the school building vibrate. The old tower the janitor spoke of was a tall, square affair, at one corner of the building. It was for ornamental purposes only, though it contained a large clock, and there was a winding stair in it that gave access to the mechanism.
A white screen was adjusted and moving pictures thrown upon it. The first series was that of battleships in practice evolutions and as the smoke rolled from the muzzles of the big guns a man behind the scenes beat a bass drum, to simulate the distant roar of the ordnance.
The audience watched one great ship as it came into view on the screen. A broadside was fired, and, as the white smoke rolled out there came a tremendous concussion that shook the entire school.
"He must have busted the drum that time," thought Bart.
An instant later there came a terrifying crash so near at hand that everyone knew it was not the sound of the drum, nor their excited imagination. Nor was it the noise of the wind.
Then, down through one corner of the auditorium, fortunately in a place where no one was seated, crashing through the ceiling, came a mass of brick and mortar.
Before the echoes of that had died away there
