An instance of the value of these inscriptions in determining the relative accuracy of Dion and Suetonius is afforded by the inscription belonging to the year A.D. 39, which gives us some historical facts about the reign of Caius, a portion of Roman history rendered difficult and obscure by the loss of the central books of the Annals of Tacitus. Suetonius states that the title of Augusta was conferred on Antonia by Claudius, whereas Dion on the contrary attributes the conference of this title to Caius. The inscription decides the question in favour of the account of Dion Cassius. Again, the date of the recognition of Caius by the Senate is fixed by the same inscription as having occurred on the 18th of March, and not on the 16th as recorded by Tacitus and Suetonius, nor the 26th, as Dion Cassius states. Many other interesting corrections or elucidations of the Latin historians will be found in Henzen’s learned treatises, or in his articles in the ‘Annali dell’ Instituto’ for 1867, and the ‘Hermes’ 1867. Besides the grove of the Arval College, which was an extensive wood, four buildings are mentioned in the Records--the Ædes Deæ Diæ, the Cesareum, the Tetrastylon and the Circus. With regard to the position of these, Pellegrini is of opinion that the Circus was situated on the ridge of the hill on the western side of the Vigna Ceccarelli, in which place some remains apparently belonging to a circus have been found. Henzen leaves the site of the Circus undetermined, thinking that there is not sufficient evidence. The Tetrastylon and the Cesareum were supposed by Mommsen to have been names of the same building, but Henzen thinks that they are mentioned as separate places in the same inscription. The college feasts and meetings were held in one or other of these, which must therefore have been large enough to contain, besides the dining hall, an assembly-room, as the Brothers are said to have met there and to have sat in rows of seats. The Cesareum was a quadrangular building, as the form of the inscriptions which were attached to its walls seems to show, since they could not have been placed on a round surface. The temple of the Dea Dia stood upon a hill, for the priests are described as ascending in order to perform the sacrifices, and descending afterwards. Yet there are no vestiges of a building upon the top of the hill. Henzen therefore concludes that the ruins of the round building, upon which the modern Casa rustica in the Ceccarelli vineyard is placed, must have belonged to this Ædes. It was not decorated with columns but with Corinthian pilasters, and the inscriptions were affixed to the interior until the year 81, when it became necessary from want of space to place them on the pedestals of the columns.[153] [Sidenote: Porto.]