"It is plain," said Ducardanoy, as they were celebrating the anniversary of their arrival at Nouvelle Saar-Louis by a dinner to their friends, "that those fellows regard us as magicians of great power, else they would have sought revenge before this."

"I don't know about that," said Bouchardy. "Everybody here is well acquainted with our story, and I'll wager that the frightened tribesmen themselves now know that there was nothing supernatural in the entertainment to which we treated them. It is the proximity of the garrison that has prevented them from taking a revenge."

"I would like another encounter with the fellows in trade or in battle," said Ducardanoy. "There would be money in it, there would be money in it." And as if in answer to his wish, there was ushered in an Arab mulatto of the giant stature that characterizes the cross of the Arab and negro. He was a messenger from the Sheik of the Mountain of Singing Sands, he said, and had come to request the professional services of the two gentlemen in the case of the Sheik's horse Sunlight, who was grievously afflicted with a corn on his right forefoot. The chiropodists opened their eyes. Everybody in Algeria had heard of the stallion Sunlight, an animal whom money could not buy, and who was said to wear shoes of gold set with precious stones.

"A corn on a horse's hoof is not the same thing as a corn on a man's foot," said Ducardanoy.

"But we can cure it, nevertheless," said Bouchardy.

"Do not interfere, Bouchardy. You know nothing of surgery of the feet," said Ducardanoy, scornfully. "I shall require more pay for curing a corn on a horse's hoof than I would in the case of a man."

"The Sheik will fill your mouth with gold," said the messenger.

The Sheik's camp was pitched in the open desert, and the men of science vainly looked about in every direction for the far-famed hill against whose western face lay an immense heap of sand that hummed and sung whenever its surface was disturbed and sent sliding downward. The Sheik was himself troubled with a bad foot, due to his imprudently wearing a pair of razor-toed patent-leather shoes presented to him by the General commanding the department, and Ducardanoy was asked to relieve him before examining the golden-shod horse.

"Where is the Mountain of Singing Sands?" asked Ducardanoy, as he finished tying the last bandage on the Sheik's foot.

"We do not always camp in one place, you know," said the Sheik; "but you will see it shortly."