The word _platea_ is likewise one of those which may mislead, and of which only vague notions are current. The general opinion, I believe, is, that platea signifies a broad street on account of its derivation from the Greek πλατεῖα; but it is something else; it is what we call _place_ or _piazza_. In the early times of Rome the name does not seem to have been used; it occurs only at a later period, when an intercourse was established with Greece. We have to understand by it a wide open space, such as we have in front of many large buildings; but not a market-place. The authority which has enabled me to establish this as the real meaning of the word, shows how necessary it is for an historical philologer not to limit his reading: for I know it from several passages of St. Augustin’s work, “De Civitate Dei.” St. Augustin, one of the greatest minds, ought to be recommended on account of his intellect, and independently of any historical information which his works may furnish; his genius is a mighty one, and was extremely developed in that agitated period, which forms the boundary line between the ancient and modern world. In his account of the conquest of Rome by the Goths, which he gives merely in passing, there are passages from which it is quite evident that _platea_ is a space such as I have described before. These are generally speaking, the only open spaces which Rome, after its rebuilding since the middle ages, now possesses, as, for example, the Piazza di Spagna below the Collis Hortulorum; a large place of the size of the market-place of Bonn is scarcely to be found at Rome. The first _aqueduct_ was built by Appius Caecus during the second Samnite war; it was very low, and for the most part under ground. It led to the Aventine, and was intended to provide a supply of good water to the districts between that hill and the Tiber, which had scarcely any water but that of the river. Water is still derived in one place, and I believe even in two, from this aqueduct, without most people being aware of it. It was built under ground, because the enemies sometimes advanced to the very neighbourhood of Rome, and might, therefore, easily have cut off the supply of water. Afterwards the number of aqueducts at Rome rose to fourteen. Fresh water is a real blessing to the inhabitants of the south; one must have lived there in order to comprehend that these aqueducts were not a matter of luxury. The _Aqua Marcia_ led to the Capitol; of the _Aqua Virgo_ (now Acqua di Trevi) a large _specus_ is still visible. The greatest aqueduct was that of the emperor Claudius, which was preserved as late as the eighth century of the Christian era; it might easily have been restored; its arches were taken down gradually after the restoration of Rome in the sixteenth century, because people wanted the bricks to build their houses.