The Roman Amphorae Average Capacity (AC)

Abstract

Summary This paper presents a methodological tool of statistical correction to assess the capacities of different Roman amphorae, whereby ceramic values are transformed into amounts of transported product. Based on scaled drawings of 1281 Roman amphorae, individual vessels’ capacities have been calculated by applying a CAD software to the inner profiles. Each vessel has been classified according to amphora types and the mean for each type has been calculated to produce a coefficient called Average Capacity (AC). The estimated capacities are highly reliable and show narrow confidence intervals. Therefore, they can be applied immediately as a correction factor in studies of quantification of amphorae aimed at characterizing trading dynamics. As such, we expect that future statistical studies of amphorae will include this statistical coefficient to produce more precise and reliable analysis of assemblages and, consequently, more accurate research on the Roman economy.

Calculating dolium capacities and material use

“…Previous studies have attempted to calculate the volume of large ceramic vessels, such as dolia, pithoi, and amphorae, using volumetric formulas and computer programs (Carrato, 2017; Christakis, 2005; Ericson & Strikel, 1973; Graham, 1987; Molina Vidal & Mateo Corredor, 2018; Mudd, 1984; Nelson, 1985; Palmer, 1994; Rigoir, 1981; Senior & Birnie III, 1995; Stronk, 1972; van Effenterre & van Effenterre, 1963; Warren, 1972; Wallace, 1986; Younger, 2003 Table 1). Barrels have also been the focus of volumetric studies (Jongmans, 2008).…”

“…Profile drawings of vessels are imported into software and scaled properly, or directly drawn in the software. The computer program, such as AutoCAD, outlines the profile of the vessel and revolves it 360 degrees around the central axis to generate a three‐dimensional model, from which the software ‘slices’ the model into thin cylinders and sums them together to produce an estimate of the vessel's capacity (Ikaheimo & Peña, 2007; Martínez, 2016; McCaw, 2007; Molina Vidal & Mateo Corredor, 2018). More recent studies have attempted to refine these computer‐aided techniques by accumulating larger datasets to find average values, especially for certain classes of amphorae (Molina Vidal & Mateo Corredor, 2018).…”

“…The computer program, such as AutoCAD, outlines the profile of the vessel and revolves it 360 degrees around the central axis to generate a three‐dimensional model, from which the software ‘slices’ the model into thin cylinders and sums them together to produce an estimate of the vessel's capacity (Ikaheimo & Peña, 2007; Martínez, 2016; McCaw, 2007; Molina Vidal & Mateo Corredor, 2018). More recent studies have attempted to refine these computer‐aided techniques by accumulating larger datasets to find average values, especially for certain classes of amphorae (Molina Vidal & Mateo Corredor, 2018). What these different methods have in common is that they all require a drawing of the vessel to scale, which means the dolium would have to be preserved and visible enough to generate a profile drawing.…”

Las importaciones anfóricas del yacimiento tardorrepublicano de El Principado (Finestrat, Alicante)

“…Por ello, para establecer comparaciones entre tipos y para limitar la sobreestimación de las ánforas de menor tamaño y la infravaloración de las más grandes, es importante cuantificar el volumen de producto transportado partiendo de las capacidades medias de cada tipo. Así, se ha realizado una segunda corrección a partir del cálculo de la Capacidad Media (CM) de los distintos tipos anfóricos (Molina y Mateo, 2018) y, por lo tanto, la información cuantitativa se indicará en porcentajes respecto al total del volumen calculado 2 .…”

“…Las ánforas Lamboglia 2 son originarias de la costa adriática itálica (Carre et al, 2014), aunque también se ha propuesto su producción en el litoral dálmata (Lindhagen, 2009:86-87). Se trata de números muy similares a los recogidos para el tipo Dressel 1 procedentes del litoral Tirreno, valores similares a los alcanzados por otros yacimientos del sureste de la península ibérica (Molina, 1997(Molina, , 2013Mateo, 2016a), aunque tras aplicar la corrección por volumen, les superan ampliamente, dado que el tipo Lamboglia 2 posee en torno a un 50% más de capacidad que el tipo Dressel 1 (Molina y Mateo, 2018).…”