“Monsieur is mad to start in the noon,” grumbled Batouch.  “But Monsieur is not like Madame.  He may live in the desert till he is old and his hair is grey as the sand, but he will never be an Arab in his heart.”

“Why, Batouch-ben-Brahim?”

“He cannot rest.  To Madame the desert gives its calm, but to Monsieur—­” He did not finish his sentence.  In front Domini and Androvsky had put their horses to a gallop.  The sand flew up in a thin cloud around them.

“Nom d’un chien!” said Batouch, who, in unpoetical moments, occasionally indulged in the expletives of the French infidels who were his country’s rulers.  “What is there in the mind of Monsieur which makes him ride as if he fled from an enemy?”

“I know not, but he goes like a hare before the sloughi, Batouch-ben Brahim,” answered Ali, gravely.

Then they sent their horses on in chase of the cloud of sand towards the southwest.

About four in the afternoon they reached the camp at Mogar.

As they rode in slowly, for their horses were tired and streaming with heat after their long canter across the sands, both Domini and Androvsky were struck by the novelty of this halting-place, which was quite unlike anything they had yet seen.  The ground rose gently but continuously for a considerable time before they saw in the distance the pitched tents with the dark forms of the camels and mules.  Here they were out of the sands, and upon hard, sterile soil covered with small stones embedded in the earth.  Beyond the tents they could see nothing but the sky, which was now covered with small, ribbed grey clouds, sad-coloured and autumnal, and a lonely tower built of stone, which rose from the waste at about two hundred yards from the tents to the east.  Although they could see so little, however, they were impressed with a sensation that they were on the edge of some vast vision, of some grandiose effect of Nature, that would bring to them a new and astonishing knowledge of the desert.  Perhaps it was the sight of the distant tower pointing to the grey clouds that stirred in them this almost excited feeling of expectation.

“It is like a watch-tower,” Domini said, pointing with her whip.  “But who could live in such a place, far from any oasis?”

“And what can it overlook?” said Androvsky.  “This is the nearest horizon line we have seen since we came into the desert.”

“Yes, but——­”

She glanced at him as they put their horses into a gentle canter.  Then she added: 

“You, too, feel that we are coming to something tremendous, don’t you?”

Her horse whinnied shrilly.  Domini stroked his foam-flecked neck with her hand.

“Abou is as full of anticipation as we are,” she said.  Androvsky was looking towards the tower.

“That was built for French soldiers,” he said.  A moment afterwards he added: 

“I wonder why Batouch chose this place for us to camp in?”