A further quaestorian department is mentioned by Cicero—the _provincia aquaria_, which was probably concerned with the water supply of the capital. It is uncertain whether this function was attached to one of the Italian quaestorships.[1013] _The Censors_ We have already described the institution of the censorship in 443 B.C.,[1014] and have seen that patrician rank was originally a necessary qualification for the post. The first mention of a plebeian censor is in 351 B.C.[1015] One of the Publilian laws of 339 B.C. is said to have extended to the censorship the provision of the Licinian law about the consulship, and to have enacted that one censor must be a Plebeian;[1016] but it is not until the year 131 B.C. that we find two plebeian censors.[1017] The election to this office, like that to the other higher magistracies, took place in the _comitia centuriata_[1018] under presidency of the consul. The election was then ratified, not, as in the case of other magistrates, by a _lex curiata_, but by a _lex centuriata_,[1019] a form of statutory approval which marks the censors as peculiarly the officials concerned with the organisation of the _exercitus_. In rank the censor occupies an anomalous position. Although lacking the _imperium_ and the right of summoning people and Senate, he is reckoned amongst the _majores magistratus_, he has the “highest _auspicia_,”[1020] he sits in the curule chair, wears the purple-striped toga, and (an honour accorded to no other magistrate) is buried in the full purple of the king.[1021] Politically the censorship was the apex of a career. Often held in its earlier period by ex-consuls, it became practically confined to the consular, and its enormous powers, its lofty ethical significance, and its comparative infrequency made it the goal of those who had already attained the chief titular dignity of the state. Four attributes of the office are very important in determining its character. The first gave it the necessary authority, the others created a healthful limitation of its powers.