"Good idea," commented Mr. Sharp. "Fine day for a sail. Come on. Blow the cobwebs from our brains."
Mr. Swift declined an invitation to accompany them, as he said he would stay home and try to straighten out his affairs, which were somewhat muddled by the robbery.
Out over the blue waters of Lake Carlopa shot the ARROW. It was making only moderate speed, as Tom was in no hurry, and he knew his engine would last longer if not forced too frequently. They glided along, crossed the lake and were proceeding up the opposite shore when, as they turned out from a little bay and rounded a point of land, Mr. Sharp exclaimed:
"Look out, Tom, there's rowboat just ahead!"
"Oh, I'll pass well to one side of that," answered the young inventor, looking at the craft. As he did so, noting that there were four men in it, one of the occupants caught a glimpse of the ARROW. No sooner had he done so than he spoke to his companions, and they all turned to stare at Tom. At first the lad could scarcely believe his eyes, but as he looked more intently he uttered a cry.
"There they are!"
"Who?" inquired Mr. Sharp.
"Those men—the thieves! We must catch them!"
Tom had spoken loudly, but even though the men in the rowboat did hear what he said, they would have realized without that that they were about to be pursued, for there was no mistaking the attitude of our hero.
Two of the thieves were at the oars, and, with one accord, they at once increased their speed. The boat swung about sharply and was headed for the shore, which they seemed to have come from only a short time previous, as the craft was not far out in the lake.