Navy Department, because they are too valuable even to patent."
Burke, who liked a good detective tale himself, seemed pleased at holding Kennedy spellbound.
"For instance," he went on, "he has on the bay up here a submarine which can be made into a crewless dirigible. He calls it the Turtle, I believe, because that was the name of the first American submarine built by Dr. Bushnell during the Revolution, even before Fulton."
"You have theories of your own on the case?" asked Craig.
"Well, there are several possibilities. You know there are submarine companies in this country, bitter rivals. They might like to have those plans. Then, too, there are foreign governments."
He paused. Though he said nothing, I felt that there was no doubt what he hinted at. At least one government occurred to me which would like the plans above all others.
"Once some plans of a submarine were stolen, I recall," ruminated Kennedy. "But that theft, I am satisfied, was committed in behalf of a rival company."
"But, Kennedy," exclaimed Burke, "it was bad enough when the plans were stolen. Now Captain Shirley wires me that some one must have tampered with his model. It doesn't work right. He even believes that his own life may be threatened. And there is scarcely a real clue," he added dejectedly. "Of course we are watching all the employés who had access to the draughting-room and tracing everybody
