Cyclopedia of Telephony and Telegraphy, Vol. 1 / A General Reference Work on Telephony, etc. etc.

by American School of Correspondence

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."