Jugerum


The jugerum or juger was a Roman unit of area, equivalent to a rectangle 240 Roman feet in length and 120 feet in width, i.e. 28,800 square Roman feet or about hectare.

Name

It was the double of the Ancient Roman units of measurement#Area, and from this circumstance, according to some writers, it derived its name. It seems probable that, as the word was evidently originally the same as iugum, a yoke, and as actus, in its original use, meant a path wide enough to drive a single beast along, that iugerum originally meant a path wide enough for a yoke of oxen, namely, the double of the actus in width; and that when actus quadratus was used for a square measure of surface, the iugerum, by a natural analogy, became the double of the actus quadratus; and that this new meaning of it superseded its old use as the double of the single actus.
Pliny the Elder states:
"That portion of land used to be known as a ‘jugerum,’ which was capable of being ploughed by a single ‘jugum,’ or yoke of oxen, in one day; an ‘actus’ being as much as the oxen could plough at a single spell, fairly estimated, without stopping. This last was one hundred and twenty feet in length; and two in length made a jugerum."

The uncial division as was applied to the iugerum, its smallest part being the scrupulum of 100 sq ft or 9.2 m². Thus, the iugerum contained 288 scrupula. The iugerum was the common measure of land among the Romans. Two iugera formed an Ancient Roman units of measurement#Area, a hundred heredia a centuria, and four centuriae a saltus. These divisions were derived from the original assignment of landed property, in which two iugera were given to each citizen as heritable property.
Columella states:
"The square actus is bounded by 120 feet each way: when doubled it forms a iugerum, and it has derived the name iugerum from the fact that it was formed by joining."

In Gaul, half of a jugerum was called an arepennis, the origin of the later French unit of area, the arpent.

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