After a century and ft half it began to recede rather than to advance.
End the hills again recede and the plain widens to include Dweru.
Islands are frequent; the banks recede and become lower until, after 50 m., they stand almost level with the water.
It has no sharp boundary, its brightness diminishes rapidly as we recede from the limb, and such structure as it shows consists of long streaks or filaments extending outwards from the limb in broad curved sweeps.
The first two predominate earlier, and gradually recede before the last-named.