Suddenly the Moon Bird, a machine of good utility, but, as Andy knew, of little lasting power, made a decided spurt, passed the Racing Star, and at a distance of half a mile got fairly abreast of the lake. It was here that Duske met his Waterloo. Hitherto he had maintained practically a steady course. More than once Andy had got near enough to this rival to hear the loud gasping of the tube exhausts drown out the sharp chug-chug of the motor. Suddenly Duske made a sharp turn.
An appalling climax followed. In consternation and suspense Andy watched aerial evolutions that fairly dizzied him.
“He is lost!” breathed Andy, a-thrill.
In an instant he recalled what Mr. Morse had told him of the unfinished model that Duske and his crowd had stolen from him. The inventor had explained to Andy that while the suction principle involved in the rudder construction was unique and bound to increase speed, there should have been added automatic caps to close the rear ends of the suction tubes where a curve was attempted.
Of this Duske evidently knew nothing. The moment he turned the machine, however, there was a whirl. The aeroplane described a dive, then a somersault. Its lateral planes collapsed, and, tipping from side to side, it began to descend with frightful velocity.
Once it half righted, balanced, went over again, and, fifty feet from the ground, shot clear of a little islet, and went down in the water of the lake, a wreck, first spilling Duske out.
“He is killed or stunned!” exclaimed Andy.
The boy aviator saw the other airships forging ahead, indifferent to the accident. Minutes counted in the sixty-mile race to Springfield and back to the starting point, but Andy was humane. He saw clearly that, if alive, the half-submerged Duske would be suffocated in a few minutes’ time.
“I can’t leave him to die,” murmured Andy, and sent the Racing Star on a sharp slant, landing on the island.
Andy was soon out of the airship. He waded to the spot where Duske lay, and dragged him bodily up on dry land. As he turned him on his face, Andy knew from its purple hue, the lifeless limbs and choked gasps of the man, that another minute in the water would have been his last.