Frank thought so himself, as he went off to his room.  Imagine his father, some forty years ago, ever dreaming of building an air-ship and speeding through the upper currents, perhaps thousands of feet above the earth, at the rate of a mile a minute!  And yet that was what he and Andy had been doing, thinking nothing of the feat, as they became accustomed to its performance.

Fast times, indeed!

Frank did not allow the startling incidents of the night to keep him awake.  He knew just how to get a grip on himself and put all these things out of his mind, once his head touched the pillow.

Time enough in the morning to begin worrying about that lost wheel and trying to figure out who the firebug could have been.

At breakfast Frank had to go over the whole story again for the benefit of Janet, who had heard enough about it from the doctor before her brother came down to whet her appetite for more.

Frank could see that she shared the suspicions entertained by Andy.  Janet knew Puss Carberry of old and despised him most heartily.  At one time he had taken a great liking to Frank’s pretty sister, but when she learned what his nature was Janet had cut him dead on the street.  And from that day on she had believed Puss capable of almost anything.

“Even after you saved his life yesterday, too!” she exclaimed, indignantly.

“Hold on there, sis,” cried Frank, laughing.  “You’re as bad as Andy, who is ready to condemn on general principles.  We haven’t got a scrap of evidence to prove Puss guilty.  Just as like as not he would show an alibi if we accused him of it, and prove that he was at home all evening.  So please don’t mention his name to anybody or I may get in a scrape.”

“But you’re going to find out, aren’t you!” demanded Janet.

“I surely hope to, and recover my poor bike in the bargain.  Luckily I’ve got my name and address scratched on the underpart of the frame, if the finder only takes the trouble to look.  And now I’m off downtown, to speak to Chief Waller about it.”

Ten minutes later Frank dropped off in front of police headquarters.  And no sooner had he alighted than the lad discovered that there was a buzz of excitement about the place, for several men were conferring and the chief himself seemed disturbed.  He looked eagerly at Frank as the boy came forward and started to relate what had occurred on the preceding night out near the residence of Colonel Josiah Whympers.

Immediately the face of the chief began to light up and an eager glow shine in his eyes.  It seemed as though what Frank was telling must have given him a connecting link that he had found himself badly in need of.

“Now we know where he went!” he exclaimed, calling to one of his men.  “Go out to Colonel Josiah Whympers’, Green, and see what traces you can get of him.”  Then once more turning to the astonished boy, he went on:  “You see, we had a jail delivery here last night.  A desperate scoundrel managed to slip away undetected and we only found it out this morning.  And the man who got out was your old friend, Jules Garrone, the French aviator, who was caught by the help of the Bird boys and their bully little aeroplane!  Get that, Frank?”