at the result. Again they had picked up the messages which had aroused their curiosity and, by turning the loop one way and then another, they were soon convinced that the sender had a station to the southeast of their own.

“Well, that’s settled,” announced Tom, “and the only things southeast of here are the East Side, the river and Brooklyn. That fellow is not far away—he’s using a very short wave and his messages are strong. I’ll bet he’s right here in New York.”

“I guess you’re right,” agreed Frank, “but that doesn’t do much good. There’s an awful lot of the city southeast from here.”

“Sure there is,” said Tom, “but, after all, what do we care. I still think he’s just some unlicensed chap—probably some kid over on the East Side who can’t pass an examination or get a license and is just having a little fun on the quiet.”

This conversation took place two days before Tom received his father’s message telling of his safe arrival in Cuba and no more messages from the mysterious stranger were heard until the day after Mr. Pauling’s message had been received.

Then, as Tom was listening at the loop aërial

set and idly turned the aërial about, he again picked up the well-known short-wave messages. Heretofore the messages had been meaningless sentences in code, dots and dashes which the boys out of curiosity had jotted down only to find them devoid of any interest—items regarding shipping which Tom had declared had been culled from the daily shipping lists and were being sent merely for practice—and so now, from mere habit, Tom wrote down the letters as they came to him over the instruments. Suddenly he uttered a surprised whistle.

“Gee Whittaker!” he exclaimed in low tones. “Come here, Frank.”

The other hurried to him and as he glanced at the pad on the table beside Tom he too gave an ejaculation of surprise. The letters which Tom had jotted down were as follows: LEAR P IN HAVANA ARRIVED YESTERDAY GET BUSY.

“They are rum runners!” cried Tom as the signals ceased.