Gold.Silver.Copper.The1stof12duellae6duellae0sextula6duellae0sextula"2nd"13"5"1"5"1""3rd"14"5"5""4th"15"4"1"4"1""5th"16"4"4""6th"17"3"1"3"1""7th"18"3"3""8th"19"2"1"2"1""9th"20"2"2""10th"21"1"1"1"1""11th"22"1"1""12th"23"1""13th"pure gold.
Some make twenty-five needles, in order to be able to detect the twoscripulaof silver or copper which are in abesof gold. Of these needles, the first is composed of twelveduellaeof gold and six of silver, and the same number of copper. The second, of twelveduellaeand onesextulaof gold and fiveduellaeand one and a halfsextulaeof silver, and the same number ofduellaeand one and a halfsextulaeof copper. The remaining needles are made in the same proportion.
Pliny is our authority that the Romans could tell to within onescripulumhow much gold was in any given alloy, and how much silver or copper.
Needles may be made in either of two ways, namely, in the ways of which I have spoken, and in the ways of which I am now about to speak. Ifunequal portions of silver and copper have been mixed with the gold, thirty-seven needles are made in the following way:—
Gold.Silver.Copper.Duellae.DuellaeSextulaeSiliquae.DuellaeSextulaeSiliquae.The1stof12900300"2nd"12800400"3rd"1275"4th"1381/221/2"5th"1371/24318"6th"1361/28414"7th"147121"8th"1461831/24"9th"14511/2448"10th"15611/221/2"11th"1563"12th"1551/2311/2"13th"1662"14th"1651/24218"15th"1641831/24"16th"1751/20111/2"17th"1741821/24"18th"1744211/28"19th"184111"20th"18402"21st"183121"22nd"19211/211/2"23rd"1931/24118"24th"19211/2824"25th"2031"26th"2021811/24"27th"2021/24118"28th"2121/211/2"29th"2121"30th"21111/211/2"31st"22111"32nd"2211/24018"33rd"221811/24"34th"2311/21/2"35th"23181/24"36th"23141/28"37th"pure gold.
Since it is rarely found that gold, which has been coined, does not amount to at least fifteenduellaegold in abes, some make only twenty-eight needles, and some make them different from those already described, inasmuch as the alloy of gold with silver and copper is sometimes differently proportioned.
These needles are made:—
Gold.Silver.Copper.Duellae.DuellaeSextulaeSiliquae.DuellaeSextulaeSiliquae.The1stof1561821/24"2nd"1564211/28"3rd"1551/2311/2"4th"1661/2111/2"5th"1651821/24"6th"16411/2834"7th"1751411/28"8th"1754111/28"9th"1741421/28"10th"184111"11th"1842"12th"183121"13th"19311/2418"14th"1931/24118"15th"19211/2428"16th"2031"17th"20211"18th"2022"19th"2121/2418"20th"21111/2418"21st"2111811/24"22nd"221181/24"23rd"22111"24th"2211/2418"25th"2311/248"26th"2311/21/2"27th"23181/24"28th"pure gold
Next follows the fourth kind of needles, by which we test silver coins which contain copper, or copper coins which contain silver. Thebesby which we weigh the silver is divided in two different ways. It is either divided twelve times, into units of fivedrachmaeand onescripulumeach,which the ordinary people callnummi[41]; each of these units we again divide into twenty-four units of foursiliquaeeach, which the same ordinary people call agrenlin; or else thebesis divided into sixteensemunciaewhich are calledloths, each of which is again divided into eighteen units of foursiliquaeeach, which they callgrenlin. Or else thebesis divided into sixteensemunciae, of which each is divided into fourdrachmae, and eachdrachmainto fourpfennige. Needles are made in accordance with each method of dividing thebes. According to the first method, to the number of twenty-four halfnummi; according to the second method, to the number of thirty-one halfsemunciae, that is to say asicilicus; for if the needles were made to the number of the smaller weights, the number of needles would again be too large, and not a few of them, by reason of the small difference in proportion of silver or copper, would have no significance. We test both bars and coined money composed of silver and copper by both scales. The one is as follows: the first needle is made of twenty-three parts of copper and one part silver; whereby, whatsoever bar or coin, when rubbed on the touchstone, colours it just as this needle does, in that bar or money there is one twenty-fourth part of silver, and so also, in accordance with the proportion of silver, is known the remaining proportion of the copper.
