﻿Molecules 
  of 
  the 
  Elements 
  and 
  their 
  Compounds. 
  31 
  

  

  charge, 
  and 
  this 
  was 
  shown 
  to 
  be 
  correct 
  by 
  applying 
  a 
  

   direct 
  potential. 
  To 
  secure 
  it 
  a 
  synchronous 
  motor 
  was 
  

   operated 
  to 
  drive 
  a 
  contact-maker 
  in 
  order 
  that 
  the 
  spheres 
  

   might 
  be 
  connected 
  to 
  the 
  alternating 
  potential 
  at 
  selected 
  

   points 
  of 
  its 
  phase. 
  This 
  method 
  proved 
  to 
  be 
  very 
  satis- 
  

   factory 
  after 
  a 
  sufficient 
  electrical 
  capacity 
  was 
  added 
  to 
  the 
  

   system 
  to 
  prevent 
  too 
  rapid 
  a 
  discharge 
  of 
  the 
  spheres. 
  No 
  

   actual 
  contact 
  is 
  required 
  at 
  the 
  contact-maker, 
  which 
  was 
  

   placed 
  in 
  the 
  high-potential 
  circuit, 
  the 
  voltage 
  being 
  suffi- 
  

   cient 
  to 
  cause 
  a 
  spark 
  to 
  pass 
  over 
  a 
  considerable 
  distance 
  in 
  

   the 
  air 
  as 
  the 
  contact 
  points 
  approach 
  the 
  proper 
  phase. 
  In 
  

   this 
  manner, 
  by 
  suitably 
  adjusting 
  the 
  contact 
  distance, 
  it 
  

   was 
  possible 
  so 
  to 
  'arrange 
  the 
  apparatus 
  that 
  one 
  spark 
  

   would 
  pass 
  at 
  intervals 
  of 
  half 
  a 
  minute 
  to 
  a 
  minute. 
  The 
  

   condenser 
  during 
  this 
  interval 
  would 
  gradually 
  lose 
  its 
  

   charge 
  as 
  it 
  leaked 
  away 
  until 
  the 
  pressure 
  became 
  low 
  

   enough 
  for 
  another 
  spark 
  to 
  pass, 
  recharging 
  it. 
  By 
  means 
  

   of 
  a 
  switch 
  in 
  the 
  high-potential 
  circuit 
  controlled 
  by 
  a 
  cord 
  

   passing 
  to 
  a 
  point 
  convenient 
  to 
  the 
  operator, 
  the 
  source 
  of 
  

   power 
  was 
  disconnected 
  and 
  the 
  condenser 
  left 
  charged 
  

   while 
  a 
  photograph 
  of 
  the 
  figures 
  assumed 
  by 
  the 
  spheres 
  

   was 
  taken 
  after 
  they 
  had 
  come 
  to 
  rest. 
  

  

  When 
  the 
  direct 
  potential 
  is 
  applied 
  to 
  the 
  point 
  supporting 
  

   the 
  spheres, 
  they 
  separate 
  to 
  a 
  greater 
  distance 
  than 
  when 
  

   the 
  alternating 
  potential 
  is 
  applied 
  if 
  a 
  wire 
  suspension 
  is 
  

   used, 
  but 
  the 
  distance 
  is 
  adjustable 
  by 
  altering 
  the 
  phase 
  of 
  

   the 
  contact, 
  and 
  it 
  is 
  thus 
  possible 
  to 
  make 
  use 
  of 
  the 
  highest 
  

   point 
  of 
  the 
  alternating 
  wave. 
  When 
  alternating 
  potential 
  

   is 
  applied 
  to 
  the 
  silk 
  fibres, 
  however, 
  there 
  is 
  no 
  separation 
  

   of 
  the 
  spheres. 
  With 
  the 
  silk 
  suspension 
  it 
  proved 
  to 
  be 
  

   possible 
  to 
  use 
  the 
  lighter 
  aluminium 
  spheres 
  and 
  secure 
  

   greater 
  deflexion 
  for 
  the 
  same 
  voltage, 
  as 
  the 
  fibre 
  is 
  

   stretched 
  taut 
  by 
  their 
  weight. 
  After 
  adjusting 
  each 
  

   pendulum 
  to 
  the 
  same 
  length 
  as 
  they 
  hang 
  quietly 
  side 
  by 
  

   side, 
  a 
  charge 
  is 
  suddenly 
  given 
  the 
  condenser, 
  and 
  the 
  high- 
  

   potential 
  switch 
  opened 
  immediately 
  thereafter, 
  leaving 
  the 
  

   condenser 
  connected 
  to 
  the 
  spheres 
  charged. 
  With 
  the 
  first 
  

   charge 
  the 
  spheres 
  suddenly 
  separate 
  from 
  each 
  other, 
  and 
  

   oscillate 
  about 
  positions 
  of 
  equilibrium, 
  finally 
  coming 
  to 
  

   rest 
  in 
  these 
  positions. 
  Each 
  silk 
  fibre 
  separates 
  from 
  its 
  

   neighbour 
  owing 
  to 
  the 
  charge 
  it 
  carries, 
  and 
  on 
  this 
  account 
  

   the 
  spheres 
  are 
  free 
  to 
  oscillate 
  without 
  so 
  much 
  danger 
  of 
  

   their 
  getting 
  twisted 
  or 
  tangled 
  together. 
  After 
  they 
  have 
  

   come 
  to 
  rest 
  a 
  photograph 
  is 
  secured. 
  The 
  camera 
  was 
  

   placed 
  about 
  30 
  cm. 
  above 
  the 
  point 
  of 
  support 
  of 
  the 
  

   spheres 
  just 
  enough 
  to 
  one 
  side 
  of 
  it 
  to 
  avoid 
  interference 
  

  

  