The Radio Boys Trailing a Voice or, Solving a Wireless Mystery   By: Allen Chapman

Or

Solving a Wireless Mystery

by

ALLEN CHAPMAN

Author of The Radio Boys' First Wireless The Radio Boys at Mountain Pass Ralph of The Roundhouse Ralph on the Army Train, Etc.

With Foreword by Jack Binns

Illustrated

[Illustration: THE MAN WAS EVIDENTLY RECEIVING A MESSAGE. The Radio Boys Trailing a Voice. Page 153]

New York Grosset & Dunlap Publishers

Made in the United States of America

BOOKS FOR BOYS BY ALLEN CHAPMAN

12mo. Cloth. Illustrated.

THE RADIO BOYS SERIES (Trademark Registered)

THE RADIO BOYS' FIRST WIRELESS Or Winning the Ferberton Prize

THE RADIO BOYS AT OCEAN POINT Or The Message that Saved the Ship

THE RADIO BOYS AT THE SENDING STATION Or Making Good in the Wireless Room

THE RADIO BOYS AT MOUNTAIN PASS Or The Midnight Call for Assistance

THE RADIO BOYS TRAILING A VOICE Or Solving a Wireless Mystery

THE RAILROAD SERIES

RALPH OF THE ROUNDHOUSE Or Bound to Become a Railroad Man

RALPH IN THE SWITCH TOWER Or Clearing the Track

RALPH ON THE ENGINE Or The Young Fireman of the Limited Mail

RALPH ON THE OVERLAND EXPRESS Or The Trials and Triumphs of a Young Engineer

RALPH THE TRAIN DESPATCHER Or The Mystery of the Pay Car

RALPH ON THE ARMY TRAIN Or The Young Railroader's Most Daring Exploit

GROSSET & DUNLAP, Publishers, New York

Copyright, 1922, By GROSSET & DUNLAP

The Radio Boys Trailing a Voice

FOREWORD

BY JACK BINNS

Within a comparatively short time after this volume is published the human voice will be thrown across the Atlantic Ocean under conditions that will lead immediately to the establishment of permanent telephone communication with Europe by means of radio.

Under the circumstances therefore the various uses of radio which are so aptly outlined in it will give the reader an idea of the tremendous strides that have been made in the art of communicating without wires during the past few months.

Of these one of the most important, which by the way is dealt with to a large extent in the present volume, is that of running down crooks. It must not be forgotten that criminals, and those criminally intent are not slow to utilize the latest developments of the genius of man, and radio is useful to them also. However, the forces of law and order inevitably prevail, and radio therefore is going to be increasingly useful in our general police work.

Another important use, as outlined in this volume, is in the detection of forest fires, and in fact generally protecting forest areas in conjunction with aircraft. With these two means hundreds of thousands of acres can now be patrolled in a single day more efficiently than a few acres were previously covered.

Radio is an ideal boy's hobby, but it is not limited to youth. Nevertheless it offers a wonderful scope for the unquenchable enthusiasm that always accompanies the application of youthful endeavor, and it is a fact that the majority of the wonderful inventions and improvements that have been made in radio have been produced by young men.

Since this book was written there has been produced in this country the most powerful vacuum tube in the world. In size it is small, but in output it is capable of producing 100 kilowatts of electrical power. Three such tubes will cast the human voice across the Atlantic Ocean under any conditions, and transmit across the same vast space the world's grandest music. Ten of these tubes joined in parallel at any of the giant transmitting wireless telegraph stations would send telegraph code messages practically around the world.

[Illustration: author's signature "Jack Binns"]

CONTENTS