At full speed he overtakes the ordinary winds.

As one of the results of the rapid advance, the face of the landscape underwent a change.

The Jebel stretched along the western horizon, like a pale-blue ribbon.

A tell, or hummock of clay and cemented sand, arose here and there.

Now and then basaltic stones lifted their round crowns, outposts of the mountain against the forces of the plain; all else, however, was sand, sometimes smooth as the beaten beach, then heaped in rolling ridges; here chopped waves, there long swells.