al 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