The Radio Detectives

innumerable difficulties, had made numbers of mistakes, had been faced with failure or negative results time after time and would have given up in despair had it not been for the e

he depths and he could see no valid reason why anything that could be accomplished on shore should not be accomplished equally well under water. He had distinguished himself by devising a submarine apparatus for taking motion pictures at the bottom of the sea and it was while engaged in making a sub-sea film that he had invented and perfected his remarkable self-contained diving

rely new system and absolutely refused to allow the boys to don suits and go down until he had thoroughly tested out and proved the new equipment. It was not an easy matter, but in the end he succeeded, and, risking his own life in the experiment, he gave th

and made it practical for any one to use without danger. In addition, there were innumerable other changes and alterations which had to be made to adapt the suits to

ter's head with the protuberance which contained the compact little receiving set like a huge goiter. Indeed, as Henry had remarked when he first saw Rawlins appearing dripping from the river, they looked like weird and fearful sea monsters. So, if the reader

dropped from the final rung of the ladder and settled, half-floating like some big, ungainly fish upon the river bottom. Through the half opaque green water he could see the irregular, grotesquely distorted and hazy form of Rawlins appearing gigantic and phantomlike. He might have been fifteen or fifty feet away, for despite the fact that Tom had been down several times he could never accustom hi

!" came Rawlins' words in respons

the diver, "but don't shout. I'm talking in

filled his helmet, and involuntarily he clapped hi

now, Mr. Rawlins. It won't happen again. I guess these helmets ac

Tom barely checked another outburst as he realized that the boys on sho

y," went on Frank's voice. "Ca

!" replied Tom. "Isn

?" inquired Frank. "I ca

g just roars. We have to talk low or we'll deafen each other

th you," Frank announced,

ween the workshop and the bottom of the river and then Ra

r success that it was a wonder the river police did not break in thinking a horde of Indians had taken possession o

down and Frank, mad to g

m. "Then you can talk loudly enough to be h

ar Rawlins and Frank talking from under the water, and indeed, it impressed him a

ithout the receivers on their heads, and even when Frank spoke in hi

to vary my wave length and see if you can pick it

waves slightly and breathlessly wai

f trouble at first, but it's all rig

er, as Tom turned the knob on his tuner, the words suddenly returned in

m jubilantly. "Come on up, F

lared Rawlins, when he and Henry came up and had remo

ot louder inside a helmet than outside. I don't just get the reason, but I expect it's either because the whole air vibrates to the diaphragm of the receivers i

hole thing gets me, there's millions in this if we can patent it. Let's go down once more and give her a real tryout. We'll take a hike down river a few hundred yards and see if the boys get us. If they don

d as soon as we lose your voice we'll send and then walk back until we get you again. Tha

already cautioned Tom to keep close to his side and to hold to his hand, for, with the mud stirred up by their feet and carried b

run down or torn to pieces with the propellers. As long as they kept close to shore, following the docks and piers, there was no danger, for the only vessels in the vicinity were canal boats and barges which were not in use, the piers for several hundred yards having been used merely for storage and as warehouses for some time. Moreover,

ance, he seemed to be standing still, although exerting himself and constantly stepping or rather pushing himself forward. He was so intent on this and so interested in the novel experience that he scarcely realized that Frank's voice had suddenly grown faint and was interrupted by an odd buzzing sound which instantly brought

ving from its barnacle-encrusted planks; a piece of trailing, rusty cable; a few rotting, water-soaked timbers protruding from the mud; and a shapeless mass which might have been almost any piece of jetsam cast into the river. Then like phantom shapes, so indistinct, hazy and formless that he was not sure they were not shadows in the water, he saw two figures-two moving things that, for a brief instant, he thought must be

. Glad, indeed, was Tom that Rawlins was beside him, that the diver was armed-for Rawlins, he knew, never went down without a hatchet in his belt ready for use in case

he odd, half-sprawling, half-floating, forward-leaning posture he knew so well. But great as was Tom's relief at this discovery his wonderment was doubly increased. Who were they and what were they doing here? Why had Rawli

n ejaculation of surprise and fairly jumped when, fain

forgetting that he was under water, cut off from all conversation with other human beings save the boys. "Come on, I don't know who they are, bu

er water. Beside them rose a dark wall of masonry and reaching this Rawlins proceeded to feel his way along it. Before they had tra

re," whispered R

tter blackness, feeling their

in. "What on earth's the matter?" he asked. "I haven't he

o sound issued from them. Clear, loud and harsh, guttural words rang in Tom's ears. This was not Frank's voice nor Henry's; the words were not even Englis

ut it and he was on the point of asking his companion if he had heard and of trying to tell Frank, when once more his words were stayed. Before him the stygian darkness suddenly grew light, a brilliant beam stabbed down from overhead and through the strangely illuminated water Tom saw the two men in diving suits standing beneath a square opening

it under the water and then, as the hook again ascended, he saw a dripping, cigar-shaped object like a torpedo slowly rise from the water and disappear in the opening above.

?" exclaimed Tom, find

voice, only to be overwhelmed and

otten going on here. Don't know what, but I i

f course not. But I heard that same chap you h

Oleander. That's a password-a countersign. Just as soon as they spoke it the door opened. There's some deep mystery here. What the deuce that torpedolike affa

is ears, striving to grasp all this astounding statement of Rawlins', Tom

If they've got radio they can hear us too! Say, perhaps th

whistle came shri

ver. "We're in a dangerous pla

kness would permit and presently, though to Tom it seemed hours, a lighter space appeare

ing along the old wall when once more they were halted in their tracks. Again

ndreds of feet or even yards distant, the two crouched back in a recess of the masonry, flattening themselves against