﻿136 
  

  

  ON 
  THE 
  LONGITUDE 
  OF 
  THE 
  HALL 
  OF 
  THE 
  SOCIETY. 
  

  

  This 
  occultation 
  is 
  valuable 
  for 
  the 
  purpose 
  of 
  determining 
  the 
  lon- 
  

   gitude 
  of 
  Philadelphia, 
  Boston, 
  and 
  Dorchester, 
  from 
  the 
  circumstances 
  

   of 
  its 
  having 
  been 
  very 
  carefully 
  observed 
  at 
  several 
  established 
  obser- 
  

   vatories 
  in 
  England. 
  It 
  was 
  selected 
  by 
  Mr 
  Henderson 
  for 
  determin- 
  

   ing 
  the 
  longitude 
  of 
  Biggleswade 
  and 
  Bedford, 
  and 
  gave 
  the 
  following 
  

   results. 
  

  

  

  By 
  aTauri, 
  Jan. 
  5 
  1830. 
  

  

  By 
  all 
  the 
  Observations 
  to 
  1832. 
  

  

  Biggleswade, 
  west 
  of 
  Greenwich. 
  

   Bedford, 
  west 
  of 
  Greenwich. 
  

   Bedford, 
  west 
  of 
  Biggleswade. 
  

  

  M. 
  S. 
  

  

  1 
  02.70 
  

  

  1 
  50.60 
  

  

  47.30 
  

  

  M. 
  s. 
  

  

  1 
  03.50 
  

   1 
  51.97 
  

  

  48.47 
  

  

  The 
  near 
  agreement 
  of 
  the 
  longitudes 
  deduced 
  from 
  this 
  occultation 
  

   with 
  the 
  mean 
  of 
  many 
  others, 
  induced 
  me 
  to 
  calculate 
  the 
  longitude 
  

   of 
  the 
  Hall 
  of 
  the 
  American 
  Philosophical 
  Society 
  from 
  my 
  observa- 
  

   tions, 
  allowance 
  being 
  made 
  for 
  the 
  place 
  where 
  the 
  observations 
  for 
  

   local 
  time 
  were 
  made, 
  and 
  for 
  the 
  place 
  where 
  the 
  occultation 
  was 
  

   observed. 
  The 
  longitude 
  of 
  this 
  Hall, 
  thus 
  deduced, 
  is 
  west 
  from 
  

   Greenwich, 
  5 
  h. 
  m. 
  46.09 
  sec. 
  

  

  This 
  longitude 
  exceeds 
  by 
  a 
  few 
  seconds 
  that 
  determined 
  byRitten- 
  

   house 
  from 
  the 
  transit 
  of 
  Venus. 
  It 
  agrees 
  more 
  nearly 
  with 
  the 
  esti- 
  

   mates 
  of 
  De 
  Ferrer 
  and 
  Bowditch, 
  and 
  with 
  the 
  recent 
  determination 
  

   of 
  R. 
  T. 
  Paine 
  from 
  Joseph 
  Roberts' 
  and 
  my 
  observations 
  of 
  the 
  solar 
  

   eclipse 
  of 
  1831. 
  

  

  The 
  parallaxes 
  in 
  declination 
  and 
  right 
  ascension 
  were 
  calculated 
  by 
  

   the 
  method 
  of 
  Maclear, 
  Mem. 
  Ast. 
  Soc. 
  London, 
  Vol. 
  IV., 
  No. 
  XXIX. 
  

   By 
  this 
  method 
  the 
  errors 
  of 
  the 
  tables 
  of 
  the 
  moon's 
  right 
  ascension 
  

   are 
  deduced 
  from 
  the 
  star's 
  right 
  ascension, 
  and 
  the 
  moon's 
  tabular 
  

   declination, 
  independently 
  of 
  the 
  tabular 
  right 
  ascension 
  of 
  the 
  moon. 
  

  

  The 
  longitudes 
  deduced 
  from 
  this 
  occultation 
  by 
  Maclear's 
  method, 
  

   confirm 
  the 
  remark 
  of 
  Captain 
  Smyth, 
  Ast. 
  Soc. 
  Mem., 
  Vol. 
  IV. 
  p. 
  567 
  ; 
  

   the 
  west 
  longitude 
  deduced 
  from 
  the 
  immersion 
  being 
  too 
  great, 
  and 
  

   that 
  from 
  the 
  emersion 
  too 
  small. 
  The 
  mean 
  of 
  the 
  results 
  is 
  however 
  

   generally 
  accurate. 
  

  

  