be much use to look for him now, though."

"Me look," spoke Koku significantly, as he hurried off in the
direction taken by the tramp. He came back later, not having
found him.

"What do you think of it, Tom?" asked Ned, when the excitement
had calmed down, and the pile of burned rags had been removed. It
was 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
dew as to how my machine works. They certainly did not want to
burn the shop, for that pile of rags could have smoldered 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.
"Develop those pictures, Tom, and I'll take the matter up with