﻿RED 
  PROMINENCES 
  SEEN 
  DURING 
  TOTAL 
  ECLIPSES 
  OF 
  THE 
  SUN. 
  471 
  

  

  envelope, 
  traversed 
  obliquely 
  by 
  tbe 
  rays, 
  which 
  reach 
  the 
  eye 
  from 
  points 
  near 
  

   his 
  limb 
  ? 
  

  

  5. 
  May 
  not 
  the 
  f 
  amice 
  and 
  luculi, 
  or 
  bright 
  portions 
  of 
  the 
  sun's 
  disc, 
  be 
  aper- 
  

   tures 
  in 
  the 
  envelope, 
  through 
  which 
  his 
  light 
  passes 
  with 
  less 
  absorption 
  than 
  at 
  

   other 
  places 
  ? 
  

  

  6. 
  Will 
  not 
  the 
  supposed 
  connexion 
  of 
  the 
  higher 
  red 
  prominences 
  with 
  the 
  

   faculse, 
  — 
  or 
  apertures 
  in 
  the 
  absorbent 
  envelope, 
  — 
  explain 
  the 
  observed 
  increase 
  

   in 
  the 
  brightness 
  of 
  the 
  corona 
  in 
  the 
  neighbourhood 
  of 
  such 
  prominences 
  ? 
  

  

  7. 
  Will 
  not 
  the 
  supposition, 
  that 
  an 
  envelope 
  of 
  cloud 
  surrounds 
  the 
  sun, 
  cap- 
  

   able 
  of 
  absorbing 
  his 
  light, 
  but 
  penetrated 
  with 
  apertures, 
  so 
  as 
  to 
  allow 
  more 
  

   light 
  to 
  escape 
  at 
  certain 
  points 
  than 
  at 
  others, 
  explain 
  the 
  want 
  of 
  uniformity 
  in 
  

   the 
  brightness 
  of 
  the 
  corona, 
  and 
  the 
  brilliant 
  beams 
  of 
  light 
  which 
  occur 
  in 
  it 
  ? 
  

  

  When 
  the 
  preceding 
  paper 
  was 
  read, 
  I 
  had 
  not, 
  as 
  has 
  already 
  been 
  noticed, 
  

   seen 
  M. 
  Arago's 
  Memoirs 
  in 
  the 
  Annuaires 
  for 
  1846 
  and 
  1852 
  ; 
  nor 
  had 
  I 
  seen 
  

   the 
  fourth 
  volume 
  of 
  Humboldt's 
  Cosmos, 
  recently 
  published, 
  which 
  contains 
  an 
  

   exposition 
  of 
  M. 
  Arago's 
  views 
  regarding 
  the 
  red 
  prominences. 
  In 
  these 
  circum- 
  

   stances, 
  it 
  may 
  be 
  proper 
  to 
  insert 
  here 
  some 
  passages 
  from 
  those 
  works, 
  which, 
  if 
  

   I 
  had 
  obtained 
  access 
  to 
  them 
  at 
  an 
  earlier 
  period, 
  I 
  should 
  have 
  embodied 
  in 
  the 
  

   preceding 
  pages. 
  

  

  " 
  Apres 
  avoir 
  constate 
  que 
  le 
  soleil 
  se 
  compose 
  d'un 
  corps 
  obscur 
  central, 
  d'une 
  

   atmosphere 
  nuageuse 
  reflechissante 
  et 
  d'une 
  photosphere, 
  nous 
  devons 
  naturelle- 
  

   ment 
  nous 
  demander 
  s'il 
  n'y 
  a 
  rien 
  au 
  dela, 
  si 
  la 
  photosphere 
  finit 
  brusquement 
  

   et 
  sans 
  etre 
  entouree 
  d'une 
  atmosphere 
  gazeuse 
  peu 
  lumineuse 
  par 
  elle-meme, 
  ou 
  

   faiblement 
  reflechissante. 
  Cette 
  troisieme 
  atmosphere 
  disparaitrait 
  ordinaire- 
  

   ment 
  dans 
  l'ocean 
  de 
  lumiere 
  dont 
  le 
  soleil 
  parait 
  toujours 
  entoure."* 
  

  

  " 
  II 
  faut 
  admettre 
  une 
  enveloppe 
  exterieure 
  qui 
  diminue 
  (etient) 
  moins 
  la 
  lu- 
  

   miere 
  qui 
  vient 
  du 
  centre, 
  que 
  les 
  rayons 
  qui 
  viennent 
  sur 
  le 
  long 
  trajet 
  du 
  bord 
  

   a 
  Fceil. 
  Cette 
  enveloppe 
  exterieure 
  forme 
  la 
  couronne 
  blanchatre 
  dans 
  l'eclipses 
  

   totales 
  du 
  soleil." 
  t 
  

  

  " 
  L'eclipse 
  de 
  1842 
  nous 
  a 
  mis 
  sur 
  la 
  trace 
  d'une 
  troisieme 
  enveloppe 
  situee 
  

   au-dessus 
  de 
  la 
  photosphere, 
  et 
  formee 
  nuages 
  obscurs, 
  ou 
  faiblement 
  lumineux." 
  j; 
  

  

  " 
  Jetons 
  un 
  coup 
  d'oeil 
  rapid 
  sur 
  une 
  quatrieme 
  hypothese, 
  celle 
  suivant 
  

   laquelle 
  les 
  protuberances 
  seraient 
  assimilees 
  a 
  des 
  nuages 
  solaires 
  nageant 
  dans 
  

   une 
  atmosphere 
  gazeuse. 
  Nous 
  ne 
  trouverions 
  aucun 
  principe 
  de 
  physique 
  qui 
  

   put 
  nous 
  empecher 
  d'admettre 
  l'existence 
  de 
  masses 
  nuageuses 
  de 
  25,000 
  a 
  30,000 
  

   lieues 
  de 
  long, 
  a 
  contours 
  arretes 
  et 
  affectant 
  des 
  formes 
  les 
  plus 
  tourmentees."§ 
  

  

  " 
  Dans 
  la 
  nombreuse 
  categorie 
  des 
  taches 
  du 
  soleil, 
  quelle 
  est 
  la 
  place 
  qu' 
  

  

  * 
  Annuaire 
  for 
  1852, 
  p. 
  342. 
  

  

  f 
  Arago, 
  quoted 
  by 
  Humboldt, 
  Cosmos, 
  Murray's 
  Edit., 
  vol. 
  iv., 
  Notes, 
  p. 
  ciii. 
  

  

  \ 
  Annuaire, 
  for 
  1846, 
  p. 
  464. 
  

  

  § 
  Annuaire 
  for 
  1852, 
  p. 
  345. 
  

  

  