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

F O U R   V O L U M E S

CHICAGO
AMERICAN SCHOOL OF CORRESPONDENCE
1919

ToC

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,