Metallury in Numismatics Cited al marco Weight Adjustment

443, Lot: 461. Estimate $100. Sold for $170. This amount does not include the buyer’s fee.

L. Titurius L.f. Sabinus. 89 BC. AR Denarius (18.5mm, 3.93 g, 9h). Rome mint. Bareheaded, bearded head of King Tatius right; palm frond before face / Tarpeia facing, buried to her waist in shields, with raised hands she tries to thrust off two soldiers who are about to cast their shields at her; star in crescent above. Crawford 344/2b; Sydenham 699; Tituria 4; Type as RBW 1301; see “The adjustment al marco of the weight of Roman Republican denarii” by Clive Stannard in Metallurgy in Numismatics, Volume 3 (RNS Special Publication No. 24, 1993), pp. 45-70, this coin cited on p. 56 as “344/2b – no. 2. private collection, 3.90 g”. VF, deeply toned, areas of weak strike due to al-marco weight adjustment before striking.

From the Andrew McCabe Collection.

Three coins in my collection have al-marco weight adjustment gouges that are referenced in the works of Clive Stannard: my Fannius denarius, RRC 275/1, is illustrated in Stannard's article in Metallurgy in Numismatics, Volume 3 (1993), pp. 45ff, pl. 1, 4, as is my Furius Crassipes, RRC 356/1, on pl. 2, 12 of the same publication. A third example, this coin, is referenced in the same publication (available at http://stannard.info/stannard_adjustment_al%20marco_of_denarii_blanks.pdf), cited as “private collection 3.90 g” (coin’s actual weight is 3.93 grams, but I’m assured it is the same). I thought it worthwhile to put this coin in the public domain with a summary of Clive Stannard’s 1993 paper as follows:“Ancient mints sometimes adjusted weights by gouging a sliver, occasionally slivers, of metal from the face of a flan, before striking the coin. The results are characteristic and easily recognizable. Examples in silver are known from Lycia, Paeonia (King Audoleon), Velia, and the Roman Republic, and there is a gold example in the coinage of Constantine I. The frequency of the use of gouging in the Roman Republic makes it possible to study whether weight adjustment was carried out al pezzo (which means that each individual flan was brought within the tolerances of the weight standard for the issue), or whether it was done al marco (which means not paying too much attention to the weights of individual coins, but ensuring that a fixed number of flans were made from a fixed weight of metal). This question can be investigated by looking at the histograms of large number of denarii, in issues known to use gouging. In al marco adjustment, a block of flans is cast a little heavy. The right number of flans for the desired weight of coins is counted out (and the overall weight will, of course be, too heavy). Flans that look heavy are successively picked out one by one, without too much attention to the weight, and a sliver of metal is gouged off. The gouged flans are tossed back into the block, until the overall weight is reduced to the correct overall weight. Figure at: https://www.flickr.com/photos/ahala_rome/3742991304/ models this process. As a result of adjustment al marco, the linked histogram is negatively skewed (the size of the upper leg has been reduced), and has high kurtosis (the center of the histogram is higher than a normal distribution.) 8,649 denarii from between 144 and 43 BC were checked to identify issues with gouging. 1.34% of all the coins looked at were gouged. The weight histograms of 4,587 Roman Republican denarii in the issues known to be gouged was negatively skewed, with high kurtosis, showing that they had been adjusted al marco. In these issues, 2.53% of the coins showed signs of gouging. A related Stannard reference with additional material on same subject is at https://www.academia.edu/1443037/Weight_adjustment_al_marco_in_Antiquity_and_the_Athenian_decadrachm.” [this summary Clive Stannard]