He turned the indicator to zero, and was relieved to find it obey with customary quickness. In a few moments he had slowed up and stopped, when he found himself suspended above another stretch of sandy plain. Being too high to see the surface of the plain distinctly he dropped down a few hundred feet to a lower level, where he discovered he was surrounded by billows of sand as far as his eye could reach.
"It's a desert, all right," was his comment; "perhaps old Sahara herself."
He started the machine again towards the east, and at a more moderate rate of speed skimmed over the surface of the desert. Before long he noticed a dark spot ahead of him which proved to be a large body of fierce looking men, riding upon dromedaries and slender, spirited horses and armed with long rifles and crookedly shaped simitars.
"Those fellows seem to be looking for trouble," remarked the boy, as he glided over them, "and it wouldn't be exactly healthy for an enemy to get in their way. But I haven't time to stop, so I'm not likely to get mixed up in any rumpus with them.
However, the armed caravan was scarcely out of sight before Rob discovered he was approaching a rich, wooded oasis of the desert, in the midst of which was built the walled city of Yarkand. Not that he had ever heard of the place, or knew its name; for few Europeans and only one American traveler had ever visited it. But he guessed it was a city of some importance from its size and beauty, and resolved to make a stop there.
