Babylon, the capital of the nations of Chaldæa, long enjoyed the greatest celebrity of all cities throughout the whole world: and it is from this place that the remaining parts of Mesopotamia and Assyria received the name of Babylonia. The circuit of its walls, which were two hundred feet in height, was sixty miles. These walls were also fifty feet in breadth, reckoning to every foot three fingers’ breadth beyond the ordinary measure of our foot. The river Euphrates flowed through the city, with quays of marvellous workmanship erected on either side. The temple there[530] of Jupiter Belus[531] is still in existence; he was the first inventor of the science of Astronomy. In all other respects it has been reduced to a desert, having been drained of its population in consequence of its vicinity to Seleucia,[532] founded for that purpose by Nicator, at a distance of ninety miles, on the confluence of the Tigris and the canal that leads from the Euphrates. Seleucia, however, still bears the surname of Babylonia: it is a free and independent city, and retains the features of the Macedonian manners. It is said that the population of this city amounts to six hundred thousand, and that the outline of its walls resembles an eagle with expanded wings: its territory, they say, is the most fertile in all the East. The Parthi again, in its turn, founded Ctesiphon,[533] for the purpose of drawing away the population of Seleucia, at a distance of nearly three miles, and in the district of Chalonitis; Ctesiphon is now the capital of all the Parthian kingdoms. Finding, however, that this city did not answer the intended purpose, king Vologesus[534] has of late years founded another city in its vicinity, Vologesocerta[535] by name. Besides the above, there are still the following towns in Mesopotamia: Hipparenum,[536] rendered famous, like Babylon, by the learning of the Chaldæi, and situate near the river Narraga,[537] which falls into the Narroga, from which a city so called has taken its name. The Persæ destroyed the walls of Hipparenum. Orchenus also, a third place of learning of the Chaldæi, is situate in the same district, towards the south; after which come the Notitæ, the Orothophanitæ, and the Grecichartæ.[538] From Nearchus and Onesicritus we learn that the distance by water from the Persian Sea to Babylon, up the Euphrates, is four hundred and twelve miles; other authors, however, who have written since their time, say that the distance to Seleucia is four hundred and forty miles: and Juba says that the distance from Babylon to Charax is one hundred and seventy-five. Some writers state that the Euphrates continues to flow with an undivided channel for a distance of eighty-seven miles beyond Babylon, before its waters are diverted from their channel for the purposes of irrigation; and that the whole length of its course is not less than twelve hundred miles. The circumstance that so many different authors have treated