This old, Roman goniometer (Latin: shell or bowl) was, along with the sextarius, one of the most widespread standard measures in ancient Rome. Liquids were originally calculated by weight. The largest known measure was the 160 congii culleus (= leather sack, tube) with 524 litres, i.e. more than two barrique barrels (450 l).
The amphora (26.25 l) was used as a commercial measure and was divided into two urna (of about 13 l). The sixth part of a congius was called a sextarius, which corresponded to 0.54 litres and was a schoppen or jug in today's terms. The third part was called triens with 0.18 litres, the fourth part quadrans with 0.135 litres, the sixth part sextans with 90 cm³ and the twelfth part the cyathus (scoop) mentioned in the novel Satyricon with 45 cm³. The list relates the most important hollow dimensions to each other (but there were many more). The measurements are not necessarily compatible and should only be understood as guidelines. On the subject of units of measurement, see the lists under barrel types, bottles, goblets and wine vessels.
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Sigi Hiss
freier Autor und Weinberater (Fine, Vinum u.a.), Bad Krozingen