Bart was about to shout to his father in front, or to his roustabout
friend, whom he expected must be somewhere near by this time, when his
captive gave a jerk, tore one arm free, and whirled the other aloft.

His hand clenched the implement he had used to pry away the bars, and
Bart now saw what it was.

The object the mysterious robber was utilizing for burglarious
purposes, was the signal flag used at the switch shanty where Lem Wacker
had been doing substitute duty that day.

It consisted of a three foot iron rod, sharpened at the end. At the
blunt end the strip of red flag was wound, near the sharp end the
conventional track torpedo was held in place by its tin strap.

"Lemme go"; again growled the man.

"Never!" declared Bart.

The man's left arm was free, and he swung the iron rod aloft. Bart saw
it descending, aimed straight for his head. If he held on to the man he
could scarcely evade it.

He let go his grip, ducked, made a pass to grasp the burglar's ankle,
but missed it.

An explosion, a sharp flare, a keen shock filled the air, and before
Bart could grip the man afresh he had sprung from the platform and
vanished.