Chapter XIV. The Telephone Call

The defect in the motor which had caused Tom Swift to shut off the power and drift down to earth was soon remedied, once the young inventor began an examination of the craft. One of the oil feeds had become choked and this automatically cut down the gasoline supply, causing one or more cylinders to miss. It was a safety device Tom had installed to prevent the motor running dry, and so being damaged.

Once the clogged oil feed was cleared the motor ran as before, and just as silently, though, as Tom had said, he was not entirely satisfied with the quietness, but intended to do further work toward perfecting it.

"I'll start the propellers now, Mr. Damon," said Tom, when the trouble had been remedied. "You know how to throw the switch, don't you?"

"I guess so," was the answer. Mr. Damon and Tom had traveled so often together in gasoline craft that the young inventor had taught his friend certain fundamentals about them, and in an emergency the eccentric man could help start an aeroplane. This he now did, taking charge of the controls which could be operated from his seat as well as from Tom's. Tom whirled the propellers, and soon the motor was in motion.

Mr. Damon, once the big wooden blades were revolving, slowed down the apparatus until Tom could jump aboard, after which the latter took charge and soon speeded up the machine, sending it aloft.

As the green meadow, dimly seen in the light of the moon, seemed to drop away below them, and the clump of trees vanished from sight, both Tom and Mr. Damon wondered who it was that had called for help, and if the matter were at all serious. They were inclined to think it was not, but Tom could not rid himself of a faint suspicion that there might have been trouble.

However, thoughts of his new silent Air Scout soon drove everything else from his mind, and as he guided the comparatively silent machine on its quiet way toward his own home he was thinking how he could best improve the muffler.

"Well, here we are again, safe and sound," remarked Tom, as he brought the craft to a stop in front of the hangar, and Jackson and his helpers, who were awaiting the return, hurried out to take charge.

"Yes, everything seems to point to success, Tom," agreed Mr. Damon. "That is, unless the slight accident we had means trouble."

"Oh, no, that had nothing to do with the operation of the silencer. But I'm going to do better yet. Some day I'll take you for a ride in a silent machine which will make so little noise that you can hear a pin drop."

"Well," remarked Mr. Damon' with a laugh, "I don't know that listening to falling pins will give me any great amount of pleasure, Tom, but I appreciate your meaning."

"Everything all right?" asked Mr. Swift, as he came out to hear the details from his son. "Do