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POPULAR SCIBNOE 

 MONTHLY. 



JUNE, 1903. 



HERTZIAN WAVE WIRELESS TELEGRAPHY. I.* 



By Dr. J. A. FLEMING, F.R.S., 



PEOFESSOK OF ELECTRICAL ENGINEERING, UNIVERSITY COLLEGE, LONDON. 



n^HE immense public interest which has been aroused of late years 

 -*- in the subject of telegraphy without connecting wires has un- 

 doubtedly been stimulated by the achievements of Mr. Marconi in 

 effecting communication over great distances by means of Hertzian 

 waves. The periodicals and daily journals, which are the chief aven- 

 ues through which information reaches the public, whilst eager to 

 describe in a» sensational manner these wonderful applications of elec- 

 trical principles, have done little to convey an intelligible explanation 

 of them. Hence it appeared probable that a service would be rendered 

 by an endeavor to present an account of the present condition of elec- 

 tric wave telegraphy in a manner acceptable to those unversed in the 

 advanced technicalities of the subject, but acquainted at least with the 

 elements of electrical science. It is the purpose of these articles to 

 attempt this task. We shall, however, limit the discussion to an 

 account of the scientific principles underlying the operation of this 

 particular form of wireless telegraphy, omitting, as far as possible, 

 references to mere questions of priority and development. 



The practical problem of electric wave wireless telegraphy, which 

 has been variously called Hertzian wave telegraphy, Marconi teleg- 



* This series of articles is based on the Cantor lectures delivered before 

 the Society of Arts, London, in March, 1903. The lectures were attended by 

 many of the leading British scientific men and electrical engineers, and at- 

 tracted wide attention as the most complete and authoritative statement hither- 

 to made of wireless telegraphy. In writing the articles for The Populab 

 Science Monthly, the author has omitted advanced technicalities in order that 

 the substance may be suitable for the general reader. — Editor. 



VOL. LXIII. — 7. 



