﻿Phil. 
  Mag. 
  Ser. 
  6, 
  Vol. 
  16. 
  PI. 
  XVI. 
  

  

  WMMSSSSSWAAAAfS-SSJW 
  

  

  Waves 
  in 
  primary 
  and 
  secondary 
  of 
  humming 
  telephone 
  instrument. 
  

  

  Fig. 
  18. 
  

  

  <!>) 
  

  

  

  (a) 
  

  

  Wave 
  Fokms. 
  Continuous 
  oscillation 
  circuit. 
  

  

  

  Fig. 
  19. 
  

  

  Mean 
  Speech 
  Wave. 
  

  

  