used 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. To-morrow, if a wind comes, perhaps there
will not be one grain left, but all will be carried up into the air
again. An Arab will sometimes have to go fifty or a hundred miles to go
round a drift. Suppose he tries to cross, his camel breaks its legs,
and he himself is sucked in and swallowed."

"How long will this be?"

"No one can say."

"Well, Cochrane, it's all in our favour. The longer the chase the
better chance for the fresh camels!" and for the hundredth time he
looked back at the long, hard skyline behind them. There was the great,
empty, dun-coloured desert, but where the glint of steel or the twinkle
of white helmet for which he yearned?

And soon they cleared the obstacle in their front. It spindled away
into nothing, as a streak of dust would which has been blown across an
empty room. It was curious to see that when it was so narrow that one
could almost jump it, the Arabs would still go for many hundreds of
yards rather than risk the crossing. Then, with good, hard country
before them once more, the tired beasts were whipped up, and they ambled
on with a double-jointed jogtrot, which set the prisoners nodding and
bowing in grotesque and l