“We must find him,” exclaimed Kennedy.  “I want him to make a flight to-day.  His contract calls for it.”

“I can do it, Kennedy,” asserted Norton.  “See, I’m all right.”

He picked up two pieces of wire and held them at arm’s length, bringing them together, tip to tip, in front of him just to show us how he could control his nerves.

“And I’ll be better yet by this afternoon,” he added.  “I can do that stunt with the points of pins then.”

Kennedy shook his head gravely, but Norton insisted, and finally Kennedy agreed to give up wasting time trying to locate Humphreys.  After that he and Norton had a long whispered conference in which Kennedy seemed to be unfolding a scheme.

“I understand,” said Norton at length, “you want me to put this sheet-lead cover over the dynamo and battery first.  Then you want me to take the cover off, and also to detach the gyroscope, and to fly without using it.  Is that it?”

“Yes,” assented Craig.  “I will be on the roof of the grand stand.  The signal will be three waves of my hat repeated till I see you get it.”

After a quick luncheon we went up to our vantage-point.  On the way Kennedy had spoken to the head of the Pinkertons engaged by the management for the meet, and had also dropped in to see the wireless operator to ask him to send up a messenger if he saw the same phenomena as he had observed the day before.

On the roof Kennedy took from his pocket a little instrument with a needle which trembled back and forth over a dial.  It was nearing the time for the start of the day’s flying, and the aeroplanes were getting ready.  Kennedy was calmly biting a cigar, casting occasional glances at the needle as it oscillated.  Suddenly, as Williams rose in the Wright machine, the needle swung quickly and pointed straight at the aviation field, vibrating through a small area, back and forth.

“The operator is getting his apparatus ready to signal to Williams,” remarked Craig.  “This is an apparatus called an ondometer.  It tells you the direction and something of the magnitude of the Hertzian waves used in wireless.”

Five or ten minutes passed.  Norton was getting ready to fly.  I could see through my field glass that he was putting something over his gyroscope and over the dynamo, but could not quite make out what it was.  His machine seemed to leap up in the air as if eager to redeem itself.  Norton with his white-bandaged head was the hero of the hour.  No sooner had his aeroplane got up over the level of the trees than I heard a quick exclamation from Craig.

“Look at the needle, Walter!” he cried.  “As soon as Norton got into the air it shot around directly opposite to the wireless station, and now it is pointing—­”

We raised our eyes in the direction which it indicated.  It was precisely in line with the weather-beaten barn.