y new
compound."

The steel chamber that was to receive the hundred-pound steel block had
been prepared in advance, as had the various gauges and registering
apparatus.

"Well, I guess we'll start things moving now," went on Tom, as he
looked over the things he had brought from his shops to the deserted
meadow. The fact of the test had been kept a secret, so there were no
spectators. "Ned, give me a hand with this block," Tom went on. "It's a
little too heavy to lift alone." He was straining and tugging at the
heavy piece of steel.

"Me do!" exclaimed Koku the giant, gently pushing Tom to one side. Then
the big man, with one hand, raised the hundred-pound weight as easily
as if it were a loaf of bread, and deposited it where Tom wanted it.

"Thanks!" exclaimed our hero, with a laugh. "I didn't make any mistake
when I brought you home with me, Koku."

"Huh! I could hab lifted dat weight when I was a young feller!"
exclaimed Eradicate, who was, it is needless to say, jealous of the
giant.

The powder had been put in the firing chamber. The steel socket had
been firmly fixed in the earth, so that if the force of the explosion
was in a lateral direction, instead of straight up, no damage would
result. The weight, even if it shot from the muzzle of the improvised
"cannon," would only go harmlessly up in the air, and then drop back.
The firing wires were so long that Tom and his friends could stand some
distance away.

"Are you all ready?" cried Tom, as he looked to see that the wiring was
clear.

"As ready as we ever shall be," replied Mr. Damon, who, with Ned and
the others, had taken refuge behind a low hill.

"Oh, this isn't going to be much of an explosion," laughed Tom. "It
won't be any worse than a Fourth of July cannon. Here she goes!"

He pressed the electric button, there was a flash, a dull, muffled
report and, for a moment, something black showed at the top of the
steel chamber. Then it dropped back inside again.

"Pshaw!" cried Tom, in disappointed tones. "It didn't even blow the
weight out of the tube. That powder's no good! It's a failure!"

Followed by the others, the young inventor started toward the small
square "cannon." Tom wanted to read the records made by the gases.

Suddenly Koku cried:

"There him be, master! There him be!" and he pointed toward a distant
path that traversed the meadow.

"He? Whom do you mean?" asked Tom, startled the giant's excited manner.

"That man what come