Chapter I: Front Matter

Cyclopedia

of

Telephony and Telegraphy

_A General Reference Work on_

TELEPHONY, SUBSTATIONS, PARTY LINE SYSTEMS, PROTECTION, MANUAL SWITCHBOARDS, AUTOMATIC SYSTEMS, POWER PLANTS, SPECIAL SERVICE FEATURES, CONSTRUCTION, ENGINEERING, OPERATION, MAINTENANCE, TELEGRAPHY, WIRELESS TELEGRAPHY AND TELEPHONY, ETC.

_Prepared by a Corps of_

TELEPHONE AND TELEGRAPH EXPERTS, AND ELECTRICAL ENGINEERS OF THE HIGHEST PROFESSIONAL STANDING

_Illustrated with over Two Thousand Engravings_

FOUR VOLUMES

CHICAGO

AMERICAN SCHOOL OF CORRESPONDENCE

1919

COPYRIGHT, 1911, 1912, BY AMERICAN SCHOOL OF CORRESPONDENCE

COPYRIGHT, 1911, 1912 BY AMERICAN TECHNICAL SOCIETY

Entered at Stationers' Hall, London All Rights Reserved

Authors and Collaborators

* * * * *

KEMPSTER B. MILLER, M.E. Consulting Engineer and Telephone Expert Of the Firm of McMeen and Miller, Electrical Engineers and Patent Experts, Chicago American Institute of Electrical Engineers Western Society of Engineers

* * * * *

GEORGE W. PATTERSON, S.B., Ph.D. Head, Department of Electrical Engineering, University of Michigan

* * * * *

CHARLES THOM Chief of Quadruplex Department, Western Union Main Office, New York City

* * * * *

ROBERT ANDREWS MILLIKAN, Ph.D. Associate Professor of Physics, University of Chicago Member, Executive Council, American Physical Society

* * * * *

SAMUEL G. McMEEN Consulting Engineer and Telephone Expert Of the Firm of McMeen and Miller, Electrical Engineers and Patent Experts, Chicago American Institute of Electrical Engineers Western Society of Engineers

* * * * *

LAWRENCE K. SAGER, S.B., M.P.L. Patent Attorney and Electrical Expert Formerly Assistant Examiner, U.S. Patent Office

* * * * *

GLENN M. HOBBS, Ph.D. Secretary, American School of Correspondence Formerly Instructor in Physics, University of Chicago American Physical Society

* * * * *

CHARLES G. ASHLEY Electrical Engineer and Expert in Wireless Telegraphy and Telephony

* * * * *

A. FREDERICK COLLINS Editor, _Collins Wireless Bulletin_ Author of "Wireless Telegraphy, Its History, Theory, and Practice"

* * * * *

FRANCIS B. CROCKER, E.M., Ph.D. Head, Department of Electrical Engineering, Columbia University Past-President, American Institute of Electrical Engineers

* * * * *

MORTON ARENDT, E.E. Instructor in Electrical Engineering, Columbia University, New York

* * * * *

EDWARD B. WAITE Head, Instruction Department, American School of Correspondence American Society of Mechanical Engineers Western Society of Engineers

* * * * *

DAVID P. MORETON, B.S., E.E. Associate Professor of Electrical Engineering, Armour Institute of Technology American Institute of Electrical Engineers

* * * * *

LEIGH S. KEITH, B.S. Managing Engineer with McMeen and Miller, Electrical Engineers and Patent Experts Chicago Associate Member, American Institute of Electrical Engineers

* * * * *

JESSIE M. SHEPHERD, A.B. Associate Editor, Textbook Department, American School of Correspondence

* * * * *

ERNEST L. WALLACE, B.S. Assistant Examiner, United States Patent Office, Washington, D. C.

* * * * *

GEORGE R. METCALFE, M.E. Editor, _American Institute of Electrical Engineers_ Formerly Head of Publication Department, Westinghouse Elec. & Mfg. Co.

