even, the formality of using the balance is introduced.

    King Servius was the first to make an impress upon copper. Before his time, according to Timæus, at Rome the raw metal only was used. The form of a sheep was the first figure impressed upon money, and to this fact it owes its name, "pecunia."13 The highest figure at which one man's property was assessed in the reign of that king was one hundred and twenty thousand asses, and consequently that amount of property was considered the standard of the first class.

    Silver was not impressed with a mark until the year of the City 485, the year of the consulship of Q. Ogulnius and C. Fabius, five years before the First Punic War; at which time it was ordained that the value of the denarius should be ten libræ14 of copper, that of the quinarius five libræ, and that of the sestertius two libræ and a half. The weight, however, of the libra of copper was diminished during the First Punic War, the republic not having means to meet its expenditure: in consequence of which, an ordinance was made that the as should in future be struck of two ounces weight. By this contrivance a saving of five-sixths was effected, and the public debt was liquidated. The impression upon these copper coins was a two-faced Janus on one side, and the beak of a ship of war on the other: the triens,15 however, and the quadrans,16 bore the impression of a ship. The quadrans, too, had, previously to this, been called "teruncius," as being three unciæ17 in weight. At a later period again, when Hannibal was pressing hard upon Rome, in the dictatorship of Q. Fabius Maximus, asses of one ounce weight were struck, and it was ordained that the value of the denarius should be sixteen asses, that of the quinarius eight asses, and that of the sestertius four asses; by which last reduction of the weight of the as the republic made a clear gain of one half. Still, however, so far as the pay of the soldiers is concerned, one denarius has always been given for every ten asses. The impressions upon the coins of silver were two-horse and four-horse chariots, and hence it is that they received the names of "bigati" and "quadrigati."

    Shortly after, in accordance with the Law of Papirius, asses were coined weighing half an ounce only. Livius Drusus, when18 tribune of the people, alloyed the silver with one-eighth part of copper. The coin that is known at the present day as the "victoriatus,"19 was first struck in accordance with the Clodian Law: before which period, a coin of this name was imported from Illyricum, but was only looked upon as an article of merchandize. The impression upon it is a figure of Victory, and hence its name.

    The first golden coin was struck sixty-two years after that of silver, the scruple of gold being valued at twenty sesterces; a computation which gave, according to the value of the sesterce then in use, nine hundred sesterces to each libra of gold.20 In later times, again, an ordinance was made, that denarii of gold should be struck, at the rate of forty denarii21 to each libra of gold; after which period, the emperors gradually curtailed the weight of the golden denarius, until at last, in the reign of Nero, it was coined at the rate of forty-five to the libra.
  9. EWC3

    EWC3 (mood: stubborn)

    Afraid I cannot agree. According to the Wiki page you initially posted, the Romans used a Euboean mina. Presumably in order to ease their trade with the Hellenised East? The specific form of Euboean /Attic they adopted seems to be very similar to that chosen, earlier, for gold in Egypt, so would ease trade with them too.

    Meanwhile the c. 3.9g Republican denarius is an eighth ounce to the oldest mina we know of (c. 500g), a version of which seems to have spread into the Mediterranean 1000 years before the birth of Rome. As such its issue would certainly ease trade with many Greek cities – which still used that c. 500g mina. The coin evidence we have hints that that system was in use in Naples in the Greek period. As such it would be less foreign to Rome than the Euboean system - that favoured in most modern coin books.

    Of course, we have no clear texts to tell us even what the Romans did – let alone why. The suggestions I make merely follow the evidence, as far as it goes.

    Rob T
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