Purification of the army and the enclosure of the city by a wall.
With the census completed, which he had expedited concerning unregistered citizens by the fear of a law passed with threats of chains or death, he proclaimed that all Roman citizens, both knights and foot-soldiers, each in their own centuries, should be present in the field of Mars at first light of dawn. There, he purified the entire marshalled army with sacrifices of pig, sheep, and bull, and this was called the closed purification, inasmuch as it was done at the ends of the census-taking. Eighty thousand citizens are said to have been counted at that purification ; Fabius Pictor, the most ancient of writers, adds that of those who were able to bear arms, this was the number. For this multitude, the city also seemed to need to be enlarged. He adds two hills, the Quirinal and the Viminal : The Viminal he subsequently increases with the Esquiline, and there he himself dwells, as rank was made by place ; by mound and trenches and a wall, he stations around the city : thus the pomerium is extended. Those who regard the etymology of the word alone interpret pomerium to be the space just beyond the wall ; it is, however, a place more on both sides of the wall, which the Etruscans, after taking auspices, formerly consecrated when founding cities, where they intended to lead the wall with fixed boundaries on either side, such that they did not make the buildings at the interior part continuous with the wall, which are even now commonly joined together, and outside some pure ground is open from human cultivation. This space, which is not inhabited and is not ploughed by divine law, not more because it is past the wall than because the wall is past it, the Romans call the pomerium ; and in the increment of the city, however much the walls were about to advance, by that much the consecrated boundaries are always extended.