"They are trying to hit the engine," cried Harry the next minute as a
third bullet whistled unpleasantly near.

"Or more likely the fuel tank," corrected Frank.

"The cowards," cried the indignant Harry.

Whatever the intentions of the men in the auto had been, however, they
came to nothing, for a sudden turn in the road compelled them to turn
off almost at right angles from the course taken by the air-craft. As
a last farewell bullet whizzed harmlessly by, Harry, through the
glasses, saw a familiar figure spring upright in the tonneau and shake
his fist upward in impotent rage.

It was Luther Barr.

His features swam in the field of the glasses as clear as if he had
been standing ten feet away. His lean, mean face was convulsed and
gray with rage. He seemed to be furiously berating Sanborn, whose
rifle, Harry now observed, was equipped with a silencer. With this
appliance bullets can be fired from an ordinary rifle without even as
much sound as an air-gun. It is a murderous device.

But now the boys' attention was imperatively centered on the rival
aeroplane. The wind had suddenly become gusty and the Buzzard was
behaving in a most eccentric manner. To the boys several times it
looked as if Malvoise had lost entire control of her.

The tents and aeroplane sheds of Mineola were now plainly in view, and