“A week, I believe.”

“A week!  Say, one day would be enough I should think.”

“You must have some special reason for being afraid Andy will do you some harm,” exclaimed Ned.  “Out with it, Tom.”

“Well, I’ll tell you what it is, Ned,” and Tom led his chum inside the shop, in front of which the two lads had been talking.  It was a shop where the young inventor constructed many of his marvelous machines, aircraft, and instruments of various sorts.

“Do you think some one may hear you?” asked Ned.

“They might.  I’m not taking any chances.  But the reason I want to be especially careful that Andy Foger doesn’t spy on any of my inventions is that at last I have perfected my noiseless airship motor!”

“You have!” cried Ned, for he knew that his chum had been working for a long time on this motor, that would give out no sound, no matter at how high a speed it was run.  “That’s great, Tom!  I congratulate you.  I don’t wonder you don’t want Andy to get even a peep at it.”

“Especially as I haven’t it fully patented,” went on the young inventor.  He had met with many failures in his efforts to perfect this motor, which he intended to install on one of his airships.  “If any one saw the finished parts now it wouldn’t take them long to find out the secret of doing away with the noise.”

“How do you do it?” asked Ned, for he realized that his chum had no secrets from him.

“Well, it’s too complicated to describe,” said Tom, “but the secret lies in a new way of feeding gasolene into the motor, a new sparking device, and an improved muffler.  I think I could start my new airship in front of the most skittish horse, and he wouldn’t stir, for the racket wouldn’t wake a baby.  It’s going to be great.”

“What are you going to do with it, when you get it all completed?”

“I haven’t made up my mind yet.  It’s going to be some time before I get it all put together, and installed, and in that time something may turn up.  Well, let’s talk about something more pleasant than Andy Foger.  I guess I won’t worry about him.”

“No, I wouldn’t.  I’d like to see the motor run.”

“You can, in a day or so, but just now I need a certain part to attach to the sparker, and I had to send to town for it.  Koku has gone after it.”

“What, that big giant servant?  He might break it on the way back, he’s so strong.  He doesn’t realize how much muscle he has.”

“No, that’s so.  Well, while we’re waiting for him, come on in the house, and I’ll show you some new books I got.”

The two lads were soon in the Swift homestead, a pleasant and large old-fashioned residence, in the suburbs of Shopton.  Tom brought out the books, and he and his chum poured over them.

“Mr. Damon gave me that one on electricity,” explained the young inventor, handing Ned a bulky volume.