ffice closed behind them before Frank co

s great! We're real detective

n't want every one in the place to know it and they'll

Henry's room and told him of their talk with Mr.

ct of a fellow near a phone. I was a fool not to have thought of it. Why, Jim told me about that long ago. He even said his brother Ed showed him with his set on the San Jacinto.

oming to them through Henry's set. "Say," he continued, "there isn't much privacy nowadays, is there? Why,

never realized it," said Frank. "Mr. Henderson must think we are great rad

eclared Tom. "If that fellow begins

m," objected Henry. "So

in thing is to hear what he says. Then

e messages the fellow mentioned a flower? First 'twas 'Azalia' and then 'Magnolia' and

lowers, but what's Frangi Pani-sounds like some sort of Japanese thing to me. I guess t

ve a whole fleet

ay be in the flower business,"

answer to that when we

remarked Henry. "Say, what

ad devised and at last left him with final cautions to be at his instruments th

e more the name of a flower had entered into the conversation and mentally wondering what in the world this meant the two boys slipped the receiver of the desk telephone from its hook. Hardly had they done so when they almost jumped, as clear and loud, th

erk, Tom hung u

Mr. Henderson knew that and just tried to jolly us. N

her voice, evidently that of a woman, and pitched in high tones. "Oh, yes!" it exclaimed. "I'm so glad, my dear. Do you know-" Tom drew

any difference if the receiver is off or not-we aren't getting

get busy. That chap's been talking for the last five

ne to see if they could hear the other party to the conversation, but each time the nasal voice of the woman, gossiping with

"How the dickens could a fellow expect to hear a

adio," chuckled Frank. "And won't the women have the ti

guess," muttered Tom. "Come on, let's go over

business with a friend, but he had written down all the words the mysterious man had spoken and showed

know then. Might have been a different tale, eh? Oh, Oscar's all right. Yes, same old place. Nothing doing, old man

mented Tom when he had finishe

r flower,"

ticed that," chuckled Frank. "I'm begi

ailed to hear anything of interest over the ordinary phones while the radio words were

ys rose from their sets on the third night. "His theory was

rate," agreed Frank. "Let's go

Mr. Henderson the next day and repor

d. "If you heard others it's pretty conclusive evidence he's n

as plain and no plainer when I was a long w

of course, this is a profound secret. No one will know who they are or what they're after. It must be a surprise visit so don't even talk it over among yourselves. But I want you to help us a bit. I'm going to start the men out at eight o'clock sharp, to-night. You must be at your sets and listening. If the fel

called attention to those names of flowers yesterday. We'd almost forgotten about th

e noticed that-that's one thing that influences me more than anything else. There's some code to tho

e boys refrained from mentioning it to one another, but could scarcely restr

n from its words or its abrupt ending of the success of the raid. But the minutes ticked by, the hands of the cloc

search, the boys hurried to Mr. H

d his office. "There wasn't a sign of a wireless out

ed that they ha

o believe that they had been mistaken. "Why, we were all around the

ine-tooth comb. Either you boys were mistaken or else the fellow's moved away. If you hear him again you'll know whether he's changed his location. I'm afraid you'll never locate him by your instrumen

ffice and for hours discussed the matter with one another, b

and now let's do something else. Dad's leaving Nassau to-morrow and we can t

think we're such dubs," said Frank. "He thinks we've made s

t the mysterious conversations almost slipped from their minds, and as no further messages were heard from the same source they decided that by some co

y before Mr. Pauling's ship docked, the

jubilantly, "and our set's only supposed to

question as to their location and the information that the inquirer was the government operator at

t. "We were heard clear down in Panam

ey who was heard in Scotland and Honduras!"

y miles distant and realized that, by some peculiar atmospheric condition, their dots and da

Tom, and rushing down the stairs he excit

should not talk to Balboa or Europe or any other point if you can talk to your father's ship ou

rcely wait to relate the story of his freak message an

Says you can send well and had no trouble in getting his message at regular speed. I'm mighty glad you've done so well, Son.

erious messages and what had come of

rs. By the way, I met a chap down at Nassau that was just about as keen on experiments as you boys only he's not a radio fan. No, he's a diver. He's invented a new type of diving suit-self-contained he calls it. Just a sort of rubber cloth shirt and a khaki-colored helmet and lead-soled shoes. He goes down without ropes or life lines or air hose. Gets

"Suppose he wants to come up from deep water

th others ashore or on the boats. Of course he can take down a line or even a telephone, but then he at once destroys one of the great advantages of his invention. A trailing line or wire is as liable to be caught or tangled in a wreck or in coral as an air pipe or any other rope or li

nt and then he suddenly le

eamed. "Radio! Submarine r

asm, he started to explai

n. "I'll take your word for the technical end of it. Wait and tell Rawlins about it. But ho

en days the two were ceaselessly at work, drawing plans and diagrams, making and discarding instruments, purchasing

s to be overcome and were almost disco

boys took a huge liking for him and as soon as Tom told

ecking business and has sold all his outfit except the things stored there. It's a fine place to work and experiment. There are tools and a machine lathe and about ten tons of odds and ends that may come in handy. My father had his office and workshop there-did all his repairing of pumps, diving suits and tugs there, and never threw anything away. I learned to dive there-my father and grandfather were deep-sea divers, too-and there's a trap

e boys' new experiments and declared he believ

s with under-water radio, but as far as I know they never came to much. Radio had not progressed so far then and there were more important things to be done and not enough men to attend to it. We did use vacuum tubes and amplifiers for detecting submarines, however. By the way, I hav

set up on Rawlins' dock and the boys and their diver

d the first time he put it on to demonstrate it to the boys they became tremendously excited. Rawlins carefu

only danger about it. If a man forgets and takes the mouthpiece from his lips to speak without shutting it off and water gets in, he'll

his legs, descend the ladder and disappear in the water without lines, pipes or ropes trailing after him. Both Tom and Frank were crazy to go down, but Rawlins refused to permit it until he had made the suits "fool

ut the radio," argued Tom, "so w

d to find a smooth, hard bottom and to see fishes swimming about and to be able to look up and see passing boats overhead. To their surprise, they found they could not walk upright, but leaned far forward and had a peculiar dreamy sensation when they attempted to walk, their feet seeming to half-drag, half-float behind them and that, despite the fact that the bottom of the river was soft and muddy, they did not sink into the bottom to any extent. As Tom put it, it was like trying to hurry in a dream when one's feet seem tied to somet

rry on their experiments with any hopes of success they must learn to

radio devices and at last Tom announced tha

stand up long under water, but if the idea's all right and we get any

vice and at Tom's suggestion was to go down alone with the receiver in his hel

om. "If it works we'll get it into good shape a

and with the receivers clamped over his ears, Rawlins backed down the ladder while the boys, feeling like explo

beyond question whether their ideas had been right and whether all their work and trouble had

cess of their efforts would mean and had gone into it

uccessful under-sea radio telephone would open up, they understo

tackle or anything else. And think what it would mean in time of war! Why, a man could walk out from shore anywhere, go under a ship and fasten a mine to her and blow her up and hear all that was going on aboard the enemy's ship. And just think what a dangerous sort of spy a man would be-out of sight under the sea and yet able to hear all the talk and messages of the enemy! I tell yo