AERARIUM. - The Exchequer or Public Treasury; the place where the annual revenues of the republic were deposited, and which derived its name from the metal of the money of the Romans, viz. aes (brass). It was in the temple of Saturn; and thence were drawn the funds to defray all needful expenses, as well in peace as in war. This Aerarium was generally filled with immense riches; and rarely, indeed, did it happen, that the state laboured under any want of money. The custody of it was confided to officers, selected from the people, and who were called Tribuni Aerarii; they were required to be men in high repute for great riches, probity, and disinterestedness. Besides this ordinary treasure, there was another, which bore the apellation of Sanctius Aerarium, because it was in the interior of the temple, or perhaps because it was not allowed to be resorted to except in pressing emergencies. Julius Caesar, wanting money for his own purposes, during the civil war, took forcible posession of this deposit of public wealth, and carried away vast sums, as is acknowledged by all the historians, although they do not agree as to the quantity. - In addition to these two treasuries, there was likewise the Aerarium Militare, formed by Augustus, for the maintenance of the Roman troops, the ancient funds proving insufficient to furnish pay for all the legions. - See Pitiscus.
On gold and silver coins struck by L VINICIVS L F, one of the moneyers of Augustus, we read the following inscription, which, as containing the initial letter of the word Aerarium, may, with propriety, be cited in this place: viz. S P Q R IMP CAE QVOD V M S EX EA P Q IS AD A DE. Senatus Populusque Romanus, Imperatori Caesari, Quod Viae Munitae Sint Ex Ea Pecunia, Quam Is Ad Ararium Detulisset. A monument this of public gratitude to the Emperor above named, who by making and repairing great roads, had contributed to the public safety; and who did this so far at his own cost, that he had caused to be conveyed to the Treasury of the State, that money which was the fruit of his victories, and of the advantages he had gained over the foreign enemies of his country. - See Eckhel 's remarks on a coin of the Neria family, corroborative of the fact that the Aerarium, or public treasury, at Rome, was in the temple of Saturn. See also the word SATVRNVS.