He knew that he might expect hard work and plenty of it all that day. There would be no chance for him to experiment with his Universal Detector. About dusk, Harvey Thurman, his assistant, came into the wireless room to relieve him while he went to dinner.
Thurman was a short, thick-set young man, with a flabby, pallid face and shifty eyes. He had got his job on the new liner through a "pull" that he possessed through a distant relationship with Mr. Jukes. Jack had not met him before, and, since they had been on board, they had exchanged only a few words, but he instinctively felt that he and Thurman were not going to make very good shipmates.
As Jack relinquished the head-receivers and the key to his "relief," Thurman's gaze rested on the Universal Detector.
"Oh, just a little idea I'm working on," said Jack, "a new invention. If I can perfect it, it may be valuable."
"Yes, but what is it? What's it for?" persisted Thurman.
Jack explained what he hoped to accomplish with the instrument, and an instant later was sorry he had done so, for he noticed an expression of cupidity creep into Thurman's eyes. The youth persisted in asking a host of questions, and Jack, having started to explain, could not very well refuse to answer. Besides, inventors are notoriously garrulous about their brain children, and Jack, even though he did not like Thurman, soon found himself talking away at a great rate.
"Huh, I don't think the idea's worth a cent," sniffed Thurman contemptuously, when Jack had finished.
"I guess that's where you and I differ," said Jack, controlling his temper with some difficulty, for the sneer in Thurman's voice had been marked. "I'm going to make it a success, and then we shall see."
He left the wireless room, and the instant he was gone Thurman, with a crafty look on his flabby face, eagerly began examining the detector. As he was doing so Jack, who had forgotten his cap, suddenly reëntered the wireless room. Thurman had been so intent on his scrutiny of the detector that he did not hear him.
"You appear to be taking great interest in that useless invention," said Jack in a quiet voice.
Thurman started and spun round. His face turned red and he had an almost guilty look.