EUPHRATES (in the oriental languages, Frat, Phrat, or Forat) is the largest river in western Asia, and, with the Tigris, forms the most important river-system of that quarter of the world. It has its source in the heart of Armenia in two branches—the Kara Su and the Murad, of which the former rises 25 m., n.e. of the town of Erzerum, and flows s.w. to a point 10 m. n. of Keban' Ma'den, where it is met by the Murad, which rises on the southern slope of Ala Tagh, and flows w.s.w. to the point of conflu ence. From Keban' Ma'den, the E. flows in a general southern direction, with a ten dency, however, to struggle westward towards the Mediterranean. In this part of its course, it breaks through the Taurus, and flows among the mountains for 45 m., emerg ing at Sumeisat, whence it continues navigable to the sea—a distance of 1195 m.—and passing Bir, at which point it is 028 ft. above the level of the Mediterranean, and 100 m. distant from its nearest shore. After passing Samosta, it changes its direction, and flowing s., separates for a considerable distance Mesopotamia from Syria and the deserts of Syrian Arabia. Curving to the s.e., it flows on without receiving almost any tribu taries for about 700 m., until it is joined at Kurnah or Kornah by the waters of the
Tigris. From Kurnali, the river, taking the name of the Shatt-el-Arab, continues to flow in a s.e. dirvtion, until, after being united by a canal with the Karun from the mountains of Pefsia, it empties itself, by several arms, into the Persian gulf, 90 m. below Kurnah. The total length of the E. is 1600 m.; the area drained by all the waters which enter the Persian gulf by the Shatt-el-Arab, is 108,000 m.; and the volume of water discharged by it is 401,010 cubic ft. per second, or 72,910 cubic ft. more than that discharged by the Danube in the same time. The average width of the Shatt-el Arab is upwards of 600 ft.; it is navigable in mid-stream for vessels of 500 tons.
The water of the E., although muddy, is not unwholesome. Its inundations, caused by the melting of the snows, take place chiefly from the beginning of Mar. till the end of May; and in ancient times, when canals and embankments regulated these inunda tions, exercised the same beneficial effect on the country as those of the Nile on Egypt. See BABYLONIA.