ing, how his father was doing. Mr. Swift was still in a semi-conscious condition, but he recognized Tom, when the youth stood at his bedside.
"Don't worry about me, son," said the brave old inventor, as he took Tom's hand. "I'll be all right. Go ahead and get ready for the race. I want you to win!"
Tears came into Tom's eyes. Would his father be well enough to allow him to take part in the big event? He feared not.
By daylight it was seen that quite a hole had been burned in the aeroplane shed. Tom and Mr. Damon, accompanied by Mr. Jackson, walked 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.
