﻿RATE 
  OF 
  PROPAGATION. 
  

  

  6i 
  

  

  The 
  Station 
  Master 
  of 
  Sealdah, 
  the 
  terminus 
  of 
  the 
  Eastern 
  Bengal 
  

   Railway, 
  gives 
  the 
  time 
  of 
  commencement 
  as 
  i6h. 
  27m. 
  

  

  A 
  mean 
  of 
  these 
  returns 
  would 
  give 
  the 
  time 
  as 
  about 
  i6h. 
  27'5m. 
  

   and 
  the 
  time 
  as 
  obtained 
  by 
  plotting 
  the 
  returns 
  from 
  the 
  stations 
  on 
  

   the 
  East 
  Indian 
  Railway 
  and 
  smoothing 
  the 
  curve 
  as 
  described 
  above, 
  

   gives 
  about 
  i6h. 
  27m. 
  40s. 
  as 
  the 
  time 
  of 
  commencement 
  at 
  Calcutta. 
  

  

  Calcutta 
  local 
  time 
  is 
  conventionally, 
  in 
  accordance 
  with 
  the 
  

  

  official 
  Telegraph 
  Guide, 
  33 
  minutes 
  in 
  advance 
  of 
  Madras 
  or 
  Railway 
  

  

  time, 
  but 
  the 
  local 
  time 
  actually 
  used 
  is 
  that 
  of 
  the 
  daily 
  time 
  

  

  signal 
  controlled 
  by 
  the 
  Alipur 
  Observatory, 
  which 
  is 
  32m. 
  20s. 
  in 
  

  

  advance 
  of 
  Madras, 
  and 
  this 
  is 
  consequently 
  the 
  correction 
  to 
  

  

  be 
  used. 
  In 
  the 
  case 
  of 
  Mr. 
  Harris' 
  record 
  from 
  Budge-Budge, 
  

  

  as 
  the 
  time 
  was 
  obtained 
  from 
  the 
  Telegraph 
  office, 
  the 
  correction 
  of 
  

  

  33 
  minutes 
  would 
  have 
  to 
  be 
  applied. 
  Reducing 
  the 
  observations 
  to 
  

  

  Madras 
  or 
  standard 
  time, 
  we 
  have 
  — 
  

  

  Tide-gauge 
  

  

  P. 
  L. 
  Mukhopadyaya 
  . 
  

  

  Telegraph 
  Central 
  Office 
  

  

  T, 
  Harris 
  . 
  

  

  Railway 
  stations, 
  mean 
  

  

  Do. 
  Smoothed 
  curve 
  . 
  . 
  . 
  i6h. 
  27m. 
  40s. 
  

  

  All 
  these 
  times 
  are 
  liable 
  to 
  an 
  error 
  of 
  30s. 
  and 
  cannot 
  be 
  regard- 
  

   ed 
  as 
  accurate 
  within 
  that 
  limit 
  ; 
  an 
  arithmetical 
  mean 
  gives 
  i6h. 
  

   27m, 
  49s., 
  which 
  is 
  probably 
  as 
  close 
  an 
  approximation 
  as 
  circum- 
  

   stances 
  permit. 
  With 
  observations 
  so 
  few, 
  and 
  with 
  so 
  large 
  a 
  probable 
  

   error 
  in 
  each 
  case, 
  more 
  refined 
  mathematical 
  treatment 
  seems 
  out 
  of 
  

   place 
  and 
  would 
  only 
  lead 
  to 
  an 
  appearance 
  of 
  accuracy 
  which 
  has 
  

   no 
  foundation 
  in 
  fact. 
  The 
  time 
  deduced 
  may 
  be 
  taken 
  as 
  accurate 
  

   within 
  a 
  quater 
  of 
  a 
  minute, 
  and 
  the 
  local 
  time 
  of 
  commencement 
  of 
  

   the 
  shock 
  was 
  between 
  5b. 
  and 
  5b. 
  om. 
  30s. 
  P.M. 
  of 
  local 
  time. 
  

  

  At 
  Bombay, 
  which 
  was 
  beyond 
  the 
  limits 
  over 
  which 
  the 
  shock 
  

   could 
  be 
  felt, 
  we 
  have 
  the 
  records 
  of 
  the 
  magnetic 
  instruments 
  

   detailed 
  in 
  chapter 
  XI, 
  and 
  also 
  the 
  barograph 
  trace 
  which 
  exhibits 
  

   a 
  disturbance 
  precisely 
  similar 
  to 
  that 
  of 
  the 
  Alipur 
  barograph. 
  

   Mr. 
  Moos, 
  the 
  Director 
  of 
  the 
  Observatory, 
  tells 
  me 
  that 
  the 
  clock 
  of 
  

  

  ( 
  61 
  ) 
  

  

  i6h. 
  

  

  27 
  m. 
  

  

  40s. 
  

  

  i6h. 
  

  

  2Sm. 
  

  

  37*. 
  

  

  i6h. 
  

  

  28m. 
  

  

  I 
  OS. 
  

  

  i6h. 
  

  

  27m. 
  

  

  OS. 
  

  

  i6h. 
  

  

  27m. 
  

  

  30s« 
  

  

  