through the place.

"And you say the fire broke out right after you had seen the mysterious
airship hovering over the house?" asked the eccentric man.

"Well, not exactly after," answered Tom, "but within an hour or so. Why
do you ask?"

But Mr. Damon did not answer. Something on the floor of the shed, amid a
pile of blackened and charred pieces of wood, attracted his attention.
He stooped over and picked it up.

"Is this yours?" he asked Tom.

"No. What is it?"

The object looked like a small iron ball, with a tube about half an inch
in diameter projecting slightly from it. Tom took it'.

"Why, it looks like an infernal machine or a dynamite bomb," he said. "I
wonder where it came from? Guess I'd better drop it in a pail of water.
Maybe Eradicate found it and brought it here. I never saw it before. Mr.
Jackson, please hand me that pail of water. We'll soak this bomb."

"There is no need," said Mr. Damon, quietly. "It is harmless now. It has
done its work. It was that which set fire to your shed, and which caused
the stifling fumes."

"That?" cried Tom.