"Your six months isn't up yet," said Mr. Bartholomew, more cheerfully. "And it doesn't matter if it is. If you see any chance of making a success of your invention, you are welcome to try it out on the tracks of the H. & P. A. for another six months."
"All right," Tom said, smiling. "Now, there is the Hercules Three-Oughts-One, Mr. Bartholomew. And there is Koku looking longingly through the window."
In fact, the giant, the moment he saw Tom, ran to unbar and open the door of the cab on that side.
"Master! If no let Koku out, Koku go amuck—crazy! No can breathe in here! No can eat! No can sleep!"
"The poor fellow!" ejaculated Ned.
"What's the matter with him?" asked Mr. Bartholomew, curiously.
"Get out, if you want to, Koku. I'll stay by while you kick up your heels."
No 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."