Wireless Telegraphy and Telephony

viii TABLE OF CONTENTS PAGES Perikon Detector; Silicon Detector; Pyron Detector; Carborundum Detector; Galena Detector; Molybdenite Detector; The Potentiometer; The Tuning Coil; What Tuning Accomplishes; How Undesirable Messages Are Ex- cluded: The Loading Coil; The Fixed Condenser; Varia- ble Condensers; The Purpose of the Condenser . . 48-69 CHAPTER V Tuning and Coupling; How Tuning Is Accomplished; The Results of Tuning; The Effects of Coupling; Inductive Helixes; The Loose Coupler; The Hot Wire Ammeter; Directive Wireless Telegraphy; The Braun System; Bel- lini and Tosi Method......................■ . . 70-82 CHAPTER VI The Dignity of Wireless Telegraphy; Its Applications and Service; Wireless Telegraphy in Warfare; Wireless in the Army; Wireless in the Navy; The Wireless Telegraph Automobile; Wireless on an Airship; Wireless Telegraphy as an Aid to Press Work; The Wireless Codes; How a Message Is Transmitted and Received; The Breaking- in System..................................83-104 CHAPTER VII The Ear; How We Hear; Sound; Sound Waves; The Nature of Sound; Speech; The Larynx and Vocal Chords; The Structure of Speech; Manometric Flames . . 105-113 CHAPTER VIII The Telephone; The Telephone Transmitter; The Telephone Receiver; The Photophone; Selenium Cells; The Thermo- phone; The Electric Arc; The Speaking Arc; Wireless Telephony by Means of a Beam of Light . ... 114-123