“It’s air sickness! Seize that controlling handle and do just as I tell you. All our lives may depend on it!” CHAPTER XIX. THE BATTLE AT THE SCHOOLHOUSE. Air sickness! With the words there flashed through Jack’s mind a recollection of having read somewhere about that strange malady of the upper regions which sometimes seizes airmen, paralyzing temporarily their every faculty. While the thought was still in his mind he had seized the wheel and awaited the next orders from Lieut. Sancho, who was holding the unconscious form of Lieut. Diaz in the machine. “Push that lever forward—so! Now a twist of your wheel to the left. _Bueno!_ You are a born airman.” Jack wished he could think so, too. From sheer nervousness the sweat stood out upon him, his hands shook and his pulses throbbed. But the consciousness that all their lives depended upon his keeping cool and obeying orders steadied him. By a supreme effort he mastered his jumping nerves and obeyed the lieutenant’s orders implicitly. To his actual surprise, for he did not think it would have been so easy to handle an air craft, the winged machine righted itself as he manipulated the lever and wheel. Before many seconds it was driving along on an even keel once more. But in its fall it had entered the region of driving sand again. Pitilessly, like needle–pointed hailstones, the sharp grains drove about them, pricking their flesh. “Up! We must go up higher!” cried Lieut. Sancho. “Pull back that lever. Now your wheel to the right—that sets the rising warping appliances! There! That’s it! Now your foot on the engine accelerator! Good! You are an aviator already.” As Jack put the lieutenant’s commands into execution one after another the desired effect was procured. The aeroplane began to rise, fighting its way up through that inferno of yellow sand. Jack feared that at any moment his eyes would be rendered useless, but he stuck to his task without flinching. At last in the upper regions, they winged along free from the ordeal of the whirling sand spouts, but still in the grasp of the furious wind. “Can we not land?” asked Jack after a time. “Surely it would be safer.” “Safer, doubtless, once we could get to earth; but it would be madness to attempt a landing in this wind.” “Then we must stay up here till the wind subsides?” “Yes, or at least until the sand thins out. We should be blinded if we got into the thick of it, let alone the danger to our engine.” “What speed are we making?” was Jack’s next question. “About fifty miles an hour, possibly more.” “Then we may be driven miles out of our way?” “I fear that is possible. But see, Lieut. Diaz appears to be reviving. Can you reach me that medical kit?”