XXI A New Explosive
XXII The Fight
XXIII A Great Blast
XXIV The Hidden City
XXV Success




TOM SWIFT AND HIS BIG TUNNEL




Chapter I

An Appeal for Aid



Tom Swift, seated in his laboratory engaged in trying to
solve a puzzling question that had arisen over one of his
inventions, was startled by a loud knock on the door. So
emphatic, in fact, was the summons that the door trembled,
and Tom started to his feet in some alarm.

"Hello there!" he cried. "Don't break the door, Koku!" and
then he laughed. "No one but my giant would knock like
that," he said to himself. "He never does seem able to do
things gently. But I wonder why he is knocking. I told him