previous next


QUADRANTAL or AMPHORA QUADRANTAL, or AMPHORA only, was the principal Roman measure of capacity for fluids. (Amphora was the later name for the quadrantal, and is not found as a measure earlier than Cic. Font. 9, 19; cf. Fest. p. 258, “quadrantal vocabant antiqui, quam ex Graeco amphoram dicunt” ; so also Volus. Maecian. Dist. Part. 79, “quadrantal, quod nunc plerique amphoram vocant.” This was in the middle of the 2nd century A.D.) All the Roman measures of capacity were founded on weight, and thus the amphora was originally the space occupied by eighty pounds of wine.

There is also preserved to us by Festus (s. v. Publica Pondera, p. 246) a plebiscitum [LEX SILIA] of unknown date, regulating the weights and measures, to the following effect:--“Ex ponderibus publicis, quibus hac tempestate populus oetier (uti) solet, uti coaequetur sedulum, uti quadrantal vini octoginta pondo siet: congius vini decem p. (i.e. pondo) siet: sex sextari congius siet vini; duodequinquaginta sextari quadrantal siet vini:” --that is, that the quadrantal should contain 80 pounds of wine,1 and the congius 10; and that the sextarius should be 1-6th of the congius, and 1-48th of the quadrantal. The quadrantal was subdivided into 2 urnae, 8 congii, 48 sextarii, 96 heminae, 192 quartarii, 384 acetabula, 576 cyathi, and 2304 ligutae. As compared with the Roman dry measure, the quadrantal was three times the [p. 2.531]modius. The only measure larger than the quadrantal was the culleus of 20 amphorae, which was used, as well as the amphora itself, in estimating the produce of a vineyard. [CULLEUS: comp. AMPHORA sub fin.]

The quadrantal was connected with the measures of length, by the law, that it was the cube of the foot, whence its name quadrantal, or, as other writers give it (using the Greek κύβος instead of the Latin quadrantal) amphora cubus. (Cato, Cat. Agr. 57; Gel. 1.20; Auct. Carm. de Mens. et Pond. vv. 59-63:--

Pes longo in spatio latoque altoque notetur:

Angulus ut par sit, quem claudit linea triplex
Quatuor et medium quadris cingatur inane:
Amphora fit cubus, quam ne violare liceret, Sacravere Jovi Tarpeio in monte Quirites.

A standard model of the amphora was kept with great care in the temple of Jupiter in the Capitol, and was called amphora Capitolina (Carm. de Mens. l.c. Capitol. Maximin. 4). It was under the charge of the aediles (C. I. L. 6.1520, 10.8067; Plb. 3.26; cf. Mommsen, Staatsrecht, ii.3 p. 500). There still exists a congius which professes to have been made according to this standard. [CONGIUS] For a full account of this congius, see H. Hase, Abhandl. d. Berl. Akad. 1824.

There are two questions connected with the Roman quadrantal: namely, (1) whether the equality to the cubic foot was originally exact, or only approximate; and (2) whether there was any exact ratio between the Roman and the Grecian measures. The full discussion of these questions would be inconsistent both with the limits and with the chief object of this work. A general statement of the matters in dispute will be found, under MENSURA pp. 160, 161. It may here be added that, whether there was or was not originally any precise ratio between the Greek and Roman measures of capacity, they were at least so nearly related to one another, that, when the two systems came to exist side by side, it was found easy to establish the following definite ratios. Of the liquid measures: the Roman amphora, or quadrantal, was 2-5ths of the Aeginetan, and 2-3rds of the Attic amphora or metretes; and the congius of the Roman system was equal to the χοῦς of the Attic. Again, comparing the Roman liquid with the Greek dry measures, the quadrantal was, 1-3rd of the Aeginetan, and one-half of the Attic, medimnus. Consequently, of the dry measures, the modius (which was 1-3rd of the quadrantal) was 1-9th of the Aeginetan, and 1-6th of the Attic, medimnus. The connecting subordinate unit in all these sets of measures is the Roman sextarius, or sixth part of the congius, which was introduced into the Greek. system under the name of εέστης, and which stands to the several measures now mentioned in the following relations:--

1. Liquid Measures.
The Roman quadrantal = 48 sextarii
The Attic metretes = 72 sextarii
The Aeginetan metretes = 120 sextarii
2. Dry Measures.
The Roman modius = 16 sextarii
The Attic medimnus = 96 sextarii
The Aeginetan medimnus = 144 sextarii

The εξ́στης, or Roman sextarius, is not to be confounded with the genuine Attic ἑκτεὺς or sixth of the medimnus, which was equal to the Roman modius.

From the preceding remarks it will be seen that the only safe mode of computing the content of the amphora in terms of our own measures of capacity is by deducing it from the value already assigned to the Roman pound, on the authority chiefly of the coins. That value may be taken, in round numbers, at 5050 grains. [PONDERA Vol. II. p. 455.] Now the imperial gallon contains 70,000 grains. Therefore the Roman amphora = 5050 [multi] 80/70000 = 5.77 imperial gallons, i. e. a very little over 5 gallons and 6 pints. It is clear, therefore, that for rough calculations, at any rate when the numbers dealt with are not very large, if we reckon the sextarius as a pint (instead of .96 of a pint) and the quadrantal or amphora at 6 gallons, it will be a close enough approximation. (Boeckh, Metrol. 167; Hultsch, Metrol. pp. 112 if., ed. 2, 1882.)

[P.S] [G.E.M]

1 The Romans were aware that there is a difference in the specific gravity of wine and of water, and in the different sorts of each, but, for the sake of simplicity, they regarded them as the same specific gravity: when, however, they wished a very exact determination, they used rain-water. (Boeckh, 100.3.)

hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: