Entering a transverse valley, it finds a way (which is still very imperfectly known) through the numerous ridges of the Himalaya to the plain at its southern base, on which it debouches about thirty miles above Attock.

It is difficult to say at what exact point it crossed the Persian frontier, but probably at least the first 700 miles of its course were through territory not Persian.

From Attock to the sea the Indus is a noble river.

It runs for 900 miles in a general direction of S.S.W.through the plain in one main stream (which is several hundred yards in width), while on its way it throws off also from time to time small side streamlets, which are either consumed in irrigation or rejoin the main channel.

A little below Tatta its Delta begins--a Delta, however, much inferior in size to that of the Nile.