Harry had trained his glasses upon the approaching machine, and from time to time announced the movements of the pilot and his passenger.
"He's almost overhead now," reported the lad. "The passenger is trying to fix another batch of arrows, I believe! Get ready for him!"
Jimmie determined to execute a daring maneuver to throw the pursuer off his trail. Calling to the boys to secure themselves with safety belts, he buckled on his own, then gave the levers a touch.
With the first impulse of the engine the Grey Eagle leaped ahead. Jimmie threw his whole weight on the lever controlling the horizontal rudders, and the machine climbed up at an angle that threatened to unseat the passengers. Apparently his motive was to ram the other machine.
With a quick movement he threw off the power, altering the rudders at the same moment. The Grey Eagle began to drop backwards toward the earth. Again Jimmie manipulated a lever and the rudders guided the craft into a complete backward somersault that brought them some distance to the rear of the other. Gasping at the sudden movement the boys stared about.
A roar came to their ears from below. Mingled with a cloud of thick black smoke they could see pieces of timbers falling where once had been the railroad bridge. The missile had passed them, thanks to Jimmie.
"The train!" gasped Jimmie, with a startled look at his friends.