3rd century AD. The upper portion of phallic military dividers or compasses (circinus), formed of a domed boss, terminal part of a larger rivet shaped like an elongated male phallus, sitting on the washer close to one leg, the second leg with a wing nut behind, shaped as a knife. Cf. Beutler, F., Farka, C., Gugl, C., Humer, F., Kremer, G., Polhammer, E. (ed.), Der Adler Roms, Carnuntum und die Armee der Caesaren, Bad Voslau, 2017, pp.331-332, nn, 638-642. Appels, Andrew & Laycock, Stuart Roman Buckles & Military Fittings, Witham, Essex, 2007; p.143, fig.AA15.31-AA15.33; accompanied by copies of the relevant pages of this published item. 18 grams, 59mm (2''"). From a North Yorkshire collection formed since the 1980s; thence by descent. This instrument, the circinus, made up of two flat-section arms, was widely used by masons and carpenters, as well as for making wall decorations, for the preparation of repetitive elements such as spirals or circumferences. It was much more widely used by the agrimensores of the army and by the military logistic system, to calculate the ballistics of war machines and the range of their bullets. [No Reserve]