﻿508 
  PROFESSOR 
  PIAZZI 
  SMYTH 
  ON 
  THE 
  

  

  one 
  meet 
  with 
  a 
  better 
  artist, 
  and 
  may 
  some 
  more 
  perfect 
  plan, 
  than 
  mezzotint 
  en- 
  

   graving, 
  be 
  found 
  for 
  reproducing 
  the 
  drawings 
  in 
  all 
  their 
  colours, 
  and 
  cheap 
  

   enough 
  to 
  admit 
  of 
  a 
  whole 
  series 
  being 
  published 
  by 
  any 
  scientific 
  society. 
  

  

  The 
  clouds 
  already 
  mentioned, 
  prevented 
  anything 
  very 
  interesting 
  being 
  done 
  

   in 
  the 
  way 
  of 
  exact 
  measurement, 
  and 
  what 
  little 
  was 
  accomplished, 
  having 
  already 
  

   appeared 
  in 
  the 
  Memoirs 
  of 
  the 
  Royal 
  Astronomical 
  Society 
  of 
  London, 
  1852, 
  need 
  

   not 
  be 
  repeated 
  here. 
  The 
  most 
  important 
  subjects 
  which 
  presented 
  themselves 
  

   for 
  observation 
  to 
  those 
  under 
  clear 
  skies, 
  were 
  the 
  corona, 
  and 
  the 
  red 
  pro- 
  

   minences. 
  Both 
  may 
  be 
  spurious 
  effects, 
  and 
  both 
  may 
  be 
  real 
  forms 
  of 
  matter 
  

   in 
  the 
  neighbourhood 
  of 
  the 
  sun, 
  but 
  of 
  such 
  faint 
  illumination 
  as 
  only 
  to 
  be 
  

   visible 
  during 
  the 
  darkness 
  of 
  a 
  total 
  eclipse. 
  

  

  Respecting 
  the 
  corona, 
  Professor 
  Baden 
  Powell 
  has 
  produced 
  such 
  excellent 
  

   imitations 
  of 
  it, 
  by 
  making 
  dark 
  bodies 
  occult 
  very 
  bright 
  points, 
  and 
  he 
  has 
  even 
  

   shewn 
  such 
  a 
  necessity 
  for 
  its 
  existence 
  to 
  some 
  extent, 
  that 
  what, 
  with 
  the 
  exces- 
  

   sive 
  difference 
  in 
  the 
  descriptions 
  of 
  different 
  observers, 
  and 
  the 
  absence 
  of 
  any 
  

   crucial 
  observations, 
  we 
  cannot 
  consider 
  that 
  the 
  corona 
  has 
  been 
  proved 
  to 
  be 
  

   anything 
  real 
  or 
  material. 
  On 
  the 
  other 
  hand, 
  we 
  must 
  not 
  refuse 
  the 
  possibility 
  

   of 
  something 
  of 
  the 
  sort, 
  inasmuch 
  as 
  the 
  best 
  theory 
  of 
  the 
  Zodiacal 
  Light, 
  re- 
  

   presents 
  it 
  to 
  be 
  a 
  nebulous 
  mass, 
  increasing 
  in 
  density 
  towards 
  the 
  sun 
  ; 
  but 
  

   no 
  part 
  of 
  the 
  sky 
  during 
  the 
  totality 
  was 
  dark 
  enough 
  to 
  exhibit 
  any 
  such 
  

   portion 
  of 
  the 
  zodiacal 
  light, 
  as 
  has 
  ever 
  been 
  seen 
  and 
  recognised 
  for 
  it 
  at 
  night. 
  

  

  The 
  red 
  prominences, 
  however, 
  are 
  much 
  more 
  precise 
  phenomena 
  in 
  them- 
  

   selves, 
  and 
  have 
  been 
  better 
  observed. 
  Indeed, 
  it 
  may 
  be 
  considered, 
  that 
  they 
  

   have 
  been 
  proved 
  to 
  lengthen 
  on 
  one 
  side, 
  and 
  shorten 
  on 
  the 
  other, 
  during 
  the 
  

   eclipse, 
  precisely 
  in 
  the 
  direction 
  in 
  which 
  they 
  should 
  do, 
  on 
  the 
  supposition 
  that 
  

   they 
  were 
  true 
  appendages 
  of 
  the 
  sun, 
  and 
  that 
  the 
  moon 
  was 
  occulting 
  them. 
  

   This, 
  however, 
  is 
  all, 
  for 
  other 
  imaginable 
  causes 
  might 
  produce 
  such 
  an 
  appear- 
  

   ance, 
  and 
  a 
  difference 
  of 
  effect 
  would 
  only 
  appear 
  on 
  comparing 
  the 
  accurately 
  

   measured 
  quantity 
  and 
  progress 
  of 
  the 
  alteration 
  of 
  length, 
  with 
  the 
  calculated 
  

   motion 
  of 
  the 
  moon. 
  

  

  This, 
  however, 
  has 
  not 
  been 
  done 
  ; 
  and 
  it 
  is 
  not 
  a 
  little 
  surprising, 
  that 
  so 
  

   many 
  astronomers 
  should 
  have 
  observed 
  the 
  phenomenon, 
  and 
  been 
  contented 
  with 
  

   merely 
  gazing. 
  A 
  few 
  of 
  them 
  measured 
  approximately 
  the 
  angular 
  position 
  of 
  

   the 
  prominences 
  on 
  the 
  sun's 
  limb, 
  but 
  none 
  measured 
  the 
  size 
  and 
  shape, 
  and 
  the 
  

   rate 
  of 
  amount 
  of 
  increase 
  or 
  decrease. 
  Indeed, 
  the 
  figures 
  given 
  by 
  different 
  

   observers, 
  vary 
  in 
  the 
  most 
  incomprehensible 
  way, 
  and 
  we 
  can 
  do 
  no 
  more 
  than 
  

   conclude, 
  that 
  something 
  red 
  was 
  seen, 
  and 
  of 
  a 
  cosmical 
  nature 
  ; 
  but 
  each 
  person 
  

   gives 
  a 
  different 
  size 
  and 
  shape, 
  and 
  each 
  person 
  is 
  quite 
  certain 
  that 
  he 
  is 
  right. 
  

   The 
  observation 
  doubtless 
  may 
  be, 
  and 
  indeed 
  from 
  this 
  must 
  be, 
  very 
  difficult 
  ; 
  

   and 
  a 
  person 
  who 
  has 
  not 
  seen 
  these 
  bodies, 
  ought 
  not 
  perhaps 
  to 
  form 
  any 
  judg- 
  

   ment. 
  But 
  it 
  must 
  be 
  apparent 
  to 
  every 
  one, 
  that 
  almost 
  every 
  observer 
  attempted 
  

  

  