﻿2 
  F. 
  II. 
  Bigelow 
  — 
  Solar 
  Corona. 
  

  

  cannot 
  justify 
  the 
  idea, 
  the 
  suspicion 
  keeps 
  forcing 
  itself 
  "upon 
  

   my 
  mind 
  that 
  matter 
  some 
  how, 
  that 
  is 
  to 
  say 
  by 
  change 
  of 
  

   conditions 
  or 
  environment, 
  can 
  be 
  made 
  to 
  pass 
  from 
  the 
  posi- 
  

   tive 
  to 
  the 
  negative 
  form 
  of 
  the 
  function 
  and 
  back 
  again. 
  We 
  

   may 
  yet 
  discover 
  that 
  this 
  is 
  illustrated 
  by 
  the 
  sun, 
  when 
  we 
  

   get 
  to 
  the 
  bottom 
  of 
  its 
  mysterious 
  nature. 
  At 
  present 
  I 
  am 
  

   concerned 
  simply 
  with 
  identifying 
  the 
  Solar 
  Corona 
  with 
  the 
  

   manifestation 
  of 
  the 
  Newtonian 
  Potential 
  Function 
  in 
  the 
  case 
  

   of 
  repulsion. 
  

  

  Whenever 
  the 
  particles 
  of 
  a 
  body, 
  not 
  undergoing 
  rotation, 
  

   are 
  free 
  to 
  move 
  among 
  themselves, 
  the 
  body 
  assumes 
  a 
  spheri- 
  

   cal 
  figure 
  about 
  a 
  center. 
  This 
  figure 
  is 
  modified 
  by 
  the 
  rota- 
  

   tion 
  of 
  the 
  body. 
  If 
  in 
  connection 
  with 
  such 
  a 
  spherical 
  body 
  

   there 
  be 
  present 
  other 
  material 
  conforming 
  to 
  the 
  case 
  of 
  repul- 
  

   sion, 
  the 
  body 
  is 
  polarized 
  along 
  an 
  axis, 
  and 
  the 
  lines 
  of 
  force 
  

   are 
  parallel 
  to 
  the 
  axis 
  of 
  polarization 
  within 
  the 
  body, 
  become 
  

   discontinuous 
  at 
  the 
  surface, 
  and 
  on 
  leaving 
  the 
  surface 
  form 
  

   curves 
  whose 
  locus 
  can 
  be 
  expressed 
  by 
  the 
  formula 
  

  

  „ 
  Stt 
  sin 
  a 
  

  

  N= 
  — 
  . 
  , 
  

  

  3 
  r 
  ' 
  

  

  where 
  N 
  is 
  the 
  given 
  line 
  (r 
  . 
  6) 
  the 
  polar 
  coordinates 
  of 
  points 
  

   measured 
  from 
  the 
  axis 
  of 
  polarization 
  and 
  the 
  center. 
  We 
  

   are 
  not 
  now 
  discussing 
  either 
  the 
  interior 
  or 
  the 
  surface 
  condi- 
  

   tions, 
  and 
  in 
  the 
  case 
  of 
  the 
  potential 
  outside 
  the 
  sun 
  we 
  may 
  

   believe 
  that 
  we 
  have 
  a 
  nearly 
  ideal 
  distribution, 
  on 
  account 
  of 
  

   the 
  prevailing 
  conditions 
  of 
  freedom 
  of 
  motion. 
  

  

  In 
  the 
  corona 
  streamers, 
  as 
  displayed 
  by 
  the 
  photographs, 
  

   we 
  must 
  remember 
  that 
  the 
  curves 
  arising 
  from 
  the 
  equation 
  

   just 
  given 
  are 
  modified 
  by 
  projection, 
  and 
  that 
  therefore 
  the 
  

   measured 
  curves 
  must 
  all 
  be 
  corrected 
  for 
  their 
  distortion. 
  

   At 
  the 
  outset 
  we 
  could 
  not 
  know 
  the 
  position 
  of 
  the 
  axis 
  of 
  

   polarization 
  or 
  the 
  center 
  of 
  reference, 
  and 
  as 
  a 
  first 
  approxi- 
  

   mation 
  we 
  supposed 
  that 
  this 
  axis 
  passed 
  through 
  the 
  center 
  

   of 
  the 
  sun, 
  and 
  coincided 
  with 
  the 
  plane 
  perpendicular 
  to 
  the 
  

   line 
  of 
  sight 
  from 
  the 
  observer, 
  which 
  also 
  passes 
  through 
  the 
  

   center 
  of 
  the 
  sun. 
  Fortunately 
  in 
  the 
  eclipse 
  photographs 
  of 
  

   July 
  29, 
  1878, 
  Jan. 
  1, 
  1889, 
  and 
  Dec. 
  22, 
  1889, 
  which 
  were 
  

   studied, 
  these 
  conditions 
  were 
  not 
  very 
  erroneous 
  in 
  their 
  

   assumption. 
  These 
  three 
  coronas 
  are 
  so 
  similar 
  in 
  their 
  

   appearance 
  that 
  they 
  are 
  spoken 
  of 
  as 
  the 
  " 
  American 
  type," 
  

   the 
  fact 
  being 
  that 
  at 
  the 
  epoch 
  of 
  the 
  eclipse, 
  the 
  pole 
  of 
  the 
  

   corona 
  in 
  its 
  rotation 
  with 
  the 
  sun 
  happened 
  to 
  be 
  near 
  the 
  

   plane 
  of 
  reference 
  just 
  defined, 
  so 
  that 
  the 
  coronas 
  were 
  

   observed 
  in 
  their 
  most 
  symmetrical 
  position 
  relatively 
  to 
  the 
  

   earth. 
  The 
  amount 
  of 
  this 
  angular 
  divergence 
  between 
  the 
  

   axis 
  of 
  polarization 
  and 
  its 
  trace 
  on 
  the 
  plane 
  of 
  the 
  disk 
  was 
  

  

  