ment the stranger caught sight of Tom, whom he had not noticed before.
"Ha!" exclaimed the man. "I have forgotten something—an important engagement—will be back directly—will see you again, Mr. Swift—excuse the trouble I have put you to—I am in a great hurry," and before father or son could stop him, had they any desire to, the man turned and walked quickly from the yard.
Mr. Swift stood staring at him, and so did Tom. Then the inventor asked:
"Do you know that man? What about him, Tom? Why did he leave so hurriedly?"
"I don't know his name," replied Tom, "but I am suspicious regarding him, and I think he left because he suddenly recognized me." Thereupon he told his father of seeing the man in the post-office, and hearing the talk of the same individual and two companions in the restaurant.
"And so you think they are up to some mischief, Tom?" asked the parent when the son had finished.
"Well, I wouldn't go quite as far as that, but I think they are interested in your patents, and you ought to know whether you want them to be, or not."
"I most certainly do not—especially in the turbine motor. That is my latest invention, and, I
