The source is to the east of the great Zagros chain; and it might have been supposed that the waters would necessarily flow northward or eastward, towards Lake Urumiyeh, or towards the Caspian.

But the Legwin river, called even at its source the Zei or Zab, flows from the first westward, as if determined to pierce the mountain barrier.

Failing, however, to find an opening where it meets the range, the Little Zab turns south and even south-east along its base, till about 25 or 30 miles from its source it suddenly resumes its original direction, enters the mountains in lat.
36 deg.

20', and forces its way through the numerous parallel ranges, flowing generally to the S.S.W., till it debouches upon the plain near Arbela, after which it runs S.W.and S.W.

by S.to the Tigris.