the tunnel camp, and Tom
attached the electric wires that were to detonate the charge.

"Well, I guess we're ready," announced the young inventor, as he looked
about him.

The tunnel workers had been allowed to go for the day, and in a log
shack, where they would be safe from flying pieces of rock, were Tom,
Mr. Damon and the two Titus brothers.

Tom held the electric switch in his hand, and was about to press it.

"This explosive works differently from any other," he explained. "When
the charge is fired there is not instantly a detonation and a bursting.
The powder burns slowly and generates an immense amount of gas. It is
this gas, accumulating in the cracks and crevices of the rock, that I
hope will burst and disintegrate it. Of course, an explosion eventually
follows, as you will see. Here she goes!"

Tom pressed the switch and, as he did so, there was a cry of alarm from
Mr. Damon.

"Bless my safety match, Tom!" cried the old man. "Look! Koku!"

For, as the charge was fired, the giant emerged from the woods and
calmly took a seat on the rock that was about to be broken up into
fragments by Tom's new explosive.

Chapter XXII

The Fight

"Get off there, Koku!"

"Stand up!"

"Run!"

"Get out uf the way! That's going up!"

Thus cried Tom and his friends to the big, good-natured, but somewhat
stupid, giant who had sat down in the dangerous spot. Koku looked
toward the hut, in front of which the young inventor and the others
stood, waving their hands to him and shouting.

"Get up! Get up!" cried Tom, frantically. The powder is going off,
Koku!"

"Can't you stop it?" asked Job Titus.

"No!" answered Tom. "The electric current has already ignited the
charge. Only that it's slow-burning it would have been fired long ago.
Get up, Koku!"

But the giant did not seem to understand. He waved his hand in friendly
greeting to Tom and the others, who dared not approach closer to warn
him, for the explosion would occur any second now.

Then Mr. Damon had an inspiration.

"Call him to come to you, Tom!" shouted the odd man. "He always comes
to you in a hurry, you know. Call him!"

Tom acted on the suggestion at once.

"Here, Koku!" he cried. "Come here, I want you! Kelos!"

This last was a word in the giant's own language, meaning "hurry." And
Koku knew when Tom used that word that there was need of haste. So,
though he had sat down, evidently to take his ease after a long tramp
through the w