﻿Relative 
  Motion 
  of 
  the 
  Earth 
  and 
  ^Ether. 
  

  

  23 
  

  

  Fig. 
  12. 
  

  

  6 
  = 
  

  

  5=0-o 
  

  

  5=3-0 
  

  

  The 
  inspection 
  of 
  these 
  figures 
  shows 
  that 
  when 
  the 
  dark 
  

  

  space 
  is 
  in 
  geometrical 
  contact 
  with 
  

   the 
  edge 
  of 
  a 
  luminous 
  source, 
  it 
  

   appears 
  as 
  a 
  dark 
  protuberance 
  pro- 
  

   jecting 
  from 
  the 
  surrounding 
  dark 
  

   space. 
  With 
  the 
  receding 
  of 
  the 
  

   dark 
  space 
  towards 
  the 
  interior 
  of 
  

   the 
  luminous 
  source, 
  the 
  connecting 
  

   ligament 
  becomes 
  thinner, 
  and 
  finally 
  

   disappears. 
  The 
  inner 
  dark 
  disk 
  

   is, 
  however, 
  a 
  little 
  elongated, 
  and 
  

   assumes 
  a 
  pear-shaped 
  appearance 
  ; 
  

   while 
  the 
  external 
  dark 
  space 
  bulges 
  

   out 
  towards 
  the 
  luminous 
  source. 
  

   The 
  change 
  is 
  only 
  transient 
  ; 
  with 
  

   further 
  ingress 
  the 
  dark 
  disk 
  be- 
  

   comes 
  circular, 
  and 
  the 
  swelling 
  of 
  

   the 
  external 
  dark 
  space 
  vanishes. 
  

   The 
  accompanying 
  diagram 
  (fig. 
  12) 
  

   will 
  represent 
  approximately 
  the 
  

   various 
  stages 
  of 
  dark 
  space 
  within 
  

   a 
  luminous 
  source, 
  as 
  observed 
  by 
  

   means 
  of 
  a 
  telescope. 
  

  

  Thus, 
  to 
  the 
  first 
  approximation, 
  

   we 
  have 
  arrived 
  at 
  the 
  explanation 
  

   of 
  drop 
  formation 
  during 
  the 
  transit 
  

   of 
  inferior 
  planets. 
  

  

  If 
  the 
  dark 
  space 
  be 
  taken 
  nearly 
  

   equal 
  to 
  the 
  luminous 
  source 
  and 
  

   have 
  small 
  protuberances, 
  we 
  can, 
  

   by 
  similar 
  process, 
  obtain 
  a 
  result 
  

   which 
  has 
  close 
  analogy 
  with 
  Baily's 
  

   beads. 
  

  

  II. 
  Relative 
  Motion 
  of 
  the 
  Earth 
  and 
  uEther. 
  

   By 
  William 
  Sutherland*. 
  

  

  rpHE 
  experiment 
  of 
  Michelson 
  and 
  Morley, 
  described 
  in 
  

   J- 
  the 
  Philosophical 
  Magazine 
  [5] 
  xxiv. 
  p. 
  449, 
  has 
  created 
  

   quite 
  a 
  dilemma 
  in 
  the 
  physics 
  of 
  the 
  aether 
  ; 
  for 
  while 
  the 
  

   great 
  body 
  of 
  general 
  evidence 
  tends 
  to 
  show 
  complete 
  inde- 
  

   pendence 
  of 
  the 
  aether 
  near 
  the 
  earth 
  on 
  the 
  earth's 
  motion, 
  

   this 
  celebrated 
  experiment 
  has 
  been 
  supposed 
  to 
  prove 
  defi- 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

  

  