But Tom did not reckon on a very simple matter, and that was the possibility of the man having a boat at hand.  For this is just what happened.  Reaching the lake shore the fugitive with a final spurt managed to put considerable distance between himself and Tom.  Drawn up on the beach was a little motor-boat.  In this, after he had pushed it from shore, the stranger leaped.  It was the work of but a second to set the engine in motion, and as Tom reached the edge of the woods and started across the narrow strip of sand and gravel that was between the water and the trees, he saw the man steering his craft toward the middle of the lake.

“Well—­I’ll—­be—­jiggered!” exclaimed the youth.  “Who would have thought he’d have a motor-boat waiting for him?  He planned this well.”

There was nothing to do but turn back.  Tom had a small rowboat and a sailing skiff on the lake, but his boathouse was some distance away, and even if he could get one of his craft out, the motor-boat would soon distance it.

“He’s gone!” thought the searcher regretfully.

The man in the motor-boat did not look back.  He sat in the bow, steering the little craft right across the broadest part of Lake Carlopa.

“I wonder where he came from, and where he’s going?” mused Tom.  “That’s a boat I never saw on this lake before.  It must be a new one.  Well, there’s no help for it, I’ve got to go back and tell dad I couldn’t catch him.”  And with a last look at the fugitive, who, with his boat, was becoming smaller and smaller every minute, Tom turned and retraced his steps.

CHAPTER X.

OFF TO ALBANY

“Did you catch him, Tom?” asked Mr. Swift eagerly when his son returned, but the inventor needed but a glance at the lad’s despondent face to have his question answered without words, “Never mind,” he added, “there’s not much harm done, fortunately.”

“Did he get anything?  Any of your plans or models, dad?”

“No; not as far as I can discover.  My papers in the shop were not disturbed, but it looked as if the turbine model had been moved.  The only thing missing seems to be a sheet of unimportant calculations.  Luckily I had my most valuable drawings in the safe in the house.”

“Yet that man seemed to be putting papers in his pocket, dad.  Maybe he made copies of some of your drawings.”

“That’s possible, Tom, and I admit it worries me.  I can’t imagine who that man is, unless—­”

“Why, he’s one of the three men I saw in Mansburg in the restaurant,” said Tom eagerly.  “Two of them tried to get information here, and now the third one comes.  He got away in a motor-boat,” and Tom told how the fugitive escaped.

Mr. Swift looked worried.  It was not the first time attempts had been made to steal his inventions, but on this occasion a desperate and well-organized plan appeared to be on foot.