﻿234 
  COLLECTION 
  OF 
  OBSERVATIONS 
  ON 
  THE 
  

  

  point 
  of 
  the 
  limb 
  at 
  which 
  the 
  eclipse 
  was 
  expected 
  to 
  commence. 
  

   This 
  served 
  as 
  an 
  additional 
  guide 
  to 
  the 
  eye, 
  which 
  was 
  accordingly 
  

   found 
  to 
  be 
  directed 
  very 
  accurately 
  to 
  the 
  point 
  at 
  which 
  the 
  indenta- 
  

   tion 
  first 
  occurred. 
  The 
  limb 
  of 
  the 
  sun 
  at 
  this 
  time 
  was 
  beautifully 
  

   defined; 
  soon 
  after 
  the 
  commencement, 
  the 
  clouds 
  began 
  again 
  to 
  accu- 
  

   mulate, 
  and 
  at 
  the 
  period 
  of 
  greatest 
  obscuration 
  the 
  sun 
  was 
  entirely 
  

   concealed. 
  About 
  twenty 
  minutes 
  before 
  the 
  end 
  the 
  clouds 
  had 
  again 
  

   dispersed, 
  leaving 
  the 
  sun 
  much 
  brighter 
  than 
  at 
  any 
  previous 
  period 
  

   during 
  the 
  eclipse, 
  and 
  giving 
  promise 
  of 
  a 
  highly 
  satisfactory 
  observa- 
  

   tion 
  of 
  the 
  end 
  ; 
  but 
  at 
  fifteen 
  or 
  twenty 
  seconds 
  before 
  the 
  final 
  sepa- 
  

   ration 
  of 
  the 
  disks 
  a 
  light 
  fleecy 
  cloud 
  passed 
  before 
  them, 
  alternately 
  

   concealing 
  the 
  sun 
  and 
  permitting 
  him 
  to 
  be 
  seen. 
  The 
  effect 
  of 
  this 
  

   was 
  to 
  dazzle 
  the 
  eye, 
  and 
  to 
  render 
  the 
  vision 
  so 
  far 
  imperfect 
  that 
  the 
  

   instant 
  of 
  separation 
  of 
  the 
  disks 
  could 
  not 
  be 
  fixed 
  as 
  satisfactorily 
  as 
  

   that 
  of 
  the 
  commencement. 
  The 
  observations 
  were 
  made 
  with 
  a 
  sixty 
  

   inch 
  refractor 
  by 
  Dollond 
  belonging 
  to 
  the 
  University 
  of 
  Pennsylvania, 
  

   the 
  diameter 
  of 
  the 
  object 
  glass 
  being 
  three 
  and 
  three-fourths 
  inches. 
  

   The 
  time 
  keeper 
  was 
  a 
  chronometer 
  of 
  excellent 
  character 
  by 
  Parkin- 
  

   son 
  and 
  Frodsham, 
  and 
  its 
  error 
  and 
  rate 
  were 
  ascertained 
  by 
  frequent 
  

   transits 
  of 
  the 
  sun 
  and 
  stars 
  on 
  the 
  day 
  of 
  the 
  eclipse 
  and 
  for 
  several 
  

   days 
  previous. 
  The 
  limbs 
  of 
  the 
  sun 
  and 
  moon, 
  when 
  not 
  obscured 
  

   by 
  clouds, 
  were 
  defined 
  as 
  distinctly 
  as 
  could 
  have 
  been 
  desired. 
  The 
  

   colour 
  of 
  the 
  sun's 
  disk, 
  as 
  seen 
  through 
  the 
  dark 
  glass 
  used, 
  was 
  a 
  

   bright 
  orange 
  extremely 
  agreeable 
  to 
  the 
  eye 
  ; 
  that 
  of 
  the 
  moon 
  in- 
  

   tensely 
  black. 
  

  

  The 
  times 
  observed, 
  reduced 
  to 
  the 
  meridian 
  of 
  Independence 
  Hall, 
  

   were 
  as 
  follows 
  : 
  

  

  h. 
  

   Commencement, 
  1 
  

  

  End, 
  3 
  

  

  Duration, 
  2 
  

  

  Observations 
  of 
  the 
  temperature 
  were 
  likewise 
  made 
  with 
  two 
  ther- 
  

   mometers 
  by 
  Pastorelli 
  (the 
  bulb 
  being 
  uncoated); 
  the 
  one 
  exposed 
  to 
  

   the 
  sun's 
  rays 
  on 
  the 
  south 
  side 
  of 
  the 
  university, 
  the 
  other 
  well 
  shel- 
  

   tered 
  from 
  the 
  sun 
  and 
  having 
  a 
  north 
  western 
  exposure. 
  The 
  sudden 
  

   and 
  frequent 
  fluctuations 
  of 
  the 
  thermometer 
  in 
  the 
  sun 
  are 
  attributable 
  

   to 
  the 
  frequent 
  interposition 
  of 
  clouds. 
  

  

  m. 
  

  

  sec. 
  

  

  00 
  

  

  10.5 
  

  

  37 
  

  

  51.5 
  

  

  37 
  

  

  41 
  

  

  