﻿TOTAL 
  SOLAR 
  ECLIPSE 
  OF 
  1851. 
  511 
  

  

  was 
  crystallised. 
  Balls 
  of 
  plaster 
  of 
  Paris, 
  zinc, 
  brass, 
  transparent 
  and 
  opal 
  

   glass, 
  were 
  tried 
  : 
  the 
  best 
  results 
  were 
  obtained 
  with 
  the 
  last 
  ; 
  when 
  scratched 
  

   with 
  a 
  diamond, 
  there 
  appeared 
  only 
  a 
  little 
  pink 
  prominence 
  here 
  and 
  there 
  ; 
  

   often 
  appearing 
  exactly 
  like 
  those 
  pictured 
  by 
  the 
  eclipse 
  observers. 
  

  

  This 
  pink 
  light 
  was, 
  however, 
  always 
  thrown 
  off 
  from 
  some 
  object 
  out 
  of 
  

   focus, 
  though 
  the 
  visibly 
  bounding 
  line 
  of 
  the 
  sphere 
  might 
  be 
  in 
  focus 
  ; 
  and 
  

   again, 
  the 
  light 
  belonged 
  to 
  the 
  ball 
  as 
  a 
  centre, 
  and 
  not 
  to 
  the 
  sun, 
  seeming, 
  

   therefore, 
  to 
  be 
  a 
  different 
  phenomenon 
  to 
  the 
  eclipse 
  prominences 
  ; 
  though 
  the 
  

   parallel 
  direction 
  of 
  the 
  rays 
  grazing 
  the 
  moon's 
  edge, 
  and 
  the 
  converging 
  of 
  

   those 
  touching 
  the 
  ball's, 
  should 
  be 
  taken 
  into 
  consideration. 
  

  

  A 
  more 
  similar 
  experiment 
  in 
  this 
  way, 
  is 
  to 
  eclipse 
  the 
  sun 
  behind 
  a 
  distant 
  

   object; 
  and 
  for 
  this 
  purpose 
  I 
  placed 
  a 
  black 
  tin 
  screen 
  on 
  the 
  top 
  of 
  Nelson's 
  

   Monument, 
  and 
  observed 
  it 
  from 
  below 
  with 
  the 
  naked 
  eye 
  and 
  a 
  small 
  telescope. 
  

   When 
  the 
  sun 
  was 
  completely 
  eclipsed 
  by 
  the 
  disc, 
  there 
  was 
  much 
  light 
  of 
  a 
  

   spectrum 
  character, 
  with 
  a 
  preponderance 
  to 
  orange 
  and 
  red, 
  thrown 
  off 
  beyond 
  

   the 
  edge, 
  and 
  this 
  light 
  was 
  most 
  abundant 
  on 
  that 
  part 
  of 
  the 
  circumference 
  of 
  

   the 
  tin 
  disc, 
  to 
  which, 
  at 
  the 
  time, 
  the 
  sun 
  was 
  closest 
  : 
  thus 
  bearing 
  some 
  sort 
  

   of 
  relation 
  to 
  the 
  observed 
  fact 
  of 
  the 
  lengthening 
  of 
  the 
  red 
  prominences 
  on 
  that 
  

   side 
  of 
  the 
  moon 
  to 
  which 
  the 
  sun 
  was 
  advancing. 
  Anything 
  transparent, 
  as 
  a 
  

   bristle, 
  on 
  the 
  edge 
  of 
  a 
  disc, 
  was 
  particularly 
  vivid, 
  and 
  some 
  ropes 
  in 
  the 
  neigh- 
  

   bourhood 
  were 
  " 
  glorified 
  " 
  over 
  an 
  extent 
  of 
  two 
  degrees. 
  This 
  effect, 
  too, 
  was 
  

   more 
  marked 
  the 
  clearer 
  and 
  more 
  transparent 
  the 
  atmosphere. 
  With 
  much 
  haze 
  

   in 
  the 
  air 
  it 
  vanished 
  altogether 
  ; 
  the 
  disc 
  and 
  ropes 
  then 
  projecting 
  themselves 
  

   blackly 
  on 
  the 
  bright 
  sky 
  behind. 
  This 
  would 
  seem 
  also 
  to 
  be 
  in 
  some 
  measure 
  

   in 
  favour 
  of 
  the 
  idea 
  of 
  a 
  spurious 
  origin 
  at 
  the 
  moon's 
  edge 
  for 
  the 
  eclipse 
  pro- 
  

   minences. 
  The 
  evidence, 
  however, 
  is 
  so 
  very 
  uncertain, 
  that 
  few 
  things 
  would 
  

   be 
  more 
  productive 
  of 
  advantage 
  in 
  the 
  present 
  state 
  of 
  the 
  subject, 
  than 
  the 
  

   repetition 
  of 
  all 
  the 
  experiments 
  with 
  a 
  better 
  instrument, 
  either 
  in 
  the 
  rarified 
  

   atmosphere 
  of 
  the 
  Peak 
  of 
  Teneriffe, 
  as 
  just 
  mentioned, 
  or 
  that 
  of 
  some 
  higher 
  

   mountain 
  : 
  such 
  observations, 
  too, 
  made 
  at 
  once, 
  might 
  tend 
  to 
  save 
  and 
  to 
  

   utilise 
  much 
  valuable 
  time 
  on 
  the 
  occasion 
  of 
  the 
  next 
  total 
  eclipse 
  of 
  the 
  sun. 
  

  

  VOL. 
  XX. 
  PART 
  III. 
  Y 
  

  

  