"Oh, well, a girl likes a change. And it can't last forever."
"No, I suppose not. Oh, well, I'm a grouch not to wish Mary to have a good time. But I did want her to see this House on Wheels," and Tom acted like a small boy who has been kept home from a party.
"She'll see it soon enough," predicted Ned. "And it will look all the better when it's complete and has had a tryout."
"Maybe," was all Tom would say, and then he plunged into work.
Ned expected that his friend would again go over to the Nestor house in the evening, but Tom, with rather a set look on his face, announced that he intended to work until late on his newest invention. However, he did telephone to Mary and arranged to call for her the next morning to take her to the station.
What took place at the train when Mary departed Ned did not know. But Tom came back looking more gloomy than before and plunged into work with a zeal which left his devoted chum far behind.
The Swift plant was a busy place in the days that followed. There was always more or less of routine labor in connection with several machines which Tom and his father had perfected, patented, and had put on the market for general sale.
The latest invention of the young man, excepting the House on Wheels, had been a machine for showing moving pictures in the home, in simultaneous connection with vocal and instrumental effects by radio. It was possible to sit in one's parlor and not only see a distant theatrical performance, but actually hear all that went on. The vision of the actors and actresses was reduced in size, but the pictures were very clear. And the radio, of an improved type, clearly brought every word and every note of music through the air.
This invention, or a share in it, had been sold to a syndicate which, for a time, had fought Tom Swift fiercely. But now matters were straightened out, though there was much detail to finish.
With that, and with overseeing the completion of his House on Wheels, Tom Swift had plenty of work to keep him busy. He was also worrying, as Ned easily guessed.