out, for all they knew he might be on 27th St. or 20th St. or even slightly north or south of one or the other, for he stated that his brother had told him that when close to a sending station the loop aërial could not be depended upon to give very accurate

directions and that only by taking cross bearings could a certain point be definitely located. This was exactly what the boys had in view, to take cross bearings, and then, by means of a map of the city, to locate the man or the station.

It may seem as if the boys were devoting a great deal of time and trouble to something of little importance, but they were, or at least Tom, Frank and Henry were, thoroughly convinced that the messages emanated from some one connected with a rum-running gang and they were as keen on finding his location and as interested as if they had been real detectives detailed to discover a fugitive from justice.

So on that Saturday night they sat at their various instruments, waiting expectantly and with high hopes. No one was stationed at Tom’s home, for, in order to provide two sets for the test, Tom’s and Frank’s had been dismantled and reinstalled at the houses of Jim’s cousin and of Paul Lathrop.

Henry was the first to pick up the sounds and instantly he hurried to the telephone and called Jim. But by the time he had Jim’s number the latter had also picked up the signals and had called the

others, for Tom had not disturbed his transmission set and ordinary phoning was the only means of communicating with one another at the boys’ disposal. For some time Tom, at the 23d St. house, could not pick up the sounds, but at last, with his loop pointed to the northeast, they came clear. “Congratulations,” was the first word he heard, instantly followed by the queer buzzing sound which Henry had described. “Golly, ’tis just like some one talking through a comb,” was Tom’s mental comment and deeply interested and tremendously puzzled he strained his ears and mind striving to formulate words or meanings from the strange sounds. Once or twice he was sure that the sounds were words—he thought he could make out “last night” following a query of “When was it?” from the other speaker but, as he told the others later, it was like trying to hear what a mosquito was saying.

So intent was he on this that he quite forgot to jot down the plain words of the other speaker and did not realize it until the sounds ceased and the conversation was over.

But he knew that the others would have it and

he had the direction, which was the main thing, and, a few minutes later all the boys were together and eagerly discussing the results of their experiment.

“He’s southeast of my set!” announced Frank, when Tom had told them what he had discovered. “That puts him in between the river front and Third Avenue and between 23d and 26th Sts.”

“Well, we’re getting him narrowed down to a few blocks now,” said Henry joyfully. “Say, what did you fellows make of the talk? Here’s my slip.”

The words that Henry had written down were as follows: “Everything O. K. Yes, haven’t an idea. Sure, Fritz told me about it. Must be careful. No, but price will drop. No use killing the goose, you know. Golden eggs is right. Not a chance in the world of their getting wise. Nonsense, no one else has anything like it. Amateurs. Oh, forget it. Well, let ’em guess, guesses don’t prove anything. Well, if they did they’d never find anything. Magnolia. Yes, same place thirty fifteen west. Oh, yes, the French stuff went like hot cakes. Sure, get all you can. Yes she

cleared. Regards to Heinrich. Expect you the eighteenth. Don’t forget Magnolia. Good-by.”

“It’s just the same as I made it,” announced Frank.

“Same here,” said Jim. “Sufferin’ cats! Do you mean to say that nut isn’t bughouse now?”

“It does sound a bit crazy, I admit,” replied Tom. “Say, did any of you fellows try tuning to different wave lengths to see if any one else came in?”

“I did,” declared Frank, “but all I got was some one who said ‘for the love of Mike get off the air.’”

“Me, too,” chimed in Jim. “No one’s talking to him, he’s just nutty and chins to himself.”

“Well, then, we have all the more reason for finding him,” said Tom. “If he’s really crazy the authorities ought to know it. Now we know he’s so close we ought to be able to locate him.”

So, day after day, the boys, their interest and enthusiasm at high pitch owing to the success of their experiments, shifted their instruments from house to house, gradually drawing their radio net about the mysterious sender until they were positive that he was located in a certain block, a district

of small, old-fashioned buildings, warehouses and garages.

But beyond this they could not go. There were no boys so far as they knew within the area and, satisfied that they had done all they could and that they had proved the value of their loops in locating the unknown speaker, all but Tom, Frank and Henry lost interest and devoted their attention to other matters.

But Tom, Frank, and, to a lesser degree, Henry were still deeply interested in the mysterious messages and were convinced that they came either from a gang of rum-runners or from some other law-breakers, for while there was nothing really suspicious in the messages they could not rid themselves of the idea, once it had entered their minds.

“I vote we go and tell Mr. Henderson all we know,” said Tom. “Dad won’t be back for two weeks or more yet and if Mr. Henderson thinks there’s anything in it he can have that block searched and find out who owns the set.”

“Well, perhaps ’twould be a good plan,” admitted Frank, and accordingly the two boys went to Mr.

Henderson’s office and related the story of their experiments and told of their suspicions.

“H-m-m,” remarked the keen-eyed man when they had ended, “this is very interesting, boys. Let me see the notes you made.”

For a time he examined the slips of paper bearing the various messages the boys had scribbled down and his forehead wrinkled in a frown of perplexity.

“It’s very indefinite,” he announced at last, half to himself, “but I agree with you that the whole matter has a suspicious appearance. Too bad you didn’t take down the earlier messages you heard. Now, let’s see. You say you have never heard the other party to the conversations and yet you have been listening in within a block of this chap. Very odd, yes, most extraordinary. There are several explanations that occur to me, however. For example, if they wished the conversation to be secret and unintelligible they might have arranged that one man was to talk through an ordinary phone and the other by radio. Or they might have arranged this because the second man had no sending set—exactly as you boys communicated with one

another with only one transmission set among you.”

“Gee, but we are dumb-bells!” exclaimed Tom. “Why the dickens didn’t we think of that? Why we are doing the same thing ourselves. It was so simple we overlooked it.”

Mr. Henderson smiled. “That’s often the way,” he declared. “During the war a lot of messages passed our censors as perfectly innocent and harmless and yet they were of the utmost importance—they were so frank and simple we overshot the mark.”

“Yes, Dad told us about some of those,” said Tom.

“As I was saying,” went on Mr. Henderson, “if one man was talking over a telephone you would not have heard him under ordinary conditions, but it often happens that through capacity inductance a phone message may come in over a radio set. That might account for your occasionally hearing those sounds which you describe as resembling words coming through a paper-covered comb. Do you remember the conditions under which you