But southward of Babel, for the distance of nearly three miles, there is almost an uninterrupted line of mounds, the ruins of vast edifices, collected together as in the heart of a great city. They are inclosed by earthen ramparts, the remains of a line of walls which, leaving the foot of Babel, stretched inland about two miles and a half from the present bed of the Euphrates, and then turning nearly at right angles completed the defences on the southern side of the principal buildings that mark the site of Babylon, on the eastern bank of the river. Between its most southern point and Hillah, as between Mohawill and Babel, can only be traced low heaps and embankments, scattered irregularly over the plain. It is evident that the space inclosed within this continuous rampart, could not have contained the whole of that mighty city, whose magnificence and extent were the wonder of the ancient world. The walls of Babylon, according to Herodotus, measured 120 stadia on each side, and formed a perfect square of 480 stadia, or nearly sixty miles. Several later writers have repeated his statement. Strabo and Diodorus Siculus have however reduced the circuit of the city to 385 and 360 stadia; and such, according to Clitarchus, were its dimensions when it yielded to Alexander. The existing remains within the rampart agree as little in form as in size with the descriptions of Babylon; for the city was a perfect square. Mr. Rich, in order to explain these difficulties, was the first to suggest that the vast ruin to the west of the Euphrates, called the Birs Nimroud, should be included within the limits of Babylon. There is no doubt that, by imagining a square large enough to include the smaller mounds scattered over the plains from Mohawill to below Hillah on one side of the river, and the Birs Nimroud at its south-western angle on the other, the site of a city of the dimensions attributed to Babylon might be satisfactorily determined. But then it must be assumed, that neither the outer wall nor the ditch so minutely described by Herodotus ever existed. According to the united testimony of ancient authors, the city was divided by the Euphrates into two parts. The principal existing ruins are to the east side of the river; there are very few remains to the west, between Hillah and the Birs Nimroud. Indeed, in some parts of the plain, there are none at all. This fact might, to a certain extent, be explained in the following manner. To this day the Euphrates has a tendency to change its course and to lose itself in marshes _to the west_ of its actual bed. We find that the low country on that side was subject to continual inundations from the earliest periods, and that, according to a tradition, Semiramis built embankments to restrain the river.