After climbing a thousand feet, they made a number of circuits of the field. Then Stanley throttled the motor and dipping the ship down at a steep angle, began the glide back to the landing-place. The propeller moved so slowly that the blades could easily be distinguished, and the wind shrieked through the wires with a shrill wail. They levelled off at a few feet above the ground, and after skimming along a short distance, touched so gently that there was scarcely any shock; after that they slowed down and rolled up to the dead-line from which they had started. The course of instruction continued daily, and under Stanley’s capable guidance Ted learned rapidly. When he had had six hours in the air he could fly the ship in a manner satisfactory to his teacher; so Stanley took it upon himself to include a few of the more commonly used stunts in the course. For this purpose, however, they always went some distance from the field, where they were safe from the observation from below of the officers in charge. “I am going to show you a new one to-day,” Stanley said one afternoon, as they were taking their places for the flight. “Be doubly sure the belt is fastened; you will need it for once.” “I can stand anything you can,” Ted replied. “Go as far as you like.” Soon they were leaving the field behind, mounting as they soared into the distance. The aneroid needle pointed to two thousand, then three, four, five, and finally six thousand feet. Ted had never been so high before in the plane, and the earth below seemed new and strange. The patches of woods looked like clusters of dark, green dots, and the fields reminded him of the squares of a checker-board. Banks of white, fluffy clouds rolled past, their upper edges tinted with glowing silver by the brilliant sunlight. Stanley shut down the engine. “Is everything all right?” he called back. “Yes!” “I am going into a whip-stall. Be sure your belt is tight.” He opened wide the throttle and nosed the plane down so that they attained a terrific speed; then he suddenly pulled it almost straight upward and shut off the engine. For a moment the ship seemed to stand still in the air in an upright position; then it whipped downward with tremendous force, sliding on the tail. Ted felt himself raised off his seat, but, thank heaven, the belt held, or he would have remained in mid-air while the plane hurtled away from beneath him. After falling some little distance Stanley again turned on the power and they swung out of the dive and levelled off gracefully. But at that instant a burst of smoke was swept back by the blast of the propeller. The engine slackened its speed and a series of sharp, pistol-like reports came from the exhausts. Ted was seized with consternation, for a thin streamer of flame shot back from under the hood; the plane was afire.