The cadet waved his hand over the side of the fuselage--the recognized signal for the mechanics to remove the skids. Slowly at first, then gradually gaining speed, the Dromedary ambled across the ground, the propeller raising enormous clouds of dust, while small spurts of warm castor oil were ejected from the engine and blown back by the wind into the goggled face of the young pilot. Unable to gauge the biplane's speed, Derek held on until the instructor bellowed plaintively into his ear: "Get a move on, my lad; you're in a 'bus, not trundling a hoop along a road." Thus stimulated Daventry actuated the elevating-lever. Submissively the huge machine parted company with mother earth, so gently and evenly that it was only the change of vibration that told Derek of the fact. "By Jove!" muttered the lad. "I'm up now. Wonder how I'll get down again." Ahead, owing to the tilt of the blunt nose of the machine, he could see nothing but sky and fleecy clouds. It was only when he glanced over the side that he saw the hangars already dwarfed to the size of dolls' houses. The ecstacy of it all! To find himself controlling a swift aerial steed, to handle the responsive joystick, and to make the machine turn obediently to a slight pressure on the rudder-bar. Anxiety was cast to the winds. The sheer lust of flight in the exhilarating atmosphere gripped the cadet in its entirety. Again Derek leant over and surveyed the now distant earth from a height of three thousand feet, as shown by the altimeter. But for the furious rush of wind there was little sensation of speed, nor was he in any degree affected by the height above the ground. Without the faintest inconvenience he could watch the vast panorama beneath him, and distinguish white ribands as dusty roads, and the variegated patches of green denoting cultivated fields, meadows, and clumps of trees. Although previously warned of the fact, he was nevertheless surprised at the aspect of the ground, which presented the appearance of a flat plain. Hills--and there were plenty in the vicinity of Averleigh--had visually ceased to exist. Suddenly the pleasing prospect was interrupted by a disconcerting movement of the hitherto docile biplane. Akin to the sensation of being in a lift that is unexpectedly put in motion, Derek found himself dropping, while at the same time the clinometer, an instrument for indicating the heel of the aerial craft, showed a dip of thirty-five degrees. Instinctively Derek sought to regain a state of stability, but the joy-stick seemed powerless to essay the task. For a brief instant Daventry wondered what was happening. It seemed to him that, notwithstanding his efforts, the 'bus was dropping earthwards, and that the tractive powers of the prop. were futile. Then, with a series of sharp jerks, the 'plane regained its normal state of progression.