* * * * *

J. P. SCHROETER Graduate, Munich Technical School Instructor in Electrical Engineering, American School of Correspondence

* * * * *

JAMES DIXON, E.E. American Institute of Electrical Engineers

* * * * *

HARRIS C. TROW, S.B., _Managing Editor_ Editor-in-Chief, Textbook Department, American School of Correspondence

Authorities Consulted

The editors have freely consulted the standard technical literature of America and Europe in the preparation of these volumes. They desire to express their indebtedness particularly to the following eminent authorities, whose well-known works should be in the library of every telephone and telegraph engineer.

Grateful acknowledgment is here made also for the invaluable co-operation of the foremost engineering firms and manufacturers in making these volumes thoroughly representative of the very best and latest practice in the transmission of intelligence, also for the valuable drawings, data, suggestions, criticisms, and other courtesies.

* * * * *

ARTHUR E. KENNELY, D.Sc. Professor of Electrical Engineering, Harvard University. Joint Author of "The Electric Telephone," "The Electric Telegraph," "Alternating Currents," "Arc Lighting," "Electric Heating," "Electric Motors," "Electric Railways," "Incandescent Lighting," etc.

* * * * *

HENRY SMITH CARHART, A.M., LL.D. Professor of Physics and Director of the Physical Laboratory, University of Michigan. Author of "Primary Batteries," "Elements of Physics," "University Physics," "Electrical Measurements," "High School Physics," etc.

* * * * *

FRANCIS B. CROCKER, M.E., Ph.D. Head of Department of Electrical Engineering, Columbia University, New York; Past-President, American Institute of Electrical Engineers. Author of "Electric Lighting;" Joint Author of "Management of Electrical Machinery."

* * * * *

HORATIO A. FOSTER Consulting Engineer; Member of American Institute of Electrical Engineers; Member of American Society of Mechanical Engineers. Author of "Electrical Engineer's Pocket-Book."

* * * * *

WILLIAM S. FRANKLIN, M.S., D.Sc. Professor of Physics, Lehigh University. Joint Author of "The Elements of Electrical Engineering," "The Elements of Alternating Currents."

* * * * *

LAMAR LYNDON, B.E., M.E. Consulting Electrical Engineer; Associate Member of American Institute of Electrical Engineers; Member, American Electro-Chemical Society. Author of "Storage Battery Engineering."

* * * * *

ROBERT ANDREWS MILLIKAN, Ph.D. Professor of Physics, University of Chicago. Joint Author of "A First Course in Physics," "Electricity, Sound and Light," etc.

* * * * *

KEMPSTER B. MILLER, M.E. Consulting Engineer and Telephone Expert; of the Firm of McMeen and Miller, Electrical Engineers and Patent Experts, Chicago. Author of "American Telephone Practice."

* * * * *

WILLIAM H. PREECE Chief of the British Postal Telegraph. Joint Author of "Telegraphy," "A Manual of Telephony," etc.

* * * * *

LOUIS BELL, Ph.D. Consulting Electrical Engineer; Lecturer on Power Transmission, Massachusetts Institute of Technology. Author of "Electric Power Transmission," "Power Distribution for Electric Railways," "The Art of Illumination," "Wireless Telephony," etc.

* * * * *

OLIVER HEAVISIDE, F.R.S. Author of "Electro-Magnetic Theory," "Electrical Papers," etc.

* * * * *

SILVANUS P. THOMPSON, D.Sc., B.A., F.R.S., F.R.A.S. Principal and Professor of Physics in the City and Guilds of London Technical College. Author of "Electricity and Magnetism," "Dynamo-Electric Machinery," "Polyphase Electric Currents and Alternate-Current Motors," "The Electromagnet," etc.

* * * * *

ANDREW GRAY, M.A., F.R.S.E. Author of "Absolute Measurements in Electricity and Magnetism."

* * * * *

ALBERT CUSHING CREHORE, A.B., Ph.D. Electrical Engineer; Assistant Professor of Physics, Dartmouth College; Formerly Instructor in Physics, Cornell University. Author of "Synchronous and Other Multiple Telegraphs;" Joint Author of "Alternating Currents."

* * * * *

J. J. THOMSON, D.Sc., LL.D., Ph.D., F.R.S. Fellow of Trinity College, Cambridge University; Cavendish Professor of Experimental Physics, Cambridge University. Author of "The Conduction of Electricity through Gases," "Electricity and Matter."

* * * * *

FREDERICK BEDELL, Ph.D. Professor of Applied Electricity, Cornell University. Author of "The Principles of the Transformer;" Joint Author of "Alternating Currents."

* * * * *

DUGALD C. JACKSON, C.E. Head of Department of Electrical Engineering, Massachusetts Institute of Technology; Member, American Institute of Electrical Engineers, etc. Author of "A Textbook on Electromagnetism and the Construction of Dynamos;" Joint Author of "Alternating Currents and Alternating-Current Machinery."

* * * * *

MICHAEL IDVORSKY PUPIN, A.B., Sc.D., Ph.D. Professor of Electro-Mechanics, Columbia University, New York. Author of "Propagation of Long Electric Waves," and "Wave-Transmission over Non-Uniform Cables and Long-Distance Air Lines."

* * * * *

FRANK BALDWIN JEWETT, A.B., Ph.D. Transmission and Protection Engineer, with American Telephone & Telegraph Co. Author of "Modern Telephone Cable," "Effect of Pressure on Insulation Resistance."

* * * * *

ARTHUR CROTCH Formerly Lecturer on Telegraphy and Telephony at the Municipal Technical Schools, Norwich, Eng. Author of "Telegraphy and Telephony."

* * * * *

JAMES ERSKINE-MURRAY, D.Sc. Fellow of the Royal Society of Edinburgh; Member of the Institution of Electrical Engineers. Author of "A Handbook of Wireless Telegraphy."

* * * * *

A. H. McMILLAN, A.B., LL.B. Author of "Telephone Law, A Manual on the Organization and Operation of Telephone Companies."

* * * * *

WILLIAM ESTY, S.B., M.A. Head of Department of Electrical Engineering, Lehigh University. Joint Author of "The Elements of Electrical Engineering."

* * * * *

GEORGE W. WILDER, Ph.D. Formerly Professor of Telephone Engineering, Armour Institute of Technology. Author of "Telephone Principles and Practice," "Simultaneous Telegraphy and Telephony," etc.

* * * * *

WILLIAM L. HOOPER, Ph.D. Head of Department of Electrical Engineering, Tufts College. Joint Author of "Electrical Problems for Engineering Students."

* * * * *

DAVID S. HULFISH Technical Editor, _The Nickelodeon_; Telephone and Motion-Picture Expert; Solicitor of Patents. Author of "How to Read Telephone Circuit Diagrams."

* * * * *

J. A. FLEMING, M.A., D.Sc. (Lond.), F.R.S. Professor of Electrical Engineering in University College, London; Late Fellow and Scholar of St. John's College, Cambridge; Fellow of University College, London. Author of "The Alternate-Current Transformer," "Radiotelegraphy and Radiotelephony," "Principles of Electric Wave Telegraphy," "Cantor Lectures on Electrical Oscillations and Electric Waves," "Hertzian Wave Wireless Telegraphy," etc.

* * * * *

F. A. C. PERRINE, A.M., D.Sc. Consulting Engineer; Formerly President, Stanley Electric Manufacturing Company; Formerly Professor of Electrical Engineering, Leland Stanford, Jr. University. Author of "Conductors for Electrical Distribution."

* * * * *

A. FREDERICK COLLINS Editor, _College Wireless Bulletin_. Author of "Wireless Telegraphy, Its History, Theory and Practice," "Manual of Wireless Telegraphy," "Design and Construction of Induction Coils," etc.

* * * * *

SCHUYLER S. WHEELER, D.Sc. President, Crocker-Wheeler Co.; Past-President, American Institute of Electrical Engineers. Joint Author of "Management of Electrical Machinery."

* * * * *

CHARLES PROTEUS STEINMETZ Consulting Engineer, with the General Electric Co.; Professor of Electrical Engineering, Union College. Author of "The Theory and Calculation of Alternating-Current Phenomena," "Theoretical Elements of Electrical Engineering," etc.

* * * * *

GEORGE W. PATTERSON, S.B., Ph.D. Head of Department of Electrical Engineering, University of Michigan. Joint Author of "Electrical Measurements."

* * * * *

WILLIAM MAVER, Jr. Ex-Electrician Baltimore and Ohio Telegraph Company; Member of the American Institute of Electrical Engineers. Author of "American Telegraphy and Encyclopedia of the Telegraph," "Wireless Telegraphy."

* * * * *

JOHN PRICE JACKSON, M.E. Professor of Electrical Engineering, Pennsylvania State College. Joint Author of "Alternating Currents and Alternating-Current Machinery."

* * * * *

AUGUSTUS TREADWELL, Jr., E.E. Associate Member, American Institute of Electrical Engineers. Author of "The Storage Battery, A Practical Treatise on Secondary Batteries."

* * * * *

EDWIN J. HOUSTON, Ph.D. Professor of Physics, Franklin Institute, Pennsylvania; Joint Inventor of Thomson-Houston System 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."

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

Common-Battery Switchboards--Line Signals--Cord Circuit--Lamps--Mechanical Signals--Relays--Jacks--Switchboard Assembly--Transfer Switchboard--Transfer Lines--Handling Transfers--Multiple Switchboard--Busy Test--Influence of Traffic--Magneto-Multiple Switchboard--Multiple Boards: Series, Branch-Terminal, Modern Magneto, Common-Battery--Western Electric No. 1 Relay Board--Western Electric No. 10 Board--Types of Multiple Boards--Apparatus--Trunking--Western Electric and Kellogg Trunk Circuits

AUTOMATIC SYSTEMS _By K. B. Miller and S. G. McMeen_ Page 135

Automatic vs. Manual--Operation--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--Lorimer System--Central-Office Apparatus--Operation--Automanual System--Operation--Subscriber's Apparatus--Operator's Equipment--Switching Equipment--Distribution of Calls--Connection--Speed

POWER PLANTS AND BUILDINGS _By K. B. Miller and S. G. McMeen_ Page 227

Currents Employed--Types--Operator's Transmitter Supply--Ringing-Current Supply--Auxiliary Signaling Current--Primary Sources--Duplicate Apparatus--Storage Batteries--Power Switchboards--Circuits--Central-Office Building--Arrangement of Apparatus--Manual Offices--Automatic Offices

SPECIAL SERVICE FEATURES _By K. B. Miller and S. G. McMeen_ Page 271

Private-Branch Exchanges--Switchboards--Supervision--With Automatic Offices--Battery Supply--Ringing Current--Inter-Communicating Systems--Magneto System--Common-Battery Systems--Types--Long-Distance Switching--Operator's Orders--Trunking--Way Stations--Traffic--Measured Service--Charging--Rates--Toll Service--Local Service

TELEGRAPH AND RAILWAY WORK _By K. B. Miller and S. G. McMeen_ Page 321

Phantom, Simplex, and Composite Circuits--Ringing--Railway Composite--Telephone Train Dispatching--Railroad Conditions--Transmitting Orders--Apparatus--Telephone Equipment--Types of Circuits--Test Boards--Blocking Sets--Dispatching on Electric Railways

REVIEW QUESTIONS Page 359

INDEX Page 373

[Footnote A: For professional standing of authors, see list of Authors and Collaborators at front of volume.]

[Footnote B: For page numbers, see foot of pages.]