Because of evidence given by Andy Foger, and his father, suspicion pointed to Tom and his friends as the robbers, and they were pursued.  But they turned the tables by capturing the real burglars, and defeating the mean plans of the Fogers.

Not satisfied with having mastered the air Tom and his father turned their attention to the water.  Mr. Swift perfected a new type of craft, and in the fourth book of the series, called “Tom Swift and His Submarine,” you may read how he went after a sunken treasure.  The party had many adventures, and were in no little danger from their enemies before they reached the wreck with its store of gold.

The fifth book of the series, named “Tom Swift and His Electrical Runabout,” told how Tom built the speediest car on the road, and won a prize with it, and also saved a bank from ruin.

Tom had to struggle against odds, not only in his inventive work, but because of the meanness of jealous enemies, including Andy Foger, who seemed to bear our hero a grudge of long standing.  Even though Tom had, more than once, thrashed Andy well, the bully was always seeking a chance to play some mean trick on the young inventor.  Sometimes he succeeded, but more often the tables were effectually turned.

It was now some time since Tom had won the prize in his electric car and, in the meanwhile he had built himself a smaller airship, or, rather, monoplane, named the butterfly.  In it he made several successful trips about the country, and gave exhibitions at numerous aviation meets; once winning a valuable prize for an altitude flight.  In one trip he had met with a slight accident, and the monoplane had only just been repaired after this when he received the message summoning him to Philadelphia.

“Well, Tom,” remarked his father that afternoon, “if you are going to the Quaker City, to see Mr. Fenwick to-morrow, you’d, better be getting ready.  Have you wired him that you will come?”

“No, I haven’t, dad,” was the reply.  “I’ll get a message ready at once, and when Eradicate comes back I’ll have him take it to the telegraph office.”

“I wouldn’t do that, Tom.”

“Do what?”

“Trust it to Eradicate.  He means all right, but there’s no telling when that mule of his may lie down in the road, and go to sleep.  Then your message won’t get off, and Mr. Fenwick may be anxiously waiting for it.  I wouldn’t like to offend him, for, though he and I have not met in some years, yet I would be glad if you could do him a favor.  Why not take the message yourself?”

“Guess I will, dad.  I’ll run over to Mansburg in my electric car, and send the message from there.  It will go quicker, and, besides, I want to get some piano wire to strengthen the wings of my monoplane.”

“All right, Tom, and when you telegraph to Mr. Fenwick, give him my regards, and say that I hope his airship will be a success.  So it’s an electric one, eh?  I wonder how it works?  But you can tell me when you come back.”