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