﻿Electrical 
  Theories 
  of 
  Matter, 
  481 
  

  

  three 
  respects; 
  this 
  involves 
  trigonometric 
  computation. 
  

   Most 
  important 
  of 
  all 
  is 
  the 
  question 
  how 
  best 
  to 
  utilise 
  the 
  

   above 
  methods 
  in 
  order 
  to 
  make 
  a 
  much 
  better 
  attempt 
  for 
  

   the 
  next 
  trigonometric 
  computation, 
  instead 
  of 
  striking 
  out 
  

   blindly. 
  

  

  Two 
  other 
  similarly 
  computed 
  objectives 
  are 
  : 
  — 
  

  

  (1) 
  For 
  u 
  l 
  —— 
  05 
  (object 
  equal 
  to 
  image): 
  c 
  1 
  = 
  0'8351, 
  

   ^=-4-0075, 
  c 
  3 
  = 
  -3*9539, 
  c 
  4 
  = 
  -1-5224. 
  

  

  (2) 
  For 
  Ml 
  =-l-0 
  (object 
  at 
  focus): 
  ^ 
  = 
  0-0414, 
  c 
  2 
  = 
  

   -4-8012, 
  c 
  3 
  = 
  -4-7498, 
  c 
  4 
  = 
  -2-3183 
  : 
  this 
  maybe 
  regarded 
  

   as 
  corrected 
  for 
  infinity, 
  but 
  with 
  flint 
  leading. 
  

  

  LVI. 
  Electrical 
  Theories 
  of 
  Matter 
  and 
  their 
  Astronomical 
  

   Consequences 
  with 
  special 
  reference 
  to 
  the 
  Principle 
  of 
  

   Relativity. 
  By 
  A 
  S. 
  Eddington, 
  M.A., 
  F.R.S., 
  Plumian 
  

   Professor 
  of 
  Astronomy 
  in 
  the 
  University 
  of 
  Cambridge* 
  '. 
  

  

  MR. 
  WALKER'S 
  paper 
  in 
  the 
  Philosophical 
  Magazine 
  

   for 
  April 
  has 
  given 
  a 
  new 
  turn 
  to 
  the 
  discussion 
  

   arising 
  out 
  of 
  the 
  motions 
  of 
  the 
  perihelia 
  of 
  the 
  planets, 
  

   and 
  perhaps 
  some 
  remarks 
  on 
  the 
  points 
  raised 
  may 
  be 
  

   useful. 
  I 
  think 
  that 
  he 
  greatly 
  overestimates 
  the 
  differences 
  

   of 
  opinion 
  between 
  us 
  ; 
  our 
  views 
  seem 
  to 
  coincide 
  on 
  what 
  

   he 
  calls 
  "the 
  main 
  point 
  at 
  issue," 
  and 
  it 
  is 
  difficult 
  to 
  believe 
  

   that 
  relativists 
  in 
  general 
  hold 
  any 
  other 
  view. 
  

  

  Walker 
  describes 
  my 
  method 
  of 
  dealing 
  with 
  the 
  problem 
  

   as 
  depending 
  on 
  an 
  unsatisfactory 
  assumption, 
  and 
  concludes 
  

   therefore 
  that 
  ray 
  treatment 
  is 
  invalid 
  ; 
  but 
  I 
  am 
  afraid 
  he 
  

   gives 
  a 
  wrong 
  impression 
  by 
  not 
  mentioning 
  that 
  my 
  argu- 
  

   ment 
  tended 
  to 
  disprove 
  the 
  assumption 
  in 
  question. 
  I 
  did 
  

   not 
  advocate 
  the 
  assumption 
  leading 
  to 
  the 
  equations 
  of 
  

   motion 
  used 
  in 
  my 
  paper 
  ; 
  on 
  the 
  contrary 
  I 
  showed 
  that 
  

   the 
  results 
  disagreed 
  with 
  observation. 
  The 
  suggestion 
  had 
  

   been 
  made 
  that 
  the 
  famous 
  discordance 
  of 
  Mercury 
  could 
  

   be 
  accounted 
  for 
  by 
  the 
  variation 
  of 
  mass 
  with 
  velocity, 
  

   according 
  to 
  the 
  well-known 
  hypothesis 
  m 
  = 
  m 
  (l 
  — 
  iv 
  2 
  /c 
  2 
  )~*, 
  

   if 
  account 
  be 
  taken 
  of 
  its 
  interaction 
  with 
  the 
  sun's 
  motion 
  

   through 
  the 
  aether. 
  This 
  hypothesis 
  was 
  examined, 
  and 
  the 
  

   conclusion 
  was 
  unfavourable, 
  the 
  detailed 
  results 
  being 
  irre- 
  

   concilable 
  with 
  astronomical 
  observation. 
  That 
  is 
  to 
  say, 
  

   I 
  attempted 
  to 
  disprove 
  the 
  hypothesis 
  m 
  = 
  m 
  [l 
  — 
  ic 
  2 
  jc 
  2 
  )~^ 
  

   which 
  Walker 
  rejects 
  more 
  summarily. 
  Sir 
  Oliver 
  Lodge 
  

   also 
  concludes 
  that 
  " 
  If 
  therefore 
  the 
  theory 
  fails 
  to 
  give 
  all 
  

   the 
  known 
  perturbations 
  correctly, 
  something 
  must 
  be 
  wrong; 
  

  

  * 
  Communicated 
  by 
  Sir 
  Oliver 
  Lodge. 
  

  

  