Varro, De re rustica 1.13.4 and 1.6.24, and Columella, De Re Rustica 9.5.1, provide directions about how to construct privies for agricultural uses. Also see Arnold and Mariette De Vos, Guide archeologiche Laterza, p. 242, for the Villa rustica alla Pisanella at Boscoreale, the most complete excavation of a working farm on the Bay of Naples in the outskirts of Pompeii.