Finally Tishmak brought his dromedary to a halt beside a huge boulder. He motioned for the others to follow suit.

“We’ll stop here for the night,” announced Fekmah, after conversing with the guide. “But we must be up very early in morning and get on way to mountains.”

That night everyone slept soundly, anxious to refresh themselves thoroughly for the tiresome march through the Ahaggars.

“Let’s go,” urged Joe, as he dressed the next morning at dawn. “We can’t get to those hidden riches any too soon for me.”

Mr. Holton laughed unwillingly.

“Who ever heard of fast traveling in the mountains?” he asked. “If we make ten or fifteen miles in a day we’ll be lucky.”

“There are stretches of smooth country, though,” Dr. Kirshner put in. “And when we get to the central plateau of the Ahaggars, it won’t be so hard to cover territory.”

A breakfast of limited food but a bountiful supply of water was prepared by Mr. Lewis, and then camp was broken.

In the early-morning light the peaks ahead looked pale purple, but, said Fekmah, this color would gradually change to mauve and blue as the sunlight became more radiant.