found that oil and chemicals had been put on them to cause a dense smoke.
"I think it was the work of those fellows who are after my camera," replied the young inventor. "They are evidently watching me, and when they saw us all go off in the airship they thought probably that the coast was clear."
"But why should they start a fire?"
"I don't know, but probably to create a lot of smoke, and excitement, so that they could search, and not be detected. Maybe the fellow after he found that the camera was gone, wanted to draw those in the house out to the shop, so he could have a clear field to search in my room for any drawings that would give him a clew as to how my machine works. They certainly did not want to burn the shop, for that pile of rags could have smouldered all day on the concrete floor, without doing any harm. Robbery was the motive, I think."
"The police ought to be notified," declared Mr. Nestor. "Develope those pictures, Tom, and I'll take the matter up with the police. Maybe they can identify the tramp from the photographs."
But this proved impossible. Tom had secured several good films, not only in the first views he took, giving the spectators the impression
