A Roman measure of length. It formed the basis of the whole system of land measurement. The
was 120 (Roman) feet long
and four feet wide. The actus quadratus
was a square of 120 feet each
way=14,400 square feet (Pliny , Pliny H. N. xviii.
). The actus is an example of the combination of the decimal with the duodecimal
system, its length being twelve times the standard decempeda
(q. v.). The
actus was half the iugerum.
In Hispania Baetica, the actus
was called acna
(also written agna
). Cf. Varro, R. R.