They had now reached such a tremendous height that the city looked like a speck on the desert beneath them. Knowing he must act quickly, Rob seized the dangling left arm of the unconscious Turk and raised it until he could reach the dial of the traveling machine. He feared to unclasp the machine just then, for two reasons: if it slipped from his grasp they would both plunge downward to their death; and he was not sure the machine would work at all if in any other position than fastened to the left wrist.

Rob determined to take no chances, so he left the machine attached to the Turk and turned the indicator to zero and then to "East," for he did not wish to rejoin either his enemies the Turks or his equally undesirable friends the Tatars.

After traveling eastward a few minutes he lost sight of the city altogether; so, still clinging to the body of the Turk, he again turned the indicator and began to descend. When, at last, they landed gently upon a rocky eminence of the Kuen-Lun mountains, the boy's strength was almost exhausted, and his limbs ached with the strain of clinging to the Turk's body.

His first act was to transfer the traveling machine to his own wrist and to see that his other electrical devices were safely bestowed in his pockets. Then he sat upon the rock to rest until the Turk recovered consciousness.

Presently the fellow moved uneasily, rolled over, and then sat up and stared at his surroundings. Perhaps he thought he had been dreaming, for he rubbed his eyes and looked again with mingled surprise and alarm. Then, seeing Rob, he uttered a savage shout and drew his dagger.

Rob smiled and pointed the electric tube at the man, who doubtless recognized its power, for he fell back scowling and trembling.

"This place seems like a good jog from civilization," remarked the boy, as coolly as if his companion could understand what he said; "but as your legs are long and strong you may be able to find your way. It's true you're liable to starve to death, but if you do it will be your own misfortune and not my fault."

The Turk glared at him sullenly, but did not attempt to reply.

Rob took out his box of tablets, ate one of them and offered another to his enemy. The fellow accepted it ungraciously enough, but seeing Rob eat one he decided to follow his example, and consumed the tablet with a queer expression of distrust upon his face.

"Brave man!" cried Rob, laughingly; "you've avoided the pangs of starvation for a time, anyhow, so I can leave you with a clear conscience."