Page:Popular Science Monthly Volume 88.djvu/181

 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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