“Guess he wants to see how close he can come to me,” thought our hero.  “Maybe he wants to show how fast he’s going.”

The red streak was now so close that the features of the occupants could easily be distinguished.  There were grins on the faces of Andy and his cronies.

“Get out of the way or we’ll run you down!” cried the bully.  “We’ve got the right of way.”

“Don’t you try anything like that!” shouted Tom in some alarm, not that he was afraid of Andy, but the red streak was getting dangerously near, and he knew Andy was not a skillful helmsman.  The auto-boat was now headed directly at the arrow and coming on speedily.  Andy was bending over the wheel and Tom had begun to turn his, in order to get well out of the way of the insolent, squint-eyed lad and his friends.

Suddenly Andy uttered a cry and leaped up.

“Look out!  Look out!” he yelled.  “My steering gear has broken!  I can’t change my course.  Look out!”

The red streak was bearing right down on Tom’s boat.

“Shut off your power!  Reverse!” shouted Tom.

Andy seemed confused and did not know what to do.  Sam Snedecker sprang to the side of his crony, but he knew even less about a motor-boat.  It looked as if Tom would be run down, and he was in great danger.

But the young inventor did not lose his head.  He put his wheel hard over and then, leaping to his motor, sent it full speed forward.  Not a moment too soon had he acted, for an instant later the other boat shot past the stern of the arrow, hitting it a severe but glancing blow.  Tom’s boat quivered from end to end and he quickly shut off the power.  By this time Andy had succeeded in slowing down his craft.  The young inventor hastily looked over the side of the arrow.  One of the rudder fastenings had been torn loose.

“What do you mean by running me down?” shouted Tom angrily.

“I—­I didn’t do it on purpose,” returned Andy contritely.  “I was seeing how near I could come to you when my steering gear broke.  I hope I haven’t damaged you.”

“My rudder’s broken,” went on Tom “and I’ve got to put back to repair it.  I ought to have you arrested for this!”

“I’ll pay for the damage,” replied Andy, and he was so frightened that he was white, in spite of his tan and freckles.

“That won’t do me any good now,” retorted Tom.  “It will delay me a couple of hours.  If you try any tricks like that again, I’ll complain to the authorities and you won’t be allowed to run a boat on this lake.”

Andy knew that his rival was in the right and did not reply.  The bully and his cronies busied themselves over the broken steering gear, and the young inventor, finding that he could make a shift to get back to his boathouse, turned his craft around and headed for there, in order to repair the damage.