﻿Prof. 
  J. 
  Trowbridge 
  on 
  the 
  Induction 
  Coil. 
  395 
  

  

  wire 
  K. 
  There 
  is 
  also 
  a 
  movable 
  brush-holder 
  yoke 
  P, 
  which 
  

   has 
  secured 
  to 
  it, 
  but 
  insulated 
  from 
  it, 
  a 
  brush-holder 
  Q 
  and 
  

   brush 
  U, 
  which 
  rest 
  on 
  disk 
  and 
  segment 
  during 
  one-fourth 
  

   of 
  its 
  revolution. 
  

  

  Fig-, 
  i. 
  

  

  The 
  electric 
  current 
  flows 
  as 
  follows 
  : 
  — 
  The 
  positive 
  wire 
  

   from 
  the 
  mains 
  (I 
  use 
  a 
  one-hundred-and-ten 
  volt 
  circuit) 
  

   connects 
  with 
  the 
  brush-holder 
  P, 
  and 
  the 
  current 
  flows 
  

   through 
  the 
  brush 
  E, 
  to 
  segment 
  0, 
  to 
  shaft 
  F, 
  to 
  base- 
  

   casting 
  E, 
  to 
  vertical 
  spindle 
  J, 
  to 
  brass 
  sleeve 
  I, 
  to 
  platinum 
  

   wire 
  K 
  ; 
  and 
  when 
  the 
  wire 
  is 
  immersed 
  in 
  the 
  liquid 
  N, 
  the 
  

  

  2D 
  2 
  

  

  