Volume and capacity
The modius and its subdivision the sextarius are
the most commonly used measure of capacity and in the Vindolanda
texts are used as measure for liquid (e.g. beer, wine) and 'dry
goods' (e.g. cereals). There is also a reference to a metreta
of beer (186). These units are usually, though not always, abbreviated,
modius (plural modii) to m with a bar above
it, sextarius (plural sextarii) to s divided
horizontally by a bar. Again half is indicated by semis,
abbreviated to s.
|| Metric (litres)
|| Imperial (gallons:
| 1 modius = 16 sextarii
|| 1.93: 15.44
| 1 metreta = 100
|| 0.12: 0.96
We have some information on the volumes of containers in which
items brought to Vindolanda as supplies would have been transported.
For example many complete amphorae have survived in shipwrecks and
burials and barrels too when re-used as linings for wells. This
allows archaeologists to calculate the volumes they would have carried.
The records of their contents
painted on amphorae (tituli dipinti) note capacities close to
these assessments. The volumes of some common types of amphora and
barrels are tabled here, recorded in Roman and modern metric and
imperial units. (NB as well as being a term for a type of container,
amphora is also a term for a Roman unit of measurement
equivalent to three modii).
|| Capacity (modii:
|| Capacity (imperial)
|Dressel 1 (wine)
|Dressel 2-4 (wine)
|Dressel 20 (olive
||40-80 litres (60-65
|Barrels (wine, beer)
The principal measure of weight used in the Vindolanda tablets
is the Roman pound, the libra, although this term itself
occurs in only one tablet (180).
The pound is more frequently referred to as pondo, abbreviated
to p. The Roman pound is less than the modern imperial
pound, at just under three quarters of its weight, or c.323g. As
usual half is indicated by semis, abbreviated to s.
The Roman pound was subdivided into 12 unciae (approximately
27g), which was in turn subdivided into 24 scrupula. These
subdivisions are not however referred to in the Vindolanda tablets.
For further information see Transport
and supplies, Diet and dining
and The use and formats of writing tablets
in the exhibition.