"Yo' suah am a wonder at inventin'!" cried the colored man gratefully. "I'll cut yo' grass all summah fo' yo' to pay fo' this, Mistah Swift." "Oh, that's too much. I didn't do a great deal, Rad." "Well, yo' saved me from bein' swindled, Mistah Swift, an' I suah does 'preciate dat." "How about the fellow you traded the cracked grindstone to, Rad?" "Oh, well, ef he done run it slow it won't fly apart, an' he'll do dat, anyhow, fo' he suah am a lazy coon. I guess we am about even there, Mistah Swift." "All right," spoke Tom with a laugh. "Sharpen it up, Rad, and start in to cut grass. It will soon be summer," and Tom, leaping upon his motor-cycle, was off like a shot. He found his father in his library, reading a book on scientific matters. Mr. Swift looked up in surprise at seeing his son. "What! Back so soon?" he asked. "You did make a flying trip. Did you give the model and papers to Mr. Crawford?" "No, dad, I was robbed yesterday. Those scoundrels got ahead of us, after all. They have your model. I tried to telephone to you, but the wires were down, or something." "What!" cried Mr. Swift. "Oh, Tom! That's too bad! I will lose ten thousand dollars if I can't get that model and those papers back!" and with a despairing gesture Mr. Swift rose and began to pace the floor. CHAPTER XVIII. HAPPY HARRY AGAIN Tom watched his father anxiously. The young inventor knew the loss had been a heavy one, and he blamed himself for not having been more careful. "Tell me all about it, Tom," said Mr. Swift at length. "Are you sure the model and papers are gone? How did it happen?" Then Tom related what had befallen him. "Oh, that's too bad!" cried Mr. Swift. "Are you much hurt, Tom? Shall I send for the doctor?" For the time being his anxiety over his son was greater than that concerning his loss. "No, indeed, dad. I'm all right now. I got a bad blow on the head, but Mrs. Blackford fixed me up. I'm awfully sorry---" "There, there! Now don't say another word," interrupted Mr. Swift. "It wasn't your fault. It might have happened to me. I dare say it would, for those scoundrels seemed very determined. They are desperate, and will stop at nothing to make good the loss they sustained on the patent motor they exploited. Now they will probably try to make use of my model and papers." "Do you think they'll do that, dad?" "Yes. They will either make a motor exactly like mine, or construct one so nearly similar that it will answer their purpose. I will have no redress against them, as my patent is not fully granted yet. Mr. Crawford was to attend to that." "Can't you do anything to stop them, dad? File an injunction, or something like that?" "I don't know. I must see Mr. Crawford at once. I wonder if he could come here? He might be able to advise me. I have had very little experience with legal difficulties. My specialty is in other lines of work. But I must do something. Every moment is valuable. I wonder who the men were?"