ĂCAENA (ἀκαίνη, ἄκαινα, or in later Greek ἄκενα, in one place ἄκαινον), a measuring rod of the length of ten Greek feet. It was used in measuring land, and thus resembles the Roman decempeda. ĂCATĬUM (ἀκάτιον, a diminutive of ἄκατος), a small vessel or boat used by the Greeks, which appears to have been the same as the Roman _scapha_. The _Acatia_ were also sails adapted for fast sailing. ACCENSUS. (1) A public officer, who attended on several of the Roman magistrates. The Accensi summoned the people to the assemblies, and those who had law-suits to court; they preserved order in the courts, and proclaimed the time of the day when it was the third hour, the sixth hour, and the ninth hour. An accensus anciently preceded the consul who had not the fasces, which custom, after being long disused, was restored by Julius Cæsar in his first consulship. Accensi also attended on the governors of provinces.--(2) The accensi were also a class of soldiers in the Roman army, who were enlisted after the full number of the legion had been completed, in order to supply any vacancies that might occur in the legion. They were taken, according to the census of Servius Tullius, from the fifth class of citizens, and were placed in battle in the rear of the army, behind the triarii. ACCLĀMĀTĬO, was the public expression of approbation or disapprobation, pleasure or displeasure, by loud acclamations. On many occasions, there appear to have been certain forms of acclamations always used by the Romans; as, for instance, at marriages, _Io Hymen_, _Hymenaee_, or _Talassio_; at triumphs, _Io Triumphe_; at the conclusion of plays, the last actor called out _Plaudite_ to the spectators; orators were usually praised by such expressions as _Bene et praeclare_, _Belle et festive_, _Non potest melius_, &c. Under the empire the name of _acclamationes_ was given to the praises and flatteries bestowed by the senate upon the reigning emperor and his family.