Tom quickly turned to one side, to avoid the worst of the dust.  The motor-cyclist glanced at the youth, but this act nearly proved disastrous for him.  He took his eyes from the road ahead for just a moment, and he did not see a large stone directly in his path.  His front wheel hit it, and the heavy machine, which he could not control very well, skidded over toward the lad on the bicycle.  The motor-cyclist bounced up in the air from the saddle, and nearly lost his hold on the handle-bars.

“Look out!” cried Tom.  “You’ll smash into me!”

“I’m—­I’m—­try—­ing—­not—­to!” were the words that were rattled out of the middle-aged man.

Tom gave his wheel a desperate twist to get out of the way.  The motor-cyclist tried to do the same, but the machine he was on appeared to want matters its own way.  He came straight for Tom, and a disastrous collision might have resulted had not another stone been in the way.  The front wheel hit this, and was swerved to one side.  The motor-cycle flashed past Tom, just grazing his wheel, and then was lost to sight beyond in a cloud of dust that seemed to follow it like a halo.

“Why don’t you learn to ride before you come out on the road!” cried Tom somewhat angrily.

Like an echo from the dust-cloud came floating back these words: 

“I’m—­try—­ing—­to!” Then the sound of the explosions became fainter.

“Well, he’s got lots to learn yet!” exclaimed Tom.  “That’s twice to-day I’ve nearly been run down.  I expect I’d better look out for the third time.  They say that’s always fatal,” and the lad leaped from his wheel.  “Wonder if he bent any of my spokes?” the young inventor continued as he inspected his bicycle.

CHAPTER II.

TOM OVERHEARS SOMETHING

“Everything seems to be all right,” Tom remarked, “but another inch or so and he’d have crashed into me.  I wonder who he was?  I wish I had a machine like that.  I could make better time than I can on my bicycle.  Perhaps I’ll get one some day.  Well, I might as well ride on.”

Tom was soon at Mansburg, and going to the post-office handed in the letter for registry.  Bearing in mind his father’s words, he looked about to see if there were any suspicious characters, but the only person he noticed was a well-dressed man, with a black mustache, who seemed to be intently studying the schedule of the arrival and departure of the mails.

“Do you want the receipt for the registered, letter sent to you here or at Shopton?” asked the clerk of Tom.  “Come to think of it, though, it will have to come here, and you can call for it.  I’ll have it returned to Mr. Barton Swift, care of general delivery, and you can get it the next time you are over,” for the clerk knew Tom.

“That will do,” answered our hero, and as he turned away from the window he saw that the man who had been inquiring about the mails was regarding him curiously.  Tom thought nothing of it at the time, but there came an occasion when he wished that he had taken more careful note of the well-dressed individual.  As the youth passed out of the outer door he saw the man walk over to the registry window.