“Oh, but I smell powder,” observed Leblance, sniffing.
“Powder?” repeated Mr. Dale.
“Yes. There has been some kind of an explosion here,” insisted the French engineer looking around.
Dave hurried over to the window where he had first discovered Jerry Dawson. There were a number of tall, slim ladders all about the working framework. He lifted one of these against the sill of the window aloft. Then he ran up its rounds nimbly.
“Aha!” suddenly exclaimed the young aviator.
“Found something, Dashaway?” called out Mr. King.
“Yes, sir.”
“What is it?”
For reply Dave quickly descended the ladder. He held in one hand a sooted tin disc. Its center showed a little heap of hard cinders.
“I found this on the window sill,” he explained.