Bonham’s (London), Sale Cat., 30 October 2003, no. 350 (ill.).

2004.01

Roman Bronze Steelyard Weight (statera)

Presented by the Friends of the Classics Museum. Max. ht 10.5cm; width at shoulders 6.1cm. Weight 1234.5g.

Well preserved; there is a green patina over the surface.

The weight is in the form of a bust of a young wavy-haired boy. He is depicted as wearing a form of tunic fastened by a simple brooch over the right shoulder. His head is somewhat raised and turned a little to the left. He has chubby, child-like features with a rather flattened nose. The eyes are slightly outlined, the pupils indented. The hair is constructed in a series of curls coming down and forward from the back of the head and framing the face. Two curls are gathered on the top of the head to provide a loop by which to hang the weight from the balance.

To judge by the style, the piece is probably to be dated to the second or third century AD. Pieces such as this are normally hollow inside to take lead to make up the exact weight needed, and it is often closed with a small sheet of bronze. This was doubtless so here (and there seems to be evidence of a narrow gap in the bronze) but it is difficult to see the underside now that it is mounted on a base.

On the use of steelyards and weights, note the attractive article by D.K. Hill, “When Romans Went Shopping”, Archaeology 5, 1952, 51-55. There is an excellent catalogue produced for the Museo della Bilancia by C. Corti and N. Giordani (eds), Pondera. Pesi e misure nell'antichità (Campogalliano [Modena] 2001). It deals with a large range of instruments for measuring and weighing, and there is a discussion of weights of this kind at 198-208. For other collections of balances and weights, see A. De Ridder, Les bronzes antiques du Louvre (Paris 1915) ii, nos 3256-3444, pll. 114-115; M. Comstock and C. Vermeule, Greek, Etruscan and Roman Bronzes in the Museum of Fine Arts, Boston (Boston 1971) nos 641-644 of a variety of dates, but without the weight of the objects; There is a useful collection in O. Tekin, Balance Weights in the Aegean World. Classical and Hellenistic Periods (Istanbul 2016); D. Onder, The Poise of the Steelyard. Balances Weight = Kantarin Topuzu. Teraziler Agirliklar Olcu Aletleri (Istanbul 2016); F. Mainardis, “La collezione di pesi romani del Civico Museo di Storia ed Arte di Trieste”, Antichità Altoadriatiche 83, 2016, 327-350. Note also the brief introduction by H. Menzel in H. Temporini (ed.), Aufstieg und Niedergang der Römischen Welt (1972-) II. 12, 3, 164 and pl. 25 with bibl. (s.v. Büstengewichte). See also now http://repository.edition-topoi.org/collection/BSYP.

Vitruvius discusses (10.3.4) the steel-yard (trutina), involving an arm with a suspension hook and pivoting attachment set towards one end, and a moveable weight that could be shifted along scale markings on the other, longer end of the bar. The merchandise was suspended

from the short end, and the sliding counterweight was moved along the longer end until the two sides balanced and the weight was read off the scale. The simple beam balance (trutina, libra) was also common, perhaps explaining why Vitruvius does not discuss it: a standardized stone or bronze weight was put on one pan and the merchandise on the other. Both types of scale could be adjusted in size to serve any sort of merchandise.

Classical and Hellenistic Greek weight-systems were complicated by the fact that many cities, as with other measurements, had their own. For a Roman relief showing a balance in use, see the cover of A. Wilson and M. Flohr (eds), Urban Craftsmen and Traders in the Roman World (Oxford 2016). See also J. Petit, Bronzes antiques de la Collection Dutuit (Paris 1980) 174-175 no. 93, for a yardarm with weight from Campania and dated by an inscription to ad 47. Berlin inv, 31921/31922 is steelyard of the second to fourth century, and inv. 30943 a weight in the form of a crouching negro slave, probably of the second century AD: Antikenmuseum Berlin. Die ausgestellten Werke (Berlin 1988) 270-271 no. 3; K. Vierneisel (ed.), Römiches im Antikenmuseum (Berlin 1978) no. 78.

On more strictly metrological issues, W.F. Richardson, Numbering and Measuring in the Classical World. An Introductory Handbook (second ed., Bristol 2004) is a very handy guide. It is possible that our weight was intended as 3.5 Roman pounds (at ca 327.45g per pound), a not-uncommon size. (The weight stated above is that given in the sale catalogue; the present weight, with wooden base and support-pin, is 1440g.) On the question of the pound’s weight, see M. Martin, “Zum Gewicht des römischen Pfundes”, in: F. Baratte (ed.), Argenterie romaine et byzantine. Actes de la Table Ronde Paris 1983 (Paris 1988) 211-225.

In J. Renn and G. Castagnetti (eds), Homo faber. Studies on Nature, Technology, and Science at the Time of Pompeii presented at a Conference at the Deutsches Museum, Munich, 21-22 March 2000 (Rome 2002) 93-108, there is an interesting article from P. Damerow et al., “Mechanical Knowledge and Pompeian Balances”, in which the authors include an examination of the degrees of error in a number of surviving steelyards. On systems rather than objects, note the introductory chapter by C. Wikander, “Technologies of Calculation, 1: Weights and Measures”, in: J.P. Oleson (ed.), The Oxford Handbook of Engineering and Technology in the Classical World (Oxford 2008) 759-769. See further the comprehensive study by N. Franken, Aequipondia. Figürliche Laufgewichte römischer und frühbyzantinischer Schnellwaagen (Alfter 1994).

There is also a good discussion in the context of an exceptionally large weight by F. Rodríguez Martorell et al., “Un aequipondium de peso excepcional y la balanza pública del puerto de Tarraco (An exceptional weighing aequipondium and the public scales of the harbour of Tarraco”, Archivo Español de Arqueología 89, 2016, 163-180.

On measurement systems more generally in the Roman world, see the range of articles in M.G. Angeli Bertinelli and A. Donati (eds), Misurare il tempo, misurare lo spazio (Faenza 2006), including that supervision of weights and easures in trade by G. Baratta, “misurare per mestiere”, at pp. 133-260; C. Saliou (ed.), La mesure et ses usages dans l’Antiquité: la documentation archéologique (Dialogues d’Histoire Ancienne Suppl. 12, 2014). Also S. Cardullo, Le antiche misure romane (Patti 2016).

The bust seems likely to represent Harpokrates, a figure enormously popular in the Roman period, a god of fertility and the child of the divine pair Isis and Osiris. Divinities in general are very common for these weights – Mercury (appropriate given his interest in commerce and trade) but also Minerva, Diana, and then other Egyptian divinities such as Attis, Isis and Serapis. It is difficult to say why they should be selected, but some at least must have had favour with Levantine traders. On his imagery, there is a good introduction by Tran Tam Tinh, B. Jaeger and S. Poulin in Lexicon Iconographicum Mythologiae Classicae iv (Zurich-Munich). They note that his depictions are at their most popular in the second and third centuries AD.

For a weight in the form of a bust of Mercury from Pompeii and used in conjunction with a pan to hold grains or liquids, see Homo faber 15 fig. 4. Also L.P. Biroli Stefanelli (ed.), Il bronzo dei Romani: arredo e suppellettile (Rome 1990) 254-255 figs 241-242 for a regular steelyard from Pompeii (and therefore before AD 79) with a bust of Mercury.

Bonham’s (London), Sale Cat., 30 October 2003, no. 350 (ill.).