That the invention was well nigh perfect, and that it could do even more than Mr. Bartholomew had hoped or Tom had claimed, was Mr. Swift's conviction.
"Tom," he said to his son, "you have done a wonderful thing. Not only have you completed a marvelous invention and gained thereby a lot of money, and more in prospect, but you have aided in the world's progress to no small degree.
"Speed in transportation is the big problem before the world of commerce today. To move goods from point to point safely and cheaply, as well as rapidly, is the great task of this age. We are entering the Age of Speed. The railroads must solve the problem to compete with motor-truck traffic and fast boats on the lakes and rivers of our land.
"You have, by your invention, shoved the clock of progress forward. I am proud of you, my boy. I know now that, no matter what may happen to me, you will make an enviable mark in the world of invention.
"You have done much before for the Government in time of stress. But war engines of any kind are not worthy examples of inventive genius beside such a thing as this.
"It is the inventions of peace, rather than those of war, that stand for human progress."
Coming back over the mountain, Mary Nestor rode in the cab with Tom. She sat on the swivel stool, in fact, and handled the controls for part of the way. But she gave up the driver's place to Tom before they reached the timber siding east of Cliff City.
"I cannot go by that place without a shudder," Mary said to the inventor. "Ned and Mr. Damon told me all about that accident. Suppose you had been killed, Tom!"
"I see I'll have to build an invention that will make that impossible," chuckled the young fellow.
"Make what impossible?"