Tom carefully inspected the hammer by the light of a powerful portable electric lamp Ned held.
"Ha! There it is!" Tom suddenly exclaimed.
"Something wrong?" Ned inquired.
"Yes. This is what's been throwing the hammer off the guides all the while," and Tom pulled out a small steel bolt that had been slipped into an oil hole. A certain amount of vibration, he explained to Ned, would rattle the bolt out so that it would force the hammer to one side, throwing it off the channel-plates, and rendering it useless for the time being.
"A foxy trick," commented Tom. "No wonder the machine got out of kilter so easily."
"Do you think it was done purposely?"
"Well, I'm not going to say. But I'm going to watch that man. He wants to be transferred to the airship department. He put this in the hammer, perhaps, to have an excuse for a change. Well, I'll give it to him."
"You don't mean that you'd take a fellow like that and put him to work on your new aerial warship, do you, Tom?"
"Yes, I think I will, Ned. You see, I look at it this way: I haven't any real proof against him now. He could only laugh at me if I accused him. But you've heard the proverb about giving a calf rope enough and he'll hang himself, haven't you?"
"I think I have."