"There's one 'bout a mile away. We can phone for an ambulance."

"Good! Well, good-bye."

With a whirr and a buzz the boy was gone, and speedily became a speck in the sky.

In the meantime the aviation field was in an uproar. Dashing toward it had come the two leading aëroplanes. From dots in the sky no bigger than shoe buttons they speedily became manifest as two aëroplanes aquiver with speed. Blue smoke poured from their exhausts. Evidently the two aviators were straining their craft to the utmost.

"It's that Cuban woman and the young girl flyer!" yelled a man who had a pair of field glasses.

The uproar redoubled. The two aëroplanes were almost side by side as they rushed onward. Which would win the $500 race?

It was a struggle that had begun some miles back. After leaving the lake Peggy, who had held some speed in reserve while her opponent had keyed her machine to its top pitch, had gradually gained on her. But still there was a gap between the two aëroplanes.

On the return trip no car blazed the way. The speed was too great for that. For this reason smudges, or smoky fires, had been lighted to guide the flyers. At a place where it was necessary to make a slight turn Peggy made the gain that brought her almost alongside her competitor. In making the turn the monoplane flown by the Cuban aviatrix could not negotiate it at as sharp an angle as Peggy's machine, owing to its not being equipped with an equalizing, or stability device.

Now it was that Peggy tensioned up the Golden Butterfly to its full power. The engine fairly roared as the propeller blurred round. The whole fabric trembled under the strain. It seemed as if nothing made by man could stand the pressure.

But the Golden Butterfly had been built by one of the foremost young aviators in the country, and it was sound and true in every part. Peggy felt no fear of anything giving out under the strain.