of Arc Lighting; Electrical Expert and Consulting Engineer.
Joint Author of "The Electric Telephone," "The Electric Telegraph," "Alternating Currents," "Arc Lighting," "Electric Heating," "Electric Motors," "Electric Railways," "Incandescent Lighting," etc.

WILLIAM J. HOPKINS

Professor of Physics in the Drexel Institute of Art, Science, and Industry, Philadelphia.
Author of "Telephone Lines and their Properties."

ToC

Foreword

The present day development of the "talking wire" has annihilated both time and space, and has enabled men thousands of miles apart to get into almost instant communication. The user of the telephone and the telegraph forgets the tremendousness of the feat in the simplicity of its accomplishment; but the man who has made the feat possible knows that its very simplicity is due to the complexity of the principles and appliances involved; and he realizes his need of a practical, working understanding of each principle and its application. The Cyclopedia of Telephony and Telegraphy presents a comprehensive and authoritative treatment of the whole art of the electrical transmission of intelligence.

The communication engineer—if so he may be called—requires a knowledge both of the mechanism of his instruments and of the vagaries of the current that makes them talk. He requires as well a knowledge of plants and buildings, of office equipment, of poles and wires and conduits, of office system and time-saving methods, for the transmission of intelligence is a business as well as an art. And to each of these subjects, and to all others pertinent, the Cyclopedia gives proper space and treatment.

The sections on Telephony cover the installation, maintenance, and operation of all standard types of telephone systems; they present without prejudice the respective merits of manual and automatic exchanges; and they give special attention to the prevention and handling of operating "troubles." The sections on Telegraphy cover both commercial service and train dispatching. Practical methods of wireless communication—both by telephone and by telegraph—are thoroughly treated.

The drawings, diagrams, and photographs incorporated into the Cyclopedia have been prepared especially for this work; and their instructive value is as great as that of the text itself. They have been used to illustrate and illuminate the text, and not as a medium around which to build the text. Both drawings and diagrams have been simplified so far as is compatible with their correctness, with the result that they tell their own story and always in the same language.

The Cyclopedia is a compilation of many of the most valuable Instruction Papers of the American School of Correspondence, and the method adopted in its preparation is that which this School has developed and employed so successfully for many years. This method is not an experiment, but has stood the severest of all tests—that of practical use—which has demonstrated it to be the best yet devised for the education of the busy, practical man.

In conclusion, grateful acknowledgment is due to the staff of authors and collaborators, without whose hearty co-operation this work would have been impossible.

Table of Contents

VOLUME II

Manual Switchboards By K. B. Miller and S. G. McMeen[A] Page[B] 11

CHAPTER XXII—Common-Battery Switchboards—Line Signals—Cord Circuit—Lamps—Mechanical Signals—Relays—Jacks—Switchboard Assembly

CHAPTER XXIII—Transfer Switchboard—Transfer Lines—Handling Transfers

CHAPTER XXIV—Multiple Switchboard—Busy Test—Influence of Traffic

CHAPTER XXV—Magneto-Multiple Switchboard—Multiple Boards: Series, Branch-Terminal, Modern Magneto, Common-Battery

CHAPTER XXVI—Western Electric No. 1 Relay Board—Western Electric No. 10 Board—Types of Multiple Boards—Apparatus

CHAPTER XXVII—Trunking—Western Electric and Kellogg Trunk Circuits

Automatic Systems By K. B. Miller and S. G. McMeen Page 135

CHAPTER XXVIII—Automatic vs. Manual—Operation

CHAPTER XXIX—Selecting Switch—Line Switch—Trunking Systems—Two- and Three-Wire Systems—Subscriber's Station Apparatus—First and Second Selector Operation—Connector—Release after Conversation—Multi-Office System—Automatic Sub-Offices—Rotary Connector—Party Lines—Two-Wire Automatic System

public@vhost@g@gutenberg@html@files@33437@[email protected]#CHAPTER_XXX"