It was the work of but a minute to unscrew the spark plugs from the tops of the cylinders. He found that both had such accumulations of carbon on them that no spark could ever have reached the mixture of gasoline and air.
"I'll put new ones in," he decided, for he carried a few spare plugs for emergencies. Inside of five minutes, with the new plugs in place, the motor was running better than before.
"Now for home!" cried Tom, "and if I meet Andy Foger I'll race him this time."
But the Red Streak was not in sight, and, a little later, Tom had run the Arrow into the boathouse, locked the door and was on his way up to the mansion.
"I suppose Mrs. Baggert and Garret will be surprised to see me," he remarked. "Maybe they'll think we don't trust them, by coming back in this fashion to see that everything is safe. But then, I suppose, dad is naturally nervous about some of his valuable machinery and inventions. I think I'll find everything all right, though."
As Tom went up the main path and swung off to a side one, which was a short cut to the house, he saw in the dusk, for it was now early evening, a movement in the bushes that lined the walk.
"Hello, Garret!" exclaimed the lad, taking it