The1stneedleis made of23parts ofcopper and1of silver."2nd""22""2""3rd""21""3""4th""20""4""5th""19""5""6th""18""6""7th""17""7""8th""16""8""9th""15""9""10th""14""10""11th""13""11""12th""12""12""13th""11""13""14th""10""14""15th""9""15""16th""8""16""17th""7""17""18th""6""18""19th""5""19""20th""4""20""21st""3""21""22nd""2""22""23rd""1""23""24thof pure silver.
The other method of making needles is as follows:—
Copper.Silver.SemunciaeSicilici.SemunciaeSicilici.The1stisof151"2nd""14111"3rd""142"4th""13121"5th""133"6th""12131"7th""124"8th""11141"9th""115"10th""10151"11th""106"12th""9161"13th""97"14th""8171"15th""88"16th""7181"17th""79"18th""6191"19th""610"20th""51101"21st""511"22nd""41111"23rd""412"24th""31121"25th""313"26th""21131"27th""214"28th""11141"29th""115"30th""1151"31stof pure silver.
So much for this. Perhaps I have used more words than those most highly skilled in the art may require, but it is necessary for the understanding of these matters.
I will now speak of the weights, of which I have frequently made mention. Among mining people these are of two kinds, that is, the greater weights and the lesser weights. Thecentumpondiumis the first and largest weight, and ofcourse consists of one hundredlibrae, and for that reason is called a hundred weight.
The various weights are:—
1st=100librae=centumpondium.2nd=50"3rd=25"4th=16"5th=8"6th=4"7th=2"8th=1libra.
Thislibraconsists of sixteenunciae, and the half part of thelibrais theselibra, which our people call amark, and consists of eightunciae, or, as they divide it, of sixteensemunciae:—
9th=8unciae.10th=8semunciae.11th=4"12th=2"13th=1semuncia.14th=1sicilicus.15th=1drachma.16th=1dimidi-drachma.
Weights for Assay Balances[Pg 262]The above is how the "greater" weights are divided. The "lesser" weights are made of silver or brass or copper. Of these, the first and largest generally weighs onedrachma, for it is necessary for us to weigh, not only ore, but also metals to be assayed, and smaller quantities of lead. The first of these weights is called acentumpondiumand the number oflibraein it corresponds to the larger scale, being likewise one hundred[42].
The1stis called1centumpondium."2nd"50librae."3rd"25""4th"16""5th"8""6th"4""7th"2""8th"1""9th"1selibra."10th"8semunciae."11th"4""12th"2""13th"1""14th"1sicilicus.
The fourteenth is the last, for the proportionate weights which correspond with adrachmaand half adrachmaare not used. On all these weights of the lesser scale, are written the numbers oflibraeand ofsemunciae. Somecopper assayers divide both the lesser and greater scale weights into divisions of a different scale. Their largest weight of the greater scale weighs one hundred and twelvelibrae, which is the first unit of measurement.
1st=112librae.2nd=64"3rd=32"4th=16"5th=8"6th=4"7th=2"8th=1"9th=1selibraor sixteensemunciae.10th=8semunciae.11th=4"12th=2"13th=1"
As for theselibraof the lesser weights, which our people, as I have often said, call amark, and the Romans call abes, coiners who coin gold, divide it just like the greater weights scale, into twenty-four units of twosextulaeeach, and each unit of twosextulaeis divided into foursemi-sextulaeand eachsemi-sextulainto three units of foursiliquaeeach. Some also divide the separate units of foursiliquaeinto four individualsiliquae, but most, omitting thesemi-sextulae, then divide the doublesextulainto twelve units of foursiliquaeeach, and do not divide these into four individualsiliquae. Thus the first and greatest unit of measurement, which is thebes, weighs twenty-four doublesextulae.