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XXIV. Notices respecting New Boohs. 



The Speaking Telephone, Talking Phonograph, and other Novelties. 

 By George B. Prescott. Fully Illustrated. New York: D. 

 Appleton and Company. 1878. (8vo, pp. 431.) 



rPHIS volume is divided into thirteen chapters, of which the first 

 -"- nine contain an account of the Speaking Telephone, the tenth 

 is devoted to the Talking Phonograph, and the last three to the 

 " other novelties," viz. Quadruple Telegraph, Electric Call Bells, 

 and the Electric Light. The subjects comprised in this list are at 

 present matters of general interest ; and a book which gives a good 

 deal of information respecting them will doubtless obtain a large 

 number of readers. The printing and general appearance of the 

 book are much in its favour. The illustrations, which are nume- 

 rous, are well executed, and will help the reader to form a distinct 

 conception of the objects they represent. 



It will be observed that the largest part of the volume is devoted 

 to the telephone. The reason of this we may state in the author's 

 words : — " The question as to whom we are indebted for the tele- 

 phone is one which, in consequence of the conflicting statements 

 that have appeared from time to time, is, to say the least, extremely 

 puzzling. We have, therefore, endeavoured to give it the attention 

 its importance demands, in order to arrive at a true solution of the 

 problem, and, in doing so, have taken every opportunity to consult 

 all available authorities on the subject. No effort has been spared 

 in our investigation to obtain all the facts as they are ; and these 

 are now given as we have found them, without favour or prejudice" 

 (p. i). Mr. Prescott's grammar is not quite perfect ; but his mean- 

 ing is sufficiently plain ; and, it comes to this, that he has written 

 his book for the purpose of advocating the claims of Mr. Gray to 

 be considered the inventor of the Telephone. This appears very 

 clearly in the first chapter, which gives a general description of the 

 instrument in its principal forms. After an account of Eeiss's 

 Musical Telephone, which transmits the pitch but not the variations 

 in the intensity and other qualities of the tone, the author describes 

 the principles on which three Telephones are constructed. All 

 three agree in the main point that vibrations caused by the voice 

 of the sender are made to transmit electric waves of varying inten- 

 sity through a circuit, and these reproduce the vibrations at another 

 point and thereby transmit the sounds to the receiver with all their 

 variations of pitch, intensity, and quality. In Gray's telephone 

 this is effected by causing the current to pass through a fluid from 

 one wire to another wire, which moves with the membrane put into 

 vibration by the voice, and thus the fluid space traversed varies with 

 the amplitudes of the vibrations and subjects the current to a vary- 

 ing resistance. In Bell's telephone the membrane carries a light 

 permanent magnet placed near the poles of an electromagnet ; the 

 vibrations of the membrane therefore induce a succession of mag- 

 neto-electric pulsations varying in intensity with their amplitudes, 



