o sooner had the inventor spoken than the giant leaped from the open
door of the locomotive and dashed away along the cinder path as though
he actually had to run away. Tom burst into a laugh, as he watched the
giant disappear beyond the strings of freight cars.

"What is the matter with him?" repeated the railroad president.

"He's got the cramp all right," laughed Tom Swift. "You don't
understand, Mr. Bartholomew, what it means to that big fellow to be
housed in for so many days, and unable to kick a free limb. I bet he
runs ten miles before he stops."

"The police will arrest him," said the railroad man.

It was then Ned's turn to chuckle. "I am sorry for your railroad police
if they tackle Koku right now," he said. "He'd lay out about a dozen
ordinary men without half trying. But, ordinarily, he is the most
mild-mannered fellow who ever lived."

"He will come back, if he is let alone, as harmless as a kitten," Tom
observed. "And when I am not with the Hercules Three-Oughts-One, and
while I continue making my tests, Koku will be on guard. You might tell
your police force, Mr. Bartholomew, to let him alone. Now come aboard
and let me show you what I have been trying to do."

They spent two hours inside the cab of the great locomotive. Mr.
Richard Bartholomew was possessed of no small degree of mechanical
education. He might not be a genius in mechanics as Tom Swift was, but
he could follow the latter's explanations regarding the improvements in
the electrical equipment of this new type of locomotive.

"I don't know what your speed tests will show, Mr. Swift," said the
railroad president, with added enthusiasm. "But if those parts will do
what you say they have already done, you've got the Jandels beat a
mile! I'm for you, strong. Yes, sir! like your friend, Newton, here, I
believe that you have hit the right track. You are going to triumph."

But Tom's triumph did not come at once. He knew more about the
uncertainties of mechanical contrivances than did either Mr.
Bartholomew or Ned Newton.

The very next day the Hercules 0001 was got out upon a section of the
electrified system of the Hendrickton & Pas Alos Railway, and the
pantagraphs of the huge locomotive for the first time came into
connection with the twin conductor trolleys which overhung the rails.

Ned accompanied Tom as assistant. Koku was allowed by the inventor to
roam about the hills as much as he pleased during the hours in which
his master w