distributions, or extraordinary grants, to places or individuals.

Castella Prlvata. When a number of individuals, living in the same neighborhood, had obtained a grant of water, they clubbed together and built a castellum^ into which the whole quantity allotted to them collectively, was transmitted from the castellum publicum. These were termed privata, though they belonged to the public, and were under the care of the curatores aquarum. Their object was to facilitate the distribution of the proper

quantity to each person, and to avoid puncturing the main pipe in too many places for ;

when a supply of water from the aqueducts was first granted for private uses, each person obtained his quantum by inserting a branch pipe, as we do, into the main, which was probably the custom in the age of Vitruvius, as he makes no mention of private reservoirs. Indeed, in earlier times, all the water brought to Rome by the aqueducts, was applied to public purposes exclusively, it being forbidden to the citizens to divert any portion of it to their own use, except such as escaped by flaws in the ducts or pipes, which was termed aqua caduca. But as even this permission opened a door for great abuses, from the fraudulent conduct of the aquarii, who damaged the ducts for the purpose of selling the aqua caduca, a remedy was sought by the institution of castella privata, and the public were henceforward forbidden to collect the aqua caduca, unless permission was given by special favor (beneficium) of the emperor. The right of water (jus aquce impetratce) did not follow the heir or purchaser of the property, but was renewed by grant upon every