“Well, have you caught any more runaway horses lately?”

“Runaway horses—­why—­what?  Oh, it’s Miss Nestor!” exclaimed the lad, recognizing the young lady whose steed he had frightened one day when he was on his bicycle.  As told in the first volume of this series, the horse had run away, being alarmed at the flashing of Tom’s wheel, and Miss Mary Nestor, of Mansburg, was in grave danger.

“So you’ve given up the bicycle for the motor-boat,” went on the young lady.

“Yes,” replied Tom with a smile, shutting off the power, “and I haven’t had a chance to save any girls since I’ve had it.”

The two boats had drifted close together, and Miss Nestor introduced her two companions to Tom.

“Don’t you want to come in and take a ride?” he asked.

“Is it safe?” asked Jennie Haddon, one of the trio.

“Of course it is, Jennie, or he wouldn’t be out in it,” said Miss Nestor hastily.  “Come on, let’s get in.  I’m just dying for a motor-boat ride.”

“What will we do with our boat?” asked Katie Carson.

“Oh, I can tow that,” replied the youth.  “Get right in and I’ll take you all around the lake.”

“Not too far,” stipulated the girl who had figured in the runaway.  “We must be back for lunch, which will be served in about an hour.  Our church and Sunday-school are having a picnic.”

“Maybe Mr. Swift will come and have some lunch with us,” suggested Miss Carson, blushing prettily.

“Nothing would give me greater pleasure,” answered Tom, and then he laughed at his formal reply, the girls joining in.

“We’d be glad to have you,” added Miss Haddon.  “Oh!” she suddenly screamed, “the boat’s tipping over!”

“Oh, no,” Tom hastened to assure her, coming, to the side to help her in.  “It just tilts a bit, with the weight of so many on one side.  It couldn’t capsize if it tried.”

In another moment the three were in the roomy cockpit and Tom had made the empty rowboat fast to the stern.  He was about to start up when from another boat, containing two little girls and two slightly larger boys, came a plaintive cry: 

“Oh, mister, give us a ride!”

“Sure!” agreed Tom pleasantly.  “Just fasten your boat to the other rowboat and I’ll tow you.”

One of the boys did this, and then, with three pretty girls as his companions in the arrow and towing the two boats, Tom started off.

The girls were very much interested in the craft and asked all sorts of questions about how the engine operated.  Tom explained as clearly as he could how the gasoline exploded in the cylinders, about the electric spark and about the propeller.  Then, when he had finished, Miss Haddon remarked naively: 

“Oh, Mr. Swift, you’ve explained it beautifully, and I’m sure if our teacher in school made things as clear as you have that I could get along fine.  I understand all about it, except I don’t see what makes the engine go.”