I gasped.  What did it mean?  Did it mean in some way another accident to Norton—­perhaps fatal this time?  Why had Kennedy allowed him to try it to-day when there was even a suspicion that some nameless terror was abroad in the air?  Quickly I turned to see if Norton was all right.  Yes, there he was, circling above us in a series of wide spirals, climbing up, up.  Now he seemed almost to stop, to hover motionless.  He was motionless.  His engine had been cut out, and I could see his propeller stopped.  He was riding as a ship rides on the ocean.

A boy ran up the ladder to the roof.  Kennedy unfolded the note and shoved it into my hands.  It was from the operator.

“Wireless out of business again.  Curse that fellow who is butting in.  Am keeping record,” was all it said.

I shot a glance of inquiry at Kennedy, but he was paying no attention now to anything but Norton.  He held his watch in his hand.

“Walter,” he ejaculated as he snapped it shut, “it has now been seven minutes and a half since he stopped his propeller.  The Brooks Prize calls for five minutes only.  Norton has exceeded it fifty per cent.  Here goes.”

With his hat in his hand he waved three times and stopped.  Then he repeated the process.

At the third time the aeroplane seemed to give a start.  The propeller began to revolve, Norton starting it on the compression successfully.  Slowly he circled down again.  Toward the end of the descent he stopped the engine and volplaned, or coasted, to the ground, landing gently in front of his hangar.

A wild cheer rose into the air from the crowd below us.  All eyes were riveted on the activity about Norton’s biplane.  They were doing something to it.  Whatever it was, it was finished in a minute and the men were standing again at a respectful distance from the propellers.  Again Norton was in the air.  As he rose above the field Kennedy gave a last glance at his ondometer and sprang down the ladder.  I followed closely.  Back of the crowd he hurried, down the walk to the entrance near the railroad station.  The man in charge of the Pinkertons was at the gate with two other men, apparently waiting.

“Come on!” shouted Craig.

We four followed him as fast as we could.  He turned in at the lane running up to the yellow house, so as to approach the barn from the rear, unobserved.

“Quietly, now,” he cautioned.

We were now at the door of the barn.  A curious crackling, snapping noise issued.  Craig gently tried the door.  It was bolted on the inside.  As many of us as could threw ourselves like a human catapult against it.  It yielded.

Inside I saw a sheet of flame fifteen or twenty feet long—­it was a veritable artificial bolt of lightning.  A man with a telescope had been peering out of the window, but now was facing us in surprise.

“Lamar,” shouted Kennedy, drawing a pistol, “one motion of your hand and you are a dead man.  Stand still where you are.  You are caught red-handed.”