Paragraph 49 49. These are the native Scythian rivers which join to swell its stream, while from the Agathyrsians flows the Maris and joins the Ister, and from the summits of Haimos flow three other great rivers towards the North Wind and fall into it, namely Atlas and Auras and Tibisis. Through Thrace and the Thracian Crobyzians flow the rivers Athrys and Noes and Artanes, running into the Ister; and from the Paionians and Mount Rhodope the river Kios, 48 cutting through Haimos in the midst, runs into it also. From the Illyrians the river Angros flows Northwards and runs out into the Triballian plain and into the river Brongos, and the Brongos flows into the Ister; thus the Ister receives both these, being great rivers. From the region which is above the Ombricans, the river Carpis and another river, the Alpis, flow also towards the North Wind and run into it; for the Ister flows in fact through the whole of Europe, beginning in the land of the Keltoi, who after the Kynesians dwell furthest towards the sun-setting of all the peoples of Europe; and thus flowing through all Europe it falls into the sea by the side of Scythia.
Paragraph 50 50. So then it is because these which have been named and many others join their waters together, that Ister becomes the greatest of rivers; since if we compare the single streams, the Nile is superior in volume of water; for into this no river or spring flows, to contribute to its volume. And the Ister flows at an equal level always both in summer and in winter for some such cause as this, as I suppose:—in winter it is of the natural size, or becomes only a little larger than its nature, seeing that this land receives very little rain in winter, but constantly has snow; whereas in summer the snow which fell in the winter, in quantity abundant, melts and runs from all parts into the Ister. This snow of which I speak, running into the river helps to swell its volume, and with it also many and violent showers of rain, for it rains during the summer: and thus the waters which mingle with the Ister are more copious in summer than they are in winter by about as much as the water which the Sun draws to himself in summer exceeds that which he draws in winter; and by the setting of these things against one another there is produced a balance; so that the river is seen to be of equal volume always.