is largely enriched throughout the whole of its course by the waters of tributary streams.  It is formed originally of three main branches:  the Diarbekr stream, or true Tigris, the Myafarekin River, and the Bitlis Chai, or Centrites of Xenophon, which carries a greater body than either of the other two.  From its entry on the low country near Jezireh to the termination of its course at Kurnah, it is continually receiving from the left a series of most important additions.  The chain of Zagros, which, running parallel to the two main springs, shuts in the Mesopotamian plain upon the east, abounds with springs, which are well supplied during the whole summer from its snows, and these when collected form rivers of large size and most refreshing coolness.  The principal are, the eastern Khabour, which joins the Tigris in lat. 37 deg. 12’:  the Upper Zabo which falls in by the ruins of Nimrud:  the Lower Zab, which joins some way below Kileh Sherghat:  the Adhem, which unites its waters half way between Samarah and Baghdad:  and the Diyaleh (ancient Gyndes), which is received between Baghdad and the ruins of Ctesiphon.

By the influx of these streams the Tigris continues to grow in depth and strength as it nears the sea, and becomes at last (as we have seen) a greater river than the Euphrates, which shrinks during the latter part of its course, and is reduced to a volume very inferior to that which it once boasted.  The Euphrates at its junction with the Khabour, 700 miles above Kurnah, is 400 yards wide and 18 feet deep; at Irzah or Verdi, 75 miles lower down, it is 350 yards wide and of the same depth; at Hadiseh, 140 miles below Werdi, it is 300 yards wide, and still of the same depth; at Hit, 50 miles below Hadiseh, its width has increased to 350 yards, but its depth has diminished to 16 feet; at Felujiah, 75 miles from Hit, the depth is 20 feet, but the width has diminished to 250 yards.  From this point the contraction is very rapid and striking.  The Saklawiyeh canal is given out upon the left, and some way further down the Hindiyeh branches off upon the right, each carrying, when the Euphrates is full, a large body of water.  The consequence is that at Hillah, 90 miles-below Felujiah, the stream is no more than 200 yards wide and 15 feet deep; at Diwaniyeh, 65 miles further down, it is only 160 yards wide; and at Lamlun, 20 miles below Diwaniyeh, it is reduced to 120 yards wide, with a depth of no more than 12 feet!  Soon after, however, it begins to recover itself.  The water, which left it by the Hindiyeh, returns to it upon the one side, while the Shat-el-Hie and numerous other branch streams from the Tigris flow in upon the other; but still the Euphrates never recovers itself entirely, nor even approaches in its later course to the standard of its earlier greatness.  The channel from Kurnah to El Khitr was found by Colonel Chesney to have an average width of only 200 yards, and a depth of about 18 or 19 feet, which implies a body of water far inferior