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LVIII. Notices respecting New Books. 



The Principles of Electric Wave Telegraphy. B>/ J. A. Fleming, 

 M.A., D.Sc, F.R.S., Professor of Electrical Engineering in 

 University College, London. Longmans, Green & Co. : London, 

 1906. Pp. xx + 671. 



A BOOK by Dr. Fleming is always looked forward to with 

 eager anticipation by all serious students of electrotech- 

 nology, for the author has established for himself a unique repu- 

 tation as a writer of clear and eminently readable text-books, and 

 the circle of admirers who are indebted to him for much of their 

 progress is a very wide one. The present volume is, therefore, in 

 spite or its bulk and price, sure to meet with a warm welcome. 

 Wireless telegraphy is one of those subjects which have taken a 

 strong hold on the popular imagination ; and in order to meet the 

 demaud for a popular account of the subject numerous books and 

 booklets, to say nothing of the flood of articles in various periodicals, 

 have been issued from time to time. Serious works dealing with 

 the subject in a thorough manner have not been so numerous, and 

 the rapid developments taking place in it have rendered it extremely 

 difficult, if not impossible, to write a well-balanced and up-to-date 

 account of it. From his close association with the practical aspects 

 of wireless telegraphy, and his important contributions to it both 

 as a theorist and an inventor, Dr. Fleming is preeminently qualified 

 to deal with the very difficult task of coordinating and presenting 

 in proper perspective the various branches of the subject on which 

 he writes. 



The book is divided into three parts, dealing respectively with 

 Electric Oscillations, Electric Waves, and Electric Wave Telegraphy. 

 The first two parts occupy over 400 pages ; so that it will be seen 

 that about two-thirds of the book are devoted to an account of the 

 scientific foundations on which the practice of wireless telegraphy 

 is based. These first two parts will therefore be found to be of 

 very great interest to the student of pure science as well as to the 

 technical man. Parti, consists of three chapters, dealing with the 

 production of high-frequency currents and electric oscillations, 

 high-frequency measurements (resistances, inductances, dielectric 

 strengths, capacities, dielectric constants, currents, frequencies), 

 damping and resonance. The three chapters in Part II. deal with 

 stationary electric waves on wires, electromagnetic waves, their 

 detection and measurement. This part of the book will appeal 

 strongly to the student of electromagnetic theory, as it contains 

 an admirable account of numerous difficult problems treated in an 

 exceptionally clear and interesting manner. Part III., which also 

 consists of three chapters, contains a historical account of the early 

 development of wireless telegraph systems, of the recent work of 

 the numerous inventors who have busied themselves with this 



