Sometimes it amused and sometimes it maddened him, and he rode onwards with alternate gusts of laughter and of fury, nursing his wounded wrist all the time like a mother with a sick baby.
Across the brown of the hard, pebbly desert there had been visible for some time a single long, thin, yellow streak, extending north and south as far as they could see.

It was a band of sand not more than a few hundred yards across, and rising at the highest to eight or ten feet.
But the prisoners were astonished to observe that the Arabs pointed at this with an air of the utmost concern, and they halted when they came to the edge of it like men upon the brink of an unfordable river.
It was very light, dusty sand, and every wandering breath of wind sent it dancing into the air like a whirl of midges.

The Emir Abderrahman tried to force his camel into it, but the creature, after a step or two, stood still and shivered with terror.

The two chiefs talked for a little, and then the whole caravan trailed off with their heads for the north, and the streak of sand upon their left.
"What is it ?" asked Belmont, who found the dragoman riding at his elbow.
"Why are we going out of our course ?" "Drift sand," Mansoor answered.

"Every sometimes the wind bring it all in one long place like that.