"I know it!" responded the young inventor, a grim look on his tense face.

CHAPTER VII

THE RACE

The House on Wheels was half way up a steep slope when the motor stopped and the heavy, and somewhat clumsy car—clumsy because of its bulk—began to go backward. Of course there were brakes. Tom had provided a double set, and they would hold. He had tested them under severe strains. But it took a moment for both the young men to realize what had happened and to decide what to do.

Of course there was only one course of action after Tom had quickly discovered that the stoppage of the motor was not momentary, and that it could not be galvanized into action by the self-starter. The thing to do was to jam on the brakes, which the young inventor did before the backward motion of the House had gained it such momentum that it could not be checked.

"Whew!" whistled Ned, as he felt the machine come to what seemed like a reluctant stop. "That was a close call!"

"Oh, no," said Tom, half smiling. "I could have let her get up even more speed than she had, rolling backward, and yet have brought her to a stop with the one set of brakes."

"On this hill?" Ned was a bit incredulous.

"Yes, or on a steeper one. I want to try her on some mountain."

"Maybe you'll get the chance," Ned remarked.