then some of it must be there yet. Probably it sifted through
the excelsior-like grains of my new explosive, and we'll find it on the
bottom of the powder-case. But enough stuck to the strands to spoil my
test. I'll just take a reading of the gauges, and then we'll make an
investigation."

Tom, with Ned to help him, made notes of how far the weight had risen
in the tube, and took data of other points in the experiment.

"Pshaw!" exclaimed Tom. "There wasn't much more force to my new powder,
doped as it apparently has been, than to the stuff I can buy in the
open market. But I'm glad I know what the trouble is, for I can remedy
it. Come on back to the shop. Koku, don't you ever do anything like
this again," and Tom spoke severely.

"No, Master," answered the giant, humbly.

"Did you ever see this man before, Koku?"

"No, Master."

"What kind of a fellow was he?" asked Ned.

"Oh, him got whiskers on him face, and stand very straight, like stick
bending backwards. Him look like a soldier, and him blink one eye more
than the other."

Tom and Ned started and looked at one another.

"That description fits General Waller," said Ned, in a low voice to his
chum.

"Yes, in a way; but it would be out of the question for the General to
do such a thing. Besides, the man who ran away, and escaped on his
motor-cycle, was larger than General Waller."

"It was hard to tell just what size he was at the distance," spoke Ned.
"It doesn't seem as though he would try to spoil your experiments,
though."

"Maybe he hoped to spoil my cannon," remarked Tom, with a laugh that
had no mirth in it. "My cannon that isn't cast yet. He probably
misunderstood Koku's story of the test, and had no idea it was only a
miniature, experimental, gun.

"This will have to be looked into. I can't have strangers prowling
about here, now that I am going to get to work on a new invention.
Koku, I expect you, after this, not to let strangers approach unless I
give the word. Eradicate, the same thing applies to you. You didn't see
anything of this mysterious man; did you?"

"No, Massa 'Tom. De only s'picious man I see was mab own cousin
sneakin' around mah chicken coop de odder night. I tooks mah ole shot
gun, an' sa'ntered out dat way. Den in a little while dere wasn't no
s'picious man any mo'."

"You didn't shoot him; did you, Rad?" cried Tom, quickly.

"No, Massa Tom--dat is, I didn't shoot on puppose laik. De gun jest
natchelly went off by i