Three windows showed no sign of damage.
Nor did the fourth.

Then Mr.Finbrink chanced to glance down at the ground.

There rested the brick, the fragments of the broken bottle lying around it.
"Say, what's that?
What's that ?" ejaculated Mr.Finbrink, much puzzled.

Soon, however, he began to see light on the riddle.
His lips parted in a grin; the grin became a chuckle.
"Humph! That goes ahead of anything I ever had the brains to think up when I was a boy," laughed the man.

"That's a good one! It sounded for all the world as though someone had smashed one of my windows with a brick-bat.