New Books on Radio Subjects 



TEXT BOOK ON WIRELESS TELEG- 

 RAPHY. By Rupert Stanley. Published 

 by Longmans, Green & Co., New York, 1914. 

 3444-XII pp., 200 illus. Price, $2.25. 



T 



HIS book, by the professor of 



grams of various Marconi, Telefunken 

 and other instruments are shown. 



The book can be recommended for 

 careful study by anyone who desires not 

 only a good technical acquaintance with 



physics and electrical engineering radio but also a fair degree of familiar- 



at the Municipal Technical Insti 

 tute, Belfast, Ireland, is intended to fur- 

 nish a proper introduction to the tech- 

 nical problems of radio signaling. The 

 common fault of assuming on the part 

 of the student either on extended knowl- 

 edge of electrical theory or an interest in 

 long mathematical discussions has been 

 avoided. The author omits considera- 

 tion of items which do not lead directly 

 to a clear understanding of radio trans- 



ity with recent wireless telegraph prac- 

 tice. 



WIRELESS TELEGRAPHY. By J. Zenneck. 

 Transl. by A. E. Seelig. Published by McGraw- 

 Hill Book Co., New York, 19 15. 443-f-XX 

 pp., 469 illus. Price, $4.00. 



This translation into English of Pro- 

 fessor Zenneck's "Lehrbuch," the classic 

 of radio telegraphic technical literature, 

 is sure to be welcomed. Although many 



mission, but gives full treatment to the of the interrelations of electrical quan- 



physical phenomena which are especially 

 concerned. 



Of the twenty chapters the first four 

 may be said to discuss the abstract topics 

 of electrical radiation and energy trans- 

 fer. The next two take up electrical 

 units as measured and calculated, and 

 the particular effects of capacity and 

 self-induction. After descriptions of in- 

 duction coil, transformer and alternator 

 operation, and of oscillatory discharges 

 of condensers, a brief history of radio is 



titles are stated mathematically and in 

 such form as to make a knowledge of 

 the calculus desirable, nearly all these 

 statements are explained so clearly that 

 even the student who possesses only slight 

 acquaintance wnth electrical matters can 

 find much information in useful form. 

 The book is thorough, and the radio 

 reader will find as he advances in his 

 work he will get out more and more as 

 he rereads it. 



Chapter I is on condenser circuits and 



given in Chapter IX. Later chapters their oscillations. Chapter II on "open" 

 describe the operation of spark and sus- 

 tained wave transmitters and receivers, 

 the phenomena appearing in coupled 

 circuits, the use and adjustment of tele- 

 phone amplifiers, etc. A final chapter 

 on radio telegraph measurements leads 

 to appendices of codes and regulations, 

 which, with a short index, complete the 

 book. 



In taking up the elements of electri- 

 city, the electron theory is used as a 

 basis of explanation. The descriptive 

 portions of the book are excellent, and 

 the discussions of theory seem clear. The 

 Goldschmidt, Poulsen, Marconi and 



or radiative circuits. Measurement, cal- 

 culation and eft'ects of frequency, damp- 

 ing, energy losses, and electromagnetic 

 fields are described. Chapter III dis- 

 cusses the relations of resistance, in- 

 ductance and capacity, current and volt- 

 age in the high frequency alternating 

 current circuit, and explains current 

 measurements. Coupled circuits, with 

 magnetic, conductive and static linking, 

 are taken up in Chapter IV, and the dis- 

 tinctions are brought out contrasting 

 quenching against non-quenching opera- 

 tion, as well as damped oscillations 

 against sustained currents. The next 



T.epel arrangements for continuous wave chapter is on resonance and its measure- 



operation are shown, and the plate 

 quenched gap and older spark appara- 

 tus are described in detail. More at- 

 tention is given to British Marconi ap- 

 paratus than that of any other firm ; 

 many constructional and wiring dia- 



ments, while Chapter VI treats grounded 

 antennas. Chapter VII, on transmitters 

 of damped oscillations, describes first the 

 plain antenna sender, second, the coupled 

 tuned-circuit transmitter and. third, the 

 quenching apparatus. This classifica- 



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