“Listen!” cried Mr. Damon, who had heard it at the same time.

Tom nodded.

“They’re just ahead of us,” whispered his companion.

“If it’s them,” was the lad’s reply.

“Speed up and we’ll soon see,” suggested Mr. Damon, and Tom shoved the timer over.  The red streak forged ahead.  The sound of the other boat came more plainly now.  It was beyond a little point of land.  The young inventor steered out to get around it and leaned eagerly forward to catch the first glimpse of the unseen craft.  Would it prove to be the arrow?

The put-put became louder now.  Mr. Damon was standing up, as if that would, in some mysterious way, help.  Then suddenly the other boat came into view.  Tom saw it in an instant and knew it for the arrow.

“There she is!” he cried.

CHAPTER XVIII

THE PURSUIT

For an instant after Tom’s exultant cry the men in the boat ahead were not aware that they were being pursued.  Then, as the explosions from the motor of the red streak sounded over the water, they turned to see who was coming up behind them.  There was no mistaking the attitude of the young inventor and his companion.  They were leaning eagerly forward, as if they could reach out and grasp the criminals who were fleeing before them.

“Put on all the speed you can, Tom!” begged Mr. Damon.  “We’ll catch the scoundrels now.  Speed up the motor!  Oh, if I only had my automobile now.  Bless my crank shaft, but one can go so much faster on land than on water.”

The lad did not reply, but thought, with grim humor, that running an automobile over Lake Carlopa would be no small feat.  Mr. Damon, however, knew what he was saying.

“We’ll catch them!  We’ll nab ’em!” he cried.  “Speed her up, Tom.”

The youth was doing his best with the motor of the red streak.  He was not as well acquainted with it as he was with the one in his boat, but he knew, even better than Andy Foger, how to make it do efficient work.  It was a foregone conclusion that the red streak, if rightly handled, could beat the arrow, but there were several points in favor of the thieves.  The motor of Tom’s boat was in perfect order, and even an amateur, with some knowledge of a boat, could make it do nearly its best.  On the other hand, the red STREAK’s machinery needed “nursing.”  Again, the thieves had a good start, and that counted for much.  But Tom counted on two other points.  One was that Happy Harry and his gang would probably know little about the fine points of a motor.  They had shown this in letting the motor of the boat they had first stolen get out of order, and Tom knew the ins and outs of a gasoline engine to perfection.  So the chase was not so hopeless as it seemed.

“Do you think you can catch them?” asked Mr. Damon anxiously.