"It was!" and the lad was now almost as excited as was his friend.

"Then I've seen it and, what's more, this morning! Bless my spark plug, I've seen it!"

"Tell me about it!" pleaded the young inventor, and Mr. Damon, calming himself after an effort, resumed:

"I was out for an early spin in my auto," he said, "and was traveling along a road that bordered the lake, about fifteen miles above here. I heard a motor-boat puffing along near shore, and, looking through the trees, I saw one containing three men. It had a red arrow on the bow, and that's why I noticed it, because I recalled that your boat was named the DART."

"ARROW," corrected Tom.

"The ARROW. Oh, yes, I knew it was something like that. Well of course at the time I didn't think that it was your boat, but I associated it in my mind with yours. Do you catch my meaning?"

Tom did and said so, wishing Mr. Damon would hurry and get to the point. But the eccentric character had to do things in his own way.

"Exactly," he resumed. "Well, I didn't think that was your boat, but, at the same time, I watched the men out of curiosity, and I was struck with their behavior. They seemed to be quarreling, and, from what I could hear, two of them seemed to be remonstrating with the third one for having taken some sort of a piece of wood from the forward compartment. I believe that is the proper term."

"Yes!" Tom almost shouted. "But where did they go? What became of them? What was the man doing to the forward compartment—where the gasoline tank is?"

"Exactly. I was trying to think what was kept there. That's it, the gasoline tank. Well, the boat kept on up the lake, and I don't know what became of the men. But about that piece of wood. It seems that one of the men removed a block, from under the tank and the others objected. That's why they were quarreling."