This sudden motion of the great winged man–made bird so terrified the ponies of the rebels, for a detachment of the revolutionists they were, that the little creatures became uncontrollable and dashed off in every direction. All the shouts and curses of their owners failed to rally them, and after running a few hundred feet the aeroplane soared aloft, unharmed except for a few bullet holes in her planes. The sensation was a delightful one. As the bumping motion caused by the run over the ground ceased, it felt to Jack as if he was riding on billows of the softest cloud fabric. He had not the slightest fear and watched Lieut. Sancho with interest while he manipulated the various levers and wheels. As they flew the officer showed Jack just how the air craft worked. He even let him take the wheel for an instant, and declared that the boy acquitted himself like a born airman. The aeroplane being fitted with stability devices of automatic construction, it was, of course, possible to do this, where in another sort of air machine it might have been dangerous to allow a novice to handle the control wheel. As they rose higher Jack cast a look back. The country was stretched out like a panorama beneath him. On the plain he could see the detachment of revolutionaries galloping about trying in vain to reform their disorganized ranks. “See if you can point out this wonderful valley of yours,” said Lieut. Diaz presently. Before long Jack sighted the hidden valley which had been the scene of his thrilling climb. He recognized it by the tumbling cascade of water that thundered whitely into the Pool of Death. “There! There it is yonder!” he cried. “It is indeed a wonderful place,” commented Lieut. Sancho as they hovered like a huge eagle above the cliff–walled valley. “If one did not know of it, it would be impossible to discover it.” “Except by airship or by the Pool of Death,” said Jack. Lieut. Sancho finally spied a good place to land and the aeroplane was dropped rapidly into the valley. It settled with hardly a jar or a quiver, much to Jack’s astonishment, who had feared it would collide with the ground with considerable force. “Well, I don’t see anything of your friend Alvarez,” commented Lieut. Sancho, looking about him after they had left the aeroplane. “Nor do I,” commented Jack in a rather astonished tone, “what can have become of him?” “Possibly he has escaped in some way. He is as cunning a fox as there is in the country,” declared Lieut. Diaz. Jack shook his head, however. “There is no chance that he could have gotten out unless he followed my path and I think he was not active enough for that.” “Which way did you get out?” inquired Lieut. Diaz. “Where is that cliff you told us about?”