"It was about four-twenty when the gentleman called me up," observed the police officer; "and he had a long way around to go after leaving here. He could never have made it if it was your boat he saw."
"There's another thing, Captain," said Jack, smiling.
"Please let me hear what it is, my boy," returned the other, eagerly now, for he was beginning to comprehend that this was no ordinary young chap with whom an error of judgment had thrown him in contact.
"Did the gentleman in the auto say that the motor boat went under the bridge at the time he saw it?" Jack pursued.
"That's just what he did say," replied the captain. "Of course he only had one quick look as his machine traveled over the bridge crossing the creek; but even then it seemed to him the boat had a familiar look. And then, later on it suddenly dawned on him that it just fitted a description he had been reading in a St. Louis paper about the mysterious motor boat of the bank thieves."
"All right, Captain. We have not been up as far as the bridge, as we anchored right here when we came in. But, Captain," Jack continued, earnestly, "both of us believed at the time that there must be some sort of a motor boat up yonder, for we saw a piece of oiled waste floating down on a chip of wood, as if some one had been wiping an engine, and thrown it aside."
"Well, what do you think of that?" exclaimed one of the listening officers. "It beats anything our best detectives could have done. But say, Cap, I hear something moving close by. There it is again! There's a boat coming down, and being poled, too."
"Turn your lights around that way, quick!" cried the police captain, as though he grasped the true significance of the sound.
As the men did so the dim outlines of a motor launch were discovered not far away, with one man using a pole at the stern to hasten its departure.
Jack understood what it meant, even as must the officers; for as seen in the faint light from the dark lanterns the strange boat was an exact duplicate of his own little Tramp!