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.
CONTENTS
| I. | Splintering Glass | [9] |
| II. | In a Dilemma | [20] |
| III. | The Stuttering Voice | [31] |
| IV. | A Puzzling Mystery | [43] |
| V. | Marvels of Wireless | [51] |
| VI. | The Forest Ranger | [61] |
| VII. | Radio and the Fire Fiend | [70] |
| VIII. | Near Disaster | [77] |
| IX. | A Happy Inspiration | [83] |
| X. | The Escaped Convict | [91] |
| XI. | Down the Trap Door | [99] |
| XII. | Groping in Darkness | [106] |
| XIII. | Cunning Scoundrels | [112] |
| XIV. | A Daring Holdup | [119] |
| XV. | Off to the Woods | [127] |
| XVI. | Put to the Test | [136] |
| XVII. | The Bully Gets a Ducking | [143] |
| XVIII. | A Startling Discovery | [151] |
| XIX. | The Robbers’ Code | [160] |
| XX. | On the Trail | [168] |
| XXI. | The Glimpse Through the Window | [177] |
| XXII. | A Nefarious Plot | [185] |
| XXIII. | Preparing an Ambush | [193] |
| XXIV. | Lying in Wait | [202] |
| XXV. | An Exciting Struggle | [208] |