Note.--For further information about electric and magnetic units get the _Bureau of Standards Circular No. 60_, called _Electric Units and Standards_, the price of which is 15 cents; also get _Scientific Paper No. 292_, called _International System of Electric and Magnetic Units_, price 10 cents. These and other informative papers can be had from the _Superintendent of Doc.u.ments, Government Printing Office_, Washington, D. C.

WIRELESS BOOKS

The Admiralty Manual of Wireless Telegraphy. 1920. Published by His Majesty's Stationery Office, London.

Ralph E. Batcher.--Prepared Radio Measurements. 1921. Wireless Press, Inc., New York City.

Elmer E. Bucher.--Practical Wireless Telegraphy. 1918. Wireless Press, Inc., New York City.

Elmer E. Bucher.--Vacuum Tubes in Wireless Communication. 1919.

Wireless Press, Inc., New York City.

Elmer E. Bucher.--The Wireless Experimenter's Manual. 1920. Wireless Press, Inc., New York City.

A. Frederick Collins.--Wireless Telegraphy, Its History, Theory, and Practice. 1905. McGraw Pub. Co., New York City.

J. H. Dellinger.--Principles Underlying Radio Communication. 1921.

Signal Corps, U. S. Army, Washington, D. C.

H. M. Dorsett.--Wireless Telegraphy and Telephony. 1920. Wireless Press, Ltd., London.

J. A. Fleming.--Principles of Electric Wave Telegraphy. 1919.

Longmans, Green and Co., London.

Charles B. Hayward.--How to Become a Wireless Operator. 1918.

American Technical Society, Chicago, Ill.

G. D. Robinson.--Manual of Radio Telegraphy and Telephony. 1920.

United States Naval Inst.i.tute, Annapolis, Md.

Rupert Stanley.--Textbook of Wireless Telegraphy. 1919. Longmans, Green and Co., London.

E. W. Stone.--Elements of Radio Telegraphy. 1919. D, Van Nostrand Co., New York City.

L. B. Turner.--Wireless Telegraphy and Telephony. 1921. Cambridge University Press. Cambridge, England.

Send to the _Superintendent of Doc.u.ments, Government Printing Office_, Washington, D. C., for a copy of _Price List No. 64_ which lists the Government's books and pamphlets on wireless. It will be sent to you free of charge.

The Government publishes; (1) _A List of Commercial Government and Special Wireless Stations_, every year, price 15 cents; (2) _A List of Amateur Wireless Stations_, yearly, price 15 cents; (3) _A Wireless Service Bulletin_ is published monthly, price 5 cents a copy, or 25 cents yearly; and (4) _Wireless Communication Laws of the United States_, the _International Wireless Telegraphic Convention and Regulations Governing Wireless Operators and the Use of Wireless on Ships and Land Stations_, price 15 cents a copy. Orders for the above publications should be addressed to the _Superintendent of Doc.u.ments, Government Printing Office, Washington, D. C._

Manufacturers and Dealers in Wireless Apparatus and Supplies:

Adams-Morgan Co., Upper Montclair, N. J.

American Hard Rubber Co., 11 Mercer Street, New York City.

American Radio and Research Corporation, Medford Hillside, Ma.s.s.

Brach (L. S.) Mfg. Co., 127 Suss.e.x Ave., Newark, N. J.

Brandes (C.) Inc., 237 Lafayette St., New York City.

Bunnell (J. H.) Company, Park Place, New York City.

Burgess Battery Company, Harris Trust Co. Bldg., Chicago, Ill.

Clapp-Eastman Co., 120 Main St., Cambridge, Ma.s.s.

Connecticut Telephone and Telegraph Co., Meriden, Conn.

Continental Fiber Co., Newark, Del.

Coto-Coil Co., Providence, R. I.

Crosley Mfg. Co., Cincinnati, Ohio.

Doolittle (F. M.), 817 Chapel St., New Haven, Conn.

Edelman (Philip E.), 9 Cortlandt St., New York City.

Edison Storage Battery Co., Orange, N. J.

Electric Specialty Co., Stamford, Conn.

Electrose Mfg. Co., 60 Washington St., Brooklyn, N. Y.

General Electric Co., Schenectady, N. Y.

Grebe (A. H.) and Co., Inc., Richmond Hill, N. Y. C.

International Bra.s.s and Electric Co., 176 Beekman St., New York City.

International Insulating Co., 25 West 45th St., New York City.

King Amplitone Co., 82 Church St., New York City.

Kennedy (Colin B.) Co., Rialto Bldg., San Francisco, Cal.

Magnavox Co., Oakland, Cal.

Manhattan Electrical Supply Co., Park Place, N. Y.