mile away.

"Yes," said the Sheikh calmly, "they are terrible, these hot whirlwinds.
Their Excellencies would be glad to bathe and clear their faces and
hair from the thick dust, but there is no water save for drinking. We
have never had a worse one than this, Excellency, in our travels."

"Never," said the professor, who knelt in the sand trying to clear his
eyes from the impalpable brownish dust, "and I don't want to meet
another. This is one of the experiences of a desert journey, Frank.
Why, lad, you are turned from black to brown."

"And you the same, but from white," replied Frank, smiling.

"I suppose so. It's bad for the Hakim's white robes, too. I say,
Ibrahim, when shall we strike the river?"

"Not for many days, Excellency; but we shall halt at fountains among the
rocks."

Five days' monotonous journeying across the sandy plains, and then five
nights of travelling, with the days devoted to rest, had passed before
the river was approached at a bend which brought it near the line of
travel which the Sheikh had traced out for himself by the stars. The
way had been marked by the bones of camels, and in two places other
bones scattered here and there told their horrible tale of suffering or
attack, one skull displaying a frightful fracture that was unmistakable;
fountain after fountain had been reached, and refreshing halts had been
made where the waters gushed from some patch of rocks, to fertilise a
small extent around, supporting a few palms and prickly, stunted bushes
of acacia-like growth, before they started away again into the sand; and
in cases where the next water-hole was too far, one, two, or three
camels bore away water-skins well filled, to carry the party over the
next halting-place.

The necessity of keeping up the supply forced their guide to adopt a
zigzag mode of progression, and to make his little caravan traverse
nearly double the distance that would have been necessary could they
have taken a bee-line towards the south. But experience had taught all
travellers who journey by the desert, instead of by the great waterway
with its vast cataracts, where the pressure of the earth forced the
water springs to the surface, and naturally these were the goals for
which all tired travellers made.

There were but few incidents during a fortnight's travel, and more than
once Frank's heart sank as he pondered upon the little advance they had
made; but as the professor said, they were two wee