ACTUS
ACTUS a Roman measure of land, which formed the basis of the
whole system of land measurement. The word
actus sometimes denotes a way between fields, along which cattle
could be driven (
Dig. 8,
1,
5;
5,
4, &c.). Varro (
L. L. 5.34, Müller)
asserts that the name of the measure was derived from this, but couples this
remark with an absurd derivation of
ager: ut ager quo agi
poterat, sic qua agi actus. According to Varro, Columella
(5.1, 5, on the authority of Varro) and Festus, s.v. the
actus simplex or
minimus was 120
(Roman) feet long and 4 feet wide. The
actus
quadratus, or simply
actus, was a
square of 120 feet each way, containing thus 14,400 square feet. Pliny
(
18.9) says of it:
actus in quo boves agerentur cum aratro uno impetu justo
(i.e. without turning) ;
hic erat cxx pedum. Mommsen
(
Hist. 1.215) explains
actus,
“the driving,” to be properly a measure of labour, denoting the
half-day's work, with reference to the marked division of the day in Italy
by the noon-tide siesta. The
jugerum, or
“yoking,” the double of the
actus, would thus denote the day's work. This is far more
probable than the earlier explanations. The
actus furnishes an example of the combination of the duodecimal
with the decimal system, its length being twelve times the standard
DECEMPEDA Columella (
l.c. § 6) says that the Gauls called the
actus quadratus, arepennis; but this could
only be an approximate identification, for the
actus
quadratus is somewhat smaller than the great French
arpent and much larger than the small
arpent. (Compare ACNA;
Niebuhr,
Hist. of Rome, vol. ii. Appendix I.)
[
A.S.W]
