Note 42 — Chapter I · ROME UNDER THE KINGS.

“When Servius Tullius had completed the taking of the census, he ordered all the citizens to assemble in arms in the greatest of the fields situated near the town, and, having arranged the horsemen in squadrons, the footmen in phalanx, and the light-armed men in respective orders, he submitted them to a lustration, by the immolation of a bull, a ram, and a he-goat. He ordered that the victims should be led thrice round about the army, after which he sacrificed to Mars, to whom this field was dedicated. From that epoch to the present time the Romans have continued to have the same ceremony performed, by the most holy of magistracies, at the completion of each census; it is what they call a lustrum. The total number of all the Romans enumerated, according to the writing of the tables of the census, gave 300 men less than 85,000.” (Dionysius of Halicarnassus, IV. 22.)