and fill them up like water raised by a pump, and then when they leave those regions and rush back hither, they again fill the hollows here, and when these are filled, flow through subterranean channels and find their way to their several places, forming seas, and lakes, and rivers, and springs. Thence they again enter the earth, some of them making a long circuit into many lands, others going to a few places and not so distant; and again fall into Tartarus, some at a point a good deal lower than that at which they rose, and others not much lower, but all in some degree lower than the point from which they came. And some burst forth again on the opposite side, and some on the same side, and some wind round the earth with one or many folds like the coils of a serpent, and descend as far as they can, but always return and fall into the chasm. The rivers flowing in either direction can descend only to the centre and no further, for opposite to the rivers is a precipice.
Now these rivers are many, and mighty, and diverse, and there are four principal ones, of which the greatest and outermost is that called Oceanus, which flows round the earth in a circle; and in the opposite direction flows Acheron, which passes under the earth through desert places into the Acherusian lake: this is the lake to the shores of which the souls of the many go when they are dead, and after waiting an appointed time, which is to some a longer and to some a shorter time, they are sent back to be born again as animals. The third river passes out between the two, and near the place of outlet pours into