Cyclopedia of Telephony and Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc.   By: American School of Correspondence

[Illustration: ALEXANDER GRAHAM BELL The Inventor of the Telephone.]

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

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