﻿Relations 
  between 
  JEther, 
  Matter, 
  and 
  Electricity. 
  375 
  

  

  The 
  reversing- 
  

  

  nearly 
  as 
  possible 
  at 
  the 
  same 
  temperature, 
  

   rod 
  was 
  touching 
  the 
  collar 
  c 
  only 
  during 
  the 
  instant 
  of 
  

   reversal. 
  The 
  switch 
  moved 
  easily, 
  but 
  was 
  held 
  firmly 
  in 
  

   position 
  at 
  the 
  end 
  of 
  the 
  throw 
  by 
  the 
  pressure 
  of 
  the 
  copper 
  

  

  Fie-. 
  3. 
  

  

  springs. 
  The 
  connexions 
  of 
  the 
  switch 
  were 
  such 
  that 
  the 
  

   positive 
  terminal 
  from 
  the 
  wheel 
  was 
  connected 
  to 
  that 
  end 
  

   of 
  the 
  shaft 
  towards 
  which 
  the 
  switch 
  was 
  thrown. 
  This 
  was 
  

   verified 
  by 
  passing 
  a 
  current 
  through 
  the 
  machine 
  and 
  noting 
  

   the 
  deflexion 
  of 
  a 
  small 
  compass 
  held 
  above 
  the 
  wheel. 
  This 
  

   test 
  was 
  also 
  applied 
  when 
  the 
  wheel 
  was 
  rotating, 
  as 
  an 
  

   assurance 
  that 
  everything 
  was 
  in 
  order. 
  Another 
  test 
  

   frequently 
  applied 
  was 
  to 
  pass 
  a 
  current 
  through 
  a 
  delicate 
  

   milliammeter 
  in 
  series 
  with 
  the 
  wheel. 
  The 
  slighest 
  change 
  or 
  

   unsteadiness 
  in 
  the 
  needle 
  when 
  the 
  machine 
  was 
  started 
  was 
  

   an 
  indication 
  of 
  trouble. 
  

  

  If 
  any 
  friction 
  exists 
  between 
  the 
  aether 
  and 
  the 
  moving- 
  

   wire, 
  and 
  if 
  there 
  is 
  any 
  viscosity 
  within 
  the 
  aether 
  itself, 
  it 
  is 
  

   probable 
  that 
  the 
  motion 
  of 
  the 
  wheel 
  would 
  produce 
  con- 
  

   vection-currents 
  which 
  would 
  greatly 
  reduce 
  the 
  amount 
  of 
  

   relative 
  motion 
  between 
  the 
  wire 
  and 
  the 
  aether 
  in 
  immediate 
  

   contact 
  with 
  it. 
  To 
  overcome 
  this 
  as 
  far 
  as 
  possible 
  a 
  copper 
  

   ring 
  or 
  shield 
  was 
  cast 
  and 
  placed 
  around 
  the 
  wheel. 
  The 
  

   width 
  of 
  the 
  shield 
  was 
  the 
  same 
  as 
  that 
  of 
  the 
  wheel, 
  the 
  

   internal 
  diameter 
  3 
  mms. 
  greater 
  than 
  the 
  diameter 
  of 
  the 
  

   wheel, 
  and 
  the 
  thickness 
  of 
  copper 
  was 
  2 
  cms. 
  The 
  weight 
  

   was 
  12 
  lbs. 
  To 
  eliminate 
  any 
  possible 
  effect 
  due 
  to 
  the 
  

   earth's 
  magnetic 
  field, 
  the 
  wheel 
  was 
  rotated 
  alternately 
  in 
  

   and 
  at 
  right 
  angles 
  to 
  the 
  plane 
  of 
  the 
  magnetic 
  meridian, 
  

   but 
  no 
  effect 
  due 
  to 
  this 
  cause 
  was 
  detected. 
  

  

  Table 
  I. 
  contains 
  the 
  results 
  of 
  920 
  readings 
  by 
  this 
  method. 
  

  

  