"Here are the tracks of the rubber tires!" exclaimed the eldest Rover boy. "See, they pushed the plank aside and steered right for the bridge!"
"But did they get over?" asked his brothers.
"I suppose so. Wait, I'll go over and see."
Lantern in hand, Dick crossed on the beams of the wooden bridge. On the opposite side he saw the same tracks of the tires in the dust and dirt.
"Yes, they came over!" he shouted.
"But the planking" came from Tom.
"They must have thrown it into place to cross and then taken it up again, so that they couldn't be followed, that is, in a carriage, or an auto, or on horseback."
"Yes, but they can't stop a biplane!" cried Sam, eagerly. "And this must have taken time to do! We must be close behind them!"
"Let's get right after 'em!" put in Tom, and all three ran once more for the Dartaway, and soon the quick explosions of the motor sounded on the night air.
If the boys had been excited before, they were more so now, for they realized that the touring car at the best could be but a few miles away. Could they catch up to it before those running the machine had a chance to slip them in the darkness?
"They must have their lights lit," said Dick. "They'd not dare run without them. Look and
