Lucae Paeti ... de mensuris, et ponderibus Romanis, et Graecis

contains, according to the opinion of Columella and Varro, in the places just mentioned. These are the words of Varro: "He established different methods by which they would measure fields; for in Further Spain they measure by yokes original: "iugis", in Campania by verses original: "uersibus"; among us, in the Roman and Latin territory, they call it a iugerum acre/yoke-measure, because joined oxen could plow it in one day." They call a verse a hundred feet square in every direction; a iugerum, because it has two square actus driving-lengths: concerning which, it is read thus in Pliny, book 18, chapter 3: "A iugerum was so called because it could be plowed by one yoke of oxen in a day; an actus, in which oxen would be driven when they are plowed with one straight run, this was of one hundred and twenty feet, and doubled in length, it made a iugerum." So he said. But that which is read as iugerum in Pliny ought to be restored as iugum yoke, otherwise Pliny would have fallen into error when he attributed to the Roman iugerum what Varro attributed to the Spanish iugum. Into which error many of the younger writers have fallen, having followed a corrupt reading. From this tradition of the iugerum measure, it appears that a iugerum is twenty-eight thousand eight hundred square feet, from Columella book 5, chapter 1. Therefore, as I said, two actus make a iugerum, with a length of two hundred and forty feet, and a width of one hundred and twenty feet: which two sums multiplied together make twenty-eight thousand eight hundred square feet. So he said. In this place, it is pleasing to note that Palladius, in De re rustica On Rural Affairs, book 2, chapter 12, did not think correctly concerning the iugerum, for he says a square iugerum board consists of one hundred and eighty feet in every direction. If these sums are multiplied together, they constitute a sum of thirty-two thousand four hundred square feet, whereas according to Columella and the opinion of all, it is only twenty-eight thousand eight hundred. He erred, as I believe, because when he saw that the iugerum was 240 feet in length and 120 in width, which two sums joined together constitute a sum of three hundred and sixty, he, not being a very good geometer, thought that by dividing this number of three hundred and sixty, he had established an equilateral iugerum, not remembering that Vitruvius, in book 9, chapter 1, following the opinion of Plato, had handed down that if anyone wishes to double a square area of a certain measure in every direction, one cannot achieve it with numbers. To which, however, if he had wished to come close, he should have established sides of one hundred and sixty-nine feet and three-quarters, and less than that.
A centuria century of land was once a measure of one hundred iugera, which afterwards was doubled